Mathematics, Statistics & Physics: Recent submissions

Now showing items 201-220 of 781

    • Radon concentration determination in some dwellings of Doha city of Qatar 

      Arafa, W.; El-Karadawi, E. ( 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 

      Al-Qaradawi, I. Y.; Abdel-Hady, E. E. ( 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 

      Al-Qaradawi, I. Y.; Britton, D. T.; Abdel-Hady, E. E.; Abdulmalik, D. A.; Al-Shobaki, M. A.; ... more authors ( 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 

      Abdulmalik, D. A.; Coleman, P. G.; Al-Qaradawi, I. Y. ( 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 

      Khaled, M. M.; Yilbas, B. S.; Al-Qaradawi, I. Y.; Coleman, P. G.; Abdulmalik, D.; ... more authors ( 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 

      Al-Qaradawi, I. Y.; Madi, N. K.; Turos, A.; Abdul-Kader, A. M. ( 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 

      Al-Qaradawi, Ilham; Coleman, Paul ( Elsevier , 2006 , Other)
      not available

    • The effect of gamma irradiation and shelf aging in air on the oxidation of ultra-high molecular weight polyethylene 

      Al-Ma'Adeed, M. A.; Al-Qaradawi, I. Y.; Madi, N.; Al-Thani, N. J. ( 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 

      Al-Qaradawi, I. Y.; Madi, N. K. ( 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 

      Al-Qaradawi, I. Y. ( 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 

      Al-Qaradawi, I. Y. ( 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 

      Al-Qaradawi, I. Y.; Sellin, P. A.; Coleman, P. G. ( 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 

      Al-Qaradawi, I. Y.; Coleman, P. G. ( 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 

      Ayoub, Houssein H.; Mahmud, Sarwat; Chemaitelly, Hiam; Abu-Raddad, Laith J. ( 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 ...

    • Formation of a cold antihydrogen beam in AEGIS for gravity measurements 

      Testera, G.; Belov, A. S.; Bonomi, G.; Boscolo, I.; Brambilla, N.; ... more authors ( AIP Publishing , 2008 , Article)
      The formation of the antihydrogen beam in the AEGIS experiment through the use of inhomogeneous electric fields is discussed and simulation results including the geometry of the apparatus and realistic hypothesis about the ...

    • Measuring the fall of antihydrogen: The AEGIS experiment at CERN 

      Doser, M.; Allkofer, Y.; Amsler, C.; Belov, A. S.; Bonomi, G.; ... more authors ( Elsevier B.V. , 2011 , Conference)
      Considerable efforts have been made and are still being made to verify the validity of the principle of the equivalence of gravitational and inertial mass, one of the cornerstones of the classical theory of general relativity. ...

    • Antihydrogen physics: Gravitation and spectroscopy in AEgIS 

      Ferragut, R.; Belov, A. S.; Bonomi, G.; Boscolo, I.; Brusa, R. S.; ... more authors ( Canadian science publishing , 2011 , Article)
      AEgIS (Antimatter experiment: gravity, interferometry, spectroscopy) is an experiment approved by CERN with the goal of studying antihydrogen physics. In AEgIS, antihydrogen will be produced by charge exchange reactions ...

    • Aqueous electrolyte system for porous silicon using electrochemical anodization 

      Manoj, K. C.; Dubey, Mukul; Bills, Braden; Al-Qaradawi, Ilham Y.; Lamsal, Buddhi Sagar; ... more authors ( IEEE Xplore , 2013 , Conference)
      Electrochemical anodization on n-type silicon was performed with silicon as anode and platinum as cathode in a weak-acid aqueous electrolyte containing orthophosphoric acid and ammonium fluoride. Anodization was carried ...

    • Creating textured surfaces using plasma electrolysis 

      Zhang, Z.; Dubey, Mukul; Galipeau, David; Fan, Qi Hua; Hoefelmeyer, James D.; ... more authors ( Materials Research Society , 2013 , Article)
      Plasma electrolysis (PE) is a combination of electrolysis and plasma discharge. Previous studies indicated that PE usually created porous surface with irregular morphology as a result of the plasma-cathode interaction that ...

    • Large sample and bootstrap intervals for the gamma scale parameter based on grouped data 

      Baklizi, Ayman; Al-Nasser, Amjad ( Wayne State University , 2006 , Article)
      Interval estimation of the scale parameter of the gamma distribution using grouped data is considered in this article. Exact intervals do not exist and approximate intervals are needed Recently, Chen and Mi (2001) proposed ...