Reusable/reusability

Another thing or two to remember when distilling is to wrap aluminum foil around the reaction flask. This will help stop heat loss so that things will distill quicker and at lower temperatures. Sometimes, if one is going to distill a solution that is just solvent and product, all that pure solvent that comes over first is perfectly reusable and should be saved for future extractions. 

Filtered or not, the ethanol/isosafrole/(sometimes junk) is relieved of its ethanol by openly boiling it on the stove or by distillation. Any ethanol removed by distillation is saved because it is clean and perfectly reusable (remember, it will still have that 5% water). One should not remove all of the solvent this way because things can get really hot really fast as the last of the ethanol boils away. 

The practice of employing reusable thermal protection systems for reentry is becoming more common. These are essentially ablative materials exposed to environments where veryHtde ablation actually occurs. Examples iuclude the space shuttle tiles and leading edges, exhaust no22le flaps for advanced engines, and the proposed stmctural surface skin for the National Aerospace plane. 

Other forms of carbon-carbon composites have been or are being developed for space shutde leading edges, nuclear fuel containers for sateUites, aircraft engine adjustable exhaust nozzles, and the main stmcture for the proposed National Aerospace plane (34). For reusable appHcations, a siHcon carbide [409-21 -2] based coating is added to retard oxidation (35,36), with a boron [7440-42-8] h Lsed sublayer to seal any cracks that may form in the coating. 

The thermal protection system of the space shutde is composed mainly of subliming or melting ablators that are used below their fusion or vaporization reaction temperatures (42). In addition to the carbon-carbon systems discussed above, a flexible reusable surface insulation composed of Nomex felt substrate, a Du Pont polyamide fiber material, is used on a large portion of the upper surface. High and low temperature reusable surface insulation composed of siHca-based low density tiles are used on the bottom surface of the vehicle, which sees a more severe reentry heating environment than does the upper surface of the vehicle (43). 

Dust Filter. The cloth or bag dust filter is the oldest and often the most reHable of the many methods for removing dusts from an air stream. Among their advantages are high (often 99+%) collection efficiency, moderate pressure drop and power consumption, recovery of the dust in a dry and often reusable form, and no water to saturate the exhaust gases as when a wet scmbber is used. There are also numerous disadvantages maintenance for bag replacement can be expensive as well as a sometimes unpleasant task these filters are suitable only for low to moderate temperature use they cannot be used where Hquid condensation may occur they may be hazardous with combustible and explosive dusts and they are bulky, requiring considerable installation space. 

The light weight of these products reduces user s shipping costs and conserves energy in transportation. These products are reusable, a key property from economic, ecological, and energy conservation standpoints. Most products are available in bulk densities of 4.0 to 4.8 kg/m (0.25 to 0.30 lb/fT). Average price is about 1.50 per pound from the manufacturer. 

MakingMetals a Reusable Resource, INMETCO (INCO Co.), Ellwood City, Pa., May 1993. 

U.N. packaging codes for metal dmms are given in Table 2 thickness requirements for reusable dmms are shown in Table 3. 

A sohd fiber paperboard package is a sandwich stmcture composed of inner pHes called filler stock and outer pHes called facings. SoHd fiber differs from cormgated in that the inner pHes are not fluted. Sohd fiber packaging is typically used where toughness is important. Many sohd fiber packages are reusable. 

Dicyclohexylarnine may be selectively generated by reductive alkylation of cyclohexylamine by cyclohexanone (15). Stated batch reaction conditions are specifically 0.05—2.0% Pd or Pt catalyst, which is reusable, pressures of 400—700 kPa (55—100 psi), and temperatures of 75—100°C to give complete reduction in 4 h. Continuous vapor-phase amination selective to dicyclohexylarnine is claimed for cyclohexanone (16) or mixed cyclohexanone plus cyclohexanol (17) feeds. Conditions are 5—15 s contact time of <1 1 ammonia ketone, - 3 1 hydrogen ketone at 260°C over nickel on kieselguhr. With mixed feed the preferred conditions over a mixed copper chromite plus nickel catalyst are 18-s contact time at 250 °C with ammonia alkyl = 0.6 1 and hydrogen alkyl = 1 1. 

Sanitization is a cleaning procedure that reduces microbial contaminants on certain surfaces to safe or relatively safe levels, as defined by the EPA or pubHc health authorities. The article is usually cleaned with hot water and various germicidal detergents. Sanitization can be safe for a product in contact with intact skin or for food utensils, but it is not considered safe for articles to be inserted in the human body. Effective sanitization is a requirement in the processing of reusable medical suppHes before packaging and sterilization. It is also a requirement in the maintenance of utensils and containers used for food preparation. 

Externally cast membranes are first formed on the iaside of paper, polyester, or polyolefin tubes. These ate then iaserted iato reusable porous stainless-steel support tubes inside diameters ate ca 12 mm. The tubes ate generally shrouded in bundles to aid in permeate collection. 

Proof Casting of Dies and Molds. Low melting ahoys make the process of diemaking faster and easier. The low temperature ahoys can be cast into a mold pattern at virtuahy any point in the manufacturing process without long delays in production and without the possibhity of heat distortion. These ahoys produce a casting that is exact in detail, requires no curing time, and is completely reusable. 

Multiblock Copolymers. Replacement of conventional vulcanized mbber is the main appHcation for the polar polyurethane, polyester, and polyamide block copolymers. Like styrenic block copolymers, they can be molded or extmded using equipment designed for processing thermoplastics. Melt temperatures during processing are between 175 and 225°C, and predrying is requited scrap is reusable. They are mostiy used as essentially pure materials, although some work on blends with various thermoplastics such as plasticized and unplasticized PVC and also ABS and polycarbonate (14,18,67—69) has been reported. Plasticizers intended for use with PVC have also been blended with polyester block copolymers (67). 

Water used as the coolant in an indirect-contact condenser (i.e., shell-and-tube heat exchanger), not in contact with contaminated gas stream, and is reusable after cooling... 

The hydraulieally tensioned, radial-fit bolt (Figure 6-32) replaees the traditional turbine shaft eoupling bolt and is reusable. The main body of the bolt is threaded at eaeh end and has a slight taper on the eenter seetion, whieh engages with the similarly internally tapered sleeve and the two nuts. The bolt is taper-bored at eaeh end to aeeept the puller that is part of the hydraulie tensioning system. 

Clausing, D. 1998 Reusability in Product Development. In Proceedings EDC 98. Bury St Edmunds Professional Engineering Publishing, 57-66. 

Reaetion due to eontaminants, e.g. in reusable eontainers or in transfer pipelines. 

Cleaning and inspection of reusable containers, tankers etc, before refilling... 

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