Small Ship Applications

Propellers are the predominant propulsive devices driving ships, although water jets are now used in some high-speed ships. An experimental installation in a small ship of a magnetohydrodynamic propulsor has been tested, but it achieved rather low propulsive efficiency. Fish-like propulsion also has been examined for possible application to ships and underwater vehicles. 

Application of nematodes in infected insect cadavers have also been described by some workers (Shapiro-Ilan et al. 2001, 2003), which enables the slow release of nematode and therefore considered effective for small-scale application. Coating the cadavers with starch and clay mixture helps in preventing rupture during storage and shipping (Shapiro-Ilan et al. 2001). 

Conventional steam reforming is also restricted to applications in which the size of the locally available supply of hydrocarbon fuel is adequate. Much of the world s total natural gas resources are what is called "static gas," i.e., natural gas resources which are individually so small and so remotely located that they can not be economically pipelined to market. In theory this static gas could be reformed into synthesis gas which could then be made into readily shipped liquids. As discussed by Che and Bredehoft (1995), the minimum size for an economically viable steam reformer based on conventional technology is 5,000,000 standard cubic feet (scf) of hydrogen per day. To give such a minimum size steam reformer a 20-year useful life, the local natural gas resource would need to be relatively large. Studies of the economics of UMR indicate that the process will be satisfactory in small-scale applications. 

Potable Water RO and NF both play a major role in providing potable water, defined either by the WHO criterion of <1000 ppm total dissolved solids (TDS) or the U.S. EPA limit of 500 ppm TDS. RO is most prominent in the Middle East and on islands where potable-water demand has outstripped natural supply. A plant awaiting startup at Al Jubail, Saudi Arabia produces over 1 mVs of fresh water (see Table 22-17). Small units are found on ships and boats. Seawater RO competes with multistage flash distillation (MSF) and multieffect distillation (MED) (see Sec. 13 Distillation ). It is too expensive to compete with conventional civil supply (canals, pipelines, w ls) in most locations. Low-pressure RO and NF compete with electrodialysis for the desalination of brackish water. The processes overlap economically, but they are sufficiently different so that the requirements of the application often favor one over the others. 

Internal-combustion engines range in size from small portable gasoline engines to over 14,914 kW (20,000 hp) diesels for ship propulsion. They are usuaUy designed for particular industrial applications and to meet specific objectives as to weight per horsepower, reliabihty, and operating conditions. 

For application in flowing media (e.g., for ships) it is also necessary that the usable current content be as large as possible not only per unit of mass but also per unit of volume, so that the volume of the installed anodes becomes as small as possible. 

The outstanding virtue of zinc-rich paints is simplicity in application. No special equipment is required and the operation can, of course, be carried out on site, large or small structures being equally suitable for treatment. While there is some evidence that the zinc-rich paints will reduce iron oxides remaining on the steel surface, proper surface preparation is as important here as with traditional paints if the best results are to be achieved. The main use of zinc-rich paints is to protect structural steel-work, ships hulls, and vulnerable parts of car bodies, and to repair damage to other zinc coatings. 

D harmless to non-target marine life Q non-toxic to applicators Q allows small repairs on wet ship cost < 1 000 000 per ship... 

Heico Chemicals is the only producer of acetamide in the United States. Small amounts are imported from Europe and Asia. It is shipped in 32-L (35-gal) drums weighing about 80 kg. Acetamide appears to have a wide spectrum of applications. It suppresses acid buildup in printing inks, lacquers, explosives, and perfumes. It is a mild moisturizer and is used as a softener for leather, textiles, paper, and certain plastics. It finds some applications in the synthesis of pharmaceuticals, pesticides, and antioxidants for plastics. 

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