RISS 학술연구정보서비스

검색
다국어 입력

http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.

변환된 중국어를 복사하여 사용하시면 됩니다.

예시)
  • 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
  • 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
닫기
    인기검색어 순위 펼치기

    RISS 인기검색어

      검색결과 좁혀 보기

      선택해제
      • 좁혀본 항목 보기순서

        • 원문유무
        • 원문제공처
        • 등재정보
        • 학술지명
          펼치기
        • 주제분류
        • 발행연도
          펼치기
        • 작성언어
        • 저자
          펼치기

      오늘 본 자료

      • 오늘 본 자료가 없습니다.
      더보기
      • 무료
      • 기관 내 무료
      • 유료
      • KCI등재

        Enhancement and optimization of gamma radiation shielding by doped nano HgO into nanoscale bentonite

        Elhassan A. Allam,Rehab M. El-Sharkawy,Atef El-Taher,E.R. Shaaban,RedaElsaman,E. El Sayed Massoud,Mohamed E. Mahmoud 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.6

        In this study, nano-scaled shielding materials were assembled and fabricated by doping different weightpercentages of Nano-mercuric oxide (N-HgO) into Nano-Bentonite (N-Bent) based on using (100-x% NBent þ x% N-HgO, x ¼ 10, 20, 30, and 40 wt %). The fabricated N-HgO/N-Bent nanocomposites werecharacterized by FT-IR, XRD, and SEM and evaluated to evaluate their shielding properties toward gammaradiation by using four different g-ray energies form three point sources; 356 keV from 133Ba, 662 keVfrom 137Cs as well as 1173, and 1332 keV from 60Co. The g-rays mass attenuation coefficients were plottedas a function of the doped N-HgO concentrations into N-HgO/N-Bent nanocomposites. The computedvalues of mass attenuation coefficients (mm), effective atomic number (Zeff) and electron density (Nel) bythe as-prepared samples were found to increase, while the half value layer (HVL) and mean free path(MFP) were identified to decrease upon increasing the N-HgO contents. It was concluded also that theincrease in N-HgO concentration led to a direct increase in the mass attenuation coefficient from 0.10 to0.17 cm2/g at 356 keV and from 0.08 to 0.09 cm2/g at 662 keV. However, a slight increase was observed inthe identified mass attenuation coefficients at (1172 and 1332 keV).

      • KCI등재

        A generalized 4-unknown refined theory for bending and free vibration analysis of laminated composite and sandwich plates and shells

        Othmane Allam,Kada Draiche,Abdelmoumen Anis Bousahla,Fouad Bourada,Abdeldjebbar Tounsi,Kouider Halim Benrahou,S.R. Mahmoud,E.A. Adda Bedia,Abdelouahed Tounsi 사단법인 한국계산역학회 2020 Computers and Concrete, An International Journal Vol.26 No.2

        This research is devoted to investigate the bending and free vibration behaviour of laminated composite/sandwich plates and shells, by applying an analytical model based on a generalized and simple refined higher-order shear deformation theory (RHSDT) with four independent unknown variables. The kinematics of the proposed theoretical model is defined by an undetermined integral component and uses the hyperbolic shape function to include the effects of the transverse shear stresses through the plate/shell thickness; hence a shear correction factor is not required. The governing differential equations and associated boundary conditions are derived by employing the principle of virtual work and solved via Navier-type analytical procedure. To verify the validity and applicability of the present refined theory, some numerical results related to displacements, stresses and fundamental frequencies of simply supported laminated composite/sandwich plates and shells are presented and compared with those obtained by other shear deformation models considered in this paper. From the analysis, it can be concluded that the kinematics based on the undetermined integral component is very efficient, and its use leads to reach higher accuracy than conventional models in the study of laminated plates and shells.

      • KCI등재

        Computer Vision in Osteoporotic Vertebral Fracture Risk Prediction: A Systematic Review

        Anthony K. Allam,Adrish Anand,Alex R. Flores,Alexander E. Ropper 대한척추신경외과학회 2023 Neurospine Vol.20 No.4

        Osteoporotic vertebral fractures (OVFs) are a significant health concern linked to increased morbidity, mortality, and diminished quality of life. Traditional OVF risk assessment tools like bone mineral density (BMD) only capture a fraction of the risk profile. Artificial intelligence, specifically computer vision, has revolutionized other fields of medicine through analysis of videos, histopathology slides and radiological scans. In this review, we provide an overview of computer vision algorithms and current computer vision models used in predicting OVF risk. We highlight the clinical applications, future directions and limitations of computer vision in OVF risk prediction.

      • Cosmology from cosmic shear with Dark Energy Survey Science Verification data

        Abbott, T.,Abdalla, F. B.,Allam, S.,Amara, A.,Annis, J.,Armstrong, R.,Bacon, D.,Banerji, M.,Bauer, A. H.,Baxter, E.,Becker, M. R.,Benoit-Lé,vy, A.,Bernstein, R. A.,Bernstein, G. M.,Bertin, E.,Bl American Physical Society 2016 Physical Review D Vol.94 No.2

        <P>We present the first constraints on cosmology from the Dark Energy Survey (DES), using weak lensing measurements from the preliminary Science Verification (SV) data. We use 139 square degrees of SV data, which is less than 3% of the full DES survey area. Using cosmic shear 2-point measurements over three redshift bins we find sigma(8)(Omega(m)/0.3)(0.5) = 0.81 +/- 0.06 (68% confidence), after marginalizing over 7 systematics parameters and 3 other cosmological parameters. We examine the robustness of our results to the choice of data vector and systematics assumed, and find them to be stable. About 20% of our error bar comes from marginalizing over shear and photometric redshift calibration uncertainties. The current state-of-the-art cosmic shear measurements from CFHTLenS are mildly discrepant with the cosmological constraints from Planck CMB data; our results are consistent with both data sets. Our uncertainties are similar to 30% larger than those from CFHTLenS when we carry out a comparable analysis of the two data sets, which we attribute largely to the lower number density of our shear catalogue. We investigate constraints on dark energy and find that, with this small fraction of the full survey, the DES SV constraints make negligible impact on the Planck constraints. The moderate disagreement between the CFHTLenS and Planck values of sigma(8)(Omega(m)/0.3)(0.5) is present regardless of the value of w.</P>

      • <i>Commiphora molmol</i> Modulates Glutamate-Nitric Oxide-cGMP and Nrf2/ARE/HO-1 Pathways and Attenuates Oxidative Stress and Hematological Alterations in Hyperammonemic Rats

        Mahmoud, Ayman M.,Alqahtani, Sultan,Othman, Sarah I.,Germoush, Mousa O.,Hussein, Omnia E.,Al-Basher, Gadh,Khim, Jong Seong,Al-Qaraawi, Maha A.,Al-Harbi, Hanan M.,Fadel, Abdulmannan,Allam, Ahmed A. Hindawi 2017 Oxidative medicine and cellular longevity Vol.2017 No.-

        <P>Hyperammonemia is a serious complication of liver disease and may lead to encephalopathy and death. This study investigated the effects of <I>Commiphora molmol</I> resin on oxidative stress, inflammation, and hematological alterations in ammonium chloride- (NH<SUB>4</SUB>Cl-) induced hyperammonemic rats, with an emphasis on the glutamate-NO-cGMP and Nrf2/ARE/HO-1 signaling pathways. Rats received NH<SUB>4</SUB>Cl and <I>C. molmol</I> for 8 weeks. NH<SUB>4</SUB>Cl-induced rats showed significant increase in blood ammonia, liver function markers, and tumor necrosis factor-alpha (TNF-<I>α</I>). Concurrent supplementation of <I>C. molmol</I> significantly decreased circulating ammonia, liver function markers, and TNF-<I>α</I> in hyperammonemic rats. <I>C. molmol</I> suppressed lipid peroxidation and nitric oxide and enhanced the antioxidant defenses in the liver, kidney, and cerebrum of hyperammonemic rats. <I>C. molmol</I> significantly upregulated Nrf2 and HO-1 and decreased glutamine and nitric oxide synthase, soluble guanylate cyclase, and Na<SUP>+</SUP>/K<SUP>+</SUP>-ATPase expression in the cerebrum of NH<SUB>4</SUB>Cl-induced hyperammonemic rats. Hyperammonemia was also associated with hematological and coagulation system alterations. These alterations were reversed by <I>C. molmol</I>. Our findings demonstrated that <I>C. molmol</I> attenuates ammonia-induced liver injury, oxidative stress, inflammation, and hematological alterations. This study points to the modulatory effect of <I>C. molmol</I> on glutamate-NO-cGMP and Nrf2/ARE/HO-1 pathways in hyperammonemia. Therefore, <I>C. molmol</I> might be a promising protective agent against hyperammonemia.</P>

      • KCI등재

        Innovation of Radically New Colorant Hybrid Nanocomposite for Printing Various Textile Fabrics

        A. A. Hebeish,A. A. Shahin,A. A. Ragheb,I. Abd El-Thalouth,E. E. Allam,H. A. Shaban 한국섬유공학회 2019 Fibers and polymers Vol.20 No.1

        New benign colorant nanoparticles were innovated. The innovation is based on reacting the Indigo Blue Vat Dye with a natural clay named montmorillonite (K10) under sonication. A mixture of the dye and clay (1:1) at a ratio was used. The obtained new colorant nanoparticles in the form of hybrid nanocomposites were applied as a nano pigment in printing on various fabrics. The new colorant succeeded in printing silk, wool, cotton, polyester, and nylon as well as their different blends in the presence and absence of binder. Prints of the new colorant were compared with those obtained usingcommercial pigment. The effect of adding different amounts of binder to the printing paste on major technical properties of the prints was also investigated. Evaluation of the various printed fabrics was performed through monitoring color strength (K/S), TEM images, SEM micrographs, and overall fastness properties.

      연관 검색어 추천

      이 검색어로 많이 본 자료

      활용도 높은 자료

      해외이동버튼