Power supply of autonomous systems using solar modules

The article shows the methods of constructing autonomous decentralized energy systems from solar modules. It shows the operation of up DC inverter. It demonstrates the effectiveness of DC inverters with varying structure. The system has high efficiency and low level of conductive impulse noise and at the same time the system is practically feasible. Electrical processes have been analyzed to determine the characteristics of operating modes of the main circuit elements. Recommendations on using the converters have been given

Unconventional magnetoresistance in long InSb nanowires

Magnetoresistance in long correlated nanowires of degenerate semiconductor InSb in asbestos matrix (wire diameter of around 5 nm, length 0.1 - 1 mm) is studied over temperature range 2.3 - 300 K. At zero magnetic field the electric conduction $G$ and the current-voltage characteristics of such wires obey the power laws $G\propto T^\alpha$, $I\propto V^\beta$, expected for one-dimensional electron systems. The effect of magnetic field corresponds to a 20% growth of the exponents $\alpha$, $\beta$ at H=10 T. The observed magnetoresistance is caused by the magnetic-field-induced breaking of the spin-charge separation and represents a novel mechanism of magnetoresistance.Comment: To be published in JETP Letters, vol. 77 (2003

Power supply of autonomous systems using solar modules

The article shows the methods of constructing autonomous decentralized energy systems from solar modules. It shows the operation of up DC inverter. It demonstrates the effectiveness of DC inverters with varying structure. The system has high efficiency and low level of conductive impulse noise and at the same time the system is practically feasible. Electrical processes have been analyzed to determine the characteristics of operating modes of the main circuit elements. Recommendations on using the converters have been given

Strong-Pinning Effects in Low-Temperature Creep: Charge-Density Waves in TaS_3

Nonlinear conduction in the quasi-one dimensional conductor o-TaS_3 has been studied in the low-temperature region down to 30 mK. It was found that at temperatures below a few Kelvins the current-voltage (I-V) characteristics consist of several branches. The temperature evolution of the I-V curve proceeds through sequential freezing-out of the branches. The origin of each branch is attributed to a particular strong pinning impurity type. Similar behavior is expected for other physical systems with collective transport (spin-density waves, Wigner crystals, vortex lattices in type-II superconductors etc.) in the presence of strong pinning centers.Comment: 11 pages, 3 ps figures, Revtex, To be published in Phys. Rev. Letters (1997

Region of Excessive Flux of PeV Cosmic Rays in the Direction Toward Pulsars PSR J1840+5640 and LAT PSR J1836+5925

An analysis of arrival directions of extensive air showers (EAS) registered with the EAS MSU and EAS-1000 prototype arrays has revealed a region of excessive flux of PeV cosmic rays in the direction toward pulsars PSR J1840+5640 and LAT PSR J1836+5925 at significance level up to 4.5sigma. The first of the pulsars was discovered almost 30 years ago and is a well-studied old radio pulsar located at the distance of 1.7pc from the Solar system. The second pulsar belongs to a new type of pulsars, discovered by the space gamma-ray observatory Fermi, pulsations of which are not observed in optical and radio wavelengths but only in the gamma-ray range of energies (gamma-ray-only pulsars). In our opinion, the existence of the region of excessive flux of cosmic rays registered with two different arrays provides a strong evidence that isolated pulsars can give a noticeable contribution to the flux of Galactic cosmic rays in the PeV energy range.Comment: 14 pages; v.2: a few remarks to match a version accepted for Astronomy Letters added. They can be found by redefining the \NEW command in the preamble of the LaTeX fil

Impurity-induced stabilization of Luttinger liquid in quasi-one-dimensional conductors

It is shown theoretically that the Luttinger liquid phase in quasi-one-dimensional conductors can exist in the presence of impurities in a form of a collection of bounded Luttinger liquids. The conclusion is based upon the observation by Kane and Fisher that a local impurity potential in Luttinger liquid acts, at low energies, as an infinite barrier. This leads to a discrete spectrum of collective charge and spin density fluctuations, so that interchain hopping can be considered as a small parameter at temperatures below the minimum excitation energy of the collective modes. The results are compared with recent experimental observation of a Luttinger-liquid-like behavior in thin NbSe$_3$ and TaS$_3$ wires.Comment: 11 pages, revtex, final version published in JETP Lett

Search for Chargino and Neutralino Production at sqrt(s) = 192-209 GeV at LEP

Approximately 438 pb-1 of e+e- data from the OPAL detector, taken with the LEP collider running at centre-of-mass energies of 192-209 Gev, are analyzed to search for evidence of chargino pair production, e+e- -> tilde chi^+_1 tilde chi^-_1, or neutralino associated production, e+e- -> tilde chi^0_2 tilde chi^0_1. Limits are set at the 95% confidence level on the product of the cross-section for the process e+e- -> tilde chi^+_1 tilde chi^-_1 and its branching ratios to topologies containing jets and missing energy, of jest with a lepton and missing energy, and on the product of the cross-section for e+e- -> tilde chi^0_2 tilde chi^0_1 and its branching ratio to jets. R-parity conservation is assumed throughout this paper. When these results are interpreted in the context of the Constrained Minimal Supersymmetric Standard Model, limits are also set on the masses of the tilde chi^+-_1, tilde chi^0_1 and tilde chi^0_2, and regions of the parameter space of the model are ruled out. Nearly model-independent limits are also set at the 95% confidence level on sigma(e+e- -> tilde chi^+_1 tilde chi^-_1) with the assumption that each chargino decays via a W boson, and on sigma(e+e- -> tilde chi^0_2 tilde chi^0_1) with the tilde chi^0_2 assumed to decay via a Z^0.Comment: 33 pages, 13 figures, Submitted to Eur Phys J.

Matrix controlled channel diffusion of sodium in amorphous silica

To find the origin of the diffusion channels observed in sodium-silicate glasses, we have performed classical molecular dynamics simulations of Na$_2$O--4SiO$_2$ during which the mass of the Si and O atoms has been multiplied by a tuning coefficient. We observe that the channels disappear and that the diffusive motion of the sodium atoms vanishes if this coefficient is larger than a threshold value. Above this threshold the vibrational states of the matrix are not compatible with those of the sodium ions. We interpret hence the decrease of the diffusion by the absence of resonance conditions.Comment: 5 pages, 4 figure

Study of the Linked Dipole Chain Model in heavy quark production at the Tevatron

We present calculations of charm and beauty production at Tevatron within the framework of kT-factorization, using the unintegrated gluon distributions as obtained from the Linked Dipole Chain model. The analysis covers transverse momentum and rapidity distributions and the azimuthal correlations between b and bbar quarks (or rather muons from their decay) which are powerful tests for the different unintegrated gluon distributions. We compare the theoretical results with recent experimental data taken by D0 and CDF collaborations at the Tevatron Run I and II.Comment: 16 page