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1.
2.
Ranjana Yadav 《European Polymer Journal》2007,43(8):3531-3537
Models capable of predicting the maximum extent of conversion (p) of cardanol-based novolac-type phenolic resin, have been developed using response surface methodology to determine the optimum reaction conditions. Three-dimensional response surface and their contour plot were drawn. The maximum extent of conversion (98.93%) was predicted when the cardanol was condensed with formaldehyde (molar ratio 1:0.652) at 119.84 °C for a time period of 3 h with the catalyst (e.g., citric acid) concentration of 1.988% of total volume of cardanol and formaldehyde. The pH of the reaction mixture was maintained at 3.0. These predicted values for optimum process conditions were in good agreement with experimental data. 相似文献
3.
A study of the nontilted diagonal Bianchi type-V perfect fluid models is undertaken in the nonlocally rotationally symmetric case. It is shown that in such a model, the singularity is necessarily velocity dominated and the upper bound for the ratio of the shear to the expansion is 1/3. A class of such exact models is also presented; the structure of the singularity and the effect of the anisotropy on the scale are discussed. Lastly, an attempt is made to solve exactly the equations of motion for the coordinates of the null geodesics. 相似文献
4.
Bhagwan S. Garg Ranjana Dixit Asha L. Singh 《Journal of Thermal Analysis and Calorimetry》1990,36(7-8):2567-2582
Three different types of iron(III) complexes, Fe(A)3, Fe(A)2(A') and Fe(A)(A')2, whereA is either piperidyldithiocarbamate or morpholyl dithiocarbamate andA' is glycine(oxine) acetylacetone have been prepared by reacting Fe(III) salt with sodium salt of piperidinedithiocarbamic acid or morpholine-dithiocarbamic acid and acetylacetone(oxine)-glycine in different ratios. The mixed ligand complexes have been characterised by elemental analysis, magnetic susceptibility measurements, infrared, electronic spectral techniques and by thermal analysis. Electronic spectral studies suggests that all the complexes possess distorted octahedral geometry. The magnetic moment of the high spin iron(III) complexes lies in the range of 5.88–6.00 and for low spin lies in the range of 3.36–4.34 B.M. TG studies show one step decomposition of complexes and formation of Fe2O3 at the end of the step. 相似文献
5.
The apparent and limiting apparent molar volumes of dilute aqueous solutions of KBF4, and the complexes [Fe(DMSO)6](BF4)3, [Fe(Py)4(H2O)2](BF4)3, [Fe(4-Mepy)2(H2O)2](BF4)3, and [Fe(4-Etpy)2(H2O)2](BF4)3 were determined from density data measured at 5, 15, and 25°C. The apparent and limiting apparent molar adiabatic compressibilities of these complexes were determined from ultrasonic sound velocities measured at the same temperatures in dilute aqueous solutions. The volume change associated with complex formation is discussed in terms of the nature of the coordinate bond and also the role of the central metal atom and ligands in the solvation behavior of these complexes. 相似文献
6.
Ashok K. Singh Amar Singh Ranjana Gupta Madhu Saxena Bharat Singh 《Transition Metal Chemistry》1992,17(5):413-416
The kinetics of oxidation of three aldoses (glucose, mannose and galactose) byN-bromoacetamide (NBA) in the presence of an alkaline solution of RuO4 as catalyst and Hg(OAc)2 as co-catalyst and as a scavenger for bromide have been investigated. The main products of the oxidation are the corresponding
aldonic acids. The reaction is zero order with respect to aldose and OH−. First order dependence of the reaction on both NBA and RuO4 at low concentrations shifts to zero order at higher concentrations. Addition of acetamide decreases the reaction rate, while
addition of Hg(OAc)2 has the opposite effect. No significant effect of ionic strength was observed. OBr− is postulated as the reactive oxidising species and a mechanism involving co-catalysis by RuO4 and HgII is proposed.
TMC 2588 相似文献
7.
Reaction of 3-hydrazonobutan-2-one oxime with aromatic aldehydes resulted in the formation of 1,2-bis(arylidene)hydrazine commonly referred as azine as an unexpected product, instead of expected product 3-(aryl)methylenehydrazonobutan-2-one oxime, which were subsequently oxidized to corresponding aromatic acids with an ecofriendly oxidizing agent iodobenzene diacetate. Azines and carboxylic acids were characterized by IR and NMR (1H, 13C, HMBC, and HMQC) studies. 相似文献
8.
9.
Recently, in several theoretical investigations, amplitude nth-power squeezing has been studied with n = 2, 3, 4, 5. In the present paper, we give a proposal for experimental detection of amplitude nth-power squeezing using ordinary homodyning with coherent light for arbitrary power n and discuss in detail its theory. The proposed scheme requires only repeated measurements of the factorial moments of number of photons in the light obtained after homodyning, with various shifts of phase of coherent light, and involves no approximations, whatsoever. This has advantage over the method proposed by Shchukin and Vogel [Phys. Rev. A 72 (2005) 043808] in that our method requires only one beam splitter and only one photodetector, and also lesser number of repetitions of experiment with phase-shifted coherent light. 相似文献
10.
Synthesis of some analogues of indole based marine alkaloid (±)gelliusine F, (±)gelliusine E, and total synthesis of 2,2-di(6′-bromo-3′-indolyl)ethylamine are reported. 相似文献