Bullet-proof vests

The Analysis of the Design of a Flexible Bullet-Proof Vest... 

The task in this study focused on enhancing the flexibihty and reducing the weight of a bullet proof vest (e.g. wearing it as a vest under tuxedos or evening dresses). Document analysis and expert consultation revealed that a number of specific structures... 

The Group A emphases are those that inform the development of chemical literacy (DeBoer, 2000) and should be made available to all students (cf scientific literacy - (Roberts, 2007). These emphases all call for an imderstanding of a macro type of representation, so that learners appreciate what it is when they encounter a chemical phenomenon e.g. a solution, a colloid, a precipitate. This understanding would enable students to answer the question what is it and possibly what to do with it how to act when they encounter such a chemical phenomenon. These emphases also call for an understanding of the submicro type of representation, so that learners can qualitatively explain the nature of the macro phenomena that they encounter and hence be able to answer the question why is it as it is In order to explore these emphases, a chemistry curriculum would need to address a variety of contexts related to the three Group A emphases that have mearung in the everyday world. Pilot, Meijer and Bulte (2008) discuss three such contexts ceramic crockery, gluten-free bread and the bullet-proof vest. 

The diaminobenzenes are made from benzene by a combination chlorination-nitration route although para-phenylene diamine is also made directly from aniline. orr/to-Phenylene diamine is widely used for the preparation of biologically active compounds such as fungicides and veterinarian medicines. The mera-diamine is used in fire-retardant textile fibers ( Nomex ) while the / ara-diamine finds use in high-strength textile fibers used for bullet-proof vests, sails, army helmets, and other types of fiber-reinforced plastics ( Kevlar ). 

Ultrahigh molecular weight ultra-oriented fibers have outstanding tensile strength and modulus, which suits them for use in bullet proof vests. 

Security personnel often rely on the integrity of bullet-proof vests to... 

Question 7.7 How Does a Bullet-Proof Vest Work How Is It Made ... 

How does a bullet-proof vest work How is it made See p. 92. 

Kevlar a polymer fiber that is stronger than steel, but very light. It is used to make bullet-proof vests and other body armor. 

Their policies range from the permissive (all law-abiding adults) to the highly restrictive (must show a definite need), cop-killer bullet Term for armor-piercing ammunition popularized by gun control advocates. The term gets its name on the basis that it especially endangers police wearing bullet-proof vests, curios and relics Firearms that are at least 50 years old or that are considered (because of their scarcity, historical value, or unusual nature) to be collector s items. A federal firearms license (FFL) is required for interstate purchase of such firearms. 

Kevlar, a polymer of aromatic amides, is several times stronger than steel, but much fighter and also fire resistant. Kevlar fibers are formed into hollow cylinders that are then woven into fabrics useful in bullet-proof vests and manufacture of automobile tires, see also Cellulose Polyesters Polymers, Synthetic. 

Polyethylene is probably the material one encounters most abundantly in daily life, such as in the form of grocery bags, shampoo bottles and toys, but now one also finds it as the material in such super high performance products as bullet-proof vests. For such a... 

Beyond the usual mechanical and electrical performances, this review also points out the emergence of other original properties, like the remarkable capability of some nanotube/PVA composites to absorb mechanical energy and shape memory phenomena that differ from traditional behaviors of other polymers. These features are opening new investigation fields, in which several fundamental questions will have to be solved. But they also offer new opportunities for a variety of applications like smart or protective clothing, helmets, bullet proof vests, or active composites. 

Polybenzazole fibers have been prepared containing blended organic pigments that are heat, moisture, and light resistant with thermal decomposition temperatures exceeding 200°C. These materials are useful as fibers for high-strength rope, cement/concrete reinforcers, and bullet proof vests. 

A synthetic fiber used in bullet-proof vests, comprised of poly(paraphenylene terephthal amide). 

Remember All armor is bullet resistant, but there is no such thing as a bullet proof vest. 

Security personnel often rely on the integrity of bullet-proof vests to protect their lives. The innovative chemistry of the fabric creates the incredible strength of these ballistic barriers. 

CH How can the same chemical process produce bullet-proof vests, insect repellents, and medicines ... 

The induction time becomes a major problem during the production of ultrahigh-MW polyethylene (UF1MW PE). This type of PE is used when extreme toughness is desired, in applications such as in ski bottoms, artificial limbs, gears, and bullet-proof vests. UF1MW PE is more resistant to abrasion than steel. To minimize chain transfer on Cr/silica, low activation and reaction temperatures are necessary, and lowering these temperatures increases the induction time. To overcome this issue, the catalyst can be reduced to Cr(II) in CO, or metal alkyl cocatalysts can... 

The liquid crystalline polymer industry now covers diverse products, from high modulus rope to high strength composite, from the tennis racket to the radial tire cord, from the cover layer of the optical fiber to the microwave oven, from the bullet-proof vest to thermal insulated clothing, and from the electro-optic display to non-linear optical material, etc. 

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