Extra Spin-Wave mode in Quantum Hall systems. Beyond the Skyrmion Limit

We report on the observation of a new spin mode in a quantum Hall system in the vicinity of odd electron filling factors under experimental conditions excluding the possibility of Skyrmion excitations. The new mode having presumably zero energy at odd filling factors emerges at small deviations from odd filling factors and couples to the spin-exciton. The existence of an extra spin mode assumes a nontrivial magnetic order at partial fillings of Landau levels surrounding quantum Hall ferromagnets other then the Skyrmion crystal.Comment: 9 pages, 4 figure

The influence of modification by superdispersed powders on the lead-tin-base bronze structure

The paper presents data on the influence of additives of the pre-treated aluminium oxide powder on the structure of cast lead-tin-based bronzes. Different quantities of the modifier, based on the superdispersed aluminum oxide powder, were added to the bronze melt. The studies have shown that addition of a small amount of aluminum oxide powder (0.07... 0.25 %) allows modifying the micro structure of the obtained castings. This modification includes grain refinement, reduction of the matrix dendrites size of tin solid solution in copper, as well as formation of spherical inclusions of the low-melting phase - lead. In this case, the addition of such modifier influences weakly the morphology and the quantity of solid eutectoid inclusions based on electron compound Cu[31] Sn[8]

MANAGEMENT ENVIRONMENTAL ACTIVITIES EFFICIENCY IN THE RAILWAY ENTERPRISES

The article describes the development trend of environmental management systems in railway transport and the importance of the impact of transport factors to ensure ecological and economic security of the society. Development management instrumentation of processing of environmental systems in railway transport is aimed at maintaining the global interest in reducing pollution and possible damage of the environment to ensure ecological and economic security of the country. The main objective of the development of environmental management systems in railway transport should be inextricably linked with the main goal of the human ecology. The basis of the human ecology is to maintain equilibrium within humanity and the outside world and its environment. Improving environmental activities of the company is achieved by applying a systematic approach. The proposed criteria for evaluating the best project options and directions of improvement of greening the economy are the basis for the establishment of a mechanism of transition to sustainable development of railway industry. The authors of the analysis of ecological and economic indicators of the enterprises of the railway industry and ecological and economic assessment of investment in the environmental management system in railway transport from In the article the formation of approaches to environmental management decisions at the enterprises of the railway industry was substantiated.The article describes the development trend of environmental management systems in railway transport and the importance of the impact of transport factors to ensure ecological and economic security of the society. Development management instrumentation of processing of environmental systems in railway transport is aimed at maintaining the global interest in reducing pollution and possible damage of the environment to ensure ecological and economic security of the country. The main objective of the development of environmental management systems in railway transport should be inextricably linked with the main goal of the human ecology. The basis of the human ecology is to maintain equilibrium within humanity and the outside world and its environment. Improving environmental activities of the company is achieved by applying a systematic approach. The proposed criteria for evaluating the best project options and directions of improvement of greening the economy are the basis for the establishment of a mechanism of transition to sustainable development of railway industry. The authors of the analysis of ecological and economic indicators of the enterprises of the railway industry and ecological and economic assessment of investment in the environmental management system in railway transport from In the article the formation of approaches to environmental management decisions at the enterprises of the railway industry was substantiated

High-Energy Approach for Heavy-Ion Scattering with Excitations of Nuclear Collective States

A phenomenological optical potential is generalized to include the Coulomb and nuclear interactions caused by the dynamical deformation of its surface. In the high-energy approach analytical expressions for elastic and inelastic scattering amplitudes are obtained where all the orders in the deformation parameters are included. The multistep effect of the 2$^+$ rotational state excitation on elastic scattering is analyzed. Calculations of inelastic cross sections for the $^{17}$O ions scattered on different nuclei at about hundred Mev/nucleon are compared with experimental data, and important role of the Coulomb excitation is established.Comment: 9 pages; 3 figures. Submitted to the Physics of Atomic Nucle

Effectiveness of using a slider-crank mechanism for waffle background milling

The paper presents the design of an experimental cutting tool feed drive based on a slider-crank mechanism. A feature of the technology of milling a regular waffle background pattern is the need for regular repetition of cells, usually rectangular shape. This requires the development of a tool feed mechanism that provides а high processing speed and a significant reduction in cutting forces to prevent deformation of the cell shape. The drive design presented in the work provides feed rate up to 43 m/min with cutting speed up to 942 m/min. This eliminates the exit of the mechanism out of the cell dimensions, as well as provides a significant reduction of cutting forces up to 10 N and removes the problem of using coolant (dry machining). This is a feature of the high-speed milling mode, when the feed rate and cutting speed are significantly higher than traditional ones, and the cutting depth does not exceed 1 mm. The productivity of this milling process is much higher than traditional milling modes and, in addition, it causes less heating of the part, as almost all the heat escapes with the chips. The practical significance of the development is the increase of productivity of the equipment for waffle background milling in fuel tanks from aluminium alloys due to the application of the high-speed drive based on the slider-crank mechanism. The authors offered to mount it instead of the standard spindle on large-sized milling gantry-type machines. This makes it possible to use the high-speed milling modes at cutting forces of several newtons for reducing the weight of the power and moving parts of the drive and increasing the feed rate

The Effect of Physical Aging on the Viscoelastoplastic Response of Glycol Modified Poly(ethylene terephthalate)

For most amorphous polymers, their long term viscoelastic behaviour is greatly affected by physical aging, referring to the transition of their non-equilibrium structure towards equilibrium. This, in turn, affects their thermomechanical properties. In this study, we successfully applied a constitutive model, originally developed for semi-crystalline polyesters to assess the impact of physical aging on stress relaxation and creep in two glycol modified poly(ethylene terephthalate) grades, (poly(ethylene-co-1,4-cyclohexylenedimethylene terephthalate) (PECT) and poly(ethylene-co-2,2,4,4-tetramethyl-1,3-cyclobutanediol terephthalate) (PETT). Both copolyesters are subject to annealing at Tg-20 °C for up to 504 h and subsequent uniaxial stress relaxation tests and, for PECT, creep tests. The results show that the annealing time has a significant influence on the viscoelastic behaviour increasing the resistance to creep and stress relaxation. The effect of physical aging on model parameters is described and analysed while it is found that the concentration of active polymer junctions decreases exponentially with annealing time. Generally, PETT and PECT showed almost identical viscoelastic behaviours at 30 °C, suggesting that the chemical structure of the glycol unit (2,2,4,4-tetramethyl-1,3-cyclobutanediol and 1,4-cyclohexylenedimethanol) does not have significant effect on their viscoelasticity. However, when stress relaxation is tested at increased temperatures, the structural effects are more apparent, demonstrating higher activation energies for PECT than those for PETT, describing the rate of the rearrangement of interchain interactions. Physical aging is also found to decrease these activation energies from 326.6 to 128.1 kJ mol−1 for PECT and from 262.7 to 78.5 kJ mol−1 for PETT.</p

Spin physics with antiprotons

New possibilities arising from the availability at GSI of antiproton beams, possibly polarised, are discussed. The investigation of the nucleon structure can be boosted by accessing in Drell-Yan processes experimental asymmetries related to cross-sections in which the parton distribution functions (PDF) only appear, without any contribution from fragmentation functions; such processes are not affected by the chiral suppression of the transversity function $h_1(x)$. Spin asymmetries in hyperon production and Single Spin Asymmetries are discussed as well, together with further items like electric and magnetic nucleonic form factors and open charm production. Counting rates estimations are provided for each physical case. The sketch of a possible experimental apparatus is proposed.Comment: Presented for the proceedings of ASI "Spin and Symmetry", Prague, July 5-10, 2004, to be published in Czech. J. Phys. 55 (2005

Observations of Radiation Belt Losses Due to Cyclotron Wave-Particle Interactions

Electron loss to the atmosphere plays a critical role in driving dynamics of the Earths Van Allen radiation belts and slot region. This is a review of atmospheric loss of radiation belt electrons caused by plasma wave scattering via Doppler-shifted cyclotron resonance. In particular, the focus is on observational signatures of electron loss, which include direct measurements of precipitating electrons, measured properties of waves that drive precipitation, and variations in the trapped population resulting from loss. We discuss wave and precipitation measurements from recent missions, including simultaneous multi-payload observations, which have provided new insight into the dynamic nature of the radiation belts

Optical and photoelectrical properties of CdSxSe1–x films produced by screen-printing technology

In this paper the optical and photoelectrical properties of CdSxSe1–x films prepared using the screenprinting and sintering technique, were studied. CdCl2 was used both as a sintering flux and as a doping agent. CuCl was also used as a doping agent. The temperatures and times of preparation varied in the range of 500–600 °С and 5–60 min, respectively. The as-prepared films were characterized by the scanning electron microscopy, micro-probe X-Ray analysis, photoluminescence and photoconductance methods. Our investigations have shown that photoresponse of the CdSxSe1–x films prepared by a screenprinting method can be suitable for the production of large-area photosensitive devices