Studies on the corrosion and the behavior of inert anodes in aluminum electrolysis

The corrosion rates of inert anodes based on tin oxide and nickel ferrite cermet materials were studied as a function of some operating parameters. To reach a better understanding of the corrosion mechanism, the behavior of the anodes was observed under some specific conditions, such as in pure cryolite, at high current densities, at different potentials, and at varying cathode surface areas. It was confirmed that low alumina concentrations led to catastrophic corrosion of the anodes and that high current densities and high as well as low NaF/AlF₃ molar ratios were also detrimental. The corrosion rate of tin oxide based anodes showed a minimum (so-called “normal corrosion”) at anodic potentials of 2.2 to 2.4 V with respect to aluminum. The normal corrosion is due to chemical dissolution of the anode material and reduction of the corrosion products into the cathode metal. The corrosion rate increased with increasing cathode surface area. At potentials higher than ～2.5 V, the anodes showed catastrophic corrosion. Catastrophic corrosion can be ascribed to decomposition of the anode material by depletion of alumina at the anode surface provoked by low bulk concentration of alumina and/or high current density.     

Designer deletion and prototrophic strains derived from Saccharomyces cerevisiae strain W303‐1a

We report the construction of Saccharomyces cerevisiae strains isogenic to W303‐1a that are designed to allow efficient genetic analysis. To facilitate the generation of null alleles of target genes by PCR‐mediated gene disruption, we constructed designer deletion alleles of the ARG4, TRP1 and URA3 genes. In addition, a single pair of oligonucleotide primers were designed that can be used to amplify any of several marker genes for use in PCR‐mediated gene disruption. A new version of the ‘reusable’ hisG‐URA3‐hisG cassette was constructed for use in PCR‐mediated gene disruption. Finally, to facilitate the formation of isogenic diploids by selection, we constructed strains that contain combinations of wild‐type alleles of ADE2, HIS3, LEU2, TRP1 and URA3. Copyright © 1999 John Wiley & Sons, Ltd.     

Wave energy: a Pacific perspective

This paper illustrates the status of wave energy development in Pacific rim countries by characterizing the available resource and introducing the region's current and potential future leaders in wave energy converter development. It also describes the existing licensing and permitting process as well as potential environmental concerns. Capabilities of Pacific Ocean testing facilities are described in addition to the region's vision of the future of wave energy.     

Clear cell differentiation in choroidal melanoma. COMS report no. 8. Collaborative Ocular Melanoma Study Group

OBJECTIVE: To describe 2 enucleated eyes of patients enrolled in the Collaborative Ocular Melanoma Study that contained primary choroidal melanoma with clear cell features. METHODS: During a 9-year period, 1493 eyes enucleated as part of the Collaborative Ocular Melanoma Study routinely processed for histologic examination were evaluated by the pathology review committee (H.E.G, D.M.A, and W.R.G). Two eyes with unusual variants of choroidal melanoma were identified and immunostained for S100 protein and HMB 45. Portions of the tumors were processed for electron microscopic examination. RESULTS: Results of electron microscopic examination of both tumors displayed malignant melanoma (mixed cell type with many malignant cells with clear cytoplasm). The cytoplasm of the clear cells stained with periodic acid-Schiff and failed to stain when pretreated with diastase. Results of immunohistochemical stains in both tumors were positive for S100 protein and HMB 45 in the tumor cells. Results of electron microscopic examination showed that the cytoplasm of the clear cells contained scattered glycogen granules, premelanosomes, and melanosomes. CONCLUSION: These cases represent a clear cell variant of malignant melanoma of the choroid. This tumor should not be confused with metastatic clear cell carcinoma to the choroid.     

A multiangle imaging spectroradiometer for terrestrial remote sensing from the earth observing system

The Multiangle Imaging SpectroRadiometer (MISR) instrument for the Earth Observing System (EOS) will provide a unique opportunity for studying the ecology and climate of the Earth through the acquisition of systematic, global multiangle imagery in reflected sunlight. MISR employs nine discrete cameras pointed at fixed angles, viewing the nadir direction and forward and aftward along the spacecraft ground track. Each camera is a charge-coupled-device –based pushbroom imager. Within a 7-minute period, every point in a 204-km-wide swath is imaged at the nine viewing angles, ensuring observations acquired under virtually identical illumination and atmospheric conditions. The cameras will image the Earth in the nadir direction and at 30.7°, 45.6°, 60.0°, and 72.5° forward and aftward of the local vertical at the Earth's surface. Images at each angle will be obtained in four spectral bands centered at 440, 550, 670, and 860 nm. MISR is capable of taking image data in two different spatial resolution modes: Local Mode, in which selected targets are observed with 240-m spatial sampling, and Global Mode, where the entire sunlit Earth is observed continuously with 1.92-km sampling. Absolute radiometric calibration of the MISR instrument will be performed in-flight using special on-board hardware. The data produced by MISR will be valuable in a number of scientific discipline areas, and MISR images and geophysical products will be archived at the EOS Data and Information System to make them available to the broad scientific community.     

Computer simulation of thinking.

"The nub of the simulation problem involves the use of similar types of 'programs' of 'instructions' to the machine in order to reproduce the steps an individual goes through in thinking out the solution to a difficult problem." Simulation methods "have a tremendous role in sharpening our formulations concerning mental processes and phenomena." The "simulation of human responses has the same overwhelming advantages for our understanding of behavioral phenomena as similar methods in other sciences." Research "on simulation of complex psychological processes is yielding results of increasing importance." From Psyc Abstracts 36:02:2CM87H. (PsycINFO Database Record (c) 2010 APA, all rights reserved)