Kinetic and Stability Study of an Investigative Antirhinovirus Compound

A hydrolytic acid and base catalyzed ring opening reaction has been demonstrated for a 1,2,4-oxadiazole antiviral compound (WIN 63843) resulting mainly in an amidoxime product. Decomposition products and related impurities were detected using a gradient HPLC method. The hydrolysis reaction was first-order for 35% ethanol/buffer solutions in a 50°C chamber or a light cabinet (1000 ft-candles), the greatest stability being between pH 4 and 6. Furthermore, increasing ethanol concentrations resulted in a great decrease in reaction rates. Therefore, for oral or aerosol solution formulations, light protection, pH control between 4 and 6 and the highest permissible ethanol concentrations would be advantageous. This study has shown that the highly electronegative trifluoromethyl group at the 5 position increases the lability of a 1,2,3-oxdiazole compound.     

Heat flow near Orlando,Florida and Uvalde,Texas determined from well cuttings

Heat flow has been determined in a borehole near Orlando. Florida and another near Uvalde, Texas. Thermal conductivities in both boreholes were obtained by divided-bar measurements on rock discs and by needle-probe measurements on rock chips. For the needle-probe method, the rock chips were pulverized into powder, saturated with water, and the conductivity of the solid rock was obtained from the conductivity of the mixture by an empirical relationship. Divided-bar measurements for the Florida borehole indicate a heat flow of 0.92 = .03 H.F.U., while needle-probe measurements on rock chips show a heat flow of 1.24 = .06 H.F.U. The discrepancy is attributed to anisotropy of the sedimentary rocks penetrated by the borehole. Heat flow obtained from these two different methods of determining conductivity show good agreement in the Texas borehole. Divided-bar measurements indicate a heat flow of 1.08 = .03 H.F.U. while the chip technique gives a value of 1.13 = .03 H.F.U.     

Release of reduced inorganic selenium species into waters by the green fresh water algae Chlorella vulgaris

The common green fresh water algae Chlorella vulgaris was exposed to starting concentrations of 10 μg/L selenium in the form of selenate, selenite, or selenocyanate (SeCN(-)) for nine days in 10% Bold's basal medium. Uptake of selenate was more pronounced than that of selenite, and there was very little uptake of selenocyanate. Upon uptake of selenate, significant quantities of selenite and selenocyanate were produced by the algae and released back into the growth medium; no selenocyanate was released after selenite uptake. Release of the reduced metabolites after selenate exposure appeared to coincide with increasing esterase activity in solution, indicating that cell death (lysis) was the primary emission pathway. This is the first observation of biotic formation of selenocyanate and its release into waters from a nonindustrial source. The potential environmental implications of this laboratory observation are discussed with respect to the fate of selenium in impacted aquatic systems, the ecotoxicology of selenium bioaccumulation, and the interpretation of environmental selenium speciation data generated, using methods incapable of positively identifying reduced inorganic selenium species, such as selenocyanate.     

Preparation of the Ge(001) surface towards fabrication of atomic-scale germanium devices

We demonstrate the preparation of a clean Ge(001) surface with minimal roughness (RMS ~0.6 ?), low defect densities (~0.2% ML) and wide mono-atomic terraces (~80-100 nm). We use an ex situ wet chemical process combined with an in situ anneal treatment followed by a homoepitaxial buffer layer grown by molecular beam epitaxy and a subsequent final thermal anneal. Using scanning tunneling microscopy, we investigate the effect on the surface morphology of using different chemical reagents, concentrations as well as substrate temperature during growth. Such a high quality Ge(001) surface enables the formation of defect-free H-terminated Ge surfaces for subsequent patterning of atomic-scale devices by scanning tunneling lithography. We have achieved atomic-scale dangling bond wire structures 1.6 nm wide and 40 nm long as well as large, micron-size patterns with clear contrast of lithography in STM images.     

The visual detectability analysis associate

The outcome of this work is a knowledge-based associate ergonomic tool that assists in determining visibility of stationary small objects critical to the work environment. The Luchlesh and Moss detection solid, a design handbook guideline, accounts for non-search visibility in terms of three fundamental variables — visual angle, brightness and contrast. To reduce the difficulty of using the solid in its current form, this effort first quantified the empirical relationships of the solid. The intelligent system building tool, Exsys, was then employed: (1) to convert the results into rules for a knowledge base, and (2) to generate a tool called the Visual Detectability Analysis Associate. An efficient, convenient and easy to use ergonomic design tool is now available that determines visibility of small stationary objects in work environments where viewing time may be limited, but visual search is not required. In current use by a company to solve visibility problems encountered in system design, the VDAA tool has demonstrated beneficial savings in both time and effort.     

Manager Associate [IKBS]

The knowledge-based Manager Associate, which assists managers in planning, organizing, staffing, scheduling, measuring, visualizing, and controlling software development processes, is described. The Manager Associate operates in a distributed Unix environment in which the manager has access to the software developer workstations through a computer network. The Manager Associate helps managers anticipate problems, which allow early corrective action. As a result, software projects can be developed on time, within budget, and to customer satisfaction