Intelligent system for accurate measurement of intima-media thicknesses as markers of atherosclerosis

Abstract – One of the anatomical methods for diagnosis of atherosclerosis involves measurement of intima-media thickness (IMT) using ultrasound. However these measurements are quite complicated using conventional approaches; for this reason we are developing an intelligent measurement system that will potentially enable inexpensive and accurate IMT measurements. In this paper the IMT measurement system architecture is discussed along with the algorithm to post-trigger the ultrasonic scans. Experimental results obtained in vivo are presented and discussed. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2881

Radiative heavy quark energy loss in a dynamical QCD medium

The computation of radiative energy loss in a dynamically screened QCD medium is a key ingredient for obtaining reliable predictions for jet quenching in ultra-relativistic heavy ion collisions. We calculate, to first order in the opacity, the energy loss suffered by a heavy quark traveling through an infinite and time-independent QCD medium and show that the result for a dynamical medium is almost twice that obtained previously for a medium consisting of randomly distributed static scattering centers. A quantitative description of jet suppression in RHIC and LHC experiments thus must correctly account for the dynamics of the medium's constituents.Comment: 21 pages, 14 figures, submitted to Physical Review

Accurate heat loss evaluation of water-cooled electric motors using a differential ultrasonic calorimeter

Measuring thermal losses of electric motors are important for their design optimization and correct pricing after manufacture. This measurement can be conducted by measuring the temperature difference of the motor coolant (commonly water) between the coolant's inlet and outlet. High speed of measurement facilitates testing various load scenarios and manufacture throughput; high measurement accuracy and resolution enables correct conclusions on efficiency of various design alterations and price bracketing of manufactured pieces. Ultrasonic temperature sensors can fast sense temperature with high resolution and accuracy across the complete ultrasonic pathway. Conventional high resolution ultrasonic sensors are expensive; however, oscillating ultrasonic temperature sensors can be implemented using mass produced transducers and electronic parts which cost a fraction of the price of conventional high resolution ultrasonic measurement equipment. The presented ongoing research focuses on development of a differential ultrasonic oscillating temperature sensor for evaluation of power losses in electrical motors. Computer simulations, electronic and firmware design, and experimental results are presented and discussed

Autonomous intrusion detection information system

Abstract – Implementation of security arrangements for insecure premises, for example, for temporary exhibitions or infrequent public events, usually results in substantial security personnel costs which can be potentially reduced by employing an easily installable ad hoc intrusion detection information system. In the paper we described the architecture, design and experimental results for a fully prototyped information system that utilizes ultrasonic sensors operating in the pulse echo mode for the perimeter control and ZigBee transceivers for wireless networking. The system consists of inexpensive autonomous sensor nodes with the component cost of less than £25 and a control terminal with a graphical user interface controlled by a touch screen. The nodes are programmed wirelessly to detect intrusion within any user set distance up to the operating distance of the node, and can operate unattended for days. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2877

Hard-Thermal-Loop Corrections in Leptogenesis I: CP-Asymmetries

We investigate hard-thermal-loop (HTL) corrections to the CP-asymmetries in neutrino and, at high temperature, Higgs boson decays in leptogenesis. We pay special attention to the two leptonic quasiparticles that arise at non-zero temperature and find that there are four contributions to the CP-asymmetries, which correspond to the four combinations of the two leptonic quasiparticles in the loop and in the final states. In two additional cases, we approximate the full HTL-lepton propagator with a zero-temperature propagator that employs the thermal lepton mass m_l(T), or the asymptotic thermal lepton mass sqrt{2} m_l(T). We find that the CP-asymmetries in the one-mode approaches differ by up to one order of magnitude from the full two-mode treatment in the interesting temperature regime T \sim M_1. The asymmetry in Higgs boson decays turns out to be two orders of magnitude larger than the asymmetry in neutrino decays in the zero-temperature treatment. The effect of HTL corrections on the final lepton asymmetry are investigated in paper II of this series.Comment: 38 pages, 14 figure

Viscosities of Quark-Gluon Plasmas

The quark and gluon viscosities are calculated in quark-gluon plasmas to leading orders in the coupling constant by including screening. For weakly interaction QCD and QED plasmas dynamical screening of transverse interactions and Debye screening of longitudinal interactions controls the infrared divergences. For strongly interacting plasmas other screening mechanisms taken from lattice calculations are employed. By solving the Boltzmann equation for quarks and gluons including screening the viscosity is calculated to leading orders in the coupling constant. The leading logarithmic order is calculated exactly by a full variational treatment. The next to leading orders are found to be very important for sizable coupling constants as those relevant for the transport properties relevant for quark-gluon plasmas created in relativistic heavy ion collisions and the early universe.Comment: 12 pages + 6 figures, report LBL-3492

Infrared Behavior of High-Temperature QCD

The damping rate \gamma_t(p) of on-shell transverse gluons with ultrasoft momentum p is calculated in the context of next-to-leading-order hard-thermal-loop-summed perturbation of high-temperature QCD. It is obtained in an expansion to second order in p. The first coefficient is recovered but that of order p^2 is found divergent in the infrared. Divergences from light-like momenta do also occur but are circumvented. Our result and method are critically discussed, particularly regarding a Ward identity obtained in the literature. When enforcing the equality between \gamma_t(0) and \gamma_l(0), a rough estimate of the magnetic mass is obtained. Carrying a similar calculation in the context of scalar quantum electrodynamics shows that the early ultrasoft-momentum expansion we make has little to do with the infrared sensitivity of the result.Comment: REVTEX4, 55 page

Ferromagnetic properties of charged vector boson condensate

Bose-Einstein condensation of W bosons in the early universe is studied. It is shown that, in the broken phase of the standard electroweak theory, condensed W bosons form a ferromagnetic state with aligned spins. In this case the primeval plasma may be spontaneously magnetized inside macroscopically large domains and form magnetic fields which may be seeds for the observed today galactic and intergalactic fields. However, in a modified theory, e.g. in a theory without quartic self interactions of gauge bosons or for a smaller value of the weak mixing angle, antiferromagnetic condensation is possible. In the latter case W bosons form scalar condensate with macroscopically large electric charge density i.e. with a large average value of the bilinear product of W-vector fields but with microscopically small average value of the field itself.Comment: Some numerical estimates and discussions are added according to the referee's suggestions. This version is accepted for publication in JCA