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  1. Vacuum packing - Wikipedia

    en.wikipedia.org › wiki › Vacuum_packing

    Vacuum packing is a method of packaging that removes air from the package prior to sealing. This method involves (manually or automatically) placing items in a plastic film package, removing air from inside and sealing the package.[1] Shrink ...

  2. Vacuum cleaner - Wikipedia

    en.wikipedia.org › wiki › Vacuum_cleaner
    • Name
    • History
    • Modern Configurations
    • Technology
    • Further Reading
    • External Links

    Although vacuum cleaner and the short form vacuum are neutral names, in some countries (UK, Ireland, USA) hoover is used instead as a genericized trademark, and as a verb. The name comes from the Hoover Company, one of the first and more influential companies in the development of the device. In New Zealand, particularly the Southland region, it is sometimes called a lux, likewise a genericized trademark and used as a verb. The device is also sometimes called a sweeper although the same term also refers to a carpet sweeper, a similar invention.

    The vacuum cleaner evolved from the carpet sweeper via manual vacuum cleaners. The first manual models, using bellows, were developed in the 1860s, and the first motorized designs appeared at the turn of the 20th century, with the first decade being the boom decade.

    A wide variety of technologies, designs, and configurations are available for both domestic and commercial cleaning jobs.[citation needed]

    A vacuum's suction is caused by a difference in air pressure. A fan driven by an electric motor (often a universal motor) reduces the pressure inside the machine. Atmospheric pressure then pushes the air through the carpet and into the nozzle, and so the dust is literally pushed into the bag. Tests have shown that vacuuming can kill 100% of young fleasand 96% of adult fleas.

    Booth, H. Cecil "The origin of the vacuum cleaner," Transactions of the Newcomen Society, 1934–1935, Volume 15.
    Gantz, Carroll. The Vacuum Cleaner: A History(McFarland, 2012), 230 pp
  3. Composite material - Wikipedia

    en.wikipedia.org › wiki › Composite_material
    • History
    • Examples
    • Overview
    • Cores in Composites
    • Methods of Fabrication
    • Physical Properties
    • Mechanical Properties of Composites
    • See Also
    • External Links

    The earliest composite materials were made from straw and mud combined to form bricks for building construction. Ancient brick-making was documented by Egyptian tomb paintings.[citation needed] Wattle and daub is one of the oldest composite materials, at over 6000 years old. Concrete is also a composite material, and is used more than any other synthetic material in the world. As of 2006[update], about 7.5 billion cubic metres of concrete are made each year—more than one cubic metre for every person on Earth. 1. Woody plants, both true wood from trees and such plants as palms and bamboo, yield natural composites that were used prehistorically by mankind and are still used widely in construction and scaffolding. 2. Plywood, 3400 BC,by the Ancient Mesopotamians; gluing wood at different angles gives better properties than natural wood. 3. Cartonnage, layers of linen or papyrus soaked in plaster dates to the First Intermediate Period of Egypt c. 2181–2055 BC and was used for death mask...

    Composite materials

    Concrete is the most common artificial composite material of all and typically consists of loose stones (aggregate) held with a matrix of cement. Concrete is an inexpensive material, and will not compress or shatter even under quite a large compressive force. However, concrete cannot survive tensile loading (i.e., if stretched it will quickly break apart). Therefore, to give concrete the ability to resist being stretched, steel bars, which can resist high stretching (tensile) forces, are ofte...

    Products

    Fibre-reinforced composite materials have gained popularity (despite their generally high cost) in high-performance products that need to be lightweight, yet strong enough to take harsh loading conditions such as aerospace components (tails, wings, fuselages, propellers), boat and scull hulls, bicycle frames and racing car bodies. Other uses include fishing rods, storage tanks, swimming pool panels, and baseball bats. The Boeing 787 and Airbus A350 structures including the wings and fuselage...

    Composite materials are created from individual materials. These individual materials are known as constituent materials, and there are two main categories of it. One is the matrix (binder) and the other reinforcement.A portion of each kind is needed at least. The reinforcement receives support from the matrix as the matrix surrounds the reinforcement and maintains its relative positions. The properties of the matrix are improved as the reinforcements impart their exceptional physical and mechanical properties. The mechanical properties become unavailable from the individual constituent materials by synergism. At the same time, the designer of the product or structure receives options to choose an optimum combination from the variety of matrix and strengthening materials. To shape the engineered composites, it must be formed. The reinforcement is placed onto the mould surface or into the mould cavity. Before or after this, the matrix can be introduced to the reinforcement. The matri...

    Several layup designs of composite also involve a co-curing or post-curing of the prepreg with many other media, such as foam or honeycomb. Generally, this is known as a sandwich structure. This is a more general layup for the production of cowlings, doors, radomes or non-structural parts. Open- and closed-cell-structured foams like polyvinylchloride, polyurethane, polyethylene or polystyrene foams, balsa wood, syntactic foams, and honeycombs are generally utilized core materials. Open- and closed-cell metal foamcan also be utilized as core materials. Recently, 3D graphene structures ( also called graphene foam) have also been employed as core structures. A recent review by Khurram and Xu et al., have provided the summary of the state-of-the-art techniques for fabrication of the 3D structure of graphene, and the examples of the use of these foam like structures as a core for their respective polymer composites.

    Normally, the fabrication of composite includes wetting, mixing or saturating the reinforcement with the matrix. The matrix is then induced to bind together (with heat or a chemical reaction) into a rigid structure. Usually, the operation is done in an open or closed forming mould. However, the order and ways of introducing the constituents alters considerably. Composites fabrication is achieved by a wide variety of methods, including advanced fibre placement (Automated fibre placement), fibreglass spray lay-up process, filament winding, lanxide process, tailored fibre placement, tufting and z-pinning.

    Usually, the composite's physical properties are not isotropic (independent of the direction of applied force) in nature. But they are typically anisotropic(different depending on the direction of the applied force or load). For instance, the composite panel's stiffness will usually depend upon the orientation of the applied forces and/or moments. The composite's strength is bounded by two loading conditions, as shown in the plot to the right.

    Particle Reinforcement

    In general, particle reinforcement is strengthening the composites less than fiber reinforcement. It is used to enhance the stiffness of the composites while increasing the strength and the toughness. Because of their mechanical properties, they are used in applications in which wear resistance is required. For example, hardness of cementcan be increased by reinforcing gravel particles, drastically. Particle reinforcement a highly advantageous method of tuning mechanical properties of materia...

    Continuous Fiber Reinforcement

    In general, continuous fiber reinforcement is implemented by incorporating a fiber as the strong phase into a weak phase, matrix. The reason for the popularity of fiber usage is materials with extraordinary strength can be obtained in their fiber form. Non-metallic fibers are usually showing a very high strength to density ratio compared to metal fibers because of the covalent nature of their bonds. The most famous example of this is carbon fibers that have many applications extending from sp...

    The Effect of Fiber Orientation

    The change is in the fiber orientation can affect the mechanical properties of the fiber-reinforced composites especially the tensile strength. The composite tensile strength can be predicted to depending on the θ {\\displaystyle \\theta } (0° to 10° angles), the angle between the applied for, and the orientation of the fibers. ( T . S . ) ( l o n g i t u d i n a l f r a c t u r e ) = σ ∥ ∗ c o s 2 ( θ ) {\\displaystyle (T.S.)(longitudinalfracture)={\\frac {\\sigma _{\\parallel }^{*}}{cos^{2}(\\thet...

  4. IKEA - Wikipedia

    en.wikipedia.org › wiki › IKEA

    IKEA ( Swedish: [ɪˈkêːa]) is a Swedish - origin Dutch (Netherlands) -headquartered multinational conglomerate that designs and sells ready-to-assemble furniture, kitchen appliances and home accessories, among other goods and home services. ...

  5. Antibiotic - Wikipedia

    en.wikipedia.org › wiki › Antibiotic

    An antibiotic is a type of antimicrobial substance active against bacteria.It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention of such ...

  6. Coca-Cola - Wikipedia

    en.wikipedia.org › wiki › Coca-Cola

    Coca-Cola, or Coke, is a carbonated soft drink manufactured by The Coca-Cola Company.Originally marketed as a temperance drink and intended as a patent medicine, it was invented in the late 19th century by John Stith Pemberton and was bought out ...

  7. Dyson (company) - Wikipedia

    en.wikipedia.org › wiki › Dyson_(company)
    • History
    • Research Projects
    • James Dyson Award and James Dyson Foundation
    • The Dyson Institute of Engineering and Technology
    • Lawsuits and Controversies
    • External Links

    In 1974, James Dyson bought a Hoover Junior vacuum cleaner, which lost suction after a period of use. Frustrated, Dyson emptied the disposable paper bag to try to restore the suction but this had no effect. On opening the bag to investigate, he noticed a layer of dust inside, clogging the fine material mesh. Later, Dyson was working on his ballbarrow at a company he had founded (but no longer entirely owned) where a large vacuum system was used to contain the fusion bonded epoxy coating that was sprayed on the wheelbarrow arms as a powder coating. Dyson found the system inefficient, and was told by equipment manufacturers that giant cyclone systems were better. Centrifugal separators are a typical method of collecting dirt, dust and debris in industrial settings, but such methods usually were not applied on a smaller scale because of the higher cost. He knew sawmills used this type of equipment, and investigated by visiting a local sawmill at night and taking measurements. He then b...

    Robotic vacuum cleaners

    In 2014, Dyson invested in a joint robotics lab with Imperial College London to investigate vision systems and engineer a generation of household robots.In 2001 the company had been close to launching a robot vacuum, the DC06, but James Dyson pulled it from the production line as it was too heavy and slow.

    Collaboration with universities

    Dyson funded a professorship at the University of Cambridge Department of Engineering in November 2011, adding to earlier funding of post-doctorate research. The Dyson Professor of Fluid Mechanics focuses on teaching and researching the science and engineering behind air movement. In addition, Dyson invested hundreds of thousands of pounds in a Dyson research branch at Newcastle Universityin May 2012, to investigate the next generation of Dyson digital motors and motor drives.

    Solid-state batteries

    In March 2015, Dyson invested in its first outside business, paying $15m for an undisclosed stake in US battery start-up Sakti3, which is developing solid-state batteries. Dyson acquired the remaining stake in Sakti3 for $90m in October 2015. Dyson researchers had been working on battery technology since 2010.In 2017, Dyson abandoned its licensing of patents held by the University of Michigan, casting doubt on Sakti3's technology.

    The James Dyson Awardis an international student design award running in 18 countries. It is run by the James Dyson Foundation, James Dyson's charitable trust, and is presented jointly to students and their university. Over 727 schools in Great Britain and Northern Ireland have used Dyson's educational "Ideas Boxes", sent to teachers and pupils, in order to learn more about the design process. The James Dyson Foundation also provides bursaries and scholarships to aspiring engineers.

    In November 2016, James Dyson announced plans to open a higher education college to address the engineering skills gap in the UK. In September 2017 it welcomed its first cohort of undergraduates, partnering with the University of Warwick to offer BEng degrees in Engineering, whilst also employing them as engineers three days a week.The second cohort of students, joining in September 2018, was 40% female, compared to a national average of 15.1% for engineering subjects.

    Criticisms regarding foreign students

    In March 2011, James Dyson reportedly said in an interview for The Sunday Times that British universities were allowing Chinese nationals to study engineering and spy on the departments where they were working, enabling them to take technology back to China after completing their studies.In the interview he was quoted as saying that "Britain is very proud about the number of foreign students we educate at our universities, but actually all we are doing is educating our competitors. [...] I've...

    Lobbying on copyright issues with China

    In December 2011, The Independent reported that Bell Pottinger executive Tim Collins had been filmed by the Bureau of Investigative Journalism saying that David Cameron had raised a copyright issue with Chinese premier Wen Jiabaoon behalf of Dyson Limited "because we asked him to".

    Dyson suit alleging industrial espionage on motor technology

    In 2012, Yong Pang, an engineer specialist in electric motors, was accused of stealing Dyson's digital motor technology which was a part of future product development projects. The motors, in development over 15 years, incorporated microchip "digital impulse technology" to spin at 104,000 rpm in order to draw high volumes of air through the appliance, and were not licensed to any other companies. Yong Pang and his wife Yali Li allegedly set up a front company "ACE Electrical Machine Design" t...

  8. New Zealand - Wikipedia

    en.wikipedia.org › wiki › New_zealand

    New Zealand (Māori: Aotearoa [aɔˈtɛaɾɔa]) is an island country in the southwestern Pacific Ocean.It consists of two main landmasses—the North Island (Te Ika-a-Māui) and the South Island (Te Waipounamu)—and more than 700 smaller islands, [13] ...

  9. The Walt Disney Company - Wikipedia

    en.wikipedia.org › wiki › The_Walt_Disney_Company

    The building in the Los Angeles neighborhood of Los Feliz which was home to the studio from 1923 to 1926. [9] In early 1923, Kansas City, Missouri, animator Walt Disney created a short film entitled Alice's Wonderland, which featured child ...

  10. Mother's Day - Wikipedia

    en.wikipedia.org › wiki › Mother&

    Mother's Day is a celebration honoring the mother of the family or individual, as well as motherhood, maternal bonds, and the influence of mothers in society.It is celebrated on different days in many parts of the world, most commonly in the ...

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  1. 真空包裝袋 相關
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