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91.
Polyester resin-quartzite aggregate composites have been investigated for the effect of two silane coupling agents (γ-aminopropyl triethoxy silane andγ-methacryloxy propyl trimethoxy silane) on the mechanical and thermal properties. The integral blend additive method of application of the coupling agent was used in the preparation of the samples. Variation of the thermal stability and the compressive strength with the nature and the content of the silane coupling agent were quite consistent. The properties showed maxima around a certain value of the coupling agent content, which is suggested as the optimum value. Results are also presented on the samples containing an additional filler, namely, the CaCO3. 相似文献
92.
The calculation of equilibrium binding constants for a specific receptor-hormone interaction requires the exact determination of the unbound ligand concentration and the specifically bound concentration at equilibrium. These determinations usually require corrections for the contribution of non-specific binding. We introduce several parameters allowing equilibrium concentrations to be calculated from experimental concentration values; these parameters can be measured for the particular receptor assay procedure used. These parameters are used in a microassay of estradiol-receptor complex by selective retention on DE-81 cellulose paper. 相似文献
93.
Erörterungen zur homogenen Keimbildung und zur Berechnung der kritischen Übersättigung bei der Desoxidation von Eisenschmelzen mit Mangan. Behandlung des Wachstums der Desoxidationsprodukte durch Diffusion und Kollision. Aussagen über die zeitliche Verteilung der Desoxidationsprodukte unter Berücksichtigung von Stokes- und Gradient-Kollision. Angaben über die Bedeutung der Grenzflächenspannung zwischen Schmelze und Einschluß für die Abscheidung der Desoxidationsprodukte. 相似文献
94.
95.
Hari Krishna Varma P. Krishna Pillai Themanam Veettil Mani Krishna Gopa Kumara Warrier Alathoor D. Damodaran 《Journal of the American Ceramic Society》1994,77(1):129-132
Conditions for obtaining a stable sol in an isopropyl alcohol–water medium containing titanium isopropoxide and strontium nitrate, and acetic acid as a modifier, have been described. Spray drying of the sol results in submicrometer spherical agglomerates which on further thermal decomposition yield submicrometer particles of strontium titanate at temperatures as low as 500°C. The thermal decomposition characteristics of the spray-dried precursor and the development of strontium titanate phase have been discussed. Calcined precursor powder possesses a specific surface area of 12m2 /g, a comp action density of 57%, and a sintered density of > 98%. The optimum sintering temperature of such a powder was 1450°C, which resulted in a sintered grain size around 1.5 μm. Further, such a sintered sample had a dielectric constant of 260 and a loss factor of 0.008 at 1 kHz. This method appears to be very convenient with respect to handling of stable sols and thus avoids the usual difficulties regarding extended gelation as well as inhomogeneous precipitation. 相似文献
96.
Amol P. Amrute Ankur Bordoloi Nishita Lucas K. Palraj S. B. Halligudi 《Catalysis Letters》2008,126(3-4):286-292
MoO3/SiO2 composite with varying amounts of MoO3 loading (1–20 wt.%) were prepared by sol–gel method and calcined at 500 °C. These catalysts were employed for the liquid phase condensation of anisole with paraformaldehyde. All the catalysts were characterized by N2 sorption, XRD, and NH3-TPD. The activities of synthesized MoO3/SiO2 catalysts were compared with p-toluene sulfonic acid (p-TSA), the most frequently used catalyst for the condensation reactions, and with a supported metal oxide (WO x /ZrO2). Under the similar reaction conditions, synthesized 10 wt.% MoO3/SiO2 catalyst calcined at 500 °C was found to be the most active in the condensation of anisole with paraformaldehyde. 相似文献
97.
Soon Young Min Sanjeev Maken Jin-Won Park Ankur Gaur Jang Soo Hyun 《Korean Journal of Chemical Engineering》2008,25(2):323-328
In this study, we melted four types of waste asbestos containing material such as spread asbestos, plasterboard asbestos,
slate asbestos and asbestos 99 wt%, in a melting furnace at 1,450–1,550 that uses a mixture of hydrogen and oxygen (Brown’s
gas) as a fuel. More volatile components (CaO, K2O) are enriched in spread asbestos, plasterboard asbestos, and slate asbestos, while less volatile compounds (SiO2, Fe2O3, MgO) remain in asbestos 99%. Through basicity of raw materials, spread asbestos, plasterboard asbestos, and slate asbestos
were found to have more alkalinity, and asbestos 99% was found more acidic. SEM and EDX results revealed that all raw materials
had various kinds of asbestos fiber. Spread asbestos, plasterboard asbestos, and slate asbestos were considered as tremolite
asbestos, whereas asbestos 99% was considered as chrysotile asbestos. It was further confirmed by SEM and XRD studies that
all waste materials contained some crystalline structures which transformed into amorphous glassy structure on melting. Also,
in case of added glass cullet during the melting of spread asbestos, it transformed the raw material into a perfect vitrified
product having more glassy surface and amorphous in nature 相似文献
98.
In this paper the viscosity and thermal conductivity of both the liquid and vapour for the refrigerants R152a and R142b have been estimated and presented. Available properties of liquid thermal conductivity of R142b and R152a and the liquid viscosity of R152a are compared with the estimated values. It is found that the agreement is good. Transport properties of R142b, which is a potential replacement for R114 in medium temperature heat pump applications, is compared with that of R114. Also, the properties of R152a, which is considered as a possible replacement of R12 in refrigeration and low-temperature heat pump applications, is compared with the properties of the other possible replacement of R134a. 相似文献
99.
100.
V. V. S. Mani Gollamudi Lakshminarayana 《European Journal of Lipid Science and Technology》1971,73(4):235-237
Tri-(2-hydroxyethyl)-orthoborate, obtained by reaction of ethylene glycol with boric acid, was esterified with palmitic, stearic, arachidic, oleic, hydnocarpic, elaidic and stearolic acids. Pure monoesters were obtained on hydrolysis with water in high yields. Monoelaidate and monostearolate are reported for the first time. The monoesters were reacted with acyl chlorides to yield the mixed diesters, viz., oleostearate, oleopalmitate, oleoarachidate, oleoelaidate, oleostearolate, elaidohydnocarpate, stearocaproate and stearolaurate. Except oleostearate the other compounds are reported for the first time. 相似文献