1,089 research outputs found

    Optical Properties of Wide Band Gap Indium Sulphide Thin Films Obtained by Physical Vapor Deposition

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    Thin films of indium sulphide containing oxygen have been synthesized following a dry physical process. The constituents are deposited by thermal evaporation on glass substrates and then annealed under argon flow. Polycrystalline β-In2S3 containing oxygen thin films are obtained as soon as the temperature of annealing is between 623 and 723 K. In this paper, these β-In2S3 thin films have optically been studied. The optical band gap is direct. Its value is not dependent on the temperature of annealing. It is about 2.8 eV, which is higher than that of β-In2S3 single crystal. This high value is related to the presence of oxygen in the films. The extinction coefficient k and the refractive index n of the films have also been found independent of the annealing temperature. These optical properties make the films studied good candidates to be substituted to CdS in Cu(In,Ga)Se2 based solar cells

    Predictive factors for nutritional behavior among pregnant women attending antenatal care clinic in 6th of October City

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    Background: Good maternal nutrition during pregnancy is important to ensure health for the mother and the fetus. This study aimed to assess nutritional knowledge and behavior among a group of Egyptian pregnant women in addition to identify the factors influencing their nutritional behavior. Methods: This comparative cross sectional study included 300 pregnant women attending the antenatal care clinics in 6th of October University private hospital and El-Hosary primary healthcare (PHC) unit. The data was collected through a modified nutritional survey that was translated from Spanish to Arabic and revised by language experts for clarity.  Results: Almost all of the women attending the private hospital were university educated while about half of the women attending the PHC unit were graduated from technical education. In general, the level of knowledge about food requirements of both groups was satisfactory good; however, neither of them fulfilled the WHO recommendations of food intake during pregnancy or the optimum number of meals per day. The average random blood glucose was higher among the women attending the PHC unit; the BMI, mid arm circumference and subcutaneous fat were higher among the same group as well. In regard to fulfilling the WHO recommended servings per day, only starch and fat items were fulfilled by both groups, whereas the other three items (vegetables, fruits, meat and dairy products) were merely included in the diets of both groups. Conclusion: Healthy behavior among pregnant women in both group were influenced by their educational level, occupation as well as their pre-gestational BMI. Those were the only three significant predictive factors, where women with higher education showed an active lifestyle. In addition, women starting with normal BMI before pregnancy had better healthy behaviors including the choice of healthy diets

    TriFormer: A Multi-modal Transformer Framework For Mild Cognitive Impairment Conversion Prediction

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    The prediction of mild cognitive impairment (MCI) conversion to Alzheimer's disease (AD) is important for early treatment to prevent or slow the progression of AD. To accurately predict the MCI conversion to stable MCI or progressive MCI, we propose Triformer, a novel transformer-based framework with three specialized transformers to incorporate multi-model data. Triformer uses I) an image transformer to extract multi-view image features from medical scans, II) a clinical transformer to embed and correlate multi-modal clinical data, and III) a modality fusion transformer that produces an accurate prediction based on fusing the outputs from the image and clinical transformers. Triformer is evaluated on the Alzheimer's Disease Neuroimaging Initiative (ANDI)1 and ADNI2 datasets and outperforms previous state-of-the-art single and multi-modal methods

    Immunomodulation Induced by Host Pathogen Interaction

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    Controlling and preventing infections require deep understanding of the complex interplay that occurs between the host and pathogen following infection. In essence, immunomodulation is any process leading to an immune response that can be altered to a desired level. In mammals, the immune system has developed an extensive array of cells and immunomodulators to recognize, identify, and eliminate foreign invaders. On the other hand, pathogens have evolved multiple mechanisms to combat the host immune system as they establish infections. In this context and under certain circumstances, an infection may result in a subverted immune system, which may lead to an exacerbated illness. Recent advances in biotechnology have enhanced our knowledge of the complex interplay that occurs between the host and invading pathogens following infection, through understanding of the microbial virulence strategies as well as the host’s approaches to combat the infection

    Experimental Study of a Beta Stirling Thermal Machine Type Functioning in Receiver and Engine Modes

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    In this paper we studied a beta type Stirling machine. At first, we present the adopted theoretical quasi-stationary model. Then, we pass to the physical and geometrical presentation of this machine. The Latter was experimented according to two configurations: motor configuration and receiver configuration. For the first configuration, in order to improve the performances of the machine, we proceeded to the insulation of the machine hot room to reduce losses by radiation. For the second configuration, the machine is experimented as a heat pump and refrigerator. Comparisons between the theoretical and experimental results are also presented. We finally validated the results obtained by the model with experiments

    Reorganization of Coherent Structures Downstream a Circular Cylinder Located between Two Parallel Walls

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    Experiments were performed at low Reynolds numbers in the range 75 Re 275 in the wake of a circular cylinder of dc diameter placed symmetrically between two parallel walls of H height. 2D2C particle image velocimetry (PIV) was used to investigate the flow downstream the cylinder. In the unsteady flow regime downstream the cylinder, the detached primary vortices (Pi) interact with walls generating secondary ones (Pi’) and modify the cylinder wake dynamic. The kinematical properties (advection velocity, circulation, rotation kinetic energy, etc.) of the generated secondary vortices are studied and compared with the primary ones in order to show how the walls influence the von Kármán vortex street. The authors propose here a relation between the circulations and kinetic energies of primary and secondary vortices

    Two photon decay of the pseudoscalars, the chiral symmetry breaking corrections

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    The extrapolation of the decay amplitudes of the pseudoscalar mesons into two photons from the soft meson limit where it is obtained from the axial-anomaly to the mass shell involves the contribution of the 0^ - continuum. These chiral symmetry breaking corrections turn out to be large. The effects of these corrections on the calculated pi ^0 decay rate, on the values of the singlet-octet mixing angle and on the ratios f_8 / f_pi and f_0 / f_pi are discussed. The implications for the transition form factors gamma gamma* --> pseudoscalars are also evaluated and confronted with the available experimental data.Comment: Computational errors straightened and study of the implications on the form factors of the transitions gamma gamma* --> pseudoscalars adde

    Prevalence of anelloviruses (TTV, TTMDV, and TTMV) in healthy blood donors and in patients infected with HBV or HCV in Qatar

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    Background Anelloviruses (TTV, TTMV, and TTMDV) have been associated with non A-G hepatitis. The goal of the current study was to estimate the prevalence of these anelloviruses in Qatar. Methods A total of 607 blood samples (500 healthy donors, and 53 HBV-and 54 HCV-positive patients) representing different nationalities were tested for the presence of TTV, TTMV, and TTMDV DNA by nested PCR. Results Prevalence rates for the three viruses were high in all studied groups, and exceeding 95% in the HBV group (for TTV and TTMDV). Infection with more than one type of viruses was common and significant in most of the positive patients (p  0.05) albeit the detection of higher infection rates among females and Qatari subjects. Conclusion This was the first published study to look at prevalence of Anellowviruses in the Middle East. High prevalence rates of the three viruses in all studied groups was noted. Further studies are needed to explore and compare the different genotypes of these viruses in the region.This work was made possible by UREP grant # (UREP 15-015-3-006) from the Qatar National Research Fund (a member of Qatar Foundation)

    Chiral condensates from tau decay: a critical reappraisal

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    The saturation of QCD chiral sum rules is reanalyzed in view of the new and complete analysis of the ALEPH experimental data on the difference between vector and axial-vector correlators (V-A). Ordinary finite energy sum rules (FESR) exhibit poor saturation up to energies below the tau-lepton mass. A remarkable improvement is achieved by introducing pinched, as well as minimizing polynomial integral kernels. Both methods are used to determine the dimension d=6 and d=8 vacuum condensates in the Operator Product Expansion, with the results: {O}_{6}=-(0.00226 \pm 0.00055) GeV^6, and O_8=-(0.0053 \pm 0.0033) GeV^8 from pinched FESR, and compatible values from the minimizing polynomial FESR. Some higher dimensional condensates are also determined, although we argue against extending the analysis beyond dimension d = 8. The value of the finite remainder of the (V-A) correlator at zero momentum is also redetermined: \Pi (0)= -4 \bar{L}_{10}=0.02579 \pm 0.00023. The stability and precision of the predictions are significantly improved compared to earlier calculations using the old ALEPH data. Finally, the role and limits of applicability of the Operator Product Expansion in this channel are clarified.Comment: Replaced versio

    QCD Sum Rule Determination of α(MZ)\alpha(M_Z) with Minimal Data Input

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    We present the results of a new evaluation of the running fine structure constant α\alpha at the scale of the ZZ mass in which the role of the e+e−e^+e^- annihilation input data needed in this evaluation is minimized. This is achieved by reducing the weight function MZ2/(s(MZ2−s))M_Z^2/(s(M_Z^2-s)) in the dispersion integral over the e+e−e^+e^- annihilation data by subtracting a polynomial function from the weight function which mimics its energy dependence in given energy intervals. In order to compensate for this subtraction the same polynomial weight integral is added again but is now evaluated on a circular contour in the complex plane using QCD and global duality. For the hadronic contribution to the shift in the fine structure constant we obtain Δαhad(5)=(277.6±4.1)⋅10−4\Delta\alpha^{(5)}_{\rm had}=(277.6\pm 4.1)\cdot 10^{-4}. Adding in the leptonic and top contributions our final result is α(MZ)−1=128.925±0.056\alpha(M_Z)^{-1}=128.925\pm 0.056.Comment: no changes, PostScript figures included in the text for convenienc
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