Thermodynamic properties of liquid metals

Technique for determining heats of fusion and heat capacities of liquid metals at high temperatur

Thermodynamic property determination in low gravity

Techniques for determining heat capacities and other properties of molten metals were investigated and critically evaluated. Precisely determining heat capacities calorimetrically in space poses several problems. The weight of a drop calorimeter block along with the necessity of obtaining a large number of data points tend to make traditional approaches appear infeasible. However, for many substances exhibiting sufficiently high thermal conductivities and with known emissivities, it appears possible to investigate their properties by observing the rate of cooling of a levitated sphere which is initially at a uniform temperature above the melting point. A special advantage of the levitation method is that considerable supercooling is expected, making the study of the heat capacities of molten metals both above and below their melting points possible

Matrix isolation as a tool for studying interstellar chemical reactions

Since the identification of the OH radical as an interstellar species, over 50 molecular species were identified as interstellar denizens. While identification of new species appears straightforward, an explanation for their mechanisms of formation is not. Most astronomers concede that large bodies like interstellar dust grains are necessary for adsorption of molecules and their energies of reactions, but many of the mechanistic steps are unknown and speculative. It is proposed that data from matrix isolation experiments involving the reactions of refractory materials (especially C, Si, and Fe atoms and clusters) with small molecules (mainly H2, H2O, CO, CO2) are particularly applicable to explaining mechanistic details of likely interstellar chemical reactions. In many cases, matrix isolation techniques are the sole method of studying such reactions; also in many cases, complexations and bond rearrangements yield molecules never before observed. The study of these reactions thus provides a logical basis for the mechanisms of interstellar reactions. A list of reactions is presented that would simulate interstellar chemical reactions. These reactions were studied using FTIR-matrix isolation techniques

Materials science experiments in space

The criteria for the selection of the experimental areas and individual experiments were that the experiment or area must make a meaningful contribution to the field of material science and that the space environment was either an absolute requirement for the successful execution of the experiment or that the experiment can be more economically or more conveniently performed in space. A number of experimental areas and individual experiments were recommended for further consideration as space experiments. Areas not considered to be fruitful and others needing additional analysis in order to determine their suitability for conduct in space are also listed. Recommendations were made concerning the manner in which these materials science experiments are carried out and the related studies that should be pursued

Sublimation Pressures of Refractory Fluorides

Vapor species identification, absolute vapor pressures and heats of sublimation of refractory metal fluoride

Accurate peak list extraction from proteomic mass spectra for identification and profiling studies

<p>Abstract</p> <p>Background</p> <p>Mass spectrometry is an essential technique in proteomics both to identify the proteins of a biological sample and to compare proteomic profiles of different samples. In both cases, the main phase of the data analysis is the procedure to extract the significant features from a mass spectrum. Its final output is the so-called peak list which contains the mass, the charge and the intensity of every detected biomolecule. The main steps of the peak list extraction procedure are usually preprocessing, peak detection, peak selection, charge determination and monoisotoping operation.</p> <p>Results</p> <p>This paper describes an original algorithm for peak list extraction from low and high resolution mass spectra. It has been developed principally to improve the precision of peak extraction in comparison to other reference algorithms. It contains many innovative features among which a sophisticated method for managing the overlapping isotopic distributions.</p> <p>Conclusions</p> <p>The performances of the basic version of the algorithm and of its optional functionalities have been evaluated in this paper on both SELDI-TOF, MALDI-TOF and ESI-FTICR ECD mass spectra. Executable files of MassSpec, a MATLAB implementation of the peak list extraction procedure for Windows and Linux systems, can be downloaded free of charge for nonprofit institutions from the following web site: <url>http://aimed11.unipv.it/MassSpec</url></p

Signal Processing for NDE

Nowadays, testing and evaluating of industrial equipment using nondestructive tests, is a fundamental step in the manufacturing process. The complexity and high costs of manufacturing industrial components, require examinations in some way about the quality and reliability of the specimens. However, it should be noted, that in order to accurately perform the nondestructive test, in addition to theoretical knowledge, it is also essential to have the experience and carefulness, which requires special courses and experience with theoretical education. Therefore, in the traditional methods, which are based on manual testing techniques and the test results depend on the operator, there is the possibility of an invalid inference from the test data. In other words, the accuracy of conclusion from the obtained data is dependent on the skill and experience of the operator. Thus, using the signal processing techniques for nondestructive evaluation (NDE), it is possible to optimize the methods of nondestructive inspection, and in other words, to improve the overall system performance, in terms of reliability and system implementation costs. In recent years, intelligent signal processing techniques have had a significant impact on the progress of nondestructive assessment. In other words, by automating the processing of nondestructive data and signals, and using the artificial intelligence methods, it is possible to optimize nondestructive inspection methods. Hence, improve overall system performance in terms of reliability and Implementation costs of the system. This chapter reviews the issues of intelligent processing of nondestructive testing (NDT) signals

VACUUM U.V. SPECTRA OF HF AND F2F_{2}

Author Institution: Department of Chemistry, Rice UniversityThe absorption spectra of fluorinc an hydrogen fluoride have been observed in the vacuum ultraviolet at wavelengths shorter than 1500 {\AA}. at a dispersion of 3.75 {\AA/}mm. For HF two band systems have been observed and are believed to arise from transitions A $^{1}\Pi\leftarrow X^{1}\Sigma^{+}$ and $B^{1}\Sigma^{+}\leftarrow X^{1}\Sigma^{+}$ in neutral HF. A Birge-Sponer extrapolation for the progression of state A leads to a dissociation energy of $134.6 \pm, 1$ keals/mole for the ground state of HF in good agreement with previous $results.^{1}$ For $F_{2}$, previous $spectra^{2,3}$ have been re-interpreted and extended. Rydberg series converging to the first ionization potential of $F_{2}$ have been established and extended. Further Rydberg series are discussed. Some evidence suggests that the ground state electronic configuration for $F_{2}$ is best written as KK(1\sigma_{g})^{2}(1\sigma_{\mu})^{2}(2\sigma_{g})^{2}(2\sigma_{\mu})^{2}(1\pi_{\mu})^{4}(3\sigma_{g})^{2}(1\pi_{g})^{4}{^{1}\Sigma}_{g}{^{+}} The previously indentified progression of bands a \@ 877 {\AA} is re-interpreted yielding a dissociation energy for fluorine at 38.4 $\pm$ 1.6 keals/mole. $^{1}$J. W. C. Johns and R. F. Barrow, Proc. Roy. Soc., 251, 504 (1959). $^{2}$R. P. Izckowski and J. L. Margrave, J. Chem. Phys., 30, 403 (1959). $^{3}$W. Stricker and L. Krauss, Z. Naturforsch 23a, 486 (1968)

INFRARED AND EPR SPECTRA OF MATRIX ISOLATED ALKALI METAL WATER COMPLEXES

$^{1}$ J.P. Goldsborough and T.R. Koehler, Phys. Rev. A135, 133 (1964).Author Institution: Department of Chemistry, Rice UniversityAll of the alkali metals are shown to form a weakly bonded complex with water. For lithium a di-water complex has been identified via EPR spectra. Previously published EPR $spectra^{1}$ of the alkali metals in unusual matrix sites have been reinterpreted as due to a water complex. All spectral evidence suggests the water is hydrogen bonded to the metal through equivalent hydrogens. Infrared and EPR spectra of the complexes will be presented