FT-IR Emission Spectra of Chemisorbed Species, with Application to Species Adsorbed on Alumina

The principles of infrared emission spectroscopy are briefly reviewed with emphasis on the aspects of its application to the study of chemisorbed species. The ma in problems of sample preparation, selection of measurement conditions and the most suitable methods of data treatment are discussed. IR emittance spectra of two typical support materials for supported metal catalysts, alumina and silica, are presented. On the example of a rhenium complex, tetrakisttricarbonyl-us-hydroxo- rhenium), formed on alumina support in catalytic amounts (1.5 to 5% Re) it is shown that the four-measurement technique can lead to observation of the adsorbate bands also in the regions of high substrate emission (between 1300 and 400 cm-1)

Контроль параметров воздушной среды для построения систем обнаружения пожароопасного состояния

В данной статье дан анализ процесса развития пожара, показавший, что пожар развивается в течение семи стадий, каждой из которых соответствует совокупность явлений (факторов, признаков) пожароопасного состояния, характеризуемая набором определенных параметров. Показано, что понижение стадийности регистрируемого фактора приводит к построению противопожарных профилактико-диагностических систем, поскольку чем ниже регистрируемая стадия, тем неопределеннее связь факта ее обнаружения с пожаром. Указано, что с развитием электронной техники стадийность используемых для обнаружения факторов пожарных ситуаций, в целом, понижается, а также отмечено, что для каждого объекта контроля необходим выбор (выявление) оптимального фактора, в частности, по многим характеристикам оптимальным фактором для летательных аппаратов являются дымы, их ТВ-изображения. This article analyzes the development process of the fire, which showed that a fire develops over seven stages, each of which corresponds to a set of phenomena (factors, signs) fire risk condition characterized by a set of defined parameters. It was shown that the decrease of the registered staging factor leads to the construction of fire preventive and diagnostic systems as recorded by the lower stage, the more uncertain the fact of its connection with the detection of a fire. It is indicated that the development of electronic equipment staging used for the detection of the factors fire situations, in general, is reduced, and also noted that for each control object is necessary to choose (identify) the optimal factor, in particular, in many ways the best factor for aircraft are smoke their TV picture

Predictors of gallstone composition in 1025 symptomatic gallstones from Northern Germany

BACKGROUND: Gallstones represent a prevalent and costly health problem. The changing epidemiology and the emerging non-surgical interventions for gallstone disease necessitate the definition of target populations for future therapies. This study aimed to define patterns of gallstone composition and identify demographic predictors of gallstone composition in a large sample of symptomatic gallstones from Northern Germany. METHODS: One thousand and seventy-four post-cholecystectomy gallstone specimens were obtained. Demographic and clinical information was provided by questionnaire (N = 1025 independent individuals with complete information). Two samples from each gallstone were analyzed using Fourier transformed infrared spectrometry. RESULTS: The most prevalent substance was cholesterol, which was detected in 95.0% of gallstone specimens. Bilirubin and bilirubinate were present in 30.0% and calcium was detected in 10.0% of the spectra. Ninety-two percent of measurements from the same stone yielded the same "main" substances, indicating a homogenous stone composition in most cases. Female sex and higher body mass index (BMI) were associated with the presence of cholesterol as a main substance in the gallstones (p < 0.001). CONCLUSION: The changing epidemiology of gallstone disease is reflected by a marked shift in stone composition: Only two percent of stones in this study were pigment stones as compared to 91% percent of stones containing cholesterol as a main substance. Obese individuals from Germany with a BMI > 30 kg/m(2 )have in 95% cholesterol-dominant gallstones and represent a potential target population for non-surgical interventions for the prevention or treatment of cholesterol stones

Vibrational spectra of hydrazine carbothioamide and its 15N- and D-labelled species

Raman and infrared spectra of hydrazine carbothioamide (HCTA) and its three 15N-labelled molecules (H2N NH CS15NH2, H2 15N15NHCSNH2 and H2 15N15NHCS15NH2) and their deuterated compounds have been obtained. A complete normal coordinate analysis of HCTA has been made and revised assignments are presented. The factor group splittings of HCTA have been interpreted

Investigation of Ta2O5 Thin Film Evolution

The thermal evolution process of a Ta2O5 thin film from a TaCl5 precursor was followed by thermogravimetry combined with mass spectrometry. The TaCl5 coating was prepared by the deposition of dissolved TaCl5 (in 2-propanol) onto a titanium metal support. After evaporation of the solvent, the gel-like film was heated in an atmosphere containing 20% O2 and 80% Ar to 600 °C. Mass spectrometric ion intensity curves show the liberation of chlorinated species in a uniform, slow process between 200 and 500 °C and in a fast reaction in the 500-600 °C range. Bonded solvent is decomposed in an oxidative cracking process between 120 and 220 °C, resulting in the formation of elemental carbon trapped in the film. Combustion of trapped carbon takes place in the 500-600 °C range resulting in the formation of CO2 gas inclusions in the quickly solidifying surface layer as evidenced by diffuse reflectance Fourier transform infrared spectrometry