Mathematics, Statistics & Physics: Recent submissions
Now showing items 221-240 of 807
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The Reliability, Validity and Normative Scores of the Bene-Anthony Family Relations Test for Use With Arab Children
( Frontiers Media S.A. , 2021 , Article)Background: The Bene-Anthony Family Relations Test (BAFRT) is one of the most widely used measures of family dynamics seen from a child's perspective. However, the most common issue surrounding this test is the lack of ... -
Genomic and Bioinformatics Approaches for Analysis of Genes Associated With Cancer Risks Following Exposure to Tobacco Smoking
( Frontiers Media S.A. , 2018 , Article Review)Cancer is a significant health problem in the Middle East and global population. It is well established that there is a direct link between tobacco smoking and cancer, which will continue to pose a significant threat to ... -
SEIRD model for Qatar COVID-19 outbreak: A case study
( Intercollegiate Biomathematics Alliance , 2021 , Article)The COVID-19 outbreak of 2020 has required many governments to develop mathematical-statistical models of the outbreak for policy and planning purposes. This work provides a tutorial on building a compartmental model using ... -
Microstructure of heat-treated steel probed by positron annihilation
(2001 , Conference)Positron annihilation lifetime technique has been applied to study the microstructure change in steel after heat treatment. For this purpose, the specimens are heat treated in various manners; normalizing, annealing, ... -
Three-body effects in the annihilation of positrons on molecules
( APS , 2002 , Article)The three body effects in the annihilation of positrons on molecules were discussed. The positron annihilation in ethylene gas at room temperature and at densities below one amagat, showed that the mean free positron ... -
Thermalization times of positrons in molecular gases
(2000 , Article)The time that a particle takes to reach thermal equilibrium in gas is a gross measure of the efficiency with which such particle can exchange its kinetic energy with the medium. The time taken for positrons to reach thermal ... -
Radon concentration determination in some dwellings of Doha city of Qatar
( Elsevier , 1997 , Article)Yearly average radon concentrations have not been reported yet in Qatar. Only few measurements on indoor radon concentrations have been conducted during the autumn season in 1992. To complete these measurements a determination ... -
Positron annihilation lifetime study of pure and treated polyvinyl chloride
( scientific.net , 1997 , Article)Positron annihilation lifetime technique (PAL) has been applied to investigate the behavior of the free volume in pure and doped polyvinyl chloride (PVC) as a function of Pb concentration and temperature. It is noticed ... -
Positron annihilation studies of the effect of gamma irradiation dose in polymers
( Elsevier Ltd , 2003 , Conference)Positron annihilation lifetime (PAL) technique has been applied to study the effect of gamma irradiation dose on the structure of low-density polyethylene and polystyrene. The positron annihilation lifetime measurements ... -
Self-implantation of Cz-Si: Clustering and annealing of defects
( Elsevier , 2006 , Article)Observations of vacancy clusters formed in Czochralski (Cz) Si after high energy ion implantation are reported. Vacancy clusters were created by 2 MeV Si ion implantation of 1 × 10 15 ions/cm 2 and after annealing between ... -
Corrosion properties of duplex treated Ti-6Al-4V alloy in chloride media using electrochemical and positron annihilation spectroscopy techniques
( Elsevier B.V. , 2006 , Article)The corrosion properties of duplex-treated and nitrided Ti-6Al-4V have been investigated in 0.025, 0.25 and 2.5 M NaCl using electrochemical techniques, Positron Annihilation Spectroscopy (PAS), X-ray diffraction (XRD), ... -
Positron annihilation and ion beam analysis of ion-bombardment-induced hydrogen release and oxidation of ultra high molecular weight polyethylene
( Elsevier , 2007 , Article)Ultra high molecular weight polyethylene was bombarded with He+ and Ar+ ions to fluences ranging from 1013 to 2×1016 ions/cm2. Rutherford backscattering and nuclear reaction analysis were applied to study mechanism of ... -
Applied surface Science: Preface
( Elsevier , 2006 , Other)not available -
The effect of gamma irradiation and shelf aging in air on the oxidation of ultra-high molecular weight polyethylene
( Elsevier , 2006 , Article)This study has investigated the effect of shelf aging, for up to one year in air, on the properties of gamma-irradiated ultra-high molecular weight polyethylene (UHMWPE). A variety of techniques were used to characterize ... -
Positron annihilation lifetime study of helium ions implanted polyethylene blends
( Trans Tech Publications Ltd , 2004 , Conference)The structural defects of linear low density polyethylene (LLDPE) and high density polyethylene (HOPE) blends implanted with helium ions were investigated using position annihilation lifetime (PAL) technique. The positron ... -
Investigations of He <sup>+</sup> implantation and subsequent annealing effects in InP
( Elsevier , 2006 , Article)The influence of 70 keV He + ion implantation and subsequent annealing of Cz-indium phosphide (InP) samples has been investigated using a slow positron beam-based Doppler broadening spectrometer. Three samples with ion ... -
Electron irradiated low-density polyethylene studied by positron annihilation lifetime spectroscopy
( Elsevier Ltd , 2003 , Conference)A study of the degree and rate of cross-linking of low-density polyethylene (LDPE) as a result of irradiation by high-energy electron beam has been performed using positron annihilation lifetime (PAL) technique. The PAL ... -
Tests of a diamond field-assisted positron moderator
( Elsevier , 2002 , Conference)Diagnostic studies have been performed on a 70 μm thick diamond film with a view to its development as a possible field-assisted moderator (FAM) for slow positron emission. The film was coated on one side with a 200 nm ... -
Re-emission of slow positrons from tungsten at elevated temperatures
( Elsevier , 2002 , Conference)A series of measurements have been made on the dependence of the intensity and energy spectrum of slow positrons re-emitted from polycrystalline tungsten foil held at temperatures of up to 500 °C. Irrespective of target ... -
Treatment as prevention for hepatitis C virus in the Middle East and North Africa: a modeling study
( Frontiers Media SA , 2023 , Article)Background: Direct-acting antivirals opened an opportunity for eliminating hepatitis C virus (HCV) infection in the Middle East and North Africa (MENA), the region most affected by HCV infection. Impact of HCV treatment ...
