0-dialgebras with bar-unity and nonassociative Rota-Baxter algebras

We describe all homogeneous structures of Rota-Baxter algebras on a 0-dialgebra with associative bar-unity and give a corollary on the structure of a Rota-Baxter algebra on an arbitrary associative dialgebra with bar-unity as well as a unital associative conformal algebra. We prove that an arbitrary alternative dialgebra may be embedded into an alternative dialgebra with associative barunity. We suggest the definition of variety of dialgebras in the sense of Eilenberg which is equivalent to that introduced earlier by Kolesnikov.     

Development of ferroelectric liquid crystals with low birefringence

We propose an approach for development of ferroelectric liquid crystals (FLC) with low birefringence Δn. Two basic principles have been used to get lowering of Δn: selection of molecules with short chains of conjugation as components for achiral matrix and averaging of local refractive indices by FLC helical structure. FLC mixtures with low birefringence (0.07 < Δn < 0.10 at wavelength 589.3 nm of sodium line) were elaborated and investigated. They consist of an achiral matrix including both nematic and smectic liquid crystal components and of phenylpyrimidine derivatives as chiral dopants. The materials developed can be used for all basic electro-optical FLC modes such as surface stabilised FLC (SSFLC), deformed helix ferroelectrics (DHF) and electrically suppressed helix (ESH). The mixtures developed allow to reduce the FLC cells chromatic retardance variation due to the weaker birefringence dispersion as compared with the known FLC materials to date.     

Thermodynamic characteristics of hydrocarbon and chloroalkane adsorption by polymethylsilsesquioxane

Adsorption of n-alkanes (C₇H₁₆–C₁₁H₂₄), cyclohexane, benzene, CHCl₃, CCl₄, and ClCH₂CH₂Cl by polymethylsilsesquioxane [MeSi(OH)_0.4O_1.3] _n was investigated by inverse gas chromatography in the Henry region. The adsorption isotherms are linear for all adsorbates. The standard changes in the thermodynamic parameters of adsorption were determined. The absence of specific selectivity with respect to aliphatic, cyclic, or aromatic hydrocarbons or chloroalkanes indicates that the adsorbent is chemically homogeneous.     

A gas chromatographic study of the residual contents of a medieval sphero-conical vessel

Black deposit was discovered on the inner wall of a sphero-conical vessel found during archaeological excavations on the territory of the Volga Bulgars. Compounds from the deposit were extracted with organic solvents and studied by gas chromatography with flame ionization and mass spectrometry detectors. Abietic acid derivatives, including retene, present in the composition of soft wood turpentine were identified. The relatively high retene concentration in the remains of the spherocone and also the presence of other polycyclic aromatic hydrocarbons suggest the thermal version of their origin. Probably, the vessel was used as a part of alambik, which is an ancient distillation apparatus for the distillation of soft wood turpentine.     

Synthesis of α-mercaptobenzhydryldiphenylphosphine and some of its properties

Conclusions Diphenylphosphine reacts with thiobenzophenone to give-mercaptobenzhydryldiphenylphosphine, which is rearranged by heat to benzhydryldiphenylphosphine thiooxide, whereas rearrangement in conc. HCl leads to benzhydryldiphenylphosphine oxide.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2800–2802, December, 1978.     

Reaction of phenylphosphine with p-quinones

Conclusions The reaction of phenylphosphine with p-quinones gives the corresponding hydroquinones and diphenyldiphosphine.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1660–1661, July, 1978.     

Universal technique for studying electron transport in polymers

A universal technique was developed for studying electron transport in polymers, which consists in the combination of the time-of-flight technique in the surface and bulk carrier generation modes with measurement of transient radiation-induced conductivity. Central to the technique in question is the time-of-flight method with homogeneous irradiation. The procedure was implemented on the basis of an ELA-50 electron beam device with variable electron energy (3–50 keV). The practicability of the universal technique was demonstrated using the model polymers polyvinylcarbazole and molecularly doped polycarbonate as examples.     

Theoretical analysis of the Rose-Fowler-Vaisberg model: Dipolar conductivity

Results of numerical calculations on the kinetics of radiation-induced conductivity (current transients) in a case polymer in terms of the Rose-Fowler-Vaisberg model assuming dipolar carrier transport (irradiation times of 10⁴–10⁶ s) are reported. Unlike the case of unipolar transport, the pattern of current transients noticeably changes at times after passing a maximum in current. A steady-state value is still attained; however, its increase relative to the case of unipolar conductivity is disproportionately high with respect to a relatively small value of the parameter χ, which characterizes the relative contribution of minority carriers to the current. Allowance for the formation of radiation traps during irradiation somewhat mitigates this effect; however, the discrepancy between the conclusions of the theory for the two types of conduction strongly increases for the estimates of polymer recovery time after preliminary irradiation.