Elution and decomposition of cyanide in soil contaminated with various cyanocompounds

Standard soil samples contaminated with various standard cyanocompounds were prepared. Column elution experiments and analyses were conducted. Compounds with an easy capacity for dissociation to ions, such as KCN and potassium hexacyanoferrate(III), were found to be eluted by forming free cyanide even in fresh water. Hexacyanoferrate(II) salts, such as potassium hexacyanoferrate(II) and iron(III) hexacyanoferrate(II), were found not to be dissociated in water, but were dissociated and diffused under alkaline conditions (pH >13). Hexacyanoferrate(II) ion was found to be more easily dissociated in water with a higher pH.Column tests as above were also conducted for soil samples taken from a former paint ink factory using iron(III) hexacyanoferrate(II), cyanogen chloride, potassium cyanate, copper cyanide, as well as potassium cyanide, as raw materials. It was demonstrate that iron(III) hexacyanoferrate(II) was dissociated and eluted under alkaline conditions. The elution rate was reduced when the contaminated soil was sandwiched with standard soil layers.Further, it was found that the Fe(CN)(6)(4-) ion eluted with NaOH from hexacyanoferrate acid in soil, were easily decomposed into cyanic acid or other byproducts by UV with the addition of ozone and H(2)O(2).     

Ice clouds and Asian dust studied with lidar measurements of particle extinction-to-backscatter ratio, particle depolarization, and water-vapor mixing ratio over Tsukuba

The tropospheric particle extinction-to-backscatter ratio, the depolarization ratio, and the water-vapor mixing ratio were measured by use of a Raman lidar and a polarization lidar during the Asian dust seasons in 2001 and 2002 in Tsukuba, Japan. The apparent (not corrected for multiple-scattering effects) extinction-to-backscatter ratios (Sp) showed a dependence on the relative humidity with respect to ice (RHice) obtained from the lidar-derived water-vapor mixing ratio and radiosonde-derived temperature; they were mostly higher than 30 sr in dry air (RHice < 50%), whereas they were mostly lower than 30 sr in ice-supersaturated air (RHice > or = 100%), where the apparent extinction coefficients were larger than 0.036 km(-1). Both regions showed mean particle depolarization ratios of 20%-22%. Comparisons with theoretical calculations and the previous experiments suggest that the observed dependence of Sp on RHice is attributed to the difference in the predominant particles: nonspherical aerosols (mainly the Asian dust) in dry air and cloud particles in ice-supersaturated air.     

Improvement of treatment efficiency of thermophilic oxic process for highly concentrated lipid wastes by nutrient supplementation

The biodegradation of highly concentrated lipid wastes was conducted by a thermophilic oxic process (TOP). In order to improve the treatment efficiency of TOP, the stimulatory effect of nutrient supplementation was examined. A model nutrient supplement that satisfied the essential components necessary to promote degradation of lipid wastes was developed. The importance of balanced nutrient supplement consisting of organic and inorganic components was demonstrated. Regardless of the source of either vegetable oil or animal fat, the combination of 1.5 g of yeast extract, 1 g of urea and 60 ml of trace-element solution was effective to stimulate the degradation of 15 g of lipids by TOP. With this combination, degradation efficiencies of 68% and 77% in a 120-h treatment were attained for salad oil and lard, respectively. The conversion ratio of degraded lipid materials to CO2 was 0.91, confirming the advantage of TOP, i.e., very low excess sludge generation. The effectiveness of the model nutrient supplement for stimulating the degradation of lipid materials by TOP was also confirmed when tested on three kinds of actual highly concentrated lipid wastes. A constant degradation efficiency of around 60% in a 120-h treatment was attained for all lipid wastes although further improvement of degradation efficiency was possible by some nutrient addition into the model supplement combination. Based on the model nutrient supplement, the essential components for stimulating oil degradation by TOP and the possible alternative materials for the model nutrient supplement were discussed. The results demonstrated the possibility of employing TOP (stimulated by nutrient supplement) as a new biological treatment strategy for highly concentrated lipid wastes.     

Organic Solar Cells by Annealing Stacked Amorphous and Microcrystalline Layers

Organic solar cells were fabricated by stacking aromatic amine and C₆₀ layers. The energy conversion efficiency of these solar cells was low because of poor photoabsorption by these layers and short diffusion length of excitons. However, the photocurrent density was increased by about 3 times by the application of heat treatment to the stacked organic layers at 140 °C, and the maximum energy conversion efficiency reached 1.1 % under AM 1.5, 100 mW cm^–2 simulated solar light. The internal quantum efficiency of the photocurrent after the annealing reached about 45 %. When the aromatic amine layer was about 100 nm thick, the organic layers after the annealing showed a wrinkled structure under an optical microscope. The annealing temperature needed for the formation of this structure was in good agreement with the temperature needed for the increase in the photocurrent. The morphological change caused by the annealing was attributed to infiltration of the amorphous aromatic amine compound into grain boundaries of the microcrystalline C₆₀ layer, resulting in expansion of the C₆₀ layer and the wrinkled structure of the organic layers. From observation by electron microscopy, the mixed form of these two compounds near the interface was found to be suited to solar cells because the C₆₀ and aromatic amine phases wedge each other in a direction normal to two electrodes. However, the annealing slightly lowered photovoltage of the solar cell. This effect was attributed to a partial contact of the C₆₀ layer with a counter electrode through the aromatic amine layer.     

Development of new‐type outdoor termination using composite insulator with SF6 gas: Commercial use for 77‐kV transmission lines and development for 154‐kV XLPE cable

Recently, composite insulators have been increasingly employed mainly for economic reasons. We have developed a new type of outdoor termination using a composite insulator, which can be installed horizontally on a steel tower in order to reduce the construction cost. In this outdoor termination, SF₆ gas is filled in the composite insulator and a cold shrinkable premolded rubber unit is applied instead of the combined use of a rubber‐molded stress relief cone, epoxy resin insulator and spring unit. The application of the composite insulator, SF₆ gas and cold shrinkable premolded rubber unit reduces the total weight and makes it possible to install the termination horizontally on the tower. The new‐type outdoor termination for 77‐kV XLPE cable has already been applied in commercial use and enabled a reduction of the construction costs for power transmission lines. A 154‐kV new‐type outdoor termination has been developed and its initial electrical tests were successfully completed. This paper describes the design and performance of both 77‐kV and 154‐kV new‐type outdoor termination, and a follow‐up survey of the 77‐kV new termination in a commercial use. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 159(4): 18– 26, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20511     

Future prospect of remote Cat-CVD on the basis of the production, transportation and detection of H atoms

The future prospect of remote Cat-CVD, in which the decomposition and the deposition chambers are separated, is discussed on the basis of the absolute density measurements of H atoms. It is now well recognized that uniform deposition is possible on a large area without plasma damages by Cat-CVD. However, we may not overlook the demerits in Cat-CVD. One of the demerits is the poisoning of the catalyzer surfaces by the material gases, both temporary and permanent. One technique to overcome this problem is remote Cat-CVD. The question is how to separate the decomposition and deposition areas. If the separation is not enough, there should be back diffusion of the material gases, which will poison the catalyzers. If the separation is too tight, radicals may not effuse out from the decomposition chamber. These problems are discussed and it is shown that SiO₂ coating to reduce the radical recombination rates on walls is promising. The possibility of the polytetrafluoroethene coating by Cat-CVD is also discussed.     

RHINOS: a consultation system for diagnosis of headache and facial pain

This paper is intended to describe the expert system RHINOS for diagnosing patients whose chief complaints are headache and facial pain. RHINOS assists physicians in diagnosing the above-mentioned disease. For this purpose the authors surveyed diagnosing processes used by physicians to determine what advice physicians want. As a result, the author reached the conclusion that knowledge for diagnosing the above-mentioned disease should be categorized according to four types of rules: exclusive rules (if the patient has disease D, he must have symptoms S1, S2,....,Sn), inclusive rules (if the patient has symptoms S1, S2,...,Sn, he has disease D with a probability X (0 less than X less than 1)), associate rules (if the patient has symptoms S1, S2,...,Sn the probability that he has the disease D increases) and disease image (if the patient has disease D, he may have symptoms S1, S2,...,Sn). Through harmonious use of these four types of rules, RHINOS gives the advise that physicians want. RHINOS is widely available because it is implemented by Prolog-KABA which is operative on personal computers such as NEC PC9801 and IBM-PC.     

TARGET YIELDS AND HYDROGEN CONSUMPTION IN BROWN COAL LIQUEFACTION

A simple mechanistic model for brown coal liquefaction has been developed and used in conjunction with data from PDU operation to examine the factors which contribute to hydrogen consumption. It is found that after allowing for hydrogen generation requirements, the maximum achievable refined product yield from Morwell brown coal ((ssuming a naphtha/middle distillate ratio of 5:6 together with refined product H/C ratios of 1.8 for naphtha and 1.5 for middle distillate) is 46 - 48%, corresponding to a hydrogen consumption of 6.6 - 7.6%. Alternatively, if consideration of hydrogen generation is excluded (as in pilot plant operation), the maximum yield would be around 54%, corresponding to 6.6% net hydrogen consumption. These results suggest that an aim of maximizing product yield by decreasing Cl-C4 gas formation may not be as desirable as at first thought.