Доска объявлений

llkktth105

• Создано: 03-12-21
• Последний вход: 03-12-21

×

Контакты

Имя

Электронная почта

Сообщение

Код

Отправить сообщение

Workers Squeezing Honda With Especially Costly Strike

Описание:     Workers Squeezing Honda With Especially Costly Strike When you’re looking for Honda Civic Auto Parts near Rochester, you want them as quickly as possible. Thanks to Tom Kadlec Honda’s extensive inventory and knowledgeable staff members, we likely have the Original Equipment Manufacturer part you need, when you need it, as opposed to other parts stores, which sell aftermarket parts that may not be an exact match for your body parts for Honda accord. Whether you’re just looking to change your own oil or are a car aficionado with the sort of know-how to upgrade your own vehicle, we’ve got the parts to accomplish the task. With convenient business hours and a convenient location, there’s no reason not to come on in and get the auto parts you need for your vehicle today. If you’re going to do your own tune-ups, there are multiple steps you’ll want to take but, first, come by Tom Kadlec Honda’s Parts Department to gather your array of supplies. Make sure you’ve got the year, make, and model of your vehicle, along with the VIN, so we can get you the proper equipment. You’ll need a funnel to avoid spillage during your oil change, on top of the correct oil, don’t forget! Checking your tires is a necessary part of vehicle ownership, and we’ve got pressure gauges for you, so that your tires’ air pressure is always correct and you can get the most out of that rubber. You can find the maximum psi for your tires both in the Owner’s Manual and on the tire placard in the door jamb! We admire the do-it-yourself attitude, which is why we’ve got a Live Chat function, as well. If you have questions while repairing or tuning up your vehicle with auto parts from Tom Kadlec Honda, you can chat and ask us anything. Head on over to the Ask A Tech feature to submit questions directly to our highly-trained technicians. We’ll respond in a timely and informative fashion, or feel free to give us a call. We’re happy to confirm that we have a part, discuss repairs you’re working on, or just chat about vehicles – it’s our passion. Whether you’re looking for a cabin air filter, the plethora of fluids your vehicle requires regularly, replacement brake pads, or a new muffler, we’ve got body parts for Honda accord 2016 Civic auto parts for sale near Rochester. Come down to Tom Kadlec Honda and see for yourself! With our superb customer service and our well-trained staff, we pride ourselves on customer retention – we hope to see you soon! To keep your Honda Passport looking fresh and running like new, it’s essential to bring it into your local auto body shop near Sunnyvale. When you take your vehicle to your service shop, new or used, our certified technicians have the knowledge and experience to efficiently inspect your car, and will address any damages, dents, and other issues immediately, so your Passport looks its very best. Whether you have just purchased a new body parts for Honda accord 2018 or have been driving your car for years, it’s recommended that you take in your vehicle for a proper look over, so you keep driving in style! At Larry Hopkins Honda, we make sure your vehicle looks great, and is updated with all using all the latest equipment available. And our service team is here to ensure that your car or truck is looking polished and fresh, so you make a long-lasting impression wherever you go! Larry Hopkins Honda auto body shop near Sunnyvale 94085 will order the proper parts you need to make your vehicle look shiny, sleek, and like-new. Providing you with all different services like glass repair and replacement, car detailing and paint touching, and dent removal, you get just what you’re looking for when you use Larry Hopkins Honda’s auto body shop. We have a reputation in the area of only providing our customers with quality service, and our sales and service teams take the time to get to know you on a personal level, and will answer any questions you have regarding our inventory and services. With our auto body shop technicians’ experience, you can rest assured knowing that your Honda Passport will be attended to with the utmost care, no matter what you need. We know you have lots of choices to consider, but you can trust us here at Larry Hopkins Honda to get the job done right the first time. Our skilled staff at our auto body service shop gives you one of the best deals for a quality job in the area, and we can promise you that once you leave our garage, you’ll feel valued as a customer. Here at Larry Hopkins body parts for Honda Crv, we take pride in our excellent staff members, easy-to-use online tools, and our dedication to you as a customer, so you know you are getting exactly what you need when you come in for service at our auto body shop near Sunnyvale. Schedule an appointment today right on our website, or by stopping into our service department at Larry Hopkins Honda Sunnyvale 94085. FOSHAN, China ? In going on strike at a transmission factory, workers here have Honda by the jugular, although it was not entirely clear at the employees’ dormitory on Friday that they realized this. Transmission factories are the most expensive auto plants of all to build, because they are huge and highly automated. Each costs as much as $1 billion, more than twice the cost of an assembly plant, and typically supplies several assembly plants. The factory here supplies four Honda plants in China, all of which have been shut down. Automakers tend to put transmission factories only in the most politically stable and strike-free countries, because a shutdown for even a day is costly. Until now, China was seen as a safe bet. Striking at a vital plant to achieve an auto-industry domino effect was a tactic first used to good effect in the United States by the United Automobile Workers. The U.A.W. won recognition from General Motors in 1937 through sit-down strikes at two other kinds of factories: making engine parts and stamping auto body parts for many other assembly plants. The U.A.W. has repeatedly held strikes at crucial parts factories to shut down many assembly plants quickly, particularly at G.M. in the 1990s. But the U.A.W. has benefited from a tight-knit union leadership. Workers here say they are operating more by consensus. And there has been no sign that the Chinese authorities are ready to let a cohesive group of labor activists emerge to lead a national independent union. It’s a bit of a catch-22 situation: should you drive on and take the depreciation as it comes, or should you sell pronto? Stuck with a discontinued car model and clueless on what to do with it? Fret not. We brought in the car experts to weigh in on how to deal with a discontinued model. Base your decision on these factors… Examine why the model was discontinued Each year, a few car models are discontinued for various reasons and it’s important to understand why a particular car was stopped before choosing to buy/keep/sell that model. “The most common reason is product lifecycle. Most cars follow a 5-to-7-year lifecycle, after which an all-new model replaces it,” says Rush Parekh, Founder of Team-BHP.com. For example, Chevrolet Blazer, which was replaced with the far more modern Chevrolet Trailblazer in the early 2000s. However, there could be a number of other reasons and Rajat Sahni, CEO – Used Cars, CarDekho.com, lists them: Outdated design and change in demand pattern, is one. For example, the Nissan Xterra, which débuted when truck-based, body-on-frame SUVs were popular, before the rise of the car-based crossover. Another reason could be the unexpected exit of major market players, like in the case of General Motors’ exit from India. It forced Chevrolet to discontinue the Beat. The third reason could be performance-related issues, as compared with competitors, or a shift in market trends. For example, the Renault Pulse, introduced in India in 2012 as a slightly altered version of the Nissan Micra, failed to capture the Indian market and continued to sell in poor numbers. In 2017, Renault decided to discontinue the hatchback. Similarly, body parts for Honda Crv 2020 launched its first MPV, the Mobilio, in 2014 with high expectations, but the seven-seater did not click in the Indian market. The main reasons behind its failure were its looks and the entry-level trim lacked features. In July 2017, Honda discontinued the Mobilio after facing tough competition from rivals like Maruti and Toyota. Look at the brand The brand definitely makes a difference in the decision to sell/keep a car. “As an example, if you own a discontinued model from Maruti or Toyota, parts and service shouldn’t be an issue. However, you are in for challenging times if you have a discontinued model from brands like Fiat or Chevrolet,” says Mr. Parekh. Brand does impact the resale value, says Mr. Sahni. “If a brand shuts down completely, then it may not be the best decision to discard your car, as no one would be willing to buy it at a decent price.” Check for after-sales support It’s an unspoken rule that manufacturers must support their cars for 10 years after they have been discontinued. “Of course, in reality, after-sales support depends on a variety of things. There are cases where even two- or-three-year-old models aren’t supported well,” says Mr. Parekh. “The discontinued vehicles are still part of a brand with an image to uphold, so after-sales service/support still follows the same policy,” says Mr. Sahni. “But if the brand shuts down in a particular country, then there are no provisions for such services, and the owner may have to find an alternate solution for servicing or any other kind of support.” Check for availability of spare parts Though understandably, companies continue to manufacture spare parts for these models, it’s always an ordeal to source them. “In that case, look at the big shops in prominent spare part markets, like Shetty Motor Stores in Opera House, Mumbai. If you are finding it difficult to source parts, also consider shopping online. There are lots of parts suppliers who might be able to help you,” says Mr. Parekh. However, Binu Vijayan, Deputy General Manager, Popular Maruti in Thiruvananthapuram, urges caution over sourcing spares from online dealers, as the parts may not be certified by manufacturers, even as a large number of ‘local’ spares also flood the market. “Sometimes, it so happens that a particular part may not be in stock and will have to be ordered directly from the dealer or original maker. This may cost more and take more time,” he says. One advantage is that, many modern cars share parts with other cars, says Mr. Sahni. “So even if the vehicle has been cancelled, it’s likely that the automaker will still build parts for other vehicles that share its engine, transmission or even smaller pieces, such as window switches.” Ask about resale value There is no fixed algorithm for calculating a fair price of discontinued models. Only demand and supply drives this. Mr. Sahni suggests two ways to evaluate this: 1. Inspecting the vehicle to know its exact value after considering various factors like wear and tear, depreciation and other factors. 2. Arriving at a tentative fair value of the model through inspection, though exact figures are known only after analysing the market demand for that particular model. Paradoxically, for certain popular models, the resale value can actually go up, just like, say, motorbike models like Yezdi or old Yamaha RX 100, which retain a vintage appeal, says Mr. Vijayan.         

Дата Публикации: 03-12-21

Care of instruments and equipment: a success story

Описание:     Care of instruments and equipment: a success story “When a person is hungry and you give him a fish, his hunger is satisfied for that occasion. If you teach him how to catch a fish, it can take care of his hunger for the rest of his life.” This is a teaching principle that is often repeated, and one that is also very useful in the maintenance of medical equipment. The nasal instruments and equipment used in modern eye care have become very sophisticated and expensive. Keeping them in good working condition can become a nightmare, especially if hospitals are located in places where there is little service support from manufacturers or suppliers. These items can fail to work unexpectedly and the resultant downtime can compromise outcomes and patient safety. An important fact about instruments and equipment is that, when manufactured by well-established firms and supplied by reliable dealers, they seldom fail, provided they are maintained as described in the user manual. A machine is more likely to fail when it is first set up, often due to shortcomings in its installation, use, or handling. For this reason, most manufacturers usually offer a free warranty contract for the first year. Machines should be used often during that period; any malfunction, however trivial, should be brought to the attention of the supplier and rectified immediately. If this is done, the machine will usually work well for the rest of its lifespan. It is generally believed that doctors and/ or paramedical staff who use an instrument or machine will take care of it, but this cannot always be expected. The patient is the primary concern of doctors or paramedical staff. If there is a conflict, patient care will take precedence – so nasal suction forceps care is bound to suffer. Also, some equipment is too complex to maintain for a person who is not technically trained. At Aravind Eye Hospital, we took these factors into account and devised a scheme whereby a technically trained person is responsible for a sophisticated pediatric nasal instrument or piece of equipment. This person's responsibility is to take care of it: to turn it on or off, and to go meticulously through all the stipulated steps before it is ready to be handed over for use by doctors and paramedical staff. This considerably lightens the workload of doctors – they can devote their full attention to the procedure and the patient. When a procedure is over, doctors and paramedical staff may be tired. Shutting the machine off in the sequence suggested by the manufacturer is then the responsibility of the technically trained person. There is no need for a fully fledged biomedical engineer to do this job, as it is always possible to train a person with some engineering background on the various aspects of a particular instrument or machine. That person can in turn train others to keep equipment running in good condition. We find that graduates of our polytechnics (technical colleges) do such jobs well. We use such trained persons to maintain our phacoemulsification (phaco) machines, ERG machine, fundus cameras, and expensive surgical instruments used in operations. We have had great success with our LASIK machines: they are being used regularly and have functioned, without any hitch, for the last seven years, which has surprised the supplier! It is difficult to train many people within an organisation to look after sophisticated nasal opertion forceps and equipment. Not all will have the competence or the aptitude required to understand the technical details. Training one or two persons with the right aptitude and making them responsible for looking after instruments and equipment will ensure better maintenance and performance in the long term. Medical equipment maintenance and use of personnel, is crucial. Used properly and rational division of engineering and technical personnel, strict management, to train engineering technical personnel with professional spirit, all-round for clinical medical services; To strengthen the training of equipment use of personnel, highlight the preventive maintenance and maximize or prolonged trouble-free of medical instrument equipment, ensure the effective operation of the clinical diagnosis and treatment work. The complexity of medical devices has increased over the past 10 years, and outbreaks of infections due to contaminated devices have focused attention on the need to adequately clean medical devices in order to ensure the adequacy of disinfection and sterilization. There has been a paradigm shift in reprocessing of medical devices, with increased emphasis on a quality management systems approach that requires validated cleaning instructions from manufacturers and ongoing monitoring by reprocessing personnel to ensure adequacy of cleaning. This article reviews the current issues related to medical device reprocessing and summarizes the approaches used for monitoring cleaning efficacy for surgical instruments and flexible endoscope system&accessory. Forty to 70 % of medical devices and equipment in low- and middle-income countries are broken, unused or unfit for purpose; this impairs service delivery to patients and results in lost resources. Undiscerning procurement processes are at the heart of this issue. We conducted a systematic review of the literature to August 2013 with no time or language restrictions to identify what product selection or prioritization methods are recommended or used for medical device and equipment procurement planning within low- and middle-income countries. We explore the factors/evidence-base proposed for consideration within such methods and identify prioritization criteria. Results We included 217 documents (corresponding to 250 texts) in the narrative synthesis. Of these 111 featured in the meta-summary. We identify experience and needs-based methods used to reach procurement decisions. Equipment costs (including maintenance) and health needs are the dominant issues considered. Extracted data suggest that procurement officials should prioritize devices with low- and middle-income country appropriate technical specifications – i.e. devices and equipment that can be used given available human resources, infrastructure and maintenance capacity. Conclusion Suboptimal device use is directly linked to incomplete costing and inadequate consideration of maintenance services and user training during procurement planning. Accurate estimation of life-cycle costing and careful consideration of device servicing are of crucial importance. The absence of safe, effective and well-functioning medical devices and equipment (MDEs) impairs health service provision, leads to poor patient outcomes and poses substantial health system and national security risks . Nowhere has this been more evident than the recent Ebola Virus Disease outbreak in West Africa . The absence of laboratory equipment to enable quick and accurate diagnosis, and personal protective equipment to ensure effective infection prevention and control measures and health worker safety, directly resulted in delays to emergency response, difficulties in care delivery and lost patient and health worker lives . The absence of appropriate technologies impairs more than emergency care, however: routine services in maternal, child and reproductive care (e.g. immunizations or reproductive control), interventions for non-communicable (e.g. diabetes management) and communicable diseases (e.g. HIV/AIDS diagnosis) all require suitable infrastructure and functioning technologies. From basic products such as weighing scales and condoms, to glucometers and flow-cytometers, health service delivery is predicated upon the availability, appropriateness, affordability and acceptability of MDEs . Estimates suggest that between 40 and 70% of MDEs in resource poor settings are broken, unused or unfit for purpose . Indiscriminate procurement methods, a mismatch in technology design and demand, high costs as well as deployment, maintenance and human resource training challenges all contribute towards this issue . Low- and middle-income countries (LMICs) particularly lack the regulatory authorities, or biomedical engineering capacity, to advise on what MDEs are suitable for use in harsh deployment settings: i.e. facilities with high temperature, fluctuating electricity or no clean water supply. The problem is compounded by a mismatch in MDE supply: manufacturers are located and attuned to users in lucrative high-income markets . Installation, preventive and corrective maintenance services and user training programs are also traditionally absent in LMICs, leading to unsafe device handling practices with potentially harmful consequences for patients (e.g. in cases of misdiagnosis due to mis-calibration or infection propagation due to device re-use). This paper targets one aspect of the above problem: MDE procurement and resource allocation in LMICs. To assist decision-makers in conducting informed and evidence-based product selection decisions, we have conducted a systematic review of internationally recommended methods for procurement planning and prioritization in settings experiencing severe resource constraints, describing the context for these activities and summarising normative recommendations. Little is known about how MDE procurement takes place within resource-constrained settings; the WHO Baseline Surveys on Medical Devices are recent attempts to explore this . The survey’s findings suggest that LMICs predominantly conduct procurement at central ministry level within the public sector ; however, the surveys do not provide further granular information on how LMIC conduct or plan MDE procurement. For the purposes of this paper, we adopt the MDE definition laid out by the Global Harmonization Task Force and WHO . The identification of best practices and common pitfalls in MDE procurement may lead to improvements in MDE management and use. This would not only ensure improved use of scarce financial resources, but also translate to devices being operational and used competently for improved patient care. The systematic review is particularly timely given global efforts for health system strengthening in LMICs: MDEs are recognized as critical components in ensuring health system resilience to shocks and in achieving universal health coverage. Substantial increases in MDE utilization have already been noted in middle-income countries in Europe in line with expanding provision of health care services; similar trends will undoubtedly follow in LMICs globally .         

Дата Публикации: 03-12-21

Carbon Fibre : Sweeping technical world off its feet

Описание:     Carbon Fibre : Sweeping technical world off its feet In 1879, the world experienced a novel level of innovation that peacefully took over the reins of technical textile. It was in this year that Edison took out a patent for the manufacture of carbon filaments suitable for use in electric lamps. However, it was in the early 1960s when successful commercial production was started, as the requirements of the aerospace industry - especially for military aircraft - for better and lightweight materials became of paramount importance. The use of carbon fiber fabric is now widespread and it is in everything from tennis rackets to bicycle frames. It has become a big part of Formula 1 cars and many supercars as well. Several cruisers use carbon fibre extensively. However, as carbon fibre is not part of daily textile needs of consumers, many are unaware that this fibre has become an undeniable part of everyday lives. The truth is that it is everywhere to be found in the technological world. Carbon fibre is an exceptionally lightweight strengthening fibre derived from the element carbon. Sometimes known as graphite fibre, when this extremely strong material is combined with a polymer resin, a superior composite product is produced. Also called graphite fibre or carbon graphite, carbon fibre consists of very thin strands of the element carbon. Carbon fibres have high tensile strength and are very strong for their size. In fact, carbon fibre might be the strongest material there is. Speaking in technical terms, each fibre is 5-10 microns in diameter. One micron (um) is 0.000039 inches. In Textile Terms and Definitions, 3k carbon fiber fabrics has been described as a fibre containing at least 90 percent carbon obtained by the controlled pyrolysis of appropriate fibres. The term graphite fibre is used to describe fibres that have carbon in excess of 99 percent. Large varieties of fibres called precursors are used to produce carbon fibres of different morphologies and different specific characteristics. The most prevalent precursors are polyacrylonitrile (PAN), cellulosic fibres (viscose rayon, cotton), petroleum or coal tar pitch and certain phenolic fibres. Based on modulus, strength, and final heat treatment temperature, carbon fibres are classified into different categories. As far as carbon fibre cloth is concerned, spools of carbon fibre are taken to a weaving loom, where the fibres are then woven into cut resistant fabric. The two most common types of weaves are plain weave and twill. Plain weave is a balanced checker board pattern, where each strand goes over then under each strand in the opposite direction. Whereas a twill weave looks like a wicker basket. Here, each strand goes over one opposing strand, then under two. Both twill and plain weaves have an equal amount of carbon fibre going each direction, and their strengths will be almost same. The two are aesthetically different. Carbon fibre is primarily used for producing sporting goods, which account for nearly 11 million lb of that material. Currently, the United States of America consumes nearly 60 percent of the world production of carbon fibres, while the Japanese represent for almost 50 percent of the world capacity for production. The world production capacity of pitch-based carbon cloth is almost totally based in Japan. The key to further carbon fibre market expansion is continued development of high-rate manufacturing methods and considering this, it is predicted that demand of the fibre will increase by 235 percent by 2020. Carbon fiber is composed of carbon atoms bonded together to form a long chain. The fibers are extremely stiff, strong, and light, and are used in many processes to create excellent building materials. Carbon fiber material comes in a variety of "raw" building-blocks, including yarns, uni-directional, weaves, braids, and several others, which are in turn used to create composite parts. The properties of a carbon fiber part are close to that of steel and the weight is close to that of plastic. Thus the strength to weight ratio (as well as stiffness to weight ratio) of a carbon fiber part is much higher than either steel or plastic. Carbon fiber is extremely strong. It is typical in engineering to measure the benefit of a material in terms of strength to weight ratio and stiffness to weight ratio, particularly in structural design, where added weight may translate into increased lifecycle costs or unsatisfactory performance. Carbon fibers or kevlar fabrics are fibers about 5–10 micrometres in diameter and composed mostly of carbon atoms. Carbon fibers have several advantages including high stiffness, high tensile strength, low weight, high chemical resistance, high temperature tolerance and low thermal expansion. These properties have made carbon fiber very popular in aerospace, civil engineering, military, and motorsports, along with other competition sports. However, they are relatively expensive when compared with similar fibers, such as glass fibers or plastic fibers. The raw material used to make carbon fiber is called the precursor. About 90% of the carbon fibers produced are made from polyacrylonitrile. The remaining 10% are made from rayon or petroleum pitch. All of these materials are organic polymers, characterized by long strings of molecules bound together by carbon atoms. The exact composition of each precursor varies from one company to another and is generally considered a trade secret. During the manufacturing process, a variety of gases and liquids are used. Some of these materials are designed to react with the fiber to achieve a specific effect. Other materials are designed not to react or to prevent certain reactions with the fiber. As with the precursors, the exact compositions of many of these process materials are considered trade secrets. Before the fibers are carbonized, they need to be chemically altered to convert their linear atomic bonding to a more thermally stable ladder bonding. This is accomplished by heating the fibers in air to about 390-590° F (200-300° C) for 30-120 minutes. This causes the fibers to pick up oxygen molecules from the air and rearrange their atomic bonding pattern. The stabilizing chemical reactions are complex and involve several steps, some of which occur simultaneously. They also generate their own heat, which must be controlled to avoid overheating the fibers. Commercially, the stabilization process uses a variety of equipment and techniques. In some processes, the fibers are drawn through a series of heated chambers. In others, the fibers pass over hot rollers and through beds of loose materials held in suspension by a flow of hot air. Some processes use heated air mixed with certain gases that chemically accelerate the stabilization. Once the fibers are stabilized, they are heated to a temperature of about 1,830-5,500° F (1,000-3,000° C) for several minutes in a furnace filled with a gas mixture that does not contain oxygen. The lack of oxygen prevents the fibers from burning in the very high temperatures. The gas pressure inside the furnace is kept higher than the outside air pressure and the points where the fibers enter and exit the furnace are sealed to keep oxygen from entering. As the fibers are heated, they begin to lose their non-carbon atoms, plus a few carbon atoms, in the form of various gases including water vapor, ammonia, carbon monoxide, carbon dioxide, hydrogen, nitrogen, and others. As the non-carbon atoms are expelled, the remaining carbon atoms form tightly bonded carbon crystals that are aligned more or less parallel to the long axis of the fiber. In some processes, two furnaces operating at two different temperatures are used to better control the rate de heating during carbonization. After carbonizing, the fibers have a surface that does not bond well with the epoxies and other materials used in composite materials. To give the fibers better bonding properties, their surface is slightly oxidized. The addition of oxygen atoms to the surface provides better chemical bonding properties and also etches and roughens the surface for better mechanical bonding properties. Oxidation can be achieved by immersing the fibers in various gases such as air, carbon dioxide, or ozone; or in various liquids such as sodium hypochlorite or nitric acid. The fibers can also be coated electrolytically by making the fibers the positive terminal in a bath filled with various electrically conductive materials. The surface treatment process must be carefully controlled to avoid forming tiny surface defects, such as pits, which could cause fiber failure. Resistance to Fatigue in Carbon Fiber Composites is good. However when carbon fiber fails it usually fails catastrophically without much to announce its imminent break. Damage in tensile fatigue is seen as reduction in stiffness with larger numbers of stress cycles, (unless the temperature is hight) Test have shown that failure is unlikely to be a problem when cyclic stresses coincide with the fiber orientation. Carbon fiber is superior to E glass in fatigue and static strength as well as stiffness. Carbon Fiber has good Tensile Strength Tensile strength or ultimate strength, is the maximum stress that a material can withstand while being stretched or pulled before necking, or failing. Necking is when the sample cross-section starts to significantly contract. If you take a strip of plastic bag, it will stretch and at one point will start getting narrow. This is necking. It is measured in Force per Unit area. Brittle materials such as carbon fiber does not always fail at the same stress level because of internal flaws. They fail at small strains. Testing involves taking a sample with a fixed cross-section area, and then pulling it gradually increasing the force until the sample changes shape or breaks. Fibers, such as carbon fibers, being only 2/10,000th of an inch in diameter, are made into composites of appropriate shapes in order to test. Fire Resistance/Non Flamable Depending upon the manufacturing process and the precursor material, carbon fiber can be quite soft and can be made into or more often integreted into protective clothing for firefighting. Nickel coated fiber is an example. Because carbon fiber is also chemically very inert, it can be used where there is fire combined with corrosive agents. Carbon Fiber Fire Blanket excuse the typos. Thermal Conductivity of Carbon Fiber Thermal conductivity is the quantity of heat transmitted through a unit thickness, in a direction normal to a surface of unit area, because of a unit temperature gradient, under steady conditions. In other words its a measure of how easily heat flows through a material. Because there are many variations on the theme of carbon fiber it is not possible to pinpoint exactly the thermal conductivity. Special types of Carbon Fiber have been specifically designed for high or low thermal conductivity. There are also efforts to Enhance this feature. Low Coefficient of Thermal Expansion This is a measure of how much a material expands and contracts when the temperature goes up or down. Units are in Inch / inch degree F, as in other tables, the units are not so important as the comparison. In a high enough mast differences in Coefficients of thermal expansion of various materials can slightly modify the rig tensions. Low Coefficient of Thermal expansion makes carbon fiber suitable for applications where small movements can be critical. Telescope and other optical machinery is one such application. Non Poisonous, Biologically Inert, X-Ray Permeable These qualities make Carbon fiber useful in Medical applications. Prosthesis use, implants and tendon repair, x-ray accessories surgical instruments, are all in development. Although not poisonous, the carbon fibers can be quite irritating and long term unprotected exposure needs to be limited. The matrix either epoxy or polyester, can however be toxic and proper care needs to be exercised. Carbon Fiber is Relatively Expensive Although it offers exceptional advantages of Strength, Rigidity and Weight reduction, cost is a deterrent. Unless the weight advantage is exceptionally important, such as in aeronautics applications or racing, it often is not worth the extra cost. The low maintenance requirement of carbon fiber is a further advantage. It is difficult to quantify cool and fashionable. Carbon fiber has an aura and reputation which makes consumers willing to pay more for the cachet of having it. You might need less of it compared to fiberglass and this might be a saving. Carbon Fibers are brittle The layers in the fibers are formed by strong covalent bonds. The sheet-like aggregations readily allow the propagation of cracks. When the fibers bend they fails at very low strain.         

Дата Публикации: 03-12-21

Welded roll forming system versus tube mills: What’s the difference?

Описание:     Welded roll forming system versus tube mills: What’s the difference? Steel pipe rolling forming process is an elastic-plastic deformation process, the boundary conditions is very complicated and nonlinearity, so it is difficult to get the exact solution by using the analytical method and the traditional implicit static algorithm based on finite element method. The contact collide arithmetic based on explicit dynamic program LS-DYNA provides an effective way for accurate research on the elastic-plastic deformation of the hot-rolled seamless pipe rolling process. This paper takes the SMS MEER rolling mill of Φ 177PQF steel tube rolling units in Ansteel seamless steel pipe rolling mill as the research object, makes a coupled thermo-mechanical finite element method computation on steel pipe rolling process, gets the residual stress and strain change rule in the rolling process. Written the rolling process parametric programs by APDL, analyzed the influence of roller spacing and velocity parameters on residual stress and strain, which provides a reliable theory basis for improving the performance of hot rolling seamless steel pipe and the optimization of rolling technological parameters. The welding of streel strip into a product, such as round tube or pipe, box frames, and structural members, is a multibillion-dollar industry that had its beginnings more than a century ago. Many items that we use today, like furniture tubing, oil pipe, and fuel lines, are manufactured on welded pipe cold rolling mill. In the last 20 years OEMs have been asked to apply the principles learned from cold pilger to the much larger roll forming processing market. This has created another technology area today known as welded roll forming. Companies may move from nonwelded open shapes to welded roll formed shapes for many reasons. Welded roll formed shapes have structural strength and integrity, help eliminate secondary operations in downstream manufacturing, and can offer savings in steel and construction labor. While there are benefits, there are also costs, which typically involve an investment in capital equipment and skilled people who know how to use the technology. What are the differences between a tube mill and a welded roll form system? Which one should you consider? Can the same parts be run on both systems? Will the part quality be affected? These questions, asked often within the industry, are plagued with many conditional aspects that cloud the final answer. Intricate details often are required to help machine builders focus on the best option. Terminology In the classic sense, a tube mill is a kind of welded roll form system; however, not every welded roll form system is a tube mill. Tube mills are welded roll form systems that have been fine-tuned to run a specific diameter range, typically at fast speeds (see Figure 1). Diameter range is mentioned because a tube mill welds a round product. Progressive male and female roller dies (or rolls) shape the incoming strip for welding a specific diameter. On all welded roll form systems, including tube mills, welding can occur with processes like high-frequency (HF) induction, HF contact, electric resistance, and laser beam welding. For the sake of this discussion, it is assumed that the correct welding process has been determined based on the specific material requirements. Figure 2 shows the typical forming flower of a tube mill forming the strip into a round product just before welding. From there the round product can stay round or can be sized or reshaped into a square or rectangle. In a tube mill, the forming machine forms the strip into a round, weldable product. The forming machine has two main parts: breakdown and fin-pass sections. Once welded, the tube can be left round, though it undergoes further forming to size it to a more accurate outside diameter. The sizing section shown in Figure 3 has round roll stands with specialty reshaping stands toward the exit and a double turks-head to finish. Used for straightening, a turks-head has two pairs of rolls, one arranged vertically and the other horizontally. Defining a welded roll forming system is a little more difficult. Again, in the classical sense, a pipe hot rolling mill is one kind of a welded roll forming system. But if someone refers to a “welded roll forming system,” that person is probably not talking about a tube mill, but other roll forming machines able to form various, often highly complex shapes to within tight tolerances. Much like forming on the tube mill, with breakdown and fin-pass sections, welded roll forming systems have a similar forming setup, with the fin-pass section occurring in the last few stands before welding (see Figure 4). When working with nonround shapes, such as a step beam (see Figure 5), the roll forming system tends to form the shape as is before welding. Some in the industry call this near-net-shape forming. Others call this the form square-weld square process. Once the shape is formed and welded, most recommend at least two additional passes to work the welded shape once more to finalize the dimensions. Pass Configurations Tube mills tend to have alternating driven forming pass and idle side pass patterns. These patterns tend to help alleviate springback from the previous forming pass. This specialty pass progression has led tube mill builders to design systems with a given diameter range to have between five and nine driven forming passes, with their sister idle side passes. The actual pass count often is a function of the ratio of the workpiece diameter to the material thickness, material yield strength, as well as the minimum to maximum range for both material OD and thickness. Welded roll forming mills tend to have mostly driven passes, though using idle side passes is becoming more common. Many factors come into play when determining the most robust pass count for stable welding. Pass counts depend not only on material wall thickness and yield strength, but also on the overall complexity of the shape to be formed. The pass count also depends on material movement during the process, as well as the experience of the roll tooling designer. Which Is Best? For round shapes, a tube mill probably is the best choice. But what if you only want to make squares or rectangles? What if you want to have prepunched holes? To determine the best machine, consider the strengths and weaknesses of each. Tube mills specialize in simple shapes. Besides round shapes, they’re capable of producing squares, rectangles, and ellipses. If you’re looking to form a few complicated shapes, the tube mill may not be the best choice. Forming some shapes on the steel pipe production line simply isn’t possible, but a welded roll forming mill can form highly complicated shapes quite readily. Also consider the outside corner radii of those shapes. In some cases, a tube mill can form those radii down to 2 times the material thickness, but this isn’t typical. Usually a tube mill can form radii down to between 2.5 to 3 times the material thickness. Welded roll forming mills have a different tooling setup that allows for tight, accurate radii. Specifically, it has to do with how the forming rolls engage the material on the corner. On a welded roll forming mill, both the female and the male roll engage the corner, making forming very exact. Typically, radii can be formed down to less than 2 times the material thickness. Also consider the consistency of the corner radius, as measured from corner to corner on the roll formed product. Shapes formed on a tube mill may have discrepancies between opposite and/or adjacent corners. This occurs because of one-sided bending, with just one roll (not both male and female) fully engaged with the material. Male and female roll engagement in welded roll form systems has another benefit: It helps produce consistent flat sides or features, with no crowning or other reshaping. Because tooling on a tube mill gives the workpiece no inside support, flat sides or features tend to reshape during the process and emerge from the tube mill with a crown. Also take into account any pre-punching operations that a job might benefit from or require. Punching typically is not recommended on tube mills. This is because of inconsistencies with so-called round-to-shape material movement. It can be very difficult to “lock” the hole location in a round shape and then reshape it into a square, hoping the hole ends up in the correct position. Moreover, punched holes may warp during the reshaping phase. Pre-punching in welded roll forming is usually better because it allows you to accurately locate hole features. The punched holes also tend to hold their shape during forming, if those holes are put in the right location. If the hole is near a corner, however, the hole shape still can change. Finally, consider processing speed. This hinges mainly on pre-punching operations. Since pre-punching is not normally performed on tube mills, these mills have been designed to run up to 750 feet per minute (FPM), depending on the product OD and wall thickness. If a pre-punching job is running on a welded roll forming mill, processing speeds typically are 100 FPM or less, though they can be improved with special tooling like a rotary pierce tool, which looks like a roll with punches sticking out of it. These punch or pierce the material as the roll rotates. (Rotary piercing does have limits and may not work in some applications.) If pre-punching is not required, then a welded roll forming system can process at the same speeds as a tube mill. To achieve and maintain these speeds, however, a welded roll form system needs some tube mill specialty equipment added, such as an accumulator and high-performance cutoff. So again, which is best? If you have only simple shapes to form, a cold drawing machine may be the way to go; if you have complex shapes with multiple radii, holes, and other features, a welded roll forming system is the way to go. But what if you have a simple shape with tight tolerances? What if those radii need to be consistent from corner to corner? What if you need sides to be precisely flat, with no chance of crowning? In these cases, a welded roll forming system may be more suitable for the job, unless product specifications can be changed. As with anything else, choosing a roll forming system involves considering product requirements and weighing those against your current and future production needs.         

Дата Публикации: 03-12-21

Wanna a better selfie? Get a selfie stick

Описание:     Wanna a better selfie? Get a selfie stick Selfies at tourist attractions are nothing new. But until recently, if you wanted a perfectly composed picture of yourself with a landmark in the background, you might have asked a passer-by to take the photo. Now, though, relatively new gadgets called selfie sticks make it easy to take your own wide-angled self-portraits or group shots. Fans say the expandable rods, which allow users to hold their cellphones a few feet away, are the ultimate convenience. No more bothering passers-by to take pictures. No more fretting about strangers taking lousy shots or running off with a pricey iPhone. But some travelers bemoan the loss of that small interaction that came with politely asking a local to help preserve a memory. And critics express outright hatred of selfie sticks. They see them as obnoxious symbols of self-absorption. They even have a derisive name for them: narcissi (nar-sissy) stick. Sarah Kinling of Baltimore said she was approached "17 times" by vendors selling intergrated selfie stick at the Colosseum in Rome. "They're the new fanny pack. The quickest way to spot a tourist," she said. "The more I saw them in use, the more I saw how much focus people were putting on selfies. And not turning around to see what they were there to see." When Kinling wanted a photo of herself with her sister and sister-in-law, she asked strangers to take the shot. "Even when the other person didn't speak English, you hold your camera up and make the motion and they understand," she said. But some travelers say it's better to stage your own vacation photos. Andrea Garcia asked a passer-by to take her photo in Egypt and later realized he'd zoomed in on her face, cutting out the pyramids behind her. "I couldn't really be mad at him. He wasn't my photographer, I didn't pay him," she said. The experience made her appreciate the selfie sticks. She sees tourists using them at 1 World Trade near her office in New York's Lower Manhattan. "Take control of your image!" she says. Selfie sticks are just starting to show up at attractions in the U.S. But they're found in many destinations overseas, from Dubai's skyscraper, the Burj Khalifa, to the Eiffel Tower in Paris. A soccer stadium in London, White Hart Lane, has even banned them because they obstruct other fans' views. The Four Seasons Hotel in Houston just started making them available to guests, "similar to the way many hotels provide umbrellas," said hotel spokeswoman Laura Pettitt. The sticks range in price from $5 to $50. Simpler models merely grip the phone. So users must trigger the shot with a self-timer on the camera. More sophisticated versions use Bluetooth technology. Or they connect the phone to the stick with a cord. A button on the grip triggers the shot. The mobile phone with camera can be mounted on a selfie stick with light by securing it tightly to the phone holder. After ensuring adequate lighting, the telescopic pole of selfie stick holding the mobile phone can be positioned at a desired length and angle placing the camera close to the lesion . The camera has autofocus which focuses the lesion and the lesion can be seen clearly on the screen of the smartphone, without getting closer to the patient, or the lesion can be magnified by the user while examining or the image of the lesion can also be clicked from a distance of one meter . Then the mobile phone mounted selfie stick can be brought closer to examine the lesion further. Also, the clicked images can be saved for subsequent examination. Besides, when the undersurface of scrotum or any other inaccessible part needs to be examined, the mobile phone camera mounted on a selfie stick can be used in selfie mode. It is also possible to examine oral mucosa using a selfie stick. To examine oral mucosa and for dental examination, the patient is instructed to retract the buccal mucosa with a mouth mirror and guided to turn his head slightly to the opposite side of retraction to enhance the view of the oral cavity. Then with the help of mobile phone camera mounted on the selfie stick complete examination can be performed . Love it or hate it, 2015 has been, without a doubt, the year of the selfie. Whether you were standing in front of the Eiffel Tower, meeting the cast of "Mad Men" or showing off your new haircut, everyone across your social media platforms knew exactly what you were up to in 2015. And with the invention of the now somewhat notorious selfie stick in 2014, it seemed that the selfie is, for better or worse, here to stay.   Notorious might be a bit of a stretch, but a device that started as a harmless tool to help over-share vacations has snowballed into a near-controversial issue, with selfie sticks increasingly banned around the world for reasons that range from safety to privacy to just plain obnoxious behavior. Walt Disney World's ban on selfie sticks earlier this year was probably the most publicized, but it is just one in a long list of landmarks and tourist attractions doing the same.    The selfie fad started humbly in 2010 when Apple introduced the iPhone 4 with the front-facing camera, inspiring people to snap self-portraits and broadcast them across their social media platforms. Today, the practice has mushroomed into a full-on phenomenon as tourist attractions, city streets, national parks and landmarks are packed with travelers memorializing their self-portraits in front of the world's destination icons. As of June, it was reported that 300 million selfies had been posted to Instagram to date, according to DMR (formerly Digital Marketing Ramblings). And that doesn't even take into account SnapChat, Facebook or Twitter. The selfie stick, an extendable metal rod to which one can attach a smartphone, revolutionized this fad by making it easier for users to capture themselves at wider angles beyond the reach of one's arm. Some of the latest models are even equipped with remote or Bluetooth controls that enable the user to better time photographs. But if you've traveled anywhere in the last two years you're probably quite up to speed on this phenomenon because, let's face it, they are everywhere. The ubiquity of selfie sticks has met with mixed reviews. While they are, in fact, sweeping the globe (more than 100,000 selfie stick ring light had been sold as of December 2014, according to Bloomberg News), not everyone is a fan.   A spokesman for Disney said of Walt Disney World's decision to ban selfie sticks from its theme parks around the globe, "The main reason we did this is because it has become a safety concern for guests and cast. Even though they were never allowed on roller coasters and rides, people would still bring them in." "They shot photos while riding Big Thunder Mountain Railroad with sticks," the spokesman said. "We had to stop the rides and take time to reload and get them going again. It was a big safety issue for everyone on the ride. That was the reason we made that decision." The ban became effective in the U.S. on June 30 and at the international parks on July 1. Selfie sticks are, however, still allowed in Downtown Disney and at Disney hotels and resorts. Disney has been far from alone in the fight against selfie sticks. The Coachella and Lollapalooza music festivals banned the devices this year, as have Beijing's Forbidden City, the Van Gogh Museum in Amsterdam, all of Mecca in Saudi Arabia, the Sistine Chapel, Versailles, the Metropolitan Museum of Art in New York, the National Gallery in London and all sports stadiums in Brazil. "Banning selfie sticks in stadiums began as a gradual process in a couple of cities and states," said Joao H. Rodrigues, U.S. & Canada Media Relations executive in charge of the international promotions for the Brazilian Ministry of Tourism and the Ministry of Sports. "Local police, in charge of security at the stadiums, realized that people could be injured by selfie sticks, either by accident or during fights,"  Rodrigues said. "Fast forward a few months and now all soccer stadiums in the country have banned them." Selfie sticks are also not allowed during most Carnival parades and, most recently, the organizers of Rock in Rio announced that they wouldn't allow anyone to bring selfie sticks to the concert grounds. In places like national monuments, theme parks and museums it is understandable that hordes of tourists toting 2-foot-long metal rods could gum up the works. Not only do they disrupt the aesthetics of otherwise picturesque photo ops, they present safety and privacy issues. London's National Gallery issued a statement banning separate self filling light as part of its promise to protect paintings, copyrighted materials, individual privacy and the overall visitor experience. In other places around the world, the ban on selfie sticks is more widespread and extreme, as people have gone above and beyond in an attempt to out-selfie their fellow followers on Instagram and Facebook, suggesting that the selfie craze is reaching ridiculous levels.    In July, the Russian Interior Ministry revealed a brochure highlighting selfie safety tips; according to Tass, Russia's news agency, at least 100 people were injured in 2015 while taking selfies, and 10 people died. "The guide entitled 'Take Safe Selfies -- A Cute Selfie May Cost You Your Life' aims to minimize the number of selfie fatalities and stop the dangerous selfie trend," Tass reported. Similarly, Lake Tahoe felt it had to go so far as to ask visitors to refrain from taking selfies with bears. As if it were not abundantly obvious, the destination has had to spell out specifically that having one's back to the animals presents a safety issue, a clear indication that common sense flies out the window in the name of out-selfie-ing Instagram and Facebook followers. South Korea banned the selfie-stick nationwide last November, although since then the government has limited this ban to sticks that use Bluetooth technology because, according to the country's radio management agency, the sticks might interfere with other devices using the same radio frequencies and therefore are seen as "communication devices." Still, despite the bans, despite rising safety issues and despite overall questions of common sense, folding selfie stick portable are as prevalent as ever. The public will not be denied a quality selfie, and photophile suppliers are only too happy to feed the frenzy. In December 2013, Turkish Airlines released a YouTube video ad called "Kobe vs. Messi: The Selfie ShootOut," in which Kobe Bryant and Lionel Messi engage in an epic battle of selfies. The spot, which was voted "ad of the decade" by YouTube as part of its 10th anniversary celebrations, has drawn 142 million views to date. In fact, many travel brands -- hotels in particular -- are capitalizing on the selfie trend as a marketing and promotion tool, realizing it can be a brilliant promotional strategy since guests who show themselves having wonderful experiences offer priceless free publicity by inspiring their friends and family back home to have similar experiences. Kimpton Hotels & Restaurants noticed the volume of guests posting selfies at Kimpton properties: at the pool, the beach, at Wine Hour and even hundreds of #RockTheRobe selfies in its signature animal-print robes. "We love the 'selfie movement' because it gives us a glimpse into what people love about the brand and what they are experiencing and feeling at our hotels," said a Kimpton spokesperson. "Next, we wanted to find a way to reward people for continuing to post and share these moments with us."   In order to make the selfie experience easier, the brand has been hosting an ongoing social contest built around selfies and has stocked every hotel with selfie sticks, which are available for guests to borrow from the front desk. Using the hashtag #AdoreTheSelfie, participants post a selfie and are automatically entered to win an array of prizes. Similarly, the JW Marriott Desert Springs Resort & Spa in Palm Desert, Calif., has an Indulge Your Selfie promotion: Guests are given a loaner selfie stick upon arrival and are encouraged to tag themselves around the property with a variety of hashtags.         

Дата Публикации: 03-12-21

AlphaSunglasses Articles & Reviews

Описание:     AlphaSunglasses Articles & Reviews This is a page from AlphaSunglasses with general information about big frame sunglasses. Eyewear is a hugely important industry and wearing sunglasses is not just about making a fashion statement, there is plenty of evidence that our eyes need protection from damaging light rays. But finding the right frames and lenses is not always easy. Many frames look great online but can be most unflattering when you put them on. There are lots of ways you can cut down on the effort to find the sunglasses that flatter your face and enhance your lifestyle. We have articles on picking big square sunglasses that will fit your face, on what are the most sought-after shades and how far manufacturers will go to sell you a pair of high fashion branded sunglasses. We have articles to help you choose from expensive designer brands, whether it is worth paying extra and why sunglasses can be good for your eyesight. We also take a long look at lenses and ask how long UV protection will last, what types of lens give what level of protection and how lenses are tested for optical clarity and toughness. Performance eyewear is all the rage with many sports personalities promoting their favourite sports sunglasses. It's not just a case of cutting out the glare these days; sunglasses can be tailored for sport-specific environments where crisp, clear vision can give a real competitive edge. Most of today's top-selling big round sunglasses brands are owned by just a few conglomerates and they spend thousands of dollars on promotion and celebrity endorsement. With so much money at stake, it's no surprise that the sunglasses market is awash with cheap fakes. We look at whether buying fakes makes you a sharp player or a gullible clown. Whatever your interest we hope you find something to educate or amuse in this collection of articles about the world of sunglasses. Please contact us if you have views of your own to share. Sunglasses are a real character builder. Or at least they play a large roll in the character that you play to others. They’re front and center and they can literally change the shape of your face. So before you buy your next pair of shades, think about what you might be saying to the world. With that said, here are some popular sunglass shapes along with what what they might be saying about your style. Wrap-around sunglasses are great for hiking, outdoor sports, and playing golf. They can also double as safety goggles. Think of them as equipment. Probably not ideal for a suit and tie or a date in the park. These are the official shades of the All American guy. The jeans and t-shirt guy (although they can look great with a suit too). They’re called “aviators” because they were originally developed to protect the eyes of pilots in the American military. This particular pair was made in America and has the wrap-around ear pieces to keep them locked in place – a design created for fighter pilots who had to fly upside down. Chunky square frames are often associated with rappers, or guys trying to live rapstar lifestyles. Usually seen paired with high-end designer streetwear, a lot of black, and unnecessary leather. It’s a bold, in your face, “I’m getting mine” kind of look, which can be cool if done with at least some air of subtlety. A petite round frame in black is smart, sophisticated, and a bit dandy. It has a European, perhaps French, feel. If not borderline snobbish, it’s a smart look that’s intriguing because of it’s understated simplicity and delicate scale. Browline glasses are old school. Retro. They were the gold standard for style in the 1950s and 1960s. Think Don Draper. The style’s popularity rose to the point that browline glasses (and sunglasses) accounted for half of all eyewear sales in America in the 1950s. As a result, many famous figures wore browlines, including activist Malcolm X and movie star James Dean. It’s a smart, slightly serious style that has a timeless appeal.  Sunglasses might be a small accessory, but they have a large impact. A great pair can elevate your outfit and your style, but the best small frame sunglasses for women can boost your mood too. After a year spent mostly indoors, this spring and summer call for getting outside—and you’re going to need a great new pair of shades when you do.  So what does summer have in store for eyewear? An everyday exuberance to match the season’s optimistic fashion. On the runway, the season brought us bright-colored clothing and eccentric prints, and for sunglasses, this means a pair of statement-making glasses. Among the best offerings, shop pairs with square-shaped rims and colored tinted lenses or cheeky cat-eyes done up to look like a new classic. Or consider a style that delivers a quirky take on a mainstay trend like oversized ’60s mod shades or retro aviators. Should you want your glasses to make a statement that all can hear, opt for a pair that doubles as jewelry. An option from Chanel comes complete with a pearl-strung sunglasses chain, while Magda Butrym’s collaboration with Linda Farrow is decked out in removable bling. As summer sets in, it’s time to pick up a new pair—or two—for sunnier days ahead. Below, shop the best sunglasses for women. Mod Mania These bug-eyed shades landed on Mars long before NASA’s 2021 Perseverance rover. Reminiscent of the bold, space-age goggles made famous by the likes of Pierre Cardin, Andre Courrèges, and Paco Rabanne, they are the perfect match for that miniskirt you’ve been dying to bust out this summer. Sunglasses are one of the world's most ubiquitous fashion accessory, but also play an important part in protecting our eyes from harmful UV rays. We take a look at how they came into being... Snow goggles: the first sunglasses The earliest known use of glasses to protect eyes from the sun was the Inuit use of “sun goggles” to shield their eyes from the blinding glare of light reflected off the snow. These were made from carved driftwood, bone, walrus ivory, or caribou antler that formed a strip worn across the eye area, with thin slits that the wearer could see through. The goggles were cut so that they fit tightly to the face, and often soot or gunpowder was rubbed on the outside to absorb the light and further cut down on glare. The use of these goggles dates back to around 2,000 years ago, and as a bonus, even improved the wearers vision as the narrow slits helped focus eyesight. The Inuits weren't the only people in history to find an innovative way to protect their eyes from glare: Pliny the Elder wrote in his Natural History that the Roman Emperor Nero used to watch the gladiator fights through polished gemstones to reduce the glare from the sun—potentially the most expensive and most ineffective form of small square sunglasses in history. Another form of eye protection also cropped up in 12th century China, when flat planes of smoke-tinted quartz lenses were worn by magistrates in court proceedings. However these were supposedly used to hide the expressions of the wearer, not while outside catching rays. By the 18th century the modern form of eyeglasses had been invented, made with lenses held together by wire and the frame extending over the ear to hold them in place. A man called James Ayscough believed that changing the color of the actual lens could further help with specific vision impairments. He experimented with blue and green-tinted glass as ways to improve poor eyesight—little did he know that his idea would go on to be one of modern day’s must-have fashion accessories. The first instance of lenses being used to actually protect a wearer’s eyesight from light was around the early 20th century, when yellow and brown tinted glasses were prescribed to sufferers of syphilis. Syphilis causes eyes to become sensitive to light, so wearing darkened spectacles would have eased discomfort. However, not long later, sunglasses stopped becoming associated with poor health, and began to be a symbol of celebrity. Around the 1920s, it became common for famous movie stars to be seen out in public wearing small round frame sunglasses. Not only would shielding their eyes make their identity more covert when they didn't want to be noticed, but it hid the fact that it was common for actors to have red eyes due to the powerfully bright klieg lamps used in studios. With the trend firmly set by the glamorous stars of the era, the demand for sunglasses skyrocketed. Savvy businessman Sam Foster began mass-producing sunglasses made from celluloid in 1929, which he began selling on the beaches of Atlantic City in New Jersey. The market was willing with their appeal stretching beyond sun-soaked beaches, and by 1938 Life Magazine reported that sunglasses were a: “new fad for wear on city streets...a favorite affectation of thousands of women all over the U.S." The same article also stated that in 1937, 20 million pairs of sunglasses were sold, but only 25% wore them to protect their eyes. Polarized lenses, which contain a special filter invented by Edwin H. Land that blocks intense light reflected off other surfaces like sand or snow, became available in 1936. Ray Ban, a glasses brand founded by American eye health company Bausch and Lomb, created aviator-style sunglasses using polarized lenses that were widely used by US Air Force pilots during World War II to block the glare from the sun. In 1937, they went on sale to the public and function finally met fashion with the shape of frames and color of lenses changing drastically to keep up with the catwalk. Here is a selection of some of the styles that have emerged throughout the years:         

Дата Публикации: 03-12-21

A Guide To Lube Oil Purifier

Описание:     A Guide To Lube Oil Purifier A ship has hundreds of machinery and systems which helps in its day to day operations. Lubrication plays a vital role in smooth running of these machineries by overcoming and reducing heat, neutralizing acid combustion by-products, preventing scuffing, lessening friction and thereby combating wear and tear between two running surfaces. The main engine lube oil system on ships ensure lubrication of the main bearings through pumping of lube oil by duplex oil filters, to the crossheads, and guides, piston cooling and bottom end bearings through the swivel jointed pipes in the engine casings. The engine cylinders have their own lube oil system, which lubricates the surfaces between the cylinder wall and the piston rings through a set of concentric nozzles or quills fitted around the cylinder liner. It is imperative to maintain the lubricating oil’s properties and to ensure it is in good condition. This is executed by the watchkeeping engineer who is responsible for carrying out proficient engine room watch especially, on lube-oil temperature, pressure and the condition of oil. The common contamination of the lube oil can occur because of: Jacket Water Leaking Cooler Leakage Fuel Contamination through Poor Atomization of fuel and unburnt fuel. High Exhaust Temperature, Burned Cylinder Oil, Carbon from incomplete combustion and products of fuel composition Scale formation, wear and tear and biological contamination. Such contamination need to be purified to maintain the quality of lube oil throughout as the quality of lube oil determines equipment lifetime and its productivity. As impure lube oil leads to: Reduction in fuel efficiency. Corrosion on mechanical parts. Increase in acid formation in trunk type piston engine. Reduce Load Carrying capacity Microbial Degradation Case Crankcase Explosion. Therefore, we need Lube oil purifier on ships for proper purification of lube oil with minimum throughput or batch purification in case of heavy contamination. There are three ways in which lube oil purification can be done: centrifugation, filtration and coalescence. A high-speed centrifugal purifier is installed on a ship to get rid of the unwanted contaminants and pollutants from the lube oil. On ships, separate marine purifiers are used for fuel and lube oil. Lube oil is purified only through centrifugation while the fuel oil uses both centrifugation and gravity separation. On ships, it is also referred to as Centrifuge. It is a purifier that separates two liquid substances based on their difference in density with the use of gravity disc to separate solid and water and sealing water as an operator with two-holed lower discs; one for water and other for oil. Construction Features of Centrifugal Purifier or “Centrifuge”: Electric Motor: This is responsible for driving various components such as bowl, tachometer, gear-pump via pinion gear, and rotating counter. Friction Clutch: Friction clutch is installed on the horizontal shaft to safeguard and protect the electric motor from damage as the complete purifier assembly is too heavy for a motor to take the full load from the start without overheating. Once the system attends a preset required momentum, the pads gradually move out under centrifugal force connecting the motor directly to the bowl. It is necessary for the friction clutch to engage with the drum for the revolution of the bowl. It safeguards against heavy starting current. A solid coupling, then due to a large starting current, would simply overheat and burn the motor winding. Therefore, friction coupling allows for some time, and after the motor reaches a certain RPM, the coupling gets engaged thereon. Gear Box: The Gear Box Assembly in Marine Lube oil Centrifugal purifier consists of a motor shaft, friction clutch, the breaking lever, spur gear, worm gear and the attached gear pump. The Bowl & Disc Stack: The Bowl is a solid assembly made up of high tensile steel working within purifier frame with ample space to accumulate and discharge sludge. Disc Stacks are incorporated with small holes to form the interface line and carry out separation using centrifugal force that causes oil to move inward and water and solid particle to move outward. Dry Air Generator For Power Systems Dry air generators are more unique in power systems for large transformers and reactors. When the transformer is shipped out from the factory, the heavier insulating oil is extracted and replaced with light dry air, which reduces the transportation cost of the large transformer. Due to the long maintenance and accident repair time of a large transformer, sometimes it is more than half a month. If there is no absolute dry air filled into the transformer continuously, the transformer body will be seriously wet and rusted, accordingly the transformer insulation performance will be destroyed. The dry air generator ensures that the internal insulation of the transformer will not get wet during the maintenance process, and the maintenance personnel will not suffocate due to lack of oxygen when working inside the equipment. It can avoid the influence of external climate change, avoid the traditional transformer oil thermal circulation drying method. It can improve the oil’s insulation performance and reduce the moisture, and also ensure the personal safety of maintenance personnel. Our GF series dry air generator is mainly composed of air compressor, gas storage tank, cold dryer, suction dryer, three-stage precision dry air filter, pressure reducing valve, flow meter and electric control system. Its features are as below: The air compressor takes the latest patent Injection screw rotor from ATLAS COPCO and driven by the efficient and maintenance-free device. It features barely supervised, long-term stable and reliable work, self-diagnostic fault and alarm. The machine has an automatic restart function after power-off. No heat regenerative dryer uses the principle of pressure swing adsorption to make the desiccant agent absorbing under the pressure of pipe network, and then switch to desorption under the atmospheric pressure and lead back about 14% of the dry gas from the outlet of drier for further purification regeneration. The two towers are working as above alternatively to provide the user with dry compressed air Means of control: It adopts the advanced and reliable microcomputer program controller featured automatic timing, auto-switching work. The machine is working stably and reliably and won’t be affected by the power grid, voltage, electric field effects. This machine has a power supply voltage, air outlet pressure, air outlet dew point, air outlet temperature, adsorption tower pressure and a series of parameters of real-time display instruments for the operation of equipment at any time can be observed, recorded, and greatly facilitate the management. Lesser known facts about TTR testing that are affecting your results Transformer Turns Ratio (TTR) testing is one of the most common ways of assessing the condition of a transformer’s windings and core. Throughout the life of a transformer, TTR results are compared against the nameplate ratings to reveal insulation deterioration, shorted turns, core heating or other abnormalities. TTR tester is simple, so is often taken for granted without fully understanding the basis of the test. As a result, when measurements are not within expected limits, it is hard to determine the cause and resolve the problem. This article focusses on some of the lesser known aspects of TTR testing, such as the effect of applied test voltage, step-up versus step-down excitation; differences between nameplate ratio, voltage ratio and turns ratio; sources of error; per phase testing vs true three-phase testing; and more. The basics Transformers transfer power between circuits, usually at different levels of voltage and current, by electromagnetic induction. This function depends on the relationship between the number of turns of a specific pair of windings in the transformer. As this relationship is so important, TTR testing is typically performed many times throughout the life of a transformer – during manufacture, at acceptance and then during routine maintenance and as an aid to fault finding. Modern TTR instruments will work by applying a voltage on one winding of the transformer (VP), measuring the resulting voltage on another winding (VS) and then calculating the ratio of these two voltages. This is the transformer voltage ratio (TVR), but it should be noted that for three-phase transformers, a correction factor, which depends on the vector configuration of the windings, has to be applied. As TTR measurements are made under no load conditions, impedance will have a negligible effect on the results. The measured value of TVR will, therefore, be approximately equal to TTR, the turns ratio. For this reason, it is standard industry practice to validate TTR with an instrument that in reality measures TVR. SF6 Gas analyzer Description of the SF6 Gas analyzer The model GA11 SF6 Gas analyzer are innovative and reliable instruments for determining the quality of different insulating gases. Among these insulating gases are included SF6, Novec? 4710 gas mixture (g3 gas) as well as applications for technical air (clean air/ dry air, based on oxygen and nitrogen). The SF6 Gas analyzer GA11 can measure the concentration of up to six parameters, depending on the selected equipment variant. Set up A clearly arranged menu structure and a 7" colourtouchscreen allow for intuitive operation. Sensors for the measurement of purity and humidity are included as standard. Optionally, the SF6 gas recovery and refilling system can be extended with electrochemical sensors for determining the SF6 gas decomposition products. Applications of the SF6 Gas analyzer Analysis of the gas quality in gas-filled equipment For the analysis of SF6 gas, g3 gas or N2 gas Special features of the SF6 Gas analyzer Provides measured values for humidity, gas composition (purity) and decomposition products (optional) Low transport weight of 25 kg Three methods for emission-free treatment of the measurement gas: - Direct pumping back into the tested compartment - Pumping into an external gas cylinder - Collecting in an external gas bag Battery power for min. 5 measurements or mains supply Not compromised by transport restrictions (IATA)                                                     

Дата Публикации: 03-12-21

THE GUIDE TO SUMMER SHIRT FABRICS

Описание:     THE GUIDE TO SUMMER SHIRT FABRICS The aim of a shirt bought for summer might seem easy: to stay cool. But there are several variations here, and crossovers with styles and other functionality. This, then, is our substantive yet focused guide to buying a shirt fabric for the warmer months. As ever, it is not aimed at recommending specific cloths, because the mills don’t vary that much in the things discussed here – fibres, weaves and finishes. Rather, it should enable you to know whether you want a linen, a muslin or a zephyr, and why. Then you can pick what weight and colour you want. So, how do you make a cool shirting fabric? Well generally you want it to be breathable – that’s the priority, rather than being lightweight. Superfine fabrics, for example, are often lightweight. But they are also densely woven, which makes them not very breathable and so not great in warm weather. That breathability will come from three things: the fibre, the yarn or the weave. First, the fibre. Most shirtings are cotton, and this is pretty breathable and cool – certainly more than fibres like wools, cashmere or synthetics. However, linen is better. Linen is such a strong fibre that it can be woven quite loosely, making it breathable. It is also cool to the touch, because the fibre is a good conductor. (Metal feels cool for the same reason.) Linen wrinkles of course. For some, that’s part of the charm, but it might also make it too casual for smarter shirts. In that situation it’s worth turning to linen/cotton mixes, which balance the sharpness of cotton and the breathability of linen. In fact, I’d recommend linen/cotton through most of the year, because it has that breathability (but not too much) and because it looks more casual than cotton (but not too much). And while you do often need a cooler shirt in the summer, in the winter it’s easy to just wear knitwear or heavier tailoring over the top. Next, the weave. In general here you want a more open, less dense weave. So in a basic cotton, a plain weave (or broadcloth) is more open than a twill, and will breathe better. Then there are more specialist warm-weather weaves, such as zephyr. Zephyr has a square weave construction, with an almost equal number of threads per inch in warp and weft, which makes it very breathable. Specialist cotton yarns can also make a difference. So voile, for example, uses a high-twist yarn. This gives the yarn extra strength (like linen) and enables it to be woven more openly. Muslin, on the other hand, uses a normal yarn but a very lightweight one. This makes it softer, but also quite liable to wrinkle, and therefore not as smart. Both voile and muslin are more commonly used in women’s clothing. What Is Mesh Fabric? There are a few different versions of mesh fabric, but this type of fabric is typified by its lightweight heft and permeable texture. Unlike most types of fabric, which feature closely-woven textures, mesh is woven loosely, which results in thousands of tiny holes being present in each mesh garment. The idea of mesh has been around for thousands of years; for instance, every type of net in existence is made from mesh, and this material has also been used to make items like hammocks. However, it wasn't until the end of the 19th century that textile innovators started using mesh for apparel. Mesh fabric is made with a variety of different techniques depending on the type of fiber from which it is composed. While nylon and polyester are very similar in a number of ways, polyester was developed a few decades after nylon, which means that the production of this synthetic material follows significantly more advanced manufacturing processes. Though the processes used to make these two types of fabric fibers differ, for each type of fiber, the process begins with the refining of petroleum oil. Polyamide monomers are then extracted from this oil, and these monomers are then reacted with various forms of acid to make polymers. Lining Fabric for Clothing Lining fabric refers to a group of materials inserted into various garments, from skirts and shorts to dresses, jackets and coats. Such fabrics can be made of natural or synthetic fibers and range from sheer to opaque. While most of them are produced in solid colors, you can still find lots of patterned lining materials. This F. A. Q. section covers the most popular questions about lining fabrics, their types, and properties. The purpose of lining fabric is to make your garment more wearable, long-lasting and comfortable. They are usually lightweight and have a soft or silky texture. Not all items need to be lined, though. When choosing the appropriate lining for a project, one needs to pay attention to the stretch factor. If the garment is not stretchy, e.g. a cotton shirt or a wool jacket, non-stretch lining fabric is ok. But if the item is made with elastic materials like jersey, tulle or stretch satin, the lining one ends up choosing should be stretchy as well. Blended or inlaid conductive fibers The mechanism of the first two methods is to increase the moisture regain rate of the fabric, reduce the insulation, and accelerate the electrostatic leakage. Therefore, if the processing effect is not durable or not significant in a dry environment or after repeated washing, it is usually applied to ordinary clothing fabrics. Only the third method can permanently and efficiently solve the static electricity problem of textiles. It is an anti-static fabric woven from a new type of conductive yarn (or metal fiber blended yarn). The addition of conductive wire (yarn) is divided into two kinds of inlaid and interwoven (specifically twill, according to customer requirements). The fabric has good durability, anti-static, dustproof and other properties. Therefore, it is widely used in the production of anti-static work clothes. Application of anti-static fabric Anti static fabric is fabric that has undergone anti-static processing and is widely used in the workwear of explosive industries such as petroleum industry, mining and smelting industry, chemical industry, coal mine, gas station, liquefied gas station, oil tanker, fireworks and firecrackers, and atomic energy, aerospace, Weapons, precision instruments, microelectronics, automobiles and other static sensitive industries, and other industries, such as: food, medicine and other industrial work clothes that require high cleanliness. The conductive wire in the conductive fabric is mainly embedded in the back of the fabric to facilitate the appearance and smoothness of the fabric. The back of the fabric is a semiconductor and the front of the fabric is an insulator. Therefore, after the garment is finished, the static electricity generated by the friction between the clothing and the human body is mainly eliminated, and the static electricity generated by friction with external equipment cannot be eliminated. There is still a charge accumulation on the front of the garment. Since the blended fabric is made by adding conductive fibers to the yarn during the weaving process, the front and back of the fabric are both semiconductors, and the positive and negative charges on the surface of the fabric can be conducted and cancel each other, which can quickly and evenly eliminate the body and clothing. The static electricity, and the static electricity generated on the surface of the clothing in contact with the outside, the clothing has no charge accumulation. Waterproof Breathable Fabrics Waterproof fabric completely prevents the penetration and absorption of liquid water in, in contrast to water-repellent fabric, which only delays the penetration of water. Traditionally, fabric was made waterproof by coating it with a continuous layer of impervious flexible material. The first coating materials used were animal fat, wax and hardened vegetable oils. Nowadays synthetic polymers such as polyvinylchloride (PVC) and polyurethane are used. Conventional polymers coatings are considered to be more uncomfortable to wear than water-repellent fabric, as they are relatively stiff and do not allow the escape of perspiration vapour. Consequently they are now used for emergency rainwear. Water-repellent fabric is more comfortable to wear but its water-resistant properties are short lived. Coating Fabrics for Men and Women Coating fabrics are designed to protect your body from cold, wind and rain during early spring, autumn and winter seasons. Coat fabric comes in a variety of weights and finishes, from lightweight materials for cooler weather to heavy cloths that are up to the challenge even on the most freezing day. In this article we’re going to cover the most popular types of coat fabrics used for casual and special occasion coats and jackets. While one can definitely buy a ready-made piece, sometimes finding the perfect one seems almost impossible. Lightweight materials include jacquard, tweed and boucle, thin wool fabrics, velvet, etc. Some of them can be made into stylish outerwear to be worn on top of an elegant dress or a mind-blowing two-piece suit. Medium weight fabrics comprise denser wool materials and jacquards, cashmere, various wool blends. Properly lined or quilted, they make all kinds of coats, jackets and capes that are a pleasure to wear in the demi-season. Heavy coat fabrics are created to keep you super warm and comfortable in snowy and otherwise severe winters. The most popular ones are 100% wool materials, wool blends, furs and padded puffer fabrics. Now, let’s dive deeper into the types of fibers you should have your eyes open for when choosing a coat material. What Is Fleece Fabric? When you read the word fleece, the first thing you may think of is sheep. Interestingly, fleece fabric doesn’t come from sheep’s wool at all. Rather than wool, fleece fabric is a form of synthetic fabric. This means these warm, soft, and cozy garments are man-made. They’re usually made from polyester. Sometimes, it’s referred to as polar fleece or polyester fleece. Introduction Of Home Textile Home textile is a branch of technical textile comprising application of textiles in household purposes. Home textiles are nothing but an internal environment, which deals with internal spaces and their furnishings. Home textiles are mainly used for their functional and aesthetic properties which provides us the mood and also gives mental relaxation to the people. Definition Of Home Textile Home textiles can be defined as the textiles used for home furnishing. It consists of a various range of functional as well as decorative products used mainly for decorating our houses. The fabrics are used for home textiles consists of both natural and man-made fibres. Sometimes we also blend these fibres to make the fabrics stronger. Generally, home textiles are produced by weaving, knitting, crocheting, knotting, or pressing fibers together. Different Types Of Home Textile Products A considerable portion of home furnishings consists of textiles. A number of these furnishings are typical in households and are made according to certain general methods of construction and composition. The basic items may be grouped as Sheets and Pillowcases, Blankets, Terry towels, Table cloths, and carpets and Rugs. Jacquard Fabrics Review Jacquard fabric is a type of cloth featuring an intricate pattern woven into the warp on a special mechanical loom, rather than printed on the surface. It was a French weaver Joseph-Marie Jacquard who invented this technology in 1804, so the jacquard fabric was named after him. These fabrics are available in a variety of compositions and weights and serve various purposes. Lightweight jacquards are often picked for spring and summer apparel, whereas heavy cloths have their say in colder seasons. Any jacquard fabric is all about the pattern, which looks that unique due to the way it is applied. Very often, if you look at the back of the cloth, long floats can be found; these are threads used to produce the pattern, and it tells you straight away that you are dealing with jacquard. 

Дата Публикации: 03-12-21

Application-Specific Integrated Circuit (ASIC) Miner

Описание:     Application-Specific Integrated Circuit (ASIC) Miner An application-specific integrated circuit (ASIC) is a type of circuit that has been designed for a single specific purpose. An ASIC miner refers to a device that uses microprocessors for the sole purpose of "mining" digital currency. Generally, each ASIC miner is constructed to mine a specific digital currency. So, a bitcoin ASIC miner can mine only bitcoin. One way to think about bitcoin ASICs is as specialized bitcoin mining computers, or “bitcoin generators," that are optimized to solve the mining algorithm. Developing and manufacturing ASICs as mining devices is costly and complex. Because ASICs are built especially for mining cryptocurrency, they do the job faster than less powerful computers. ASIC chips for cryptocurrency mining have become increasingly efficient, with the latest generation operating at around just 29.5 Joules per Terahash. Understanding Application-Specific Integrated Circuit (ASIC) Miners Instead of being general-purpose integrated circuits—like RAM chips or PC or mobile device microprocessors—ASICs employed in cryptocurrency mining are specific integrated circuits designed solely to maintain the bitcoin blockchain—a public shared database that stores digital information. Originally, bitcoin’s creator intended for bitcoin to be mined on central processing units (CPUs)—your laptop or desktop computer. However, bitcoin ASICs surpassed both CPUs and graphics processing units (GPUs) in terms of their reduced electricity consumption and greater computing capacity. After first gaining traction in mid-2013 when other hardware mining devices started hitting their bottlenecks in mining, Bitcoin ASIC miners have retained their lead. Bitmain Confirms Halting Its Shipment of Antminers to Chinese Customers Bitmain, one of the world’s largest manufacturers of bitcoin mining machines, confirmed it will halt shipping Antminers to mainland China. “From October 11, 2021, Antminer will stop shipping to mainland China (excluding Hong Kong and Taiwan),” according to a statement from Bitmain’s official WeChat account. The move doesn’t affect Bitmain’s overseas customers and the company said that it has increased the supply of Antbox to speed up the construction of overseas mines. On Sept. 28 CoinDesk cited three sources who said that Bitmain was planning to suspend sales of its machines to miners in mainland China, after the sweeping ban on crypto activity imposed by the country’s government. China’s crackdown on the crypto industry has created an opportunity for the miners outside of the region to participate in the sector, resulting in a recovery in bitcoin network’s hashrate, or computing power, which is a key gauge of mining activity. What's inside a WhatsMiner? Disassembling a Bitcoin ASIC In early December of last year, mining machine manufacturer MicroBT announced the parameters of the WhatsMiner M30 series, indicating that the power consumption ratio of the entire series of bitcoin mining rigs would be lower than 50W/T, which caused concern among cryptocurrency mining practitioners. In mid-May this year, Bitcoin will usher in the third halving of its block subsidy in history, also regarded as a critical period for the computing power of the entire Bitcoin network. Miners are also updating their equipment for the arrival of the halving. In the current epidemic situation, miners and people in the entire cryptocurrency industry are in a difficult winter period. At this difficult time, MicroBT hopes to spend the time with users and stick to their beliefs. At 10:30 p.m. EDT on April 16, 2020 MicroBT will hold the Global WhatsMiner M30 Launch Event to explain in detail the full lineup of the M30 series products and sales strategies. In the current epidemic situation, the online event can break the shackles of physical space by going digital and delivering the latest news of the M30 launch efficiently. Since MicroBT announced the news of the new product launch of the WhatsMiner M30 series, it has aroused concern among peers in the mining and blockchain industries. Therefore, MicroBT has also been sharing the latest news through its twitter and telegram group. In addition to the official community, MicroBT is also accelerating the expansion and improvement of the company's internal and external business. MicroBT is expanding in overseas markets and improving the quality of after-sales services. It has officially established a cooperation with HMTech which has become the first after-sales partner of WhatsMiner in North America. In terms of user operations, Jorden Chen, who is experienced in traditional industry operations, serves as the COO of MicroBT, bringing mature management and operational experience to the emerging bitcoin mining industry, which has enabled MicroBT's business operations and customer service capacity to grow rapidly. What Is Bitcoin Mining? Bitcoin mining is the process by which new bitcoins are entered into circulation; it is also the way that new transactions are confirmed by the network and a critical component of the maintenance and development of the blockchain ledger. "Mining" is performed using sophisticated hardware that solves an extremely complex computational math problem. The first computer to find the solution to the problem is awarded the next block of bitcoins and the process begins again. Cryptocurrency mining is painstaking, costly, and only sporadically rewarding. Nonetheless, mining has a magnetic appeal for many investors interested in cryptocurrency because of the fact that miners are rewarded for their work with crypto tokens. This may be because entrepreneurial types see mining as pennies from heaven, like California gold prospectors in 1849. And if you are technologically inclined, why not do it? However, before you invest the time and equipment, read this explainer to see whether mining is really for you. We will focus primarily on Bitcoin (throughout, we'll use "Bitcoin" when referring to the network or the cryptocurrency as a concept, and "bitcoin" when we're referring to a quantity of individual tokens). A New Gold Rush The primary draw for many mining is the prospect of being rewarded with Bitcoin. That said, you certainly don't have to be a miner to own cryptocurrency tokens. You can also buy cryptocurrencies using fiat currency; you can trade it on an exchange like Bitstamp using another crypto (as an example, using Ethereum or NEO to buy Bitcoin); you even can earn it by shopping, publishing blog posts on platforms that pay users in cryptocurrency, or even set up interest-earning crypto accounts. An example of a crypto blog platform is Steemit, which is kind of like Medium except that users can reward bloggers by paying them in a proprietary cryptocurrency called STEEM. STEEM can then be traded elsewhere for Bitcoin. The Bitcoin reward that miners receive is an incentive that motivates people to assist in the primary purpose of mining: to legitimize and monitor Bitcoin transactions, ensuring their validity. Because these responsibilities are spread among many users all over the world, Bitcoin is a "decentralized" cryptocurrency, or one that does not rely on any central authority like a central bank or government to oversee its regulation. Mining to Prevent Double Spend Avalon miner is getting paid for their work as auditors. They are doing the work of verifying the legitimacy of Bitcoin transactions. This convention is meant to keep Bitcoin users honest and was conceived by Bitcoin's founder, by verifying transactions, miners are helping to prevent the "double-spending problem." Double spending is a scenario in which a Bitcoin owner illicitly spends the same bitcoin twice. With physical currency, this isn't an issue: once you hand someone a $20 bill to buy a bottle of vodka, you no longer have it, so there's no danger you could use that same $20 bill to buy lotto tickets next door. While there is the possibility of counterfeit cash being made, it is not exactly the same as literally spending the same dollar twice. With digital currency, however, as the Investopedia dictionary explains, "there is a risk that the holder could make a copy of the digital token and send it to a merchant or another party while retaining the original." Mining and Bitcoin Circulation In addition to lining the pockets of miners and supporting the Bitcoin ecosystem, mining serves another vital purpose: It is the only way to release new cryptocurrency into circulation. In other words, miners are basically "minting" currency. For example, as of September 2021, there were around 18.82 million bitcoins in circulation, out of an ultimate total of 21 million. Aside from the coins minted via the genesis block (the very first block, which was created by founder Satoshi Nakamoto), every single one of those bitcoins came into being because of miners. In the absence of miners, Bitcoin as a network would still exist and be usable, but there would never be any additional bitcoin. However, because the rate of bitcoin "mined" is reduced over time, the final bitcoin won't be circulated until around the year 2140. This does not mean that transactions will cease to be verified. Miners will continue to verify transactions and will be paid in fees for doing so in order to keep the integrity of Bitcoin's network. Aside from the short-term Bitcoin payoff, being a coin miner can give you "voting" power when changes are proposed in the Bitcoin network protocol. This is known as a BIP (Bitcoin Improvement Protocol). In other words, miners have some degree of influence on the decision-making process on such matters as forking. What You Need to Mine Bitcoins Although early on in Bitcoin's history individuals may have been able to compete for blocks with a regular at-home personal computer, this is no longer the case. The reason for this is that the difficulty of mining Bitcoin changes over time. In order to ensure the smooth functioning of the blockchain and its ability to process and verify transactions, the Bitcoin network aims to have one block produced every 10 minutes or so. However, if there are one million mining rigs competing to solve the hash problem, they'll likely reach a solution faster than a scenario in which 10 mining rigs are working on the same problem. For that reason, Bitcoin is designed to evaluate and adjust the difficulty of mining every 2,016 blocks, or roughly every two weeks.1 When there is more computing power collectively working to mine for bitcoins, the difficulty level of mining increases in order to keep block production at a stable rate. Less computing power means the difficulty level decreases. At today's network size, a personal computer mining for bitcoin will almost certainly find nothing. All of this is to say that, in order to mine competitively, miners must now invest in powerful computer equipment like a GPU (graphics processing unit) or, more realistically, an application-specific integrated circuit (ASIC). These can run from $500 to the tens of thousands. Some miners—particularly Ethereum miners—buy individual graphics cards (GPUs) as a low-cost way to cobble together mining operations.         

Дата Публикации: 03-12-21

How the Baseball Cap Went From Athletic Gear to Fashion Statement

Описание:      How the Baseball Cap Went From Athletic Gear to Fashion Statement The “Philadelphia style,” with a sturdier brim, debuted in 1908, and was quickly embraced by major-league teams. Designers continued to tinker, as crowns grew higher and materials became sturdier. The advent of television—the first major-league game was telecast on August 26, 1939—brought a whole new audience to the sport and precipitated a rush of uniform redesigns and team relocations. By 1945 every team was wearing its own branded hat, and the accessory soon threaded its way into the hearts of children, especially those who played Little League and would take the look into adulthood. In the 1960s and ’70s, agricultural companies began embellishing their foam-front hats with company logos and cheap, plastic adjustable straps. Mesh backing also made the hats more breathable for workers, and long-haul drivers embraced these new accessories, inaugurating the phenomenon of the trucker hat. In the 1980s, New Era, the company that had supplied Major League Baseball for decades, started selling authentic team-branded hats to fans. Soon they were de rigueur. Tom Selleck’s character in “Magnum, P.I.,” set in Hawaii, wore a Tigers hat. You could see baseball hats on the cover of French Elle, in rap videos and atop the head of Princess Diana, whose occasional appearance in jeans and a baseball cap helped nurture her reputation as the “people’s princess”: It signaled approachability, even for a royal. And it worked for other luminaries as well. Steve Reich, a composer whose work has been played in some of the grandest halls in the world, and Paul Simon, one of the most successful pop musicians of the last 50 years, are both inseparable from rumpled, unbranded caps, even when they’re wearing black tie. No stuffy art-world or rock-star glamour here, the hats say. These are millionaires you could have a beer with. The Advantages of a Snapback Cap Adjustable Hats Fit Better There is one problem that many people have with fitted caps, and this is that they do not always fit very well. They are either a bit too loose, or a bit too tight, and the next size up or down is way too loose or tight. The caps that come in small, medium and large are just not always right for everyone. With a snapback, you can adjust it so that it is a perfect fit, which is going to make your hat really comfortable too. Adjustable hats are easy to adjust, and can be fitted to many different sizes quickly and easily. There are no buckles to jab into the back of your head or straps hanging out, and no Velcro for your hair to get caught up in. Show Your Team Spirit When people go to sporting events, they often wear clothing with the logos of their favorite teams to show their support. One great way to show your team spirit is to wear a snapback tap with the team logo on it. It is a lot less expensive to get a hat than other sports-related clothing items, such as jackets and shirts, and unlike these pieces of clothing, you can wear the same hat every day if you want, and no one is going to notice or even care. If you were to wear a team shirt every day, people will notice, so a hat is a much better way to be able to show your team spirit whenever you feel like it. Great Gifts If you are looking for a fun gift that will not cost a lot of money, an adjustable baseball cap is the ideal gift. If you have a sports enthusiast in your family, they will love getting a hat that has their favorite team's logo on it. The best part is, with a snapback cap, you never have to worry about whether or not you have gotten the right size, because it can be adjusted to just about any size. Trucker Caps Let Israelis Stand Out, but Not Too Much TEL AVIV—A craze for trucker cap in Israel this year is allowing people here to finally express themselves sartorially—and at the same time look just like everyone else. Israelis have an easy-going fashion sense that doesn’t much stick out in a crowd. Thanks to the lasting influence of the state’s founding socialist ethos, many avoid bold fashion statements. Among the nonreligious, plain T-shirts with jeans, or shorts when it’s hot, are the most common uniform. High-powered CEOs shun suits. The fanciest restaurants rarely have a dress code. ut the mania for the caps—preferably with an animal on the front—is giving Israelis an opportunity to express themselves, up to a point. Made by San Francisco-based hat maker Goorin Bros., the hats come embossed with different animals, often accompanied by a play on words. People choose which one they wear to offer a hint as to their personality. “It’s a hat with a presence,” said Amit Deutsch, a 36-year-old Tel Avivi, who sported a cap with a black panther, and had bought five of them at 150 Israeli shekels, or $46. “It’s become a type of icon.” Hodaya Elkayam, 23, who purchased a blue suede cap with an eagle and the word “America” in a Tel Aviv market on a sunny Friday afternoon, said the hats “have got style, they’re pretty and comfortable. So they’re good for all occasions.” RESERVED FOR PEOPLE WHO ARE NOT BLENDING IN In HBO Max's abortion road trip movie Unpregnant, Simonelli introduces Barbie Ferreira's character, Bailey — who's all of the above — wearing a purple angora Kangol bucket hat as she pops up over a bathroom stall divider. The hat's unexpected color and plushness, which match and clash with her shaggy green stuffed animal backpack, also help convey Bailey's innate but unintentional style. "I don't know if she's registered the cool factor that she has," adds Simonelli. Plus, her face-framing headwear was actually inspired by Ferreira serving her own outfit inspo in a textured white variation on Instagram. A nostalgic look back at the bucket hat icons of decades past really does run the gamut of individual style and creative talents. Simonelli references late-'80s hip-hop legends Run-DMC, the white cotton canvas classic of author and founder of the '70s gonzo journalism movement Hunter S. Thompson, and, of course, all the floppy and floral-accented toppers worn by Mayim Bialik in Blossom, which ran from 1990 to 1995. "Then you think of some of the late-'80s and '90s R&B singers, like Brandy, SWV, Missy Elliot, and Janet Jackson," says Smith, who also name-checked Blossom. "That cool sense of style that's laid-back and chill." During the early-2000s return of carefree teen pop, a trifecta of Mandy Moore, Jessica Simpson, and Britney Spears in the relaxed look, also come to mind. All About Knitted Hats Who knows when the first person decided to put something over their head to keep it warm, but knitters know that knitted hat is some of the most fun and easy things to knit. When they’re worked in the round there is little in the way of shaping, except when you get to the crown. Most hats are worked from the bottom up, with stitches cast-on and worked in a snug stitch pattern such as ribbing, or in stockinette for a rolled bring hat, using a smaller size needle than is used for the head portion of the hat. In many hat patterns, the hat is worked straight for the desired length of the crown, then nearly all of the stitches are evenly decreased over the course of just a few rounds. The yarn is cut, the tail threaded through the remaining stitches, pulled tight, and fastened off to the inside of the hat. The hat can be topped with a pom pom, i-cord, tassel, or whatever embellishment strikes your fancy. A great book for learning to make hats is Ann Budd’s Handy Book of Patterns, from which some of the material on this page is excerpted. There are chapters on basic hats as well as the type of hats called “tams.” There are several types of hats, but the most popular knitted hats are beanie-type caps, tams (sometimes called “berets”), slouch hats, earflap hats, and tuques. Beanies: These hats can be super simple or dressed up with a lace or cable patterns. In cooler climates, they’re wonderful gifts for knitters to make. Tams/Berets: There are so many different stitch patterns to use in this style. Tams and berets can be plain stockinette or intricate Fair Isle. This style of hat is really flattering on just about every face shape, too. Earflap Hats: These hats are popular in cold climates. They’re great for keeping ears warm and they’re fun to knit. The knitters of Peru specialize in these hats, as shown in the photo at right. THE HISTORY OF THE STRAW HAT Reaching for a straw hat to complete our seaside look—or frankly, any summer outfit—is as instinctive to us as say, oh I don’t know, breathing. Next to sunglasses, it’s one of the most obvious accessories to use as protection against the sun’s harmful UV rays, but its origins are less than clear. When an item is as ubiquitous as that of a straw hat, it’s virtually impossible to determine its original maker or even pinpoint the first documentation of its existence. (Fun fact about hats: Historians believe that some type of head-covering piece—as protection against inclement weather—was the first article of clothing ever worn by humans.) Straw hats—distinguished by their woven makeup of different types of straw or fibers similar in texture and strength, like braided hemp, raffia, and jute—are believed to have been worn in Europe and Asia as early as the 15th century (after the Middle Ages). In most countries in Asia, including Japan, China, Indonesia, Malaysia, and Vietnam, rice paddy workers topped their heads with conical-shaped hats to shield themselves from the sun and the rain, though legend in Vietnam has it that the hat, or nón lá in Vietnamese, originated from when a goddess descended from the sky wearing an enormous hat made of four large leaves held together by bamboo sticks, which protected the people from a torrential downpour. In the Très Riches Heures du Duc de Berry, the most famous surviving example of an illuminated French Gothic manuscript created from 1412 to 1416, short-brim straw hats are shown mostly worn by men. Though by the 1700s, French women wore straw bonnets and in the 1800s, European paintings all depict women posing for portraits in ribbon-adorned floppy straw hats and floral-strewn ones with an upturned brim. Vincent Van Gogh even immortalized his straw hat in a self-portrait in 1887. The first cowboy hat—made of straw, might we add—was invented by John B. Stetson in 1865, and the silhouette basically remains unchanged to this day. By the late 1800s and early 1900s, straw hats were embraced by everyone. But it wasn’t until President Theodore Roosevelt’s 1906 visit to the Panama Canal—when he was photographed at the construction site in his pale suit and Panama hat—that the accessory catapulted to fame. Light in weight, the summertime staple exuded equal parts casual and polish; by 1944, it became Ecuador’s number-one export. Conclusion As an experienced manufacturer and supplier, in addition to the above hats, we also provide various other types of caps and hats, such as children's baseball cap,knitted hats, straw hats and so on. 

Дата Публикации: 03-12-21