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Making High-Tensile-Strength Amalgam Components

Instead of spheroids or flakes, wires are used as the solid constituents. Structural components made of amalgams can be made to have tensile strengths much greater than previously known to be possible. Amalgams, perhaps best known for their use in dental fillings, have several useful attributes, including room- temperature fabrication, corrosion resistance, dimensional stability, and high compressive strength. However, the range of applications of amalgams has been limited by their very small tensile strengths. Now, it has been discovered that the tensile strength of an amalgam depends critically on the sizes and shapes of the particles from which it is made and, consequently, the tensile strength can be greatly increased through suitable choice of the particles.

Posted in: Materials, Briefs

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Hybrid Wound Filaments for Greater Resistance to Impacts

PBO fibers are used in addition to high-strength carbon fibers. The immediately preceding article includes an example in which a composite overwrap on a pressure vessel contains wound filaments made of a hybrid of high-strength carbon fibers and poly(phenylene benzobisoxazole) [PBO] fibers. This hybrid material is chosen in an effort to increase the ability of the pressure vessel to resist damage by lowspeed impacts (e.g., dropping of tools on the vessel or bumping of the vessel against hard objects during installation and use) without significantly increasing the weight of the vessel. Heretofore, enhancement of the impact resistances of filament-wound pressure vessels has entailed increases in vessel weight associated, variously, with increases in wall thickness or addition of protective materials.

Posted in: Materials, Briefs

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Lightweight Tanks for Storing Liquefied Natural Gas

These tanks are also relatively inexpensive. Single-walled, jacketed aluminum tanks have been conceived for storing liquefied natural gas (LNG) in LNG-fueled motor vehicles. Heretofore, double- wall steel tanks with vacuum between the inner and outer walls have been used for storing LNG. In comparison with the vacuum-insulated steel tanks, the jacketed aluminum tanks weigh less and can be manufactured at lower cost. Costs of using the jacketed aluminum tanks are further reduced in that there is no need for the vacuum pumps heretofore needed to maintain vacuum in the vacuum-insulated tanks.

Posted in: Materials, Briefs

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SiO2/TiO2 Composite for Removing Hg From Combustion Exhaust

This material could remove mercury from exhaust streams of coal-burning power plants. Pellets made of a high-surface-area composite of silica and titania have shown promise as means of removing elemental mercury from flue gases. With further technical development and commercialization, this material could become economically attractive as a more-effective, less-expensive alternative to activated carbons for removing mercury from exhaust streams of coal-burning power plants, which are the sources of more than 90 percent of all anthropogenic airborne mercury.

Posted in: Materials, Briefs

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Gimballed Shoulders for Friction Stir Welding

Digging of edges of shoulders into workpieces would be reduced or eliminated. In a proposed improvement of tooling for friction stir welding, gimballed shoulders would supplant shoulders that, heretofore, have been fixedly aligned with pins. The proposal is especially relevant to self-reacting friction stir welding.

Posted in: Manufacturing & Prototyping, Briefs

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Patterning of Indium Tin Oxide Films

The patterns are formed by laser printing directly onto the films. A relatively rapid, economical process has been devised for patterning a thin film of indium tin oxide (ITO) that has been deposited on a polyester film. ITO is a transparent, electrically conductive substance made from a mixture of indium oxide and tin oxide that is commonly used in touch panels, liquid-crystal and plasma display devices, gas sensors, and solar photovoltaic panels. In a typical application, the ITO film must be patterned to form electrodes, current collectors, and the like. Heretofore it has been common practice to pattern an ITO film by means of either a laser ablation process or a photolithography/etching process. The laser ablation process includes the use of expensive equipment to precisely position and focus a laser. The photolithography/etching process is time-consuming.

Posted in: Manufacturing & Prototyping, Briefs, TSP

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Efficient G4FET-Based Logic Circuits

Fewer G4FETs than conventional transistors would be needed to implement logic functions. A total of 81 optimal logic circuits based on four-gate field-effect transistors (G4FETs) have been designed to implement all Boolean functions of up to three variables. The purpose of this development was to lend credence to the expectation that logic circuits based on G4FETs could be more efficient (in the sense that they could contain fewer transistors), relative to functionally equivalent logic circuits based on conventional transistors.

Posted in: Semiconductors & ICs, Briefs, TSP

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