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      • KCI등재

        First Measurements of Carbonaceous Aerosol across Urban, Rural and Residential Areas in Jeddah City, Saudi Arabia

        Iqbal M. Ismail,Ahmad S. Summan,Jalal M. Basahi,Essam Hammam,Mohamed F. Yassin,Ibrahim A. Hassan 한국대기환경학회 2021 Asian Journal of Atmospheric Environment (AJAE) Vol.15 No.2

        Concentrations of black carbon (BC), organic carbon (OC), and total suspended particulate matter (TSP) were simultaneously assessed in urban, rural and residential areas in Jeddah city for one year from January to December 2017. It was aimed in the present study to provide information about the spatial and seasonal variability of these aerosol species in Jeddah, and insight into sources, processes and effects of meteorological conditions. To the best of our knowledge, this is the first study investigating the variability of carbonaceous aerosols (OC and BC) in Saudi Arabia. The average concentrations of OC, BC, and TSP varied spatially and temporally. The annual average concentrations of OC, BC, and TSP were 134.05, 7.16, and 569.41 μg m-3 and 34.32, 5.14, and 240.64 μg m-3 and 10.67, 4.39 and 101.31 μg m-3 in the urban, residential and rural areas, respectively. Moreover, there was a clear seasonal variation in the concentration of carbonaceous aerosols; the highest concentrations were recorded in February and September, while the lowest concentrations of OC were recorded during April, May and August in the urban, residential and rural sites, respectively. Nevertheless, the lowest concentrations of BC were recorded during March in the urban and residential sites and during November in the rural site. The relative concentrations of OC and BC to the TSP were relatively high, and they have a significant correlation with prevalent wind speed (-0.636, and -0.581 in the urban area), (-0.539 and -0.511 in the residential area), and (-0.508 and -0.501 in the rural area), respectively. The marked differences in the concentrations of BC and OC were reflected on OC/BC ratio, which is a good representative of different source types. This preliminary study showed that the potential local sources were emissions from traffic (fossil fuel), biomass burning, anthropogenic activities (e.g. car drifting and outdoor cooking), and industrial activities. The present study suggest the presence of highly inefficient combustion sources and highlight the need for the regulation of such emissions.

      • KCI등재후보

        Phytochemical and Pharmacological Investigations on Moringa peregrina (Forssk) Fiori

        Seham A. Elbatran,Omar M. Abdel-Salam,Khaled A. Abdelshfeek,Naglaa M. Nazif,Shams I. Ismail,Faiza M. Hammouda 한국생약학회 2005 Natural Product Sciences Vol.11 No.4

        Investigation of M. peregrina aerial parts revealed the isolation and identification of 4-flavonoidalcompounds, quercetin, quercetin-3-0-rutinoside (rutin), chrysoeriol-7-0-rhamnoside and 6,8,3/,5/-tetramethoxyapigenin. The compounds were identified by TLC, PC, MS, and H1-NMR. The fatty acids and unsaponifiablematter were studied. The LD50 for M. peregrina was 113.4 mg/100 g b.wt. Repeated intraperitoneal injection of 1/20 and 1/10 LD50 (5.67 mg and 11.34 mg/100 g b.wt.) of defatted alcoholic extract of M. peregrina for 30 daysinduced significant decrease in serum glucose, liver enzymes and lipid components. M. peregrina administeredi.p., 30 min prior to carrageenan at the above doses significantly inhibited the rat paw oedema response. In acuteM. peregrina exhibited markedanalgesic properties. In addition, M. peregrina administered at time of indomethacin injection inhibited thedevelopment of gastric lesions in rats.

      • The Role of Genetic Polymorphisms in Nrf2 and P73 in Egyptian Women with Breast Cancer

        Azhary, Nevin M Al,Kamel, Mahmoud M,Ismail, Yahia M,Mahmoud, Amal A,Radwan, Enas M Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.11

        Background: Breast cancer is the commonest cancer in Egyptian females. Nrf2 is involved in oxidative stress while P73 functions in response to DNA damage. This study aimed to assess the role of Nrf2 promoter and P73 G4C14 to A4T14 SNPs in breast cancer in Egypt. Patients: Eighty-five female patients with breast tumours (41 malignant, 44 benign) were included. Nrf2 (rs6721961) and p73 (G4A) SNPs were determined by PCR- CTPP assay. Results: Genotype frequencies of the Nrf2 promoter SNP were 34.2% and 37.9% for AA in benign and malignant groups respectively, and 43.9% and 40.5% for CC and, 21.9 % and 21.6% for CA. Genotype frequencies for the P73 G4A SNP were 52.9% and 44.7% for GA in benign and malignant groups respectively, and 47.1% and 55.3% for GG. Discussion: Nrf2 genotypes in pre - and post-menopausal patients, showed significantly different distributions in the 2 patient groups, the AA genotype being significantly more common in pre-menopausal patients. The P73 G4A SNP showed no relation to age of disease onset. Conclusion: The Nrf2 (rs6721961) AA genotype might be related to early breast cancer onset. In contrast the P73 G4A polymorphism showed no relation to either disease risk or age at presentation.

      • KCI등재

        NEW CCD OBSERVATIONS AND THE FIRST PHOTOMETRIC STUDY OF THE CONTACT BINARY AP UMI

        N. S. AWADALLA,M. A. HANNA,M. N. Ismail,I. A. Hassan,M. A. Elkhamisy 한국천문학회 2016 Journal of The Korean Astronomical Society Vol.49 No.3

        We obtain the first complete CCD light curves (LCs) of the contact binary AP UMi in the VRI bands and analyzed them by means of the PHOEBE code. A spotted model is applied to treat the asymmetry in the LCs. The LC morphology clearly shows the O'Connell effect and the solution shows an influence of star spots on both components. Such effect of star spots is common between the RS CVn and W UMa chromospherically active stars. Based on the obtained solution of the LCs we investigate the evolutionary state of the components and conclude that the system is a pre-intermediate contact binary ($f=0.29$) with mass ratio $q=0.38$, and it is an A-type W UMa system where the less massive secondary component is cooler than the more massive primary one.} We obtain the first complete CCD light curves (LCs) of the contact binary AP UMi in the VRI bands and analyzed them by means of the PHOEBE code. A spotted model is applied to treat the asymmetry in the LCs. The LC morphology clearly shows the O'Connell effect and the solution shows an influence of star spots on both components. Such effect of star spots is common between the RS CVn and W UMa chromospherically active stars. Based on the obtained solution of the LCs we investigate the evolutionary state of the components and conclude that the system is a pre-intermediate contact binary ($f=0.29$) with mass ratio $q=0.38$, and it is an A-type W UMa system where the less massive secondary component is cooler than the more massive primary one.

      • KCI등재

        Comparative study on photocatalytic performances of crystalline a- and b-Bi2O3 nanoparticles under visible light

        Mohammed Jalalah,Adel A. Ismail,M. Faisal,Houcine Bouzid,Jea-Gun Park,S.A. Al-Sayari 한국공업화학회 2015 Journal of Industrial and Engineering Chemistry Vol.30 No.-

        a- and b-Bi2O3 nanoparticles were synthesized in the presence of either urea or polyethylene glycol. TheXRD, TEM, and Raman analysis indicated that a-(monoclinic) Bi2O3 nanoparticles were obtained usingeither sol–gel or hydrothermal method in the presence of urea; however b-(tetragonal) phase of Bi2O3was formed using hydrothermal method in the presence of polyethylene glycol. The b-Bi2O3nanoparticles exhibited higher photocatalytic activity than a-Bi2O3. MB was completely photodegradedafter 6 h of visible light illumination using b-Bi2O3 photocatalyst whereas only 30% was photodegradedusing a-Bi2O3. The photodegradation rate of b-Bi2O3 was 5.7 times greater than that a-Bi2O3nanoparticles.

      • KCI등재

        Strengthening of bolted shear joints in industrialized ferrocement construction

        M. Ismail,M. Shariati,A.S.M. Abdul Awal,C.E. Chiong,E. Sadeghipour Chahnasir,A. Porbar,A. Heydari,M. Khorami 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.28 No.6

        This paper highlights results of some experimental work that deals with strengthening of bolted shear joints in thin-walled ferrocement structure where steel wires, bent into U-shape are considered as simple inserts around the bolt hole. The parameters investigated include the number of layers of wire mesh, edge distance of bolt hole, size and location of the inserts. Test results have shown that for small edge distance, failure occurred either in cleavage or shearing mode, and the strength of the joint increased with an increase in the edge distance. This continued up to an upper limit set by either tension or bearing failure. The experimental study further revealed that for a given edge distance the strength of a joint can significantly be enhanced by using U-inserts. The equations developed for predicting joint strength in ferrocement composites can also be modified to include the effects of the inserts with a good level of accuracy.

      • KCI등재

        New issue of GaN nanoparticles solar cell

        M.A. Qaeed,K. Ibrahim,K.M.A. Saron,M.S. Mukhlif,A. Ismail,Nezar G. Elfadill,Khaled M. Chahrour,Q.N. Abdullah,K.S.A. Aldroobi 한국물리학회 2015 Current Applied Physics Vol.15 No.4

        This study involves the synthesis of gallium nitride (GaN) nanoparticles (NPs) under different low temperatures using a simple chemical method. The nanoparticles are spin coated on Si substrate to fabricate the solar cell. The FESEM images obtained indicate the presence of cubic GaN nanoparticle with average diameter of 50 nm synthesized at 90 ℃. The spin coating technique deposited n-GaN NPs/Si(111) produced a heterojunction solar cell with fill factor of 0.56 and conversion efficiency of 2.06%. Based on these results, this study proposes a novel low cost technique for the fabrication of GaN NPs solar cells.

      • SCOPUSKCI등재

        Optimization of Several Environmental Factors to Human Performance by Using Taguchi Method

        Ismail, A.R.,Haniff, M.H.M.,Yusof, M.Y.M.,Rahman, M.N.A.,Ghani, J.A. Korean Institute of Industrial Engineers 2010 Industrial Engineeering & Management Systems Vol.9 No.2

        The objective of this study is to determine the dominance effects of environmental factors such as Illuminance, humidity and Wet Bulb Globe Temperature (WBGT) on the operators' productivity at Malaysian electronic industry. A case study was carried out at an electronic components assembly factory. The environmental factors examined were the Illuminance (lux), humidity and WBGT of the surrounding workstation area. Two sets of representative data including the illuminance, humidity and WBGT level and production rate were collected during the study. The production rate data were collected through observations and survey questionnaires while the illuminance level was measured using photometer model RS 180-7133, the humidity and WBGT level were measured by using Quest Temp apparatus and humidity. Taguchi Method was utilized to find the sequence of dominant factors that contributed to the productivity of operator at that specified production workstation. The study reveals that the dominant factor contributed to the productivity was WBGT, followed by illuminance and humidity.

      • KCI등재

        Optimization of Several Environmental Factors to Human Performance by Using Taguchi Method

        A. R. Ismail,M. H. M. Haniff,M. Y. M. Yusof,M. N. A. Rahman,J. A. Ghani 대한산업공학회 2010 Industrial Engineeering & Management Systems Vol.9 No.2

        The objective of this study is to determine the dominance effects of environmental factors such as Illuminance, humidity and Wet Bulb Globe Temperature (WBGT) on the operators" productivity at Malaysian electronic industry. A case study was carried out at an electronic components assembly factory. The environmental factors examined were the Illuminance (lux), humidity and WBGT of the surrounding workstation area. Two sets of representative data including the illuminance, humidity and WBGT level and production rate were collected during the study. The production rate data were collected through observations and survey questionnaires while the illuminance level was measured using photometer model RS 180-7133, the humidity and WBGT level were measured by using Quest Temp apparatus and humidity. Taguchi Method was utilized to find the sequence of dominant factors that contributed to the productivity of operator at that specified production workstation. The study reveals that the dominant factor contributed to the productivity was WBGT, followed by illuminance and humidity.

      • Impact of viscoelastic foundation on bending behavior of FG plate subjected to hygro-thermo-mechanical loads

        Ismail M. Mudhaffar,Abdelbaki Chikh,Abdelouahed Tounsi,Mohammed A. Al-Osta,Mesfer M. Al-Zahrani,Salah U. Al-Dulaijan 국제구조공학회 2023 Structural Engineering and Mechanics, An Int'l Jou Vol.86 No.2

        This work applies a four-known quasi-3D shear deformation theory to investigate the bending behavior of a functionally graded plate resting on a viscoelastic foundation and subjected to hygro-thermo-mechanical loading. The theory utilizes a hyperbolic shape function to predict the transverse shear stress, and the transverse stretching effect of the plate is considered. The principle of virtual displacement is applied to obtain the governing differential equations, and the Navier method, which comprises an exponential term, is used to obtain the solution. Novel to the current study, the impact of the viscoelastic foundation model, which includes a time-dependent viscosity parameter in addition to Winkler’s and Pasternak parameters, is carefully investigated. Numerical examples are presented to validate the theory. A parametric study is conducted to study the effect of the damping coefficient, the linear and nonlinear loadings, the power-law index, and the plate width-tothickness ratio on the plate bending response. The results show that the presence of the viscoelastic foundation causes an 18% decrease in the plate deflection and about a 10% increase in transverse shear stresses under both linear and nonlinear loading conditions. Additionally, nonlinear loading causes a one-and-a-half times increase in horizontal stresses and a nearly two-times increase in normal transverse stresses compared to linear loading. Based on the article’s findings, it can be concluded that the viscosity effect plays a significant role in the bending response of plates in hygrothermal environments. Hence it shall be considered in the design.

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