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[en] By exciting the rotational modes of vibrationally excited CHD3(v1 = 1, JK), the reactivity for the Cl + CHD3 → HCl + CD3 reaction is observed enhanced by as much as a factor of two relative to the rotationless reactant. To understand the mode specificity, the reaction dynamics was studied using both a reduced-dimensional quantum dynamical model and the conventional quasi-classical trajectory method, both of which reproduced qualitatively the measured enhancements. The mechanism of enhancement was analyzed using a Franck-Condon model and by inspecting trajectories. It is shown that the higher reactivity for higher J states of CHD3 with K = 0 can be attributed to the enlargement of the cone of acceptance. On the other hand, the less pronounced enhancement for the higher J = K states is apparently due to the fact that the rotation along the C–H bond is less effective in opening up the cone of acceptance
[en] Fast method of boron molar concentration analysis in hydrochloric medium (0,1N), that could be used 'on line' on boron improvement plant was studied. (LMJ)
[pt]Estudou-se metodo rapido de analise de concentracoes molares de boro em meio cloridrico 0,1N, que pudesse ser utilizada 'on line' na usina de enriquecimento de Boro. (AUTHOR)
[en] Alternative methods for estimating the numerical value of the equilibrium-constant of the first hydrolysis reaction of tetravalent plutonium are illustrated. They are applied to recent data on Pu oxidation-state distributions in HCl solutions. The new estimates of the hydrolysis constant typically agree with the traditional values. (author)
[en] Ureas and carbamates have been conventionally produced by the reaction of amines with phosgene. However, phosgenation processes raise severe environmental concerns, which are attributed to the toxicity of phosgene and the formation of corrosive hydrogen chloride as a co-product. The considerable industrial interest in replacing current phosgene-based processes prompted several methods using non-phosgene routes including carbonylation of amines or nitro compounds and carbomethoxylation of amines with dialkylcarbonates. Among these, catalytic oxidative carbonylation of an amine in the presence of alcohol has been studied most extensively. Catalytic systems based on precious metals such as Rh and Pd are commonly used for this purpose, but most of these catalytic systems suffer from either low reactivity or severe reaction conditions such as high temperature and pressures. In conclusion, the facile change of selenium oxidation state by CO and O2 might be the main reason for the activity of the selenium catalyst for this reaction
[en] In the article titled Development of a Doxycycline Hydrochloride-Loaded Electro spun Nano fibrous Membrane for GTR/GBR Applications , there was an error in the Acknowledgments section, which should be corrected as follows: The authors would like to acknowledge the financial support by the National Science Foundation of China (no. 81271136). This investigation was supported by School of Stomatology, Institute of Material Medical School of Pharmacy, and Department of Military Toxicology, the Fourth Military Medical University.
[en] In the present paper an attempt has been made to separate dysprosium (Dy) from the chloride solution comparable to the scrap of Nd -Fe-B permanent magnet by solvent extraction technique. Di-2-ethyl hexyl phosphoricacid (D2EHPA) and 2-ethyl hexyl phosphoric acid (PC88A)have been evaluated as extractants under wide range of experimental variable. The two phase extraction reaction was found to be exothermic in nature for the both the extraction systems. D2EHPA was found to be superior compared to PC88A. Increase in metal ion concentration, aqueous acidity and temperature lead to decrease in distribution ratio for Dy extraction. Selective separation of Dy from mixed rare earth feed consisting of Dy, Nd and Pr was achieved with 0.25 M D2EHPA at feed acidity 0.5M HCL. The purity and recovery of Dy was found to be ∼98% and 95%respectively. (author)
[en] Optimum conditions of decomposition of the Siallites of Ziddi deposits by Hydrochloric Acid have been found. The way concerns to technology of processing of sialites and kaolin which can be recommended for obtaining of several useful products for a national economy such as: coagulant, alumina, and porcelain raw material
[en] Complete text of publication follows. Molecular absorption spectra of the diatomic molecules, AlI, GaI, InI, TlI, MgI, CaI, SrI and BaI, generated in a graphite furnace were studied using a high-resolution echelle spectrometer with the aim of finding a simple, reliable and sensitive analytical method for the determination of iodine. Among them, the barium mono-iodide (BaI) was found to have the strongest absorption bands around 538 nm and 560 nm, each of them consisting of a series of well-resolved rotational lines with half-widths of about 40-50 pm. The strongest BaI line, the band head at 538.308 nm has been evaluated systematically for its analytical use for the determination of iodine. High concentrations of hydrochloric acid (or chloride), hydrofluoric acid (or fluoride), iron, potassium and sodium resulted in significant reduction of the BaI molecular absorption. Apart from this, no other serious spectral or non-spectral interference has been observed. Different chemical forms of iodine, such as iodide, iodate and organically bound iodine produced identical BaI absorption sensitivity. The detection limit for iodine was 600 pg, and the calibration curve was linear up to 250 ng iodine. Two real samples with different chemical forms of iodine were analyzed using the proposed method. The results were in good agreement with the denoted values; the deviations are 2.9% and 2.2% for the iodide and the thyroid hormone sample, respectively. The relative standard deviation of the analytical results (n = 3) is below 2%.