High-cost treatments

Table 5.28 gives the modifications in physical/chemical characteristics resulting from deeper and deeper hydrotreatment (Martin et al., 1992). The sulfur contents could thus be reduced to first as low as a few hundred ppm, then to a few ppm. The level of aromatics in the selected example drops from 39% to 7% while the cetane number increases from 49 to 60. Note here that such a treatment, possible through experimental means, does not correspond to current industrial practice because of its high cost and its very high hydrogen consumption. 

The high cost of coal handling and preparation and treatment of effluents, compounded by continuing low prices for cmde oil and natural gas, has precluded significant exploitation of coal as a feedstock for methanol. A small amount of methanol is made from coal in South Africa for local strategic reasons. Tennessee Eastman operates a 195,000-t/yr methanol plant in Tennessee based on the Texaco coal gasification process to make the methyl acetate intermediate for acetic anhydride production (15). 

Prior to the commercial development of this process benzyl alcohol was obtained from benzaldehyde [100-52-7] which undergoes the Cannizzaro reaction (2) upon treatment with potassium hydroxide. High yields of benzyl alcohol and potassium benzoate are obtained by this route which cannot compete with the present day process because of the high cost of benzaldehyde (qv). 

Compared to streptokinase, urokinase has been less extensively studied because of its high cost, ie, about 10 times that of a comparable treatment with streptokinase. In addition to the indications described for streptokinase, urokinase is indicated for use in patients with prior streptokinase treatment, or prior Streptococcal infection. Urokinase is commonly used at a loading dose of 4400 units /kg, with a maintenance intravenous infusion dose of 4400 units/kg/h for thromboses other than acute myocardial infarction. In the latter case, a much larger dose, ie, 0.5—2.0 million units/h or a bolus dose of 1.0 million units followed by a 60-min infusion with 1.0 million units, has been found optimal (106). An intracoronary dose of 2000 units/min for two hours was used in one comparative study with intracoronary streptokinase (107). In this study, urokinase exhibited efficacy equivalent to streptokinase with fewer side effects. Other studies with intracoronary urokinase have adrninistered doses ranging from 2,000 to 24,000 units/min with a reperfusion efficacy of 60—89% (108—112). In another urokinase trial, 2.0 million units were adrninistered intravenously, resulting in a thrombolytic efficacy of 60% (113). Effectiveness in terms of reduction in mortaUty rate has not been deterrnined because of the small number of patients studied. 

Chemical Oxidation This process has not been widely utihzed because of its high cost. Onlv wEere the concentration of the target compound is very low will tlie quantity of oxidant required be low enough to justify treatment by chemical oxidation. The efficiency of this process is also low, as many side reactions can occur that will consume the oxidant. In addition, complete oxidation of organics to carbon dioxide and water often will not occur unless a significant overdose is used. However, renewed interest has recently occurred for two reasons. 

Local repair of delamination originally caused by non-durable surface treatment is only temporarily successful at best. The surface treatment on the unrepaired portion of the assembly remains susceptible to attack and the area of delamination will likely continue to grow once the assembly is put back into service and exposed to moist conditions. Replacement or complete remanufacture of the component is the only way to permanently address this type of damage. However, time-limited repairs using bonded or mechanical methods can be used to extend the life of the component until a major overhaul is scheduled. In some cases such as widespread disbond of fuselage doublers, mechanical repairs (rivets and fastened doublers) and continued inspection are used to extend the life of the skin indefinitely because of the high cost of replacement. 

Thus, efficient methods for the addition of one or two carbon atoms to 17-keto steroids were of some importance, especially because of the high cost of the starting materials. A balancing factor, however, was the relatively low level of use of the natural and synthetic steroids which was in part a reflection of the cost of treatment. 

Operators who balk at the cost of providing water treatment for resistance boilers are perhaps the very same people who fail to provide adequate maintenance from the beginning of their employment and end up complaining because of unplanned production shutdowns and considerable (and unnecessary) high-cost repairs. Water treatment does not have to be sophisticated or expensive for such relatively small and simple items of boiler equipment, but some form of treatment and control is required. 

As a result of the high costs of technical services, most water treatment vendors employ a variety of methods that allows them to charge an economic rate for the programs they sell. They will negotiate a price with the customer based on providing the most suitable balance of on-site service time and chemical/equipment requirements, that anticipates and resolves problems, meets the customers needs, and relieves his or her pain. ... 

Treated wastewater salinity and the high cost of hydraulic facilities are other constraints in the development of the sector and limit project profitability. Improving quality of treated wastewater is still one important challenge for the government that could improve the reuse rate. While any quality of treated wastewater can be produced, the degree of treatment must be addressed what constituents have to be removed and what quality will be acceptable [14]. 

The high costs of schizophrenia have led ro great economic interest in treatments both old and new. The biggest barrier to the prescribing of new dmgs is probably concerns about safety and compliance, but cost is also a major factor (Kerwin, 1996). However,... 

Considerations of cultural aspects can offer an alternative framework in which various aspects that may influence the effects of treatment can be identified. With regard to how the patient responds to therapy, some of the arguments used to justify the lack of efficacy of certain treatments for mental disorders have included the elements such as the patient s dissatisfaction, unequal access to medical care or the high costs of such treatments (Wight, Botticello Aneshensel, 2006 Aneshensel Phelan, 1999). However, in order to understand this lack of efficacy it is necessary to take into account explanations that derive from, for example, anthropological and transcultural research. 

There are many obstacles that bar the way to a wide application of modern pharmacological treatment in the economically disadvantaged countries. They include the scarcity of personnel who could prescribe and supervise the application of such treatment, the omnipresent poverty, the high cost of some medications, the... 

Low-concentration plating solutions reduce the total mass of chemicals being dragged-out. The mass of chemicals removed from a bath is a function of the solution concentration and the volume of solution carried from the bath. Traditionally, the bath concentration is maintained at a midpoint within a range of operating conditions. With the high cost of replacement, treatment, and disposal of dragged-out chemicals, the economics of low-concentration baths are favorable. 

Physical color removal technologies that were reported in the literature include adsorption, chemical precipitation, and membrane separation [14—17]. The high cost and disposal problems have opened the door for further investigation of new techniques. The inability of biological treatment processes in degrading azo dye compounds makes physical treatment a necessary stage prior to biotreatment in... 

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