Future use

The element is commercially obtained from the dusts of smelters processing zinc ores, as well as recovered from combustion by-products of certain coals. A large reserve of the elements for future uses in insured in coal sources. 

The future use of lead may be decided by the resolution of an environmental paradox. Some markets for lead are being phased out because of environmental concerns, eg, the use of tetraethyllead as a gasoline additive. However, a 1990 State of California law and similar laws in nine eastern U.S. states require that 2% of new cars meet 2ero-emission standards in 1998. By 2003 this requirement rises to 10% of new vehicles. Zero emission vehicles are generally accepted to mean electric, ie, battery powered cars, and there is considerable research effort to bring suitable electric vehicles to market by 1998. 

Liquid crystal polymers are also used in electrooptic displays. Side-chain polymers are quite suitable for this purpose, but usually involve much larger elastic and viscous constants, which slow the response of the device (33). The chiral smectic C phase is perhaps best suited for a polymer field effect device. The abiHty to attach dichroic or fluorescent dyes as a proportion of the side groups opens the door to appHcations not easily achieved with low molecular weight Hquid crystals. Polymers with smectic phases have also been used to create laser writable devices (30). The laser can address areas a few micrometers wide, changing a clear state to a strong scattering state or vice versa. Future uses of Hquid crystal polymers may include data storage devices. Polymers with nonlinear optical properties may also become important for device appHcations. 

An important future use for maleic anhydride is beUeved to be the production of products in the 1,4-butanediol—y-butyrolactone—tetrahydrofuran family. Davy Process Technology has commercialized a process (93) for producing 1,4-butanediol from maleic anhydride. This technology can be used to produce the product mix of the three molecules as needed by the producer. Another significant effort in this area is the tetrahydrofuran plant under constmction in Spain by Du Pont in which butane is oxidized and recovered as maleic acid and the maleic acid is then reduced to tetrahydrofuran (109). 

Future Uses. The most recent uses for methanol can be found in the agricultural sector. Test studies are being carried out where methanol is sprayed directly onto crops to improve plant growth. Methanol can be used as a carbon source for the production of single-cell protein (SCP) for use as an animal feed supplement. The process has been commercially demonstrated by ICl at their BiUingham, U.K., faciUty. However, the production of SCP is not commercially practical at this time, in comparison to more conventional protein sources. 

Spheres. HoUow spherical fillers have become extremely useflil for the plastics industry and others. A wide range of hoUow spherical fillers are currently available, including inorganic hoUow spheres made from glass, carbon, fly ash, alumina, and 2h conia and organic hoUow spheres made from epoxy, polystyrene, urea—formaldehyde, and phenol—formaldehyde. Although phenol—formaldehyde hoUow spheres are not the largest-volume product, they serve in some important appHcations and show potential for future use. 

Superconductivity. One potential future use of vanadium is in the field of superconductivity. The compound V Ga exhibits a critical current at 20 T (20 X lO" G), which is one of the highest of any known material. Although niobium—zirconium and Nb Sn have received more attention, especiahy in the United States, the vanadium compound is being studied for possible future appHcation in this field since V Ga exhibits a critical temperature of 15.4 K as opposed to 18.3 K for Nb Sn. 

At this stage of manufacture, chocolate may be stored for future use in bulk Hquid form if usage is expected to be within one to two weeks, or at 43—50°C in a hot water jacketed agitated tank or in soHd block form where it can be stored for as long as 6 to 12 months. Blocks typically weigh between 3 and 30 kg. Storage conditions for block chocolate should be cool and dry, ie, 7 to 18°C and 40 to 45% relative humidity. If chocolate has been stored in block form, it can be remelted to temperatures up to 50°C and then processed in the same manner as freshly made Hquid chocolate. 

Wax Printing. This is a special case of resist printing and widely used in African designs. Wax is first printed onto cotton fabric to give a patterned effect, and the fabric is then dyed. The wax resists penetration of the dye and reserves the fabric. The wax is then removed by either alkaU washing or solvent when it is also recovered for future use. Other colors can then be printed, if so desired, on the nondyed areas. A2oic dyes or reactive dyes can be used for this. 

Careful attention should be paid to processing and storage equipment to assure that certain future uses will not be contraindicated based upon the nature of the products. For example, it would not be wise to allow storage of food or food chain materials in vessels that once contained agricultural chemicals, even if the vessels were first cleaned. In the event the toller will not assure appropriate future use of the equipment, the client may consider purchasing the equipment for future use elsewhere. 

Due to the greater variety of expanders and their advaneed quality and eapabilities, many future uses are possible. 

Hydrogen fluoride is at present stored in bulk and used at only the Shellhaven refinery, bat future use is envisioned. Hydrogen fluoride boils point 19° C but stored and handled as a hq lie tied gas. Its vapor is highly irritating and toxic. A cold cloud will be denser than air in the early stages when released but wall become neutral or buoyant as it warms with dispersion. This r-sessment assumes negative buoyancy... 

Two keys to the future use of composite materials are (1) achieving lower raw material cost and (2) developing innovative fabrication techniques that are uniquely suited to the characteristics of composite materials. This duality of approaches is leading to considerable success with composite structures right now, but they also hold the key to the even wider use of composite materials in the future. Let s address the two keys individually. 

Brainstorming often throws off valuable ideas or information that may be off the immediate topic (e.g., we really should review and update ourMSDSs"). These should be encouraged and recorded for future use. 

In addition to recording quantitative information, assessors can use these forms to record observations and opinions for future use. It s important, however, to make sure that the interviewer s opinion can be clearly distinguished from an interviewee s response use brackets, asterisks, or other symbols to set opinions apart. 

Making equipment reliability data commonly available requires collection of raw data, conversion of those data into failure rates, and a framework or taxonomy in which the failure rates can be stored. Unless all these tasks are coordinated, there may be no way of fitting them together to produce usable, classified reliability data. In this book, we have attempted to make these three areas, often carried out completely independently, compatible so that any data collected in the future using this book can be easily added to the store of generic reliability data. 

One of the main benefits from future use of biofuels would be the reduction of greenhouse gases compared to the use of fossil fuels. Carbon dioxide, a greenhouse gas that contributes to global warming, is released into the air from combustion. Twenty-four percent of worldwide energy-related carbon emissions in 1997 were from the United States. Carbon... 

Held open for future use, formerly used as an indicator of the provisional status of safety classifications. ... 

Features. Seven categories of bearing design and gauge protection are defined as features. Features 8 and 9 are reserved for future use. 

A series of baseline or reference data sets should be taken for each machine-train included in a predictive-maintenance program. These data sets are necessary for future use as a reference point for trends, time traces, and FFT signatures that are collected over time. Such baseline data sets must be representative of the normal... 

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