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The results of a study of the quality variability of float-glass produced with top-grade equipment and technology are presented and the reasons for the fluctuations are analyzed. It is concluded on the basis of the analysis that consistently high-quality product cannot be obtained without increasing the quality of the raw materials used for making batch. In our opinion, the best way to solve this problem is to tighten the specifications for the raw-materials components used for glass batch and to set high, firmly established quality specifications. [ABSTRACT FROM AUTHOR]

new multipurpose technical system designed under the uncertain conditions was compared in terms of the guaranteed estimate of earnings with the functioning system and the ideal system, which hypothetically could have been constructed in the presence of precise a priori information about all-in reality, uncertain, uncontrollable-factors. The guaranteed estimate-based comparisons were corroborated by the experiments with a conventional example under various, not only critical, variants of the a priori uncertain factors. [ABSTRACT FROM AUTHOR]

The features of laser drilling of highly porous composite ceramics consisting of aluminosilicate, glass, and a small addition of polystyrene (EPS) were studied experimentally. It was found that the formation of a liquid phase can contribute to the strengthening of ceramics. A list of factors determining the dynamics of hole formation is proposed. These include not only heating, melting, ablation, and ejection, previously known for metals and dense ceramics, but also a number of others: boiling-up of the mixture component with the lowest temperature of thermal decomposition and its departure from the affected zone; melt of less volatile components; compaction of ceramic adjoining the walls; glass transition of the liquid phase on cooling after irradiation. These effects depend on the density of the composite as well as on the viscosity of the liquefied material. [ABSTRACT FROM AUTHOR]

The article presents the results of studying the transfer of heat and particles in the Globus-M2 spherical tokamak in discharges with neutral injection at the current ramp up. An atomic beam was injected into the tokamak plasma at a fixed toroidal magnetic field of 0.7 T. The plasma current on the plateau was varied in the range 0.2–0.3 MA. Based on the electron temperature and concentration spatial distributions measured by the Thomson scattering method, the transport of heat and particles in plasma was simulated using the ASTRA code. The energy confinement time of the plasma was determined, as well as estimates of the coefficients of thermal diffusivity and diffusion was made. [ABSTRACT FROM AUTHOR]

Conditions for hydration of soda and their effect on batch quality are considered. Regimes for transportation and storage of batch are determined. Recommendations for charging and discharging of batch are issued. [ABSTRACT FROM AUTHOR]

On the spherical tokamak Globus-M2 in discharges with toroidal magnetic field of 0.7 T by means of magnetic probes and a number of other diagnostics during neutral beam injection at the current ramp up stage, magnetic field oscillations in the range of 100–300 kHz having their frequency increasing in time, had been observed. Eigenmodes with wavenumbers n = 1–3 and m = 2–4 were being registered. These oscillations were identified as Alfvén cascades. By means of multi-channel fluctuation reflectometer, observed eigenmodes were found to be localized near the magnetic shear reversal radius. Application of MHD-spectroscopy technique allowed us to determine safety factor temporal evolution and experimental values are in well agreement with modelling results, provided by ASTRA transport code. [ABSTRACT FROM AUTHOR]

The paper presents the latest results and summarizes the study of ion heat transport in the Globus-M spherical tokamak in regimes with neutral beam injection. Ion heat transport was investigated in discharges with various toroidal magnetic fields and plasma currents. Measurements of the ion temperature were carried out using charge-exchange recombination spectroscopy and a neutral particle analyzer. Plasma simulations using transport code ASTRA have shown that ion heat transport in Globus-M is predominantly neoclassical even for low collisionality range. The local transport analysis indicates that plasma core is stable to ion scale instabilities. [ABSTRACT FROM AUTHOR]

A method of plasma boundary location based on last closed magnetic surface position detection as a maximum of electrostatic potential measured using Langmuir probes is presented. It is demonstrated that the method can be used for an absolute calibration of magnetic diagnostics of plasma position (TUMAN-3M) and as an independent diagnostic tool (Globus-M). [ABSTRACT FROM AUTHOR]

The results of experiments and simulations of the transport of heat and particles in the Globus-M spherical tokamak are presented. Investigations were carried out in the ohmic mode in hydrogen and deuterium plasma. It is shown that in the phase of current growth under the same initial conditions, as long as the condition is met at which the minimum of the safety factor exceeds unity, two scenarios of discharge development are possible: with an electron temperature dive or with an electron density peak. After the safety factor reaches the value of 1, the differences are no longer observed. Modeling of transport processes using the ASTRA code showed that the dive of the electron temperature and density is a consequence of the decrease in the transport of heat and particles in the plasma core (i.e., the presence of internal transport barriers). [ABSTRACT FROM AUTHOR]

Presents a study which analyzed the role of the periodic structures (PS) in the process of interaction of high-intensity laser radiation with metallic surfaces. Information on the local magnitude of the absorptivity in the maxima and minima of surface electromagnetic waves (SEW) and incident radiation interference; Dependence of values of the SEW field on the PS depth; Kinetics of PS emergence.

We apply perturbation theory and cyclic spin permutation formalism to study the lowest energy states of the infinite-repulsion Hubbard model on finite fragments of n-leg ladder rings and show jump-wise behavior of the ground state spin S0 as a function of fragment parameters. [ABSTRACT FROM AUTHOR]

The results of the last (in the thermonuclear program "Magnetic compression") MAGO-IX experiment with a plasma chamber including a third compartment designed to compress plasma with a converging liner are presented. An X-ray pulse consisting of an intense peak of 1-µs duration, followed by a low-intensity tail with a duration of more than 10 µs, was recorded. In the MAGO-IX experiment, the neutrons were generated mainly in the third compartment. A neutron yield of 2 × 1012 was obtained. The results demonstrate that the expected compression of preheated plasma in chambers similar to MAGO-IX is promising for achieving thermonuclear ignition. [ABSTRACT FROM AUTHOR]

Experimental study of thermal energy confinement in magnetic confinement devices is one of the fundamental problems in plasma physics. The data processing technique covering kinetic and magnetic measurements performed for the Globus-M tokamak is described. A zero-dimensional code has been developed on the basis of this approach making it possible to calculate important discharge parameters during the experiment (between discharges): the electron and ion stored thermal energy content, plasma effective charge, and confinement time. Good agreement of the zero-dimensional calculations and ASTRA modeling indicates that this approach can be applied for routine data processing in Globus-M in view of the specifics of the device. [ABSTRACT FROM AUTHOR]

It is shown that for finite cyclic systems described by two band Hubbard Hamiltonian with strong electron repulsion the reduction to effective t-J model may give incorrect description of the ground state symmetry due to neglect of the correlated hopping terms. [ABSTRACT FROM AUTHOR]

It is noted that the efficiency of glassmaking furnaces can be increased by maintaining the content of iron oxides in glass within prescribed limits and the optimal ratio between bi- and trivalent iron oxides. More stringent requirements are formulated for the quality of raw materials used in the production of float-glass. The magnitude of the fluctuations of iron oxides in raw materials and its effect on the stability of the glass melting and working process is determined and analyzed. A method is described for introducing an iron-containing component (crocus) into the batch in order to smooth the sharp fluctuations of iron oxides in the raw material. It is shown that the changes in the temperatures of the gas space, the molten glass in the furnace, and the total consumption of the gas fuel are interrelated with the character of the changes in the amounts of FeO and FeO. [ABSTRACT FROM AUTHOR]

This study is devoted to the development of techniques for the formation of polymeric microcapsules (MC) with either liquid or solid core and with the polymer shell containing diverse functional groups on the basis of new reactive functional copolymers (FC). Two approaches to the formation of MC containing FC shell that included the stages of 'oil-in-water' or 'water-in-oil' dispersion preparation followed by slow extraction of solvents from dispersed phase by dispersive media were examined. FC with the same structure was successfully applied for both 'oil-in-water' and 'water-in-oil' systems. Spherical MC with the liquid hydrocarbon core demonstrated essential increase in their volume after heating at the temperature exceeding a boiling point of hydrocarbon encapsulated. Presence of reactive groups in the MC shell opens up new opportunity for further tuning the MC properties via their interaction with proper compounds, particularly via graft-polymerisation of diverse vinyl monomers initiated from the MC surface. [ABSTRACT FROM AUTHOR]

This paper reports on the synthesis of new macrophotoinitiators via grafting of 3 hydroxy-2-isopropoxy-1,2-diphenylpropan-1-one to co-oligomer of methylmetacrylate with maleic anhydride. The macrophotoinitiators obtained have been characterized by UV- and IR-spectroscopy which confirms the structure and makes possible to determine their composition. High activity of the obtained samples in the reactions of photo-curing of the composition materials is demonstrated. [ABSTRACT FROM AUTHOR]

The effect of carbon content on thermal properties of cast superinvar alloys subjected to two-stage annealing is studied. It is shown that carbon improves the casting properties of the alloys but raises the temperature coefficient of linear expansion (CTLE). Two-stage high-temperature annealing makes it possible to remove carbon from the solid solution and to transfer it into graphite, which is accompanied by decrease in the CTLE. [ABSTRACT FROM AUTHOR]

Optimization of the physical-chemical processes occurring during the preparation of glass batch, improvement of the batch preparation processes, transport, and feeding into the glassmaking furnace, and the quality indicators of batch are all important but not decisive to obtaining high-quality finished product - glass. Together with these factors the redox properties of the components used for preparing batch and the batch itself as well as the redox potential of molten glass made from the batch are of enormous importance for the glassmaking process and for the quality of molten glass. This article analyzes the redox processes occurring during melting of the sulfate of soda batch with float-glass composition and the optimization of sodium sulfate and carbon addition to the batch in order to obtain a batch that increases the stability of the melting process and the output and improves the quality of the final product with respect to defects such as bubbles and inclusions. [ABSTRACT FROM AUTHOR]

Abstract: The surface chemical composition and surface properties of collagen/poly(vinyl pyrrolidone) (PVP) blended films before and after UV irradiation (λ =254nm) were investigated using X-ray Photoelectron Spectroscopy (XPS), FTIR–ATR spectroscopy and Atomic Force Microscopy (AFM). The XPS results showed that collagen is enriched on the surface of the collagen/PVP blend. The surface composition of the collagen film was changed more by UV irradiation than the surface composition of the collagen/PVP blend. FTIR–ATR spectra showed that the positions of the amide bands in collagen are more altered after UV irradiation than those for the collagen/PVP blends. AFM images showed that the collagen surface is ordered contrary to PVP. The blend surface was similar to the pure collagen surface and confirms that there is more collagen present at the surface (higher concentration of collagen at the surface compared to PVP). UV irradiation caused only the small changes in the surface morphology of the collagen/PVP films. All of the results confirm that the surface of the collagen/PVP blend is more photoresistant than collagen. [Copyright &y& Elsevier]

Abstract: The surface properties of chitosan films before and after UV-irradiation (λ =254nm and 248nm, respectively) were investigated using the technique of scanning electron microscopy (SEM) and by means of contact angle measurements allowing the calculation of surface free energy. Moreover, in order to determine the film mass changes, quartz crystal microbalance (QCM) measurements were performed. Measurements of the contact angle for diiodomethane (D), formamide (F) and glycerol (G) on the surface of chitosan films were made. The chemical and structural changes during UV irradiation were studied by FTIR–ATR spectroscopy. The contact angle and the surface free energy were altered by UV irradiation of chitosan films. The microscopy images have shown that the KrF excimer laser irradiation caused visible damages on the surface in comparison with the surface exposed to the mercury UV lamp. The surface modification of chitosan films can be achieved using both, the low intensity UV lamp and the excimer laser. [Copyright &y& Elsevier]

The isotopic and chemical composition of organic matter from sediments collected on the north-western shelf of the Black Sea and the Danube River are discussed. The δ13C distribution pattern in organic carbon from surface sediments (0–1 cm) of the western part of the Black Sea has been established. It reveals a rather complicated picture, reflecting the superposition of several factors: local marine primary productivity, terrestrial input to the Danube River discharge and possible contribution from anaerobic microbial activity. The analysis of organic carbon by a pyrolysis-chromatography technique showed that the H/O indices of organic matter from marine sediments are in correlation with δ13C values. This is an indication of the mixed origin of the organic carbon in the littoral sediments. However, samples from the zone where H2S conditions prevail deviate from the correlation line of δ13C vs H/O indices. We believe that this is due to the contribution of the biomass of chemosynthetic bacteria in the sediments. Thus, we argue that in the Danube–Black Sea system several consecutive zones are distinguished. River discharge delivers organic carbon with δ13C values from −28 to −26 (PSU is used). Mixing of the land-derived material with autochtonous marine primary production gives δ13C values of about −26 to −23 for the organic carbon in coastal sediments. On the shelf area, beyond significant influence of both terrestrial and sulphide regime factors, plankton material dominates as a source of organic carbon in sediments. In the hydrogen sulphide zone, chemosynthetic bacteria produce additional amounts of organic matter with hydrogen to oxygen indices similar to those of plankton, but with different isotopic composition, which results in the appearance of relatively isotopically light organic carbon in the deep-sea sediments. [Copyright &y& Elsevier]

Examines the development of bulk surface photografting process in laminating polymer films. Permeability of the films; Formation of a bonding layer in the main valence polymer network; Radicals produced by aromatic ketones and surface-hydrogen of substrates.

Experiments designed to investigate the effect of a controlled large-scale asymmetry of a shell containing deuterium-tritium fuel on the shell compression and neutron production under indirect (x-ray) action are performed on the Iskra-5 laser fusion device. The uniformity of the x radiation near the target is not worse than 3%, and the shell asymmetry is varied from 30 to 100%. The observed decrease of the experimental neutron yield as compared with experiments using symmetric targets is in satisfactory agreement with two-dimensional calculations. © 1998 American Institute of Physics. [ABSTRACT FROM AUTHOR]