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In classical texts equations for gravitation and electromagnetic fields are proposed without deriving their right-hand sides [1–4]. In this paper, we derive the right-hand sides and analyze the energy–momentum tensor in the framework of Vlasov–Maxwell–Einstein equations and Milne–McCrea models. New models of accelerated expansion of the Universe without Einstein's lambda are proposed. [ABSTRACT FROM AUTHOR]

We consider a method for obtaining equations of the Hamiltonian dynamics for system of interacting massive charged particles using the general relativistic Einstein–Hilbert action. In the general relativistic case, Vlasov-type equations are derived in the nonrelativistic and weakly relativistic limits. Expressions are proposed for corrections to the Poisson equation, which can contribute to the effective action of dark matter and dark energy. In this case, an efficient approach to synchronizing the proper times of different particles of a many-particle system is proposed. Based on the obtained expressions for the action, we analyze the possibility of a composite structure of the cosmological term in the Einstein equations. Reduced Euler equations leading to the Milne–McCrea cosmological model are derived using a hydrodynamic substitution and are solved in the self-similar class. [ABSTRACT FROM AUTHOR]

Equations of gravitation in the form of Vlasov–Poisson relativistic equations with Lambda term are derived from the classical principle of least action. Hamilton–Jacobi consequences are used to obtain cosmological solutions. The properties of Lagrange points are investigated. [ABSTRACT FROM AUTHOR]

In classical texts, equations for fields are proposed without derivation of right-hand sides. Below, the right-hand sides of the Maxwell and Einstein equations are derived within the framework of the Vlasov–Maxwell–Einstein equations from a classical, but slightly more general principle of least action and Hamilton–Jacobi equations are used to obtain cosmological solutions. [ABSTRACT FROM AUTHOR]

In classical works, field equations are given without deriving right-hand sides. In this paper, the right-hand sides of the Maxwell and Einstein equations are derived within the framework of Vlasov–Maxwell–Einstein equations from a classical, but more general least action principle. [ABSTRACT FROM AUTHOR]

Kinetic equations describing the evolution of dispersed particles with different properties (such as the size, velocity, center-of-mass coordinates, etc.) are discussed. The goal is to develop an a priori mathematical model and to determine the coefficients of the resulting equations from experimentally obtained distribution functions. Accordingly, the task is to derive valid (physicochemically justified) aggregation equations. The system of equations describing the evolution of the discrete distribution function of dispersed particles is used to obtain continuum equations of the Fokker–Planck or Einstein–Kolmogorov type or a diffusion approximation to the distribution function of aggregating particles differing in the level of aggregation and in the number of constituent molecules. Distribution functions approximating experimental data are considered, and they are used to determine the coefficients of a Fokker–Planck-type equation. [ABSTRACT FROM AUTHOR]

In this paper, we prove the H-theorem for generalized chemical kinetics equations. We consider the following important physical examples of such a generalization: discrete models of quantum kinetic equations (Uehling–Uhlenbeck equations) and a quantum Markov process (quantum random walk). We prove that time means coincide with Boltzmann extremals for all such equations and for the Liouville equation as well. This gives us an approach to select the action–angle variables in the Hamilton–Jacobi method for the non-Hamiltonian situation. We propose a simple derivation of the Hamilton–Jacobi equation from the Liouville equations in the finite-dimensional case. [ABSTRACT FROM AUTHOR]

The problem of justification of gravitation and electrodynamic equations with the help of the minimal action principle is a classical one. A derivation of the Vlasov–Maxwell–Einstein equation is proposed from the classical principle, but the little more general principle of minimal action. So we get new derivation of the right-hand side of the Maxwell and Einstein equations and we get a closed system of equations for gravitation and electrodynamics. [ABSTRACT FROM AUTHOR]

We considered derivation of Vlasov–Einstein–Maxwell system of equations from the first principles, i.e. using classical Maxwell–Einstein–Hilbert action principle. We know many papers in which the theories indicated as Einstein–Vlasov, Vlasov–Maxwell–Einstein, Einstein–Maxwell–Boltzmann are discussed, and we discuss difficulties of usually used equations. We use another way of derivation and obtain an alternative version based on the generalized Fock–Weinberg form of equation of motion. [ABSTRACT FROM AUTHOR]

The gravitational Lagrangian of general relativity is considered together with the Lagrangian of electromagnetism. Vlasov-type equations are derived from the former in the general, nonrelativistic, and weakly relativistic limits. Expressions for the resulting corrections to the Poisson equation are proposed, which may contribute to the effective action of dark matter and dark energy. [ABSTRACT FROM AUTHOR]

The Vlasov–Poisson–Poisson equation is derived to study stationary solutions for a system of gravitating charged particles in a neighborhood of triangular libration points (Kordylewski clouds). Stationary solutions are sought in the form of functions of integrals, which leads to elliptic nonlinear equations for the gravitational and electrostatic field potentials. This yields a critical mass: gravitation dominates for bodies with large masses, while electrostatics dominates for bodies with smaller masses. [ABSTRACT FROM AUTHOR]

Abstract: An H-theorem is proved for generalizations of continuous- and discrete-time chemical kinetic equations. A mathematical model of heavy nuclei formation based on neutron capture in astrophysical conditions is constructed. The model describes both rapid and slow processes with allowance for radiative capture and photodetachment of neutrons and β-decay. An H-theorem for this model is proved. [ABSTRACT FROM AUTHOR]

An Erratum to this paper has been published: https://doi.org/10.1134/S106456242207002X [ABSTRACT FROM AUTHOR]

The coalescence and fragmentation of particles in a dispersion system are investigated by applying kinetic theory methods, namely, by generalizing the Boltzmann kinetic equation to coalescence and fragmentation processes. Dynamic equations for the particle concentrations in the system are derived using the kinetic equations of motion. For particle coalescence and fragmentation, equations for the particle momentum, coordinate, and mass distribution functions are obtained and the coalescence and fragmentation coefficients are calculated. The equilibrium mass and velocity distribution functions of the particles in the dispersion system are found in the approximation of an active terminal group (Becker-Döring-type equation). The transition to a continuum description is performed. [ABSTRACT FROM AUTHOR]

The birefringence of the new Ba 2 Na 3 [B 3 O 6 ] 2 F (BNBF) ( P 6 3 / m ) and Ba 7 (BO 3 ) 4 −y F 2+3 y ( P 6 3 ) phases has been investigated. Coefficients of the Sellmeier equations have been determined. Parallel [B 3 O 6 ] 3− rings in the Ba 2 Na 3 [B 3 O 6 ] 2 F structure generate the major anisotropic polarizabilities and produce large birefringence Δ n = 0.1097 − 0.0428 from 350 nm to 5 μm, comparable to that of commercial birefringent crystal α-BaB 2 O 4 . A new flux for growing a high quality BNBF crystal has been proposed. In the measured wavelength range from 266 nm to 1.7 μm noncentrosymmetric phase Ba 7 (BO 3 ) 4 −y F 2+3 y (y = 0.49) exhibits low birefringence Δ n = 0.0111 − 0.0037 which can be accounted for non-coplanar arrangement of the anionic groups in the structure. Low birefringence prevents the use of this crystal for nonlinear optical applications, since phase-matching conditions for second harmonic generation can not be reached. [ABSTRACT FROM AUTHOR]

New kinetic equations are proposed from which the incompressible Euler and Navier-Stokes equations are derived by making an exact substitution. A class of exact solutions of the Navier-Stokes equation and the form of singularities for a gradient catastrophe are obtained. [ABSTRACT FROM AUTHOR]

It is well known that the Schrödinger equation can be reduced to the Hamilton-Jacobi equation in Bohmian mechanics. Corresponding new equations of the Vlasov and Lamb types are derived, and their stationary solutions are investigated. [ABSTRACT FROM AUTHOR]

The article presents a mathematical proof for the statement- the Hamilton-Jacobi method in the non-Hamiltonian situation and the hydrodynamic substitution and presents mathematical theorems related to the topic.

The derivation of the Vlasov-Maxwell and the Vlasov-Poisson-Poisson equations from Lagrangians of classical electrodynamics is described. The equations of electromagnetohydrodynamics (EMHD) type and electrostatics with gravitation are obtained. We obtain and compare the Lagrange equalities and their generalizations for different types of the Vlasov and EMHD equations. The conveniences of writing the EMHD equations in twice divergent form are discussed. We analyze exact solutions to the Vlasov-Poisson-Poisson equations with the presence of gravitation where we have different types of nonlinear elliptic equations for trajectories of particles with critical mass m = e/ G, which has an obvious physical sense, where G denotes the gravitation constant and e is the electron charge. As a consequence we have different behaviors of particles: divergence or collapse of their trajectories. [ABSTRACT FROM AUTHOR]

Highlights: [•] First demonstration of optical parametric oscillation with LiGaS2 nonlinear crystal. [•] Mid-IR idler pulses generated near 5.46μm by pumping LiGaS2 at 1064nm. [•] Sub-nanosecond pulses generated with a LiGaS2 optical parametric oscillator. [•] Surface optical damage studied in LiGaS2 by nanosecond pulses at 1064nm. [Copyright &y& Elsevier]

The article focuses on the application of Vlasov-Poisson and Vlasov-Maxwell equations in two commuting vector fields. It mentions the relativity of the relation between the momentum and the velocity of particles. The electromagnetic hydrodynamic equations (EMHDEs) are discussed as well as the hydrodynamic substitution into the Liouville equation. It tackles the hydrodynamic-type equation and equations of the Hamilton-Jacobi type through hydrodynamic substitution. It notes the Vlasov-Poisson system for gravitational electrostatics and the motion of collective particles.

We describe the derivation of the Vlasov-Maxwell equations from the Lagrangian of classical electrodynamics, from which magnetohydrodynamic-type equations are in turn derived. We consider both the relativistic and nonrelativistic cases: with zero temperature as the exact consequence of the Vlasov-Maxwell equations and with nonzero temperature as a zeroth-order approximation of the Maxwell-Chapman-Enskog method. We obtain the Lagrangian identities and their generalizations for these cases and compare them. [ABSTRACT FROM AUTHOR]

Time averages are proved to coincide with Boltzmann extremals for Markov chains, discrete Liouville equations, and their generalizations. A variational principle is proposed for finding stationary solutions in these cases. [ABSTRACT FROM AUTHOR]

Abstract  Electroreduction of an equilibrium menthone-isomenthone mixture at a controlled potential in a diaphragm cell on various cathodes was studied. The influence exerted by the nature of a solvent and of an electrode, electrode material, and various additives on the reduction stereoselectivity of ketones was examined. Conditions for a predominant formation of the most stable of the four isomeric alcohols being formed, menthol, were found. [ABSTRACT FROM AUTHOR]

The effect of oxygen on diffusion of sodium implanted into silicon is studied for the first time in the temperature range from 500 to 850°C. A high-resistivity p-Si (ρ > 1 kΩ cm) grown by the Czochralski method in a magnetic field (mCz) with the oxygen concentration ∼3 × 1017 cm−3 was used. For comparison, we used silicon grown by the crucibleless floating zone method (fz). Temperature dependences of the effective diffusion coefficient of sodium in the mCz-Si and fz-Si crystals were determined and written as D mCz[cm2/s] = 1.12exp(−1.64 eV/ kT) cm2/s and D fz[cm2/s] = 0.024exp(−1.29 eV/ kT) cm2/s, respectively. It is assumed that larger values of diffusion parameters in oxygen-containing silicon are caused by formation of complex aggregates that contain sodium and oxygen atoms. [ABSTRACT FROM AUTHOR]

Current theory of gelation describes this process in terms of a set of nonlinear integral equations. In this article the uniqueness of nontrivial solutions of these equations within the unit functional hypercube has been proved. Besides, the convergence to this solution of iterations from an arbitrary point of the above hypercube has been established, which is of utmost importance for calculations of particular gelation processes. [ABSTRACT FROM AUTHOR]

It is now difficult to find any studies in psychophysiology in which the galvanic skin response (GSR) is not recorded, but there is still no consensus concerning the functional significance of this reaction. The GSR reflects the degree of emotional tension [5], and is also one of the autonomic components of an orienting response [2]. [ABSTRACT FROM AUTHOR]

The article focuses on solving partial differential equations of mathematical physics of the Hamilton-Jacobi method from the Liouville equation through the use of hydrodynamic substitutions. It discusses the hydrodynamic solution known Vlasov equation and its solution. It also mentions the equation and solution for the derivation of Euler systems. It also presents the equations on how these Euler systems are reduced and how its was derived from the Hamilton-Jacobi equation. Moreover it also shows the solution of Lagrangian coordinates for the equation motion.

Presents equations of motion for a solid moving in a chemically active gas. Analysis of solid motions by kinetic-theory method; Spiral-shaped trajectories exhibited by the solutions obtained; Momenta transferred by an adhering molecule.

Three NaBa12(BO3)7F4 crystals were grown in the BaO–BaF2–B2O3–Na2O system from three different compositions of high-temperature solution. With the use of optical spectroscopy, energy-dispersive X-ray spectroscopy, and the Schering bridge method it was found that the crystals revealed sharp differences in their optical and dielectric properties. The relative permittivity of the crystals in direction perpendicular to the optical axis reached 319(5). The minimum deviation technique was used for refractive index measurements. [ABSTRACT FROM AUTHOR]

The history of the cooperation between the staff of the Keldysh Institute of Applied Mathematics of the Russian Academy of Sciences and S.K. Godunov is described. Numerous novel and interesting results in the theory of kinetic equations and computational mathematics were obtained in the course of this cooperation. [ABSTRACT FROM AUTHOR]

There is demonstrated in the present paper, that the H -theorem in the case of explicit time discretization of the physico-chemical kinetic equations, generally speaking, is not valid. We prove the H -theorem, when the system of the physico-chemical kinetic equations with explicit time discretization has the form of non-linear analogue of the Markov process with doubly stochastic matrix, and for more general cases. In these cases the proof is reduced to the proof of the H -theorem for Markov chains. The simplest discrete velocity models of the Boltzmann equation with explicit time discretization –the Carleman and Broadwell models are discussed and the H -theorem for them in the case of discrete time is proved. [ABSTRACT FROM AUTHOR]

In this paper the generalizations of the physico-chemical kinetics equations, including classical and quantum physico-chemical kinetics, coagulation–fragmentation equations, discrete velocity models of classical and quantum kinetic equation and, generally speaking, all discrete physico-chemical kinetics is considered. We make time discrete in these equations and prove the H -theorem. [ABSTRACT FROM AUTHOR]

We present the results of an experimental investigation of the lithium based biaxial crystals' acoustic and acousto-optic properties: lithium selenogallate (LiGaSe 2), lithium indium selenide (LiInSe 2) and lithium thioindate (LiInS 2). The velocities of longitudinal and shear acoustic waves propagating along the crystal axes are determined for the first time. We have also calculated the values of the six elastic constants c ii (i = 1–6). In this paper we present the result of the experimental investigation of the acousto-optic figure of merit. We have measured the acousto-optic figure of merit for the first time in the case of diffraction by the longitudinal acoustic waves. Using the obtained experimental data we have computed the values of nine photoelastic coefficients p ij (i,j = 1–3) for each investigated lithium based biaxial crystal. • Experimental investigation of lithium based biaxial crystals is presented: acoustic phase velocities and figure of merit. [ABSTRACT FROM AUTHOR]

Mid‐infrared (mid‐IR) nonlinear optical (NLO) crystals are indispensable for the mid‐IR lasers generation with tunable wavelengths from 3 to 20 µm. AgGaSe2 is a commercial mid‐IR NLO crystal with the highest figures of merit, but suffers low laser damage threshold (LDT). To achieve the balance of optical transmission, NLO effect, and LDT, it is proposed to molecularly modify the AgGaSe2 structure by introducing the [LiSe4] tetrahedra, and successfully grow large crystals of a new selenide AgLiGa2Se4. The replacement of half of the heavy Ag+ cations with light Li+ increases the band gap to 2.2 eV (vs. 1.7 eV in AgGaSe2). The LDT value in AgLiGa2Se4 increases five times compared to that in AgGaSe2, while keeping a relatively large NLO susceptibility of 26 pm V−1. Moreover, the thermal expansion coefficients in AgLiGa2Se4 are approximately two times lower in absolute value compared with AgGaSe2, which is beneficial to the large crystal growth. All these advantages would make AgLiGa2Se4 a new promising NLO crystal for mid‐IR laser applications. [ABSTRACT FROM AUTHOR]

In the present paper we make the transition from the Becker–Döring system of equations to the hybrid (discrete and continuum) description. This new type of system of equations consists of the equation of the Fokker–Planck–Einstein–Kolmogorov type added by the Becker–Döring equations. We consider the H -theorem for it. We also consider the H -theorem for the Becker–Döring system of equations with discrete time and showed that it is true for some partially implicit discretization in time. Due to generality of the kinetic approach the present work can be useful for specialists in different spheres engaged in modeling the evolution of structures differing by properties. • We transit from the Becker–Döring equations to discrete and continuum description. • The H -theorem for these new equations is discussed. • The H -theorem for the Becker–Döring equations with discrete time is proved. [ABSTRACT FROM AUTHOR]

We present the results of analysis of the switching current during polarization reversal in wide field range in KTA single crystals. According to previously revealed stages of domain structure evolution, the switching current data have been separated into three parts. The first original hatching stage representing growth of streamer clusters with smooth current has been revealed. Fitting of the switching current by Kolmogorov-Avrami formula has allowed extracting the main characteristic times, which followed the activation field dependence. It has been demonstrated that the fraction of the area switched by hatching is almost the same for the whole field range. [ABSTRACT FROM AUTHOR]

Single crystals of potassium titanyl phosphate (KTiOPO4, KTP) family (MTiOXO4, where M is K, Rb, or Cs, and X is P or As) with periodical domain structures have emerged as one of the key platforms for enabling nonlinear photonics applications. Potassium titanyl arsenate (KTiOAsO4, KTA) crystals possess nonlinear optical properties outperforming those of KTP. However, domain kinetics in KTA, being the crucial element for periodical poling, lacks comprehensive studies. We present the results of in situ imaging of domain kinetics in KTA with high temporal resolution. The analysis of a set of instantaneous domain structure images (kinetic map) has allowed reliable revealing of the slow and fast domain walls, similar to KTP. The mobility and the threshold fields for the domain walls have been estimated. The main stages of the domain structure evolution have been revealed. The original hatching stage representing the formation of quasiperiodic structure of the narrow stripe domains has been discovered. The relative input of the hatching stage has increased with external field. The obtained qualitative difference in the domain structure evolution, compared with KTP, has been attributed to a six times larger ratio of fast to slow wall mobility in KTA. This fact results in suppression of the undesirable broadening of the stripe domains thus making KTA crystals very attractive for periodical poling. [ABSTRACT FROM AUTHOR]

The achievement of balanced properties among nonlinear optical (NLO) effect, laser induced damage threshold (LIDT) and optical birefringence is the key to obtain the excellent NLO crystals for harmonic mid-IR coherent radiation generation. In this work, we successfully synthesize and grow a new NLO chalcogenide crystal Li 0.81 Ag 0.19 InSe 2 by utilizing a molecular design strategy with rational replacement between Li and Ag. This crystal not only enlarges the very low birefringence in AgInSe 2 from ∼ 0.017 to ∼ 0.047, but also improves the rather small NLO effect in LiInSe 2 from 11.8 pm/V to ∼26 pm/V while maintaining the LIDT almost unchanged. Based on the large size Li 0.81 Ag 0.19 InSe 2 single crystals of optical quality, the spectroscopic properties are measured and the main parameters important for NLO output are determined. All these results demonstrate that Li 0.81 Ag 0.19 InSe 2 is a promising mid-IR NLO crystal with balanced properties. • A new nonlinear optical (NLO) crystal Li 0.81 Ag 0.19 InSe 2 is obtained by a rational replacement between lithium and silver. • The balanced NLO properties in infrared spectral region are achieved in Li 0.81 Ag 0.19 InSe 2. • The large size Li 0.81 Ag 0.19 InSe 2 single crystals with good optical quality are grown. • The Sellmeier equations and phase matching curves are determined from the refractive indices measured on crystal prisms. [ABSTRACT FROM AUTHOR]

The factors that determine the prospects of a crystal for frequency conversion of laser radiation in a wide range to the mid and far infrared (IR) ranges are nonlinear parameters and laser damage threshold (LDT). The latter is determined by the band gap and thermophysical characteristics. This work was devoted to studying the features of the structure change of the Li 0.81 Ag 0.19 InSe 2 crystal in the temperature range 90–490 K. The temperature dependences of the thermal expansion coefficients, dispersion and optical characteristics in this range were studied. A relationship between the temperature change in the structure and other parameters has been established. In Li 0.81 Ag 0.19 InSe 2 crystals, pyroluminescence was observed during heating or cooling in the range of 100–300 K, which indicates the crystal is attributed to pyroelectrics. The dispersion characteristics (n x , n y and n z) for wavelengths of 2 and 7 μm were studied, the values of birefringence Δn (n z - n x) were calculated in the temperature range 300–500 K. The detected fluctuations of Δn in the temperature range from 300 to 478 K may be associated with structural changes. [Display omitted] • Crystal chemical analysis of Li 0.81 Ag 0.19 InSe 2. • The singularity of structure during heating in the range of 90–490 K. • Optical spectroscopy characteristics of Li 0.81 Ag 0.19 InSe 2 in the range from 78 to 310 K. • Dispersion characteristics of Li 0.81 Ag 0.19 InSe 2 for wavelengths of 2 and 7 μm in the temperature range of 300–500 K. [ABSTRACT FROM AUTHOR]

The electrochemical behavior of phthaloyl peroxide C8H4O4 on an Au disk electrode in a 0.05 M aqueous solution of Na2SO4 was studied by cyclic voltammetry (CVA). It demonstrated a high activity in cathodic reduction with the formation of an irreversible peak on the CVA curve at E =-0.81 V. Additionally, during the anodic oxidation of C8H4O4, the surface of the Au electrode became passivated by compounds which prevented its oxidation during the registration of repeated cycles. Apparently, these compounds are surface complexes of phthaloyl peroxide with a gold cation. [ABSTRACT FROM AUTHOR]

The anodic corrosion of gold followed by its deposition on the cathode as a compact precipitate occurs upon electrolysis of weakly alkaline aqueous solutions of diaminoalkanes, among which 1,2-diaminoethane proved to be the most effective. The process has been characterized by cyclic voltammetry. [ABSTRACT FROM AUTHOR]

Using UV spectrometry, we studied for the first time the regularities of AlkNHBr consumption in two variations of the formation of 1,2,3-trialkyldiaziridines in aqueous media: by mixing acetaldehyde and AlkNHBr in excess of AlkNH (method 1) and by the reaction of MeCH=NEt with EtNHBr in excess of EtNH (method 2). We determined the rate constants of the individual stages of the reaction. Using quantum chemistry methods (DFT/B3LYP/3-21G), we performed calculations of spatial and electronic structures of the reacting compounds, indices of local reactivity, and global electrophilicity of atoms of the individual reaction intermediates, based on which we explained the decrease in the reaction rate when using EtNHBr instead of MeNHBr in method 1. In method 2, the formation of 1,2-diethyl-3-methyldiaziridine occurs exclusively through the intermediate iminium cation. [ABSTRACT FROM AUTHOR]

Electrochemical oxidation of tetracycline on a boron-doped diamond electrode in order to develop a method for purification of waste water from contamination by pharmaceutical agents was studied. It was found that under these conditions deep oxidation of tetracycline (TC) down to its full mineralization can take place. Using high resolution mass spectrometry, it was shown that in the first stage of the reaction the oxidation of TC proceeds with the formation of products with higher molecular mass than TC, but with further electrolysis TC transforms into compounds with lower molecular mass, and then into inorganic compounds. [ABSTRACT FROM AUTHOR]

Electrochemical oxidation of tetracycline on a boron doped diamond electrode within the stability potentials of water was studied in order to develop an approach for the purification of waste water containing medicinal agents. Cyclic voltammetry, HPLC, and high resolution mass spectrometry were used to establish that in the electrochemical oxidation process, tetracycline adds one oxygen atom to further form organic compounds with molecular weights higher than that of tetracycline. It was found that tetracycline in this region of potentials can be almost completely deactivated without its mineralization. [ABSTRACT FROM AUTHOR]

The regularities of AlkNHBr consumption in the reaction of formation of 1,2-dialkyldiaziridines in aqueous media were studied for the first time by UV spectrometry. The rate constants of particular steps of the reaction were estimated starting from the possibility of formation of the precursor of 1,2-dialkyldiaziridine, N-halogenaminal, due to the amination of the intermediate iminium cation along with the parallel halogenation of the intermediate gem-diamine. The quantum chemical calculations (DFT, B3LYP, 6-31++G(d,p) and 3-21G basis sets) were performed for the spatial and electronic structures of the compounds and indices of the local reactivity and global electrophilicity of the key intermediates of the reactions. The results of the calculations allowed us to explain the retardation of the reaction when using EtNHBr instead of MeNHBr. [ABSTRACT FROM AUTHOR]

The possibility is shown of electrochemical synthesis of 3,12-dimethyl-7,8,15,16-tetraoxadispiro[5.2.5.2]hexadecane that belong to the class of 1,2,4,5-tetraoxanes by oxidation of 1,1-dihydroperoxy-4-methylcyclohexane using a Pt anode. [ABSTRACT FROM AUTHOR]

Electrochemical degradation of diclofenac in aqueous solutions was studied using a thin-film boron-doped diamond electrode deposited onto a niobium plate. The process was monitored by means of UV spectroscopy and elemental analysis. [ABSTRACT FROM AUTHOR]

Abstract: LiGaTe2 crystals have been grown by the Bridgman–Stockbarger technique. The clear transparency range of LiGaTe2 extends from 2.5 to 12μm and its band-gap at room temperature is at 2.41eV (515nm). LiGaTe2 is a positive uniaxial crystal which possesses sufficient birefringence for phase-matching. Its non-linear coefficient d 36 estimated by phase-matched second harmonic generation is 43 pm/V±10% at 4.5μm. The properties of LiGaTe2 are compared to those of other mid-IR chalcopyrite non-linear optical crystals with special emphasis on the frequency doubling potential for CO2 lasers operating at 10.6μm. [Copyright &y& Elsevier]