Comparison of the prediction power of 23 generalized equations of state: Part II — Parametric evaluation

The parameters contained in the 23 generalized equations of state (EOSs) studied in the first part of this research have been evaluated in the current study in order to determine conditions at which they should not be used. At first, for the studied generic van der Waals (vdW)-type EOSs it has been illustrated that what kind of temperature-dependence for the parameters involved such as the co-volume leads to infinite or negative isochoric and isobaric heat capacities at high pressures and how large the pressures are at which negative heat capacities occur. In the next step, the temperature-dependence and limiting behavior of the attraction parameters applied in the studied generic vdW-type EOSs have been investigated. Furthermore, the dominant trend of the second Virial coefficient in terms of the temperature has been explored for a generic vdW-type EOS taking into account the temperature-dependence of the attraction parameter and the prediction power of the studied EOSs for the second Virial coefficient have been tested against the experimental data. Thereafter, some useful remarks about the constraints in the solution of the EOS and the critical reduced pressure-reduced volume isotherm predicted by the studied EOSs have been presented. Finally, the main parameters of the studied EOSs, namely the thermal cohesion function and the co-volume of the studied generic vdW-type EOSs together with the second and third Virial coefficients of the studied truncated Virial-type EOSs have been examined for anomalies caused by particular conditions of the variables used to define them, i.e. the characteristic properties and the reduced temperature.     

Photooxidation of ABS of long-wavelengths

The evolution of the photochemical degradation of ABS has been studied in conditions of long wavelength irradiation (λ's> 300 nm). The main photoproducts involved in the oxidative evolution have been identified by using FTIR spectroscopy and chemical titrations. A particular attention has been devoted to α–β unsaturated ketones that appear as secondary photoproducts. Those ketones present a low photochemical stability when exposed in the range 300–400 nm. Conditions for their formation have been experimentally studied. Formation of oxidation photoproducts has been also studied at the macroscopic level and it has been shown that their repartition in the polymer is heterogeneous. The origins of the heterogenities have been studied.     

黄腐酸对赤泥沉降性能影响的研究

研究了铝土矿中的有机物黄腐酸对赤泥沉降性能影响,考察了黄腐酸不同浓度条件下对赤泥沉降速度、溢流浮游物含量和底流压缩液固比的影响,同时研究了加入絮凝剂消除黄腐酸负面作用的条件.     

Study of physical and thermochemical properties of modified zeolites

The treatment of zeolite with a solution of NaOH at different concentrations creates modified forms of natural zeolites.These modified zeolites exhibit an increased uptake of caesium and a satisfactory uptake of cobalt. The structural changes in the modified zeolites were studied by XRD analysis, which reveals the mineral compositions of the studied materials. The thermodynamic properties of the modified zeolites were studied by means of DTA and thermogravimetry, and the chemical composition too was determined.     

Study of the electrochemical oxidation of phenothiazine derivatives in acetonitrile medium: The effect of the structure on the voltammetric behavior

The electrochemical oxidation of phenothiazine and its derivatives substituted in the 2 and 10 positions was studied. The voltammetric behavior of the studied substances was compared. An attempt was made to quantitatively characterize the effect of the substituents. The reversibility of electrode reaction was studied by CV method.Values of diffusion coefficients of phenothiazine derivatives in anhydrous acetonitrile medium were estimated; these values have not yet been published.     

Film-Forming Ability of Solutions Containing Products of Hydrolytic Polycondensation of Tetraethoxysilane

Solutions containing products of hydrolytic polycondensation of tetraethoxysilane were studied by viscometry and small-angle X-ray scattering. The growth of polymer particles participating in formation of thin films was studied in relation to the solution composition and process conditions.     

The use of trioctylphosphine oxide for solvent extraction recovery and purification of transplutonium elements

Extraction of trivalent curium, berkelium, californium, einsteinium, and europium with trioctylphosphine oxide (TOPO) from nitric acid solutions as well as extraction of curium and cerium from lactic acid solutions containing DTPA depending on aluminium nitrate concentration have been studied. The distribution of cobalt, nickel, chromium, iron, aluminium, titanium, zirconium, and niobium ions has been studied and coefficients of berkelium purification from the elements studied have been determined under the conditions of extraction-chromatographic recovery of berkelium. The influence of weighed amounts of the same impurities on the yield of berkelium in its extraction-chromatographic separation has been studied. Some examples of the practical application of the extraction-chromatographic techniques using TOPO are given.     

Method of fluxless soldering of dissimilar materials

The method of fluxless soldering of dissimilar materials using the electrodeposition of solder components (copper and gallium) was studied. The effect of a number of factors on the strength of soldered joints was studied.     

氨基酸质子化反应的滴定量热测定

在298．2K和0．1mol•dm－3（KNO3）离子强度的实验条件下，用常规滴定量热法测定了八种氨基酸羧基质子化反应的平衡常数和反应焓变；用扩展的滴定量热法测定了这些氨基酸氨基质子化反应的平衡常数和反应焓变；并讨论了各热力学性质之间的关系．     

Isolation of Pectins from Flax Pedicels and Fibers and Their Characterization

Isolation of pectins form flax pedicels and fibers was studied. Isolated pectins and flax fibers treated by various chemical procedures were studied by IR spectroscopy. The morphology of fascicles of flax fibers was studied by electron microscopy as influenced by chemical treatment.     

The catalytic properties of the InSb-CdTe system in the hydrogenation of carbon monoxide

The catalytic properties of binary semiconductors and solid solutions formed in the InSb-CdTe system in the hydrogenation of CO were studied by the flow-circulation method over the temperature range 290–473 K. Before direct catalytic measurements, the adsorption of reaction participants in the pure form and as mixtures was studied under the same temperature conditions. The results proved useful for preliminarily estimating the temperature regions of the occurrence of the reaction and determining its mechanism. The mechanism was also studied IR spectroscopically. The results obtained and the available data on the adsorption-catalytic properties of diamond-like semiconductors were used to suggest the mechanisms of the adsorption of mixtures and the reaction studied. The components of the InSb-CdTe system (predominantly, CdTe) showed high catalytic activity already at room temperature.     

Adhesion of liquid-crystalline polymer systems to substrates of varied roughness

Evolution of the adhesion behavior of a liquid crystalline system under various conditions of the adhesion joint formation was studied. A blend of hydroxypropyl cellulose with propylene glycol was selected as a model liquid crystalline system. Influence of the substrate roughness on the adhesion of the liquid crystalline systems was studied for the first time. It was found out that the roughness influence on the adhesion characteristics of the systems studied was much more pronounced than in case of the common pressure-sensitive adhesives. High values of the debonding energies for the systems studied (up to 280–330 J/m²) were obtained. These values are similar or even exceed the values obtained for the common pressure-sensitive adhesives.     

Reaction of dibromoalkanes with silyl phosphites. Synthesis and properties of mono-and diphosphonoalkanes

Reactions of dibromoethane and dibromopropane with silyl phosphites are studied. Mono-and diphosphonoalkanes of various structures were prepared, and their chemical properties were studied.     

Kinetics of Hydrogenation and Oxidation of Benzyl Alcohol in the Presence of Colloid Palladium in situ

The kinetics of hydrogenation and oxidation with molecular oxygen of benzyl alcohol in the presence of colloid palladium in situ were studied. Mechanisms of the reactions studied were proposed.     

Synthesis of ultrafine refractory oxides zirconia-hafnia-yttria by sol-gel technology

A transparent gel was prepared using a hydrolytically active solution of zirconium, hafnium, and yttrium alkoxoacetylacetonates. This gel served to synthesize ultrafine zirconia-hafnia-yttria complex oxide. The product dispersity was studied as affected by the parameters of xerogel heat treatment. The thermal behavior of the xerogel was studied by DSC-TGA. Elemental analysis (laser mass spectrometry) and phase analysis of the synthesized materials were carried out. Average crystallite sizes were calculated by the Scherrer relationship. The particle morphology was studied by TEM. Specific surface areas were determined. Sintering of ultrafine oxide powders was studied at 1000, 1200, and 1400°C.     

Effect of the modification of aluminosilicate ash microsphere surfaces on physical-mechanical properties of polyurethane foam

The rigid polyurethane foam materials based on ODF-M complex oligoester filled by hollow silicaalumina microspheres with various surface nature were studied. Physical-mechanical properties of the obtained materials were studied.     

Study of the interaction between daunorubicin and human serum albumin,and the determination of daunorubicin in blood serum samples

The interactions between daunorubicin and human serum albumin (HSA) were studied using the spectrofluorimetric method. The binding constants of daunorubicin with HSA were obtained at different temperatures. The effects of various metal ions on the binding constants of daunorubicin with HSA were also studied. The optimum conditions of fluorometric determination of daunorubicin were studied and the developed method was successfully applied to the determination of daunorubicin in serum samples.     

Stability and colloid-chemical properties of latex-stabilized emulsions of epoxy resins in the presence of a nonionic surfactant

The stability of oil-in-water emulsions of ED-20 epoxy-4,4′-isopropylidenediphenol resin was studied in relation to the emulsifier and stabilizer concentrations. The curing kinetics of coatings prepared from this resin was studied.     

Polarographic study of the substitution reactions of the chelates of triethyl-enetetraminehexa-acetic acid-I Reaction of the zinc chelate with calcium ions

The mechanism of the substitution reaction between the binuclear zinc-triethylenetetraminehexa-acetic acid (TTHA) chelate (Zn(2)X(2-)) and calcium ions was studied by the polarographic technique. The results obtained under equilibrium and kinetic conditions permitted formulation of the reaction mechanisms as depending on the ratio Zn:Ca in the system studied. The reaction studied proceeds only in the presence of ammonia. When calcium is replaced with a metal which has a TTHA chelate more stable than Zn(2)X(2-), the mixed binuclear chelate is not formed.     

Properties of aqueous solutions containing blends of poly-N-vinylformamide with carboxymethyl cellulose of various degrees of ionization and of composite films of these polymers

Rheological properties of mixtures of dilute and moderately concentrated aqueous solutions of poly-N-vinylformamide and carboxymethyl cellulose of various degrees of ionization were studied. Composite film materials were prepared, and their physicomechanical properties and structural organization were studied.