726 research outputs found

    Electron mobility in surface- and buried- channel flatband In<sub>0.53</sub>Ga<sub>0.47</sub>As MOSFETs with ALD Al<sub>2</sub>O<sub>3</sub> gate dielectric.

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    In this paper, we investigate the scaling potential of flatband III-V MOSFETs by comparing the mobility of surface and buried In&lt;sub&gt;0.53&lt;/sub&gt;Ga&lt;sub&gt;0.47&lt;/sub&gt;As channel devices employing an Atomic Layer Deposited (ALD) Al&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;3&lt;/sub&gt; gate dielectric and a delta-doped InGaAs/InAlAs/InP heterostructure. Peak electron mobilities of 4300 cm&lt;sup&gt;2&lt;/sup&gt;/V·s and 6600 cm&lt;sup&gt;2&lt;/sup&gt;/V·s at a carrier density of 3×1012 cm&lt;sup&gt;-2&lt;/sup&gt; for the surface and buried channel structures respectively were determined. In contrast to similarly scaled inversion-channel devices, we find that mobility in surface channel flatband structures does not drop rapidly with electron density, but rather high mobility is maintained up to carrier concentrations around 4x10&lt;sup&gt;12&lt;/sup&gt; cm&lt;sup&gt;-2&lt;/sup&gt; before slowly dropping to around 2000 cm&lt;sup&gt;2&lt;/sup&gt;/V·s at 1x10M&lt;sup&gt;13&lt;/sup&gt; cm&lt;sup&gt;-2&lt;/sup&gt;. We believe these to be world leading metrics for this material system and an important development in informing the III-V MOSFET device architecture selection process for future low power, highly scaled CM

    MgB2: synthesis, sound velocity, and dynamics of the vortex phase

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    The sound velocity is measured in polycrystalline MgB2 synthesized from the elements, and the bulk modulus and the Debye temperature are calculated. The conversion of an elastic wave into electromagnetic radiation is investigated in the mixed state.The dynamic parameters of the vortex lattice are estimated. This paper was published in Low Temp. Rhys., 2002, v.28, N3, p.270-274Comment: 4 pages with 4 figures, RevTex

    Elastic constants of borocarbides. New approach to acoustic Measurement technique

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    A new version of the phase method of determining the sound velocity is proposed and implemented. It utilizes the ``Nonius'' measurement technique and can give acceptable accuracy (~1%) in samples of submillimeter size. Measurements of the sound velocity are made in single-crystal samples of the borocarbides RNi2B2C (R = Y,Lu,Ho). The elastic constants and the Debye temperature are calculated.Comment: 5 figures, 2 table

    Separation of Oligosaccharides from Lotus Seeds via Medium-pressure Liquid Chromatography Coupled with ELSD and DAD

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    peer-reviewedLotus seeds were identified by the Ministry of Public Health of China as both food and medicine. One general function of lotus seeds is to improve intestinal health. However, to date, studies evaluating the relationship between bioactive compounds in lotus seeds and the physiological activity of the intestine are limited. In the present study, by using medium pressure liquid chromatography coupled with evaporative light-scattering detector and diode-array detector, five oligosaccharides were isolated and their structures were further characterized by electrospray ionization-mass spectrometry and gas chromatography-mass spectrometry. In vitro testing determined that LOS3-1 and LOS4 elicited relatively good proliferative effects on Lactobacillus delbrueckii subsp. bulgaricus. These results indicated a structure-function relationship between the physiological activity of oligosaccharides in lotus seeds and the number of probiotics applied, thus providing room for improvement of this particular feature. Intestinal probiotics may potentially become a new effective drug target for the regulation of immunity

    Mapping of Mycobacterium tuberculosis Complex Genetic Diversity Profiles in Tanzania and Other African Countries

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    The aim of this study was to assess and characterize Mycobacterium tuberculosis complex (MTBC) genotypic diversity in Tanzania, as well as in neighbouring East and other several African countries. We used spoligotyping to identify a total of 293 M. tuberculosis clinical isolates (one isolate per patient) collected in the Bunda, Dar es Salaam, Ngorongoro and Serengeti areas in Tanzania. The results were compared with results in the SITVIT2 international database of the Pasteur Institute of Guadeloupe. Genotyping and phylogeographical analyses highlighted the predominance of the CAS, T, EAI, and LAM MTBC lineages in Tanzania. The three most frequent Spoligotype International Types (SITs) were: SIT21/CAS1-Kili (n = 76; 25.94%), SIT59/LAM11-ZWE (n = 22; 7.51%), and SIT126/EAI5 tentatively reclassified as EAI3-TZA (n = 18; 6.14%). Furthermore, three SITs were newly created in this study (SIT4056/EAI5 n = 2, SIT4057/T1 n = 1, and SIT4058/EAI5 n = 1). We noted that the East-African-Indian (EAI) lineage was more predominant in Bunda, the Manu lineage was more common among strains isolated in Ngorongoro, and the Central-Asian (CAS) lineage was more predominant in Dar es Salaam (p-value<0.0001). No statistically significant differences were noted when comparing HIV status of patients vs. major lineages (p-value = 0.103). However, when grouping lineages as Principal Genetic Groups (PGG), we noticed that PGG2/3 group (Haarlem, LAM, S, T, and X) was more associated with HIV-positive patients as compared to PGG1 group (Beijing, CAS, EAI, and Manu) (p-value = 0.03). This study provided mapping of MTBC genetic diversity in Tanzania (containing information on isolates from different cities) and neighbouring East African and other several African countries highlighting differences as regards to MTBC genotypic distribution between Tanzania and other African countries. This work also allowed underlining of spoligotyping patterns tentatively grouped within the newly designated EAI3-TZA lineage (remarkable by absence of spacers 2 and 3, and represented by SIT126) which seems to be specific to Tanzania. However, further genotyping information would be needed to confirm this specificity

    TRACKING FUNCTIONAL DYNAMICS IN MOTOR POTENTIALFOR DEVELOPMENT OF WELLNESS CULTURE

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    The purpose of the study is to track the dynamics of the motor potential of students in the establishment of a Wellness culture1 . The subject of the analysis are indicators in establishing the dynamics of the motor potential in tracked cognitive periods. Object of research - the pedagogical process of establishing the Wellness culture in the subject of physical education and sports through the application of current educational tools, promoting the health and well-being of students, building motor skills - a basis for Wellness in school. In a one-year period of the academic year 2021/22, motor potential was measured at the initial stage of the educational degree. A regression analysis based on mathematical-statistical processing in deriving correlation and variation coefficients was applied to derive a relationship between the motor indicators

    Thermal structure in the Venus middle cloud layer

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    Thermal structure measurements obtained by the two Vega balloons show the Venus atmosphere in the middle cloud layer to be near-adiabatic, on the whole; but discrete air masses are present that differ slightly from one another in potential temperature and entropy. The Vega 1 temperatures are 6.5 K warmer than measured by Vega 2 at given pressures. Measurements taken by the Vega 2 lander on descent through these levels agree with the Vega 2 balloon data

    The Inviscid Limit and Boundary Layers for Navier-Stokes Flows

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    The validity of the vanishing viscosity limit, that is, whether solutions of the Navier-Stokes equations modeling viscous incompressible flows converge to solutions of the Euler equations modeling inviscid incompressible flows as viscosity approaches zero, is one of the most fundamental issues in mathematical fluid mechanics. The problem is classified into two categories: the case when the physical boundary is absent, and the case when the physical boundary is present and the effect of the boundary layer becomes significant. The aim of this article is to review recent progress on the mathematical analysis of this problem in each category.Comment: To appear in "Handbook of Mathematical Analysis in Mechanics of Viscous Fluids", Y. Giga and A. Novotn\'y Ed., Springer. The final publication is available at http://www.springerlink.co
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