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Electrical durability

The investigation described in the first paragraph must include winning the most basic raw materials such as crude oil, mineral ores or trees the steps to manufacture the article the packaging and transport in-use consumption (e.g. water and electricity) durability and results of disposal, to be able to justify the term LCA. Less complete studies can only address limited issues and may well miss environmental trade-offs from other parts of the cycle. [Pg.118]

Solar cells have been used extensively and successfully to power sateUites in space since the late 1950s, where their high power-to-weight ratio and demonstrated rehabiUty are especially desirable characteristics. On earth, where electrical systems typically provide large amounts of power at reasonable costs, three principal technical limitations have thus far impeded the widespread use of photovoltaic products solar cells are expensive, sunlight has a relatively low power density, and commercially available solar cells convert sunlight to electricity with limited efficiency. Clearly, terrestrial solar cells must be reasonably efficient, affordable, and durable. International efforts are dedicated to obtaining such devices, and a number of these activities have been reviewed (1). [Pg.466]

Diaphrag m Cell Technology. Diaphragm cells feature a porous diaphragm that separates anode and cathode compartments of the cell. Diaphragms should provide resistance to Hquid flow, requite minimum space between anode and cathode, produce minimum electrical resistance, and be durable. At the anode, which is generally a DSA, chloride ions are oxidized to chlorine (see eq. 1) and at the cathode, which is usually a woven steel wine mesh, water is reduced to hydrogen. [Pg.75]

Field coating of welds has always presented problems. Straw and jute with a greasy material was employed in 1910, but this later saponified in the soil. By chance the pharmacist Schade of Berlin learned of this problem and recommended the use of petroleum jelly in a bandage-like application. Hot-applied bitumen bands, as used by pipe works since 1928. proved to be most durable. Since 1930, electrical measuring methods have played an important part in research into insulation bands and pipe coverings carried out by the Gas Institute in Karlsruhe, the present-day Engier-Bunte Institute 18). [Pg.7]

There is a frequent dememd for materials suitable for housings for computer, domestic, electrical and automotive equipment. In these applications toughness, excellent surface finish, surface durability, reasonable rigidity, dimensional stability, good weathering behaviour and low water absorption are common requirements. In these applications ABS is frequently considered first but its limited deflection temperature and heat aging resistance may lead to other... [Pg.896]

Polyethers and polysulfides obtained by displacement reaction, in general, are rigid as well as flexible, heat resistant, tough, and melt processable polymers with good electrical, chemical, and durability properties, as well as fire and hydrolysis resistance [195,196]. [Pg.50]

Nickel-Hydrogen, Nickel-Iron, and Nickel-Metal Hydride. First developed for communication satellites in the early 1970s, nickel-hydrogen batteries are durable, require low maintenance, and have a long life expectancy. The major disadvantage is the high initial cost. For these batteries to be a viable option for electric vehicles, mass production techniques will have to be developed to reduce the cost. [Pg.123]

Unlike radioisotope generators, nuclear reactors utilize the much more intense process of nuclear chain reaction. Since this process is controlled in the reactor, the energy output could be regulated depending on the system s requirements. It actually could produce twice its nominal power, if necessai"y. Nuclear reactors can pro dde greater electrical output than radioisotope generators using the same types of thermal converters. This output is comparable to that of fuel cells and solar arrays, while nuclear reactors are more durable and compact. [Pg.1079]

The prime requirements for the separators in alkaline storage batteries are on the one hand to maintain durably the distance between the electrodes, and on the other to permit the ionic current flow in as unhindered a manner as possible. Since the electrolyte participates only indirectly in the electrochemical reactions, and serves mainly as ion-transport medium, no excess of electrolyte is required, i.e., the electrodes can be spaced closely together in order not to suffer unnecessary power loss through additional electrolyte resistance. The separator is generally flat, without ribs. It has to be sufficiently absorbent and it also has to retain the electrolyte by capillary forces. The porosity should be at a maximum to keep the electrical resistance low (see Sec. 9.1.2.3) the pore size is governed by the risk of electronic shorts. For systems where the electrode substance... [Pg.282]

Other schemes involving dichroic dyes with heat and electrical fields are also possible. Each of the possibilities could use the plastic structure of the substrates, its durability, or both. This approach would recycle the material for carrying the printed messages at the point of use, eliminating handling and distribution costs, and would require a fraction of the enormous amount of paper now consumed in delivering news and other literary material. The newspaper or periodical would have the familiar size and appearance and would present little change to the reader. The convenience of real on time home delivery and other built in aspects of the system would make it a useful successor to the present one. (This is just a point to discuss and amuse oneself but it could happen.)... [Pg.268]

Why Do We Need to Know This Material The d-block metals are the workhorse elements of the periodic table. Iron and copper helped civilization rise from the Stone Age and are still our most important industrial metals. Other members of the block include the metals of new technologies, such as titanium for the aerospace industry and vanadium for catalysts in the petrochemical industry. The precious metals—silver, platinum, and gold—are prized as much for their appearance, rarity, and durability as for their usefulness. Compounds of d-block metals give color to paint, turn sunlight into electricity, serve as powerful oxidizing agents, and form the basis of some cancer treatments. [Pg.776]

Homogeneous alloys of metals with atoms of similar radius are substitutional alloys. For example, in brass, zinc atoms readily replace copper atoms in the crystalline lattice, because they are nearly the same size (Fig. 16.41). However, the presence of the substituted atoms changes the lattice parameters and distorts the local electronic structure. This distortion lowers the electrical and thermal conductivity of the host metal, but it also increases hardness and strength. Coinage alloys are usually substitutional alloys. They are selected for durability—a coin must last for at least 3 years—and electrical resistance so that genuine coins can be identified by vending machines. [Pg.811]

Adapting the system to a mobile unit involved redesigning the instrumentation for portability and mounting it into a 3 A x 5-ft steel cart. A major requirement for this unit was containment of the Line-Lite laser, optical elements, and detection module in a clean laboratory environment. Other requirements included high ground clearance, accessibility to electricity within 100 ft, and durable construction. The entire mobile unit can be powered by a 5-kW gasoline generator. [Pg.234]

Bringing in the various utilities, such as water, gas, and electric power, has been discussed in Chapter 3. While the work benches are being installed, the utilities will be hooked up to suitable outlets, or inlets in case of the sewer. This is another area where good planning can produce significant savings with no loss in performance or durability. [Pg.86]

The reddish metal was already known in prehistoric times. It occasionally occurs as a native metal, but mostly in conspicuous green ores, from which it is extracted relatively easily. It is convenient to work, but not very hard. Not very optimal as a tool ("Otzi the Iceman" had a copper axe with him). Only through the addition of tin is the more useful bronze obtained. Its zinc alloy is the versatile and widely used brass. Copper is one of the coinage metals. Water pipes are commonly made of copper. Its very good thermal and electrical conductivity is commonly exploited (cable ), as well as its durability (roofs, gutters), as the verdigris (basic copper carbonate) protects the metal. Cu phthalocyanines are the most beautiful blue pigments. Seems to be essential to all life as a trace element. In some molluscs, Cu replaces Fe in the heme complex. A 70-kg human contains 72 mg. [Pg.131]


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Electrical durability testing

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