Economics marine systems

The biogeochemistry of organic pollutants in marine systems is of enormous economic and environmental Impact. The environmental behavior of polychlorinated biphenyls (PCB s) has been studied rather extensively because of their detrimental effects on human health and on living marine resources (30-32). As discussed in the chapters by J.W. Farrington et, due to recent advances in gas capillary chromotographic methods, it is now possible to study the biogeochemistry of individual PCB s rather than that of combined industrial mixtures of PCB s (33-36). In order to realistically assess the risks to animal health, it is important to be able to work with individual PCB levels rather than with unresolved mixtures because individual PCB s can vary greatly in terms of toxicity (37). 

Battery systems of complex design and structure using—at least for one electrode—expensive materials are (for economic reasons) mainly conceived as storage batteries. Primary (and "reserve") versions of the zinc/silver oxide battery [(-) Zn/KOH/AgO (+)] — as a first example—are only used in particular cases where the question of cost is not crucial, e.g., for marine [26-28] and space applications [29]. 

One might ask what controls the depth of the transition zone. The answer lies in chemical economics. In today s ocean, marine organisms manufacture calcitic hard parts at a rate several times faster than CO2 is being added to the ocean-atmosphere system (via planetary outgassing and weathering of continental rocks) (see Figure 3). While the state of samration in the ocean is set by... 

M. A. Champ (2003) Marine Pollution Bulletin, vol. 46, p. 935 - Economic and environmental impacts on ports and harbors from the convention to ban harmful marine anti-fouling systems . 

This is another vital part of an impressed current system. The T/R must be rugged and reliable with minimal maintenance requirements. It should be easy to maintain with good instruction manuals, circuit diagrams for maintenance and easy access to fuses and other consumable and replaceable components. Compared with pipeline or marine CP applications (steel piles, etc.) the power demand is modest. Most steel in concrete needs less than 10 mA-m to provide protection, usually at less than 10 V. The power for a 100 watt light bulb will protect 10,000 m. This means that a single phase, air cooled T/R will usually protect even the largest structure and power consumption is rarely an economic concern. 

The IPWR concept is an outgrowth of widespread interest in commercial nuclear ship propulsion in the late 1950s and early 1960s. Economic evaluations of commercial marine propulsion reactor designs based on several distinctly different reactor concepts (e.g., loop-type PWR, gas-cooled, organic-cooled, etc.) concluded that none were competitive at that time with conventional fossil-fuelled propulsion systems, at least in sizes up to 20-30,000 shp (shaft horsepower). 

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