Electrical and Dielectric Properties of Nanoisland Systems Below Percolation Threshold

Electric and dielectric properties of nanoisland metal films were studied in this work. Permittivity of these films was determined from the analysis of the dependences of the susceptance of the films. It is found that the effective permittivity of the researched structures has abnormally high positive value (107-108). The temperature dependence of the permittivity of the films practically does not differ from the temperature dependence of the conductivity of these films. Such behavior of these dependences is possible, if the reasons for the change of permittivity and conductivity of the films with the temperature are of the same nature. With the growth of the electric field effective permittivity of the films decreases and the conductivity increases. The cause behind the high effective permittivity of the films is the island nature of these metal films, and it is associated with the polarization of the dipoles, formed by couples negatively and positively charged metal islands. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3481

Multilayered Structures from Periodically Alternating Magnetic Island Layers: Magnetization Processes and Magnetoresistance

The multilayered structures from periodically alternating of island layers of various ferromagnetic are investigated. This island structures possessed a magnetoresistance of ~1-3 % and can detect of superweak magnetic fields up to 10-6 Oe at room temperature that allows using them as sensors of magnetic fields. The new specific vorticose states of magnetization which arises under some conditions in island structures is offered. Magnetization of these vortical states is distributed on many islands of island structures. It is supposed, what exactly this vortical magnetization is responsible for appearance of unidirectional magnetic anisotropy too. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3530

Measurement of Z/gamma*+jet+X angular distributions in ppbar collisions at sqrt{s}=1.96 TeV

We present the first measurements at a hadron collider of differential cross sections for Z+jet+X production in delta phi(Z, jet), |delta y(Z, jet)| and |y_boost(Z, jet)|. Vector boson production in association with jets is an excellent probe of QCD and constitutes the main background to many small cross section processes, such as associated Higgs production. These measurements are crucial tests of the predictions of perturbative QCD and current event generators, which have varied success in describing the data. Using these measurements as inputs in tuning event generators will increase the experimental sensitivity to rare signals.Comment: Published in Physics Letters B 682 (2010), pp. 370-380. 15 pages, 6 figure

Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector

A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results

Measurement of D*±, D± and Ds± meson production cross sections in pp collisions at √s=7 TeV with the ATLAS detector

The production of D∗±, D± and D±s charmed mesons has been measured with the ATLAS detector in pp collisions at √s= 7 TeV at the LHC, using data corresponding to an integrated luminosity of 280 nb−1. The charmed mesons have been reconstructed in the range of transverse momentum 3.5 <pT(D) <100 GeV and pseudorapidity |η(D)| <2.1. The differential cross sections as a function of transverse momentum and pseudorapidity were measured for D∗± and D± production. The next-to-leading-order QCD predictions are consistent with the data in the visible kinematic region within the large theoretical uncertainties. Using the visible D cross sections and an extrapolation to the full kinematic phase space, the strangeness-suppression factor in charm fragmentation, the fraction of charged non-strange D mesons produced in a vector state, and the total cross section of charm production at √s= 7 TeV were derived

Optical and magnetic properties of Al/NiFe and Al/Ge/NiFe nanosized films

Nanosized films with ferromagnetic layers are widely used in nanoelectronics, sensor systems and telecommunication. The physical and magnetic properties of nanolayers may significantly differ from those known for bulk materials due to fine crystalline structure, influence of interfaces, roughness, and diffusion. In this work, we are employing a spectral ellipsometry method, magneto-optical Kerr magnetometry and VSM to investigate the impact of layer thickness on the optical constants and magnetization processes for two and three layer films of the type Al/NiFe/sitall, Al/Ge/NiFe/sitall on sitall substrate for different thickness of the upper Al layers. The refractive indexes of two layer films are well resolved by spectral ellipsometry demonstrating their good quality. Modelling data for three-layer films show considerable discrepancy with the experiment, which can be related to a stronger influence of interfaces. The magnetization processes of two-layer films weakly depend on the type and thickness of the upper non-ferromagnetic layers. However, the coercivity of three layer films may significantly change with the thickness of the upper layer: more than twice when the thickness of Al layer increases from 4 to 20 nm

Optical and magnetic properties of Al/NiFe and Al/Ge/NiFe nanosized films

Nanosized films with ferromagnetic layers are widely used in nanoelectronics, sensor systems and telecommunication. The physical and magnetic properties of nanolayers may significantly differ from those known for bulk materials due to fine crystalline structure, influence of interfaces, roughness, and diffusion. In this work, we are employing a spectral ellipsometry method, magneto-optical Kerr magnetometry and VSM to investigate the impact of layer thickness on the optical constants and magnetization processes for two and three layer films of the type Al/NiFe/sitall, Al/Ge/NiFe/sitall on sitall substrate for different thickness of the upper Al layers. The refractive indexes of two layer films are well resolved by spectral ellipsometry demonstrating their good quality. Modelling data for three-layer films show considerable discrepancy with the experiment, which can be related to a stronger influence of interfaces. The magnetization processes of two-layer films weakly depend on the type and thickness of the upper non-ferromagnetic layers. However, the coercivity of three layer films may significantly change with the thickness of the upper layer: more than twice when the thickness of Al layer increases from 4 to 20 nm

Neuroprotective effect of the hexapeptide HLDF-6 on rat hippocampal neurons on the in vivo and in vitro models of Alzheimer's disease

The neuroprotective effect of Thr-Gly-Glu-Asn-His-Arg hexapeptide (HLDF-6), a biologically active fragment of the differentiation factor of human leukemia cells (HLDF), was demonstrated on models of Alzheimer's disease in vivo and in vitro. The syndromes of this pathology were induced in male rats by injection of beta-amyloid peptide (25-35) and ibotenic acid into the hippocampus. HLDF-6 prevented loss of long-term memory and decrease in the exploratory behavior of these animals and significantly decreased the number of pyknotic neurons in the CA1 area of the hippocampus. This peptide also exerts a protective effect in vitro on the primary cultures of the rat hippocampal and cerebellar neurons under conditions of the beta-amyloid toxicity. An increase in the dihydrotestosterone (DHT) content was demonstrated in the blood plasma of rats with the syndrome of Alzheimer's disease and in the medium of the culture of hippocampal neurons in the presence of the Aβ(25-35) peptide. HLDF-6 inhibited this increase in both cases. A probable mechanism of the neuroprotective effect of HLDF-6 was suggested as being connected to its possible effect on both the biosynthesis and the metabolism of sex steroid hormones.© Pleiades Publishing, Inc., 2006

Neuroprotective effect of the hexapeptide HLDF-6 on rat hippocampal neurons on the in vivo and in vitro models of Alzheimer's disease

The neuroprotective effect of Thr-Gly-Glu-Asn-His-Arg hexapeptide (HLDF-6), a biologically active fragment of the differentiation factor of human leukemia cells (HLDF), was demonstrated on models of Alzheimer's disease in vivo and in vitro. The syndromes of this pathology were induced in male rats by injection of beta-amyloid peptide (25-35) and ibotenic acid into the hippocampus. HLDF-6 prevented loss of long-term memory and decrease in the exploratory behavior of these animals and significantly decreased the number of pyknotic neurons in the CA1 area of the hippocampus. This peptide also exerts a protective effect in vitro on the primary cultures of the rat hippocampal and cerebellar neurons under conditions of the beta-amyloid toxicity. An increase in the dihydrotestosterone (DHT) content was demonstrated in the blood plasma of rats with the syndrome of Alzheimer's disease and in the medium of the culture of hippocampal neurons in the presence of the Aβ(25-35) peptide. HLDF-6 inhibited this increase in both cases. A probable mechanism of the neuroprotective effect of HLDF-6 was suggested as being connected to its possible effect on both the biosynthesis and the metabolism of sex steroid hormones.© Pleiades Publishing, Inc., 2006