A semi-micro spectrophotometric method of copper analysis

The Manhattan Project of the United States atomic energy program was designed essentially to produce methods and instruments of atomic warfare. Out of the many investigations made by the scientists and engineers working to attain this primary goal, much information of value was necessarily placed in the background and, as a consequence, a vast amount of material was only cursorily studied by these workers. The type of relationship between the per cent transmission and concentration decrease was to be investigated in the hope of establishing an empirical formula for use in a certain concentration range. As an added check on the precision of the experimentation a Warburg gas manometer, functioning as a coulometer (2), was incorporated in the system’s external circuit

The continuing materials analysis of the thermal control surfaces experiment (S0069)

The long term effects of the natural and induced space environment on spacecraft surfaces are critically important to future spacecraft - including Space Station Freedom. The damaging constituents of this environment include thermal vacuum, solar ultraviolet radiation, atomic oxygen, particulate radiation, and the spacecraft induced environment. The behavior of materials and coatings in the space environment continues to be a limiting technology for spacecraft and experiments. The Thermal Control Surfaces Experiment (TCSE) was flown on the National Aeronautics and Space Administration (NASA) Long Duration Exposure Facility (LDEF) to study these environmental effects on surfaces-particularly on thermal control surfaces. The TCSE was a comprehensive experiment that combined in-space measurements with extensive pre- and post-flight analyses of thermal control surfaces to determine the effects of exposure to the low Earth orbit space environment. The TCSE is the first space experiment to directly measure the total hemispherical reflectance of thermal control surfaces in the same way they are routinely measured in the laboratory. The trend analyses of selected coatings performed as part of the continuing post-flight analysis of the TCSE are described. A brief description of the TCSE and its mission on LDEF are presented. There are several publications available that describe the TCSE, it's mission on LDEF, and initial results in greater detail. These are listed in the TCSE Bibliography

Optimized Heat Interception for Cryogen Tank Support

We consider means for using the cooling available in boil-off gas to intercept heat conducted through the support structure of a cryogen tank. A one-dimensional model of the structure coupled to a gas stream gives an analytical expression for heat leak in terms of flow rate for temperature independent-properties and laminar flow. A numerical model has been developed for heat transfer on a thin cylindrical tube with an attached vent line. The model is used to determine the vent path layout that will minimize heat flow into the cryogen tank. The results are useful for a number of applications, but the one of interest in this study is the minimization of the boil-off in large cryopropellant tanks in low Earth and low lunar orbit

The Dybamic Double Façade: An Integrated Approach to High Performance Building Envelopes

The LivingLight house, an entrant in the 2011 Department of Energy Solar Decathlon, incorporates an innovative dynamic double façade system. This paper details key features of the façade system including aesthetic integration of technical components, natural and electric illumination, design of shading devices, and use of the façade cavity to harness solar-thermal energy

Study of some volumetric properties of the pharmaceutical model solvent system ethanol + ethyl acetate at several temperatures

The binary solvent system ethanol + ethyl acetate is widely used in the pharmaceutical sciences as a versatile model for studying the solubility of drugs. In this context, the excess molar volumes and the partial molar volumes of components were investigated from density measurements on the entire range of mass fractions, for this system at 293.15 K, 298.15 K, 303.15 K, 308.15 K, and 313.15 K. The excess molar volumes were fitted by Redlich-Kister equation by using third degree polynomials and compared with those reported in the literature for other solvent systems. The system tested exhibited positive excess volumes (up to 0.18 cm3 mol-1 at 313.15 K), probably due to weak interactions, like dispersion forces, between unlike molecules or, some differences in the molar volumes of pure components. The effect of temperature on the different volumetric properties studied was also analyzed.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Study of some volumetric properties of the pharmaceutical model solvent system ethanol + ethyl acetate at several temperatures

The binary solvent system ethanol + ethyl acetate is widely used in the pharmaceutical sciences as a versatile model for studying the solubility of drugs. In this context, the excess molar volumes and the partial molar volumes of components were investigated from density measurements on the entire range of mass fractions, for this system at 293.15 K, 298.15 K, 303.15 K, 308.15 K, and 313.15 K. The excess molar volumes were fitted by Redlich-Kister equation by using third degree polynomials and compared with those reported in the literature for other solvent systems. The system tested exhibited positive excess volumes (up to 0.18 cm3 mol-1 at 313.15 K), probably due to weak interactions, like dispersion forces, between unlike molecules or, some differences in the molar volumes of pure components. The effect of temperature on the different volumetric properties studied was also analyzed.Colegio de Farmacéuticos de la Provincia de Buenos Aire