Use of Surfactant-Stabilized Emulsions for the Alkalimetric Determination of Indometacin

The proton-donor properties of 1-(p-chlorobenzoyl)-5-methoxy-2-methylindole-3-acetic acid (indometacin) were studied in emulsions based on different surfactants and their mixtures. A procedure for the alkalimetric titration of indometacin with detecting the titration end-point in the presence of Cresol Red was developed using an emulsion based on dodecylpyridinium chloride. The conditions for determining indometacin in medicinal forms by pH-metric titration were selected.     

Micellar Extraction of Carboxylic Acids with Phases of OP-10 Nonionic Surfactant on Heating

Extraction of carboxylic acids from aqueous solutions with phases of OP-10 nonionic surfactant on heating was studied in relation to the concentration and hydrophobicity of the acids. A multiple linear regression equation describing the process was suggested.     

Alkalimetric Determination of the Acid Number of Oils and Fats in Surfactant-Stabilized Emulsions

It was shown that the acid number of oils and fats emulsified in aqueous solutions of surfactants can be determined by alkalimetry. Effective pK values of pure long-chain carboxylic acids and acids from some edible oils were determined in different surfactant emulsions. Effective pT values were found for some acid–base indicators in an emulsion stabilized with a mixture of dodecylpyridinium chloride and Triton X-100. Conditions were selected for the determination of the acid number of oils and fats in emulsions based on a mixture of cationic and nonionic surfactants by alkalimetry with the detection of the titration end-point by pH-metry and with the Cresol Red indicator.     

A comparative investigation of the fatty acid compositions of the seeds of a number of lines of a genetic collection of Gossypium hirsutum

A comparative analysis has been made of the amounts of lipids and their fatty-acid compositions in the seeds of the lines of agenetic collection of cotton plants of the speciesGossypium hirsutum and their hybrids and the variety Tashkent-1. The results obtained on the fatty-acid compositions of some hybrids make it possible to recommend the use of individual lines of cotton plants as donors for improving the food-value indices of cottonseed oil.Institute of Chemsitry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 173–176, March–April, 1991.     

Titrimetric Determination of Furosemide Using Aqueous–Micellar Solutions of Surfactants

The solubility and acid–base properties of 4-chloro-N-(2-furylmethyl)-5-sulfamoylanthranilic acid (furosemide) were studied in aqueous–micellar solutions of surfactants of different nature. Conditions of the determination of furosemide by acid–base titration in a micellar solution of tridecylpyridinium bromide were found.     

Micellar extraction preconcentration of silver with thiazolylazo reagents into a nonionic surfactant phase at the cloud point

The effect of the main factors on the extraction of the silver complexes of 4-(2-thiazolylazo)resorcinol and 1-(2-thiazolylazo)-2-naphthol into a micellar phase of a nonionic surfactant at the cloud point was studied. Conditions were found for the atomic absorption determination of silver with micellar extraction preconcentration into an OP-7 phase upon heating.     

高能核碰撞中带电多重数快度与能量和中心度的关系

用强子–弦级联模型JPCIAE及相应的Monte Carlo事例产生器研究相对论性核–核碰撞中带电粒子多重数的赝快度密度对能量和中心度的依赖关系.无需另调任何模型参数的条件下,此模型可以同时较好地描述相对论性pp实验数据及PHOBOS和PHENIX实验组的Au+Au实验数据.本文指出:因〈N_part〉并非严格定义的物理量,致使实验上和理论上确定〈N_part〉有一定任意性,从而使得每参加者核子对的带电粒子赝快度密度随着〈N_part〉的增加可能逐渐增大,也可能逐渐减小,因此用它来区分粒子产生机制是欠妥的.     

Inorganic Molecular Electride Mg4O3: Structure,Bonding, and Nonlinear Optical Properties

Growing demands of material science and, in particular, in the field of nonlinear optics (NLO) encourage us to look for stable highly polarizable molecules with excess diffuse electrons. An unusual class of compounds called electrides comply with these requirements. Many attempts have been made, yet only few electrides have been synthesized as solids and none of them as molecular species. In this paper, a new theoretically designed molecular species with electride characteristics is reported. The idea of this molecular electride comes from the formation of electride-like features in the MgO crystal with defect F-centers. The geometry of the investigated molecule can be described as a Mg₄O₄ cube with one oxygen atom removed. In Mg₄O₃, two 3s electrons are pushed out from the inner area of the molecule forming a diffuse electride multicentered bond. Our calculations show that this electride-like cluster possesses a noticeably large first hyperpolarizability β=5733 au. At the same time, a complete cube Mg₄O₄ and Mg₄O₃²⁺ without electride electron pair have much smaller β: 0 au and 741 au, respectively. This fact indicates the decisive role of the electride electron pair in NLO properties. Additionally, vertical detachment energies of isomers (VDE), excitation energies ΔE, polarizabilities α, and IR spectra were calculated. These properties, including β, are supposed to be observable experimentally and can serve as indirect evidence of the stable molecular electride formation.     

DIRECT SIMULATION OF DEEP INELASTIC SCATTERING OF HEAVY-IONS (I) ONE PARAMETER DISTRIBUTION

The distributions of dynamic variables in the deep inelastic scattering (DIS) of heavy-ions are studied by a direct simulation technique based on the single-nucleon-transfer-mechanism. The relative motion of the two collision partners is described by a Lagrange equation, and the transition probability of a single nucleon during the interaction time is calculated by the statisti-cal spectroscopy method.The occurrence of the transition event and the corresponding change of the dynamic variables are both treated randomly according to the transition probability. The calculated results for the reaction of ⁴⁰Ar+⁵⁸Ni(E_L=280MeV) are compared with experimental data.     

Exploration for Degradation of Λ Polarization Produced in Relativistic Nucleus Nucleus Collisions

The degradation of Λ transverse polarization produced in S+Pb central collisions at energy 200 GeV per nucleon has been studied in detail. The S+Pb central collision events have been generated using Monte-Carlo generator——LUCIAE at 200 GeV per nucleon. The various factors degrading Λ transverse polarization have been analysed quantitatively. The ratios of Λ′s produced from rescattering, secondary production and decays of Σ, Ξ hyperons to the total measurable Λ′s in experiment have been investigeted and the degradation effect of these Λ on the total polarization has been determined. The simulation and calculation show that above three factors decrease the Λ transverse polarization strongly, however, can not eliminate the polarization completely when the Λ′s are assumed to be produced from hadronic gas in the final state. To explan the experimental data of vanished Λ polarization, it probably needs to consider new mechanisms of Λ production, including a weak effect of QGP formation.