Mass-produced

Mass-produced workstation-class CPUs are much cheaper than traditional supercomputer processors. Thus, a larger amount of computing power for the dollar can be purchased by buying a parallel supercomputer that might have hundreds of workstation CPUs. 

If a linear mbber is used as a feedstock for the mass process (85), the mbber becomes insoluble in the mixture of monomers and SAN polymer which is formed in the reactors, and discrete mbber particles are formed. This is referred to as phase inversion since the continuous phase shifts from mbber to SAN. Grafting of some of the SAN onto the mbber particles occurs as in the emulsion process. Typically, the mass-produced mbber particles are larger (0.5 to 5 llm) than those of emulsion-based ABS (0.1 to 1 llm) and contain much larger internal occlusions of SAN polymer. The reaction recipe can include polymerization initiators, chain-transfer agents, and other additives. Diluents are sometimes used to reduce the viscosity of the monomer and polymer mixture to faciUtate processing at high conversion. The product from the reactor system is devolatilized to remove the unreacted monomers and is then pelletized. Equipment used for devolatilization includes single- and twin-screw extmders, and flash and thin film evaporators. Unreacted monomers are recovered for recycle to the reactors to improve the process yield. 

Rayon is unique among the mass produced man-made fibers because it is the only one to use a natural polymer (cellulose) directly. Polyesters, nylons, polyolefins, and acryflcs all come indirectly from vegetation they come from the polymerization of monomers obtained from reserves of fossil fuels, which in turn were formed by the incomplete biodegradation of vegetation that grew millions of years ago. The extraction of these nonrenewable reserves and the resulting return to the atmosphere of the carbon dioxide from which they were made is one of the most important environmental issues of current times. CeUulosic fibers therefore have much to recommend them provided that the processes used to make them have minimal environmental impact. 

From the standpoint of commercialization of fuel ceU technologies, there are two challenges initial cost and reHable life. The initial selling price of the 200-kW PAFC power plant from IFC was about 3500/kW. A competitive price is projected to be about 1500/kW orless for the utiHty and commercial on-site markets. For transportation appHcations, cost is also a critical issue. The fuel ceU must compete with conventional mass-produced propulsion systems. Furthermore, it is not clear if the manufacturing cost per kilowatt of small fuel ceU systems can be lower than the cost of much larger units. The life of a fuel ceU stack must be five years minimum for utiHty appHcations, and reHable, maintenance-free operation must be achieved over this time period. The projection for the PAFC stack is a five year life, but reHable operation has yet to be demonstrated for this period. 

Sihcon nitride is one of the few nonmetaUic nitrides that is able to form alloys with other refractory compounds. Numerous soHd solutions of P-Si N and AI2O2 have gained technical interest. Many companies have begun to mass produce reaction-sintered and hot-pressed Si N parts. 

Electrochemical Microsensors. The most successful chemical microsensor in use as of the mid-1990s is the oxygen sensor found in the exhaust system of almost all modem automobiles (see Exhaust control, automotive). It is an electrochemical sensor that uses a soHd electrolyte, often doped Zr02, as an oxygen ion conductor. The sensor exemplifies many of the properties considered desirable for all chemical microsensors. It works in a process-control situation and has very fast (- 100 ms) response time for feedback control. It is relatively inexpensive because it is designed specifically for one task and is mass-produced. It is relatively immune to other chemical species found in exhaust that could act as interferants. It performs in a very hostile environment and is reHable over a long period of time (36). 

Flavor-Masking Deodorant. In addition to its use as a constituent of perfume compositions, vanillin is also useful as a deodorant to mask the unpleasant odor of many manufactured goods. As a masking agent for numerous types of ill-smelling mass-produced industrial products, particularly those of synthetic mbber, plastics, fiber glass, inks, etc, vanillin finds extensive use. It is often the most inexpensive material for the amount of masking effect it provides. Only traces are required for this purpose as the odor of vanillin is perceptible in dilutions of 2 x 10 mg/m of air. Cmde vanillin is acceptable for such purposes. 

Since the 1960s the overall number of types has been decreasing, or at least remained unchanged (standard products), but some figures indicate that in the future the creation of new products might take place as a strong alternative to the previous mass-produced beers of less body or character. A traditional and overall grouping of beer can nevertheless stiU be made, ie, bottom-fermented beet and top-fermented beer. 

The modem interest in composite materials can be traced to the development of BakeHte, or phenoHc resin, in 1906. BakeHte was a hard, brittle material that had few if any mechanical appHcations on its own. However, the addition of a filler— the eadiest appHcations used short cellulose fibers (2)—yielded BakeHte mol ding compounds that were strong and tough and found eady appHcations in mass-produced automobile components. The wood dour additive improved BakeHte s processibiHty and physical, chemical, and electrical properties, as weU as reducing its cost (3,4). 

Henry Bessemer, the great Victorian ironmaster and the first person to mass-produce mild steel, was nearly bankrupted by this. When he changed his suppliers of iron ore, his steel began to crack in service. The new ore contained phosphorus, which we now know segregates badly to grain boundaries. Modern steels must contain less than =0.05% phosphorus as a result. 

Such skills are rare, and most students today can only afford rather indifferent mass-produced instruments. But the music trade is big business and there is a powerful incentive for improving the quality of the mass-market product. 

Fuel cells, which rely on electrochemical generation of electric power, could be used for nonpolluting sources of power for motor vehicles. Since fuel cells are not heat engines, they offer the potential for extremely low emissions with a higher thermal effidency than internal combustion engines. Their lack of adoption by mobile systems has been due to their cost, large size, weight, lack of operational flexibility, and poor transient response. It has been stated that these problems could keep fuel cells from the mass-produced automobile market until after the year 2010 (5). 

The RIM process was originally developed for the car industry for the production of bumpers, front ends, rear ends, fascia panels and instrument housings. At least one mass-produced American car has RIM body panels. For many of these products, however, a number of injection moulding products are competitive, including such diverse materials as polycarbonate/PBT blends and polypropylene/EPDM blends. In the shoe industry the RIM process has been used to make soling materials from semi-flexible polyurethane foams. 

Because the plates are made of thin pressed metal, materials resistant to corrosive attack can be easily selected. Plates are standard and mass-produced,. Specific applications are dealt with by changing plate arrangements. Stainless steels, monel, titanium, aluminum bronze, and other exotic metals... 

Due to the basic design of the compressor, its rotating and reciprocating masses produce inertia forces and moments tha cannot be completely eliminated and must be absorbed by the foundation. The manufacturer has the ability to minimize the magnitude of these forces and moments by adding counterweights to the crossheads but cannot totally eliminate them. 

The constant of proportionality in the English system of units, g, which causes one pound of mass produces one pound of force under the acceleration of gravity, equal to 32.17 Ibm-ft/lbf-sec. ... 

Catalytic reactors have worked to the benefit of the chemical and petroleum industries for many decades, under the watchful eyes of plant engineers and batteries of monitor and control instruments. The automotive catalytic converter will be the first mass produced catalytic reactor placed directly in the hands of the public, who can provide little more than benign neglect. 

Microfabrication technology has made a considerable impact on the miniaturization of electrochemical sensors and systems. Such technology allows replacement of traditional bulky electrodes and beaker-type cells with mass-producible, easy-to-use sensor strips. These strips can be considered as disposable electrochemical cells onto which the sample droplet is placed. The development of microfabricated electrochemical systems has the potential to revolutionize the field of electroanaly-tical chemistry. 

STRATEGY Begin by writing the chemical equation for the complete oxidation of octane to carbon dioxide and water. Then calculate the theoretical yield (in grams) of CO, by using the procedure in Toolbox L.l. To avoid rounding errors, do all the numerical work at the end of the calculation. To obtain the percentage yield, divide the actual I mass produced by the theoretical mass of product and multiply by 100%. 

STRATEGY First, the limiting reactant must be identified (Toolbox M.l). This limiting reactant determines the theoretical yield of the reaction, and so we use it to calculate the theoretical amount of product by Method 2 in Toolbox L.l. The percentage yield is the ratio of the mass produced to the theoretical mass times 100. Molar masses are j calculated using the information in the periodic table inside the front cover of this i book. 

The mass produced corresponds to 805 kg. The fact that the production of 1 mol Al requires 3 mol e accounts for the very high consumption of electricity characteristic of aluminum-production plants. 

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