Possible isotope effect on the resonance peak formation in high-T c cuprates

Within effective t-J Hamiltonian we analyze the influence of electronic correlations and electron-phonon interaction on the dynamical spin susceptibility in layered cuprates. We find an isotope effect on the resonance peak in the magnetic spin susceptibility Im χ(q,ω), seen by inelastic neutron scattering. It results from both the electron-phonon coupling and the electronic correlation effects taken into account beyond random-phase approximation scheme. We find at optimal doping the isotope coefficient αres≈0.4 which can be further tested experimentally

Dynamical charge and spin susceptibilities in a frame of t-J-G model

We have calculated the dynamical charge and spin susceptibilities using the new analytical expression obtained beyond a conventional random phase approximation scheme. Both susceptibilities are strongly peaked along a contour around wave vector Q = (π, π). We have analyzed the dispersions of the collective excitations near Q = (π, π) corresponding to a spin density wave and charge density wave modes, respectively. In addition we have calculated the momentum dependence of the imaginary part of the charge and spin susceptibilities along the instability contour and show that both susceptibilities display a maximum around the points (π, ±q 0), (±q0,π) in Brillouine zone with decreasing temperature that indicates that the stripe-like instability may become preferable. © 2002 Plenum Publishing Corporation

Experimental Characterization of Space Charge in IZIP Detectors

Interleaved ionization electrode geometries offer the possibility of efficient rejection of near-surface events. The CDMS collaboration has implemented this interleaved approach for the charge and phonon readout for our germanium detectors. During a recent engineering run with negligible ambient radiation, the detectors were found to lose ionization stability more quickly than expected. This paper summarizes studies done in order to determine the underlying cause of the instability, as well as possible running modes that maintain stability without unacceptable loss of livetime. Additionally, first results are shown for the new version IZIP mask which attempts to improve the overall stability of the detectors.United States. Dept. of Energy (Grant DE-AC02-76SF00515)National Science Foundation (U.S.) (Awards 0705052, 0902182, 1004714, and 0802575

Studying informativity of specific IgE levels to whole cow milk allergen and its components, as well as to soy and gluten in children

Successive development of immunological tolerance to cow’s milk proteins largely depends on the timeliness and validity of the elimination diet and is most difficult in IgE-mediated food allergy. From 2012 to 2017, when examining children aged 3 months to 10 years, we found some cases with high levels of specific IgE to beta-lactoglobulin that exceeded the levels of specific IgE to the whole cow’s milk allergen (the latter is often used as a screening allergen). The aim of this study was to assess the informativity of studying the levels of specific IgE to the whole cow’s milk allergens in blood serum of children at early, preschool and primary school age. We have also included gluten (gluten) and soy as possible components of early childhood nutrition into the list of allergens under study. The study involved 100 children aged 9 months to 12 years. Clinical selection criteria included presence of anamnestic data on exacerbation of atopic dermatitis, urticaria, exacerbation of rhinitis/asthma, diarrhea, constipation or abdominal pain in response to usage of cow’s milk and/or dairy products during the last 6 months. It is shown that extended study of specific IgE levels to whole cow’s milk allergen, its components, as well as to soy and gluten, increases the accuracy of laboratory diagnostics and differential diagnosis of IgEmediated form of food allergy to cow’s milk proteins, compared with determination of serum IgE to whole cow’s milk as a screening test. A detailed study of specific IgE to milk components allowed to confirm the presence of IgE-mediated form of allergy to cow’s milk in 7% of the examined children with signs of food allergy, but in absence of specific IgE to whole cow’s milk allergen. We have also shown that in 29% of cases, the level of specific IgE to milk components was higher than those to whole cow’s milk allergen. The results of this study may be of practical importance, since the form of food allergy, as well as intensity and dynamics of reduction of production of specific IgE, are accepted criteria to forecast development of tolerance to cow’s milk proteins. In addition, identification of specific allergen (including soy bean allergen) that causes the most intense production of specific IgE, may be importance for administration of a reasonable elimination diet. The most significant allergens for diagnosis and differential diagnostics of allergy to cow’s milk in children, in addition to the “whole cow’s milk, f2” preparation, are the following allergens: “whey, f236”, “beta-lactoglobulin, f77” and “soy, f14”

Hydrodechlorination of 4-Chlorophenol on Pd-Fe Catalysts on Mesoporous ZrO2SiO2 Support

A mesoporous support based on silica and zirconia (ZS) was used to prepare monometallic 1 wt% Pd/ZS, 10 wt% Fe/ZS, and bimetallic FePd/ZS catalysts. The catalysts were characterized by TPR-H2, XRD, SEM-EDS, TEM, AAS, and DRIFT spectroscopy of adsorbed CO after H2 reduction in situ and tested in hydrodechlorination of environmental pollutant 4-chlorophelol in aqueous solution at 30 °C. The bimetallic catalyst demonstrated an excellent activity, selectivity to phenol and stability in 10 consecutive runs. FePd/ZS has exceptional reducibility due to the high dispersion of palladium and strong interaction between FeOx and palladium, confirmed by TPR-H2, DRIFT spectroscopy, XRD, and TEM. Its reduction occurs during short-time treatment with hydrogen in an aqueous solution at RT. The Pd/ZS was more resistant to reduction but can be activated by aqueous phenol solution and H2. The study by DRIFT spectroscopy of CO adsorbed on Pd/ZS reduced in harsh (H2, 330 °C), medium (H2, 200 °C) and mild conditions (H2 + aqueous solution of phenol) helped to identify the reasons of the reducing action of phenol solution. It was found that phenol provided fast transformation of Pd+ to Pd0. Pd/ZS also can serve as an active and stable catalyst for 4-PhCl transformation to phenol after proper reduction

Possible isotope effect on the resonance peak formation in high-Tc_c cuprates

Starting from the three-band $p-d$ Hubbard Hamiltonian we derive an effective $t-J$ model including electron-phonon interaction of quasiparticles with optical phonons. Within the effective Hamiltonian we analyze the influence of electronic correlations and electron-phonon interaction on the dynamical spin susceptibility in layered cuprates. We find a huge isotope effect on the resonance peak in the magnetic spin susceptibility, ${Im}\chi({\bf q},\omega)$, seen by inelastic neutron scattering. It results from both the electron-phonon coupling and the electronic correlation effects taken into account beyond random phase approximation(RPA) scheme. We find at optimal doping the isotope coeffiecient $\alpha_{res} \approx 0.35$ which can be further tested experimentally.Comment: revised version, new figure is added. Phys. Rev. B 69, 0945XX (2004); in pres

Clinical diagnostic arrangements scheme of glaucoma detection and monitoring on specialists working in railway system

The neglected forms of glaucoma of working persons lead to the personnel losses among experienced and qualified specialists inevitably, deprive them of social adaptation, self-realization in their occupations and stable financial income. In connection with this fact we have worked out and implemented the scheme of clinical diagnostic arrangements of the detection and monitoring of glaucoma on early stage on persons of the decreed group using the step-by-step realization system. In addition to three basic steps we proposed the organizational innovation - the 4-th step - before the trip measurement, in order to measure IOP (using the indicator IGD-02) and fulfillment control hypotensive conditions of the first group workers.Запущенные формы глаукомы у работающих лиц неизбежно ведут к кадровым потерям среди опытных квалифицированных специалистов, лишая их социальной адаптации, возможности самореализовываться в профессии и иметь стабильный финансовый доход [3]. В зтой связи нами был разработан и внедрен алгоритм клинико-диагностических мероприятий по раннему выявлению и мониторингу глаукомы улиц декретированной группы с поэтапной системой ее реализации. Дополнительно к основным трем этапам нами предложена организационная инновация - 4-ый зтап - предрейсовый, с целью скринингового измерения ВГД (индикатором ИГД-02) и контроля выполнения гипотензивного режима работниками 1 группы

Forward Neutron Production at the Fermilab Main Injector

We have measured cross sections for forward neutron production from a variety of targets using proton beams from the Fermilab Main Injector. Measurements were performed for proton beam momenta of 58 GeV/c, 84 GeV/c, and 120 GeV/c. The cross section dependence on the atomic weight (A) of the targets was found to vary as $A^(alpha)$ where $\alpha$ is $0.46\pm0.06$ for a beam momentum of 58 GeV/c and 0.54$\pm$0.05 for 120 GeV/c. The cross sections show reasonable agreement with FLUKA and DPMJET Monte Carlos. Comparisons have also been made with the LAQGSM Monte Carlo.Comment: Accepted for publication in Physical Review D. This version incorporates small changes suggested by referee and small corrections in the neutron production cross sections predicted by FLUK

Analysis of the low-energy electron-recoil spectrum of the CDMS experiment

We report on the analysis of the low-energy electron-recoil spectrum from the CDMS II experiment using data with an exposure of 443.2 kg-days. The analysis provides details on the observed counting rate and possible background sources in the energy range of 2 - 8.5 keV. We find no significant excess in the counting rate above background, and compare this observation to the recent DAMA results. In the framework of a conversion of a dark matter particle into electromagnetic energy, our 90% confidence level upper limit of 0.246 events/kg/day at 3.15 keV is lower than the total rate above background observed by DAMA by 8.9$\sigma$. In absence of any specific particle physics model to provide the scaling in cross section between NaI and Ge, we assume a Z^2 scaling. With this assumption the observed rate in DAMA differs from the upper limit in CDMS by 6.8$\sigma$. Under the conservative assumption that the modulation amplitude is 6% of the total rate we obtain upper limits on the modulation amplitude a factor of ~2 less than observed by DAMA, constraining some possible interpretations of this modulation.Comment: 4 pages, 3 figure

Measurement of Charged Pion Production Yields off the NuMI Target

The fixed-target MIPP experiment, Fermilab E907, was designed to measure the production of hadrons from the collisions of hadrons of momenta ranging from 5 to 120 GeV/c on a variety of nuclei. These data will generally improve the simulation of particle detectors and predictions of particle beam fluxes at accelerators. The spectrometer momentum resolution is between 3 and 4%, and particle identification is performed for particles ranging between 0.3 and 80 GeV/c using $dE/dx$, time-of-flight and Cherenkov radiation measurements. MIPP collected $1.42 \times10^6$ events of 120 GeV Main Injector protons striking a target used in the NuMI facility at Fermilab. The data have been analyzed and we present here charged pion yields per proton-on-target determined in bins of longitudinal and transverse momentum between 0.5 and 80 GeV/c, with combined statistical and systematic relative uncertainties between 5 and 10%.Comment: 15 pages, 13 figure