Galvanic corrosion of aluminum alloy (Al2024) and copper in 1.0M hydrochloric acid solution

Ahmed Y. Musa,Abu Bakar Mohamad,Ahmed A. Al-Amiery,Lim Tien Tien 한국화학공학회 2012 Korean Journal of Chemical Engineering Vol.29 No.6

The corrosion of an aluminum alloy (Al2024) and copper in 1.0M HCl solution was investigated at 30,40, 50 and 60 oC using open circuit potential (OCP), electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) measurements. The galvanic corrosion of Al2024 and copper was studied using the zero resistance ammeter (ZRA) method. Galvanic current densities (Ig) and galvanic potential (Eg) were measured at 30 oC in 1.0M HCl solution. Thermodynamic parameters, such as activation energy (Ea), enthalpy of activation (ΔHa) and entropy of activation (ΔSa), were calculated and discussed. The results indicated that the corrosion rates of both Al2024and copper increased with temperature. The ZRA results demonstrated that Al2024 is a sacrificial anode in 1.0M HCl solution when coupled with copper.

Knowledge about Cervical Cancer Early Warning Signs and Symptoms, Risk Factors and Vaccination among Students at a Medical School in Al-Ahsa, Kingdom of Saudi Arabia

Al-Darwish, Abdulaziz Ahmed,Al-Naim, Abdullah Fouad,Al-Mulhim, Khalid Saleh,Al-Otaibi, Nasser Khaled,Morsi, Mohammed Saad,Aleem, Ansari Mukhtar Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.6

Background: Cervical cancer is the second most common cancer among females and also the most preventable. In the literature there is abundant evidence that awareness regarding cervical cancer and its prevention is low in the developing countries. Medical students are the future health professionals and can play an important role in increasing awareness among the general population. To assess the knowledge regarding symptoms, risk factors and prevention of cervical carcinoma among medical students in th Kingdom of Saudi Arabia, the present study was planned. Materials and Methods: This cross-sectional study was conducted using a self-administered questionnaire with students at the College of Medicine, King Faisal University, Al-Ahsa, KSA, from December 2012 to May 2013. Results: The responses of 188 students (males 111, females 77) in their second, third, fourth, and fifth years were recorded and used in the data analysis. The majority of the students were not aware of the early warning signs, symptoms and risk factors. On average, only 43.7% males and 56% of females were aware about the early signs and symptoms whereas 51.4% males and 57.8% females had knowledge about the risk factors of cervical cancers. Some 55% males and 46.8% females were unable to select the correct answer regarding human papilloma virus (HPV) infection as the cause of cervical cancer. Majority of the students (67%) were not aware about the availability of vaccine against HPV. Conclusions: Lack of knowledge regarding early signs and symptoms, risk factors and prevention of cervical cancer was observed in the present study.

Landslide susceptibility mapping at Al-Hasher Area, Jizan (Saudi Arabia) using GIS-based frequency ratio and index of entropy models

Ahmed M. Youssef,Mohamed Al-Kathery,Biswajeet Pradhan 한국지질과학협의회 2015 Geosciences Journal Vol.19 No.1

Mountain areas in the southern western corner ofthe Kingdom of Saudi Arabia frequently suffer from various typesof landslides due to rain storms and anthropogenic activities. Toresolve the problem related to landslides, landslide susceptibilitymap is important as a quick and safe mitigation measure and tohelp making strategic planning by identifying the most vulnerableareas. This paper summarizes findings of landslide susceptibilityanalysis at Al-Hasher area, Jizan, KSA, using two statistical models:frequency ratio and index of entropy models with the aid ofGIS tools and remote sensing data. The landslide locations (inventorymap) were identified in the study area using historical records,interpretation of high-resolution satellite images that include Geo-Eye in 2.5 m and Quickbird in 0.6m resolution, topographic mapsof 1:10,000 scale, and multiple field investigations. A total of 207landslides (80% out of 257 detected landslides) were randomlyselected for model training, and the remaining 50 landslides (19%)were used for the model validation. Ten landslide conditioning factorsincluding slope angle, slope-aspect, altitude, curvature, lithology,distance to lineaments, normalized difference vegetation index (NDVI),distance to roads, precipitation, and distance to streams, were extractedfrom spatial database. Using these conditioning factors and landslidelocations, landslide susceptibility and weights of each factorwere analyzed by using frequency ratio and index of entropy models. Our findings showed that the existing landslides of high and very highsusceptibility classes cover nearly 80.4% and 79.1% of the susceptibilitymaps produced by frequency ratio and index of entropy modelsrespectively. For verification, receiver operating characteristic (ROC)curves were drawn and the areas under the curve (AUC) were calculatedfor success and prediction rates. For success rate the resultsrevealed that for the index of entropy model (AUC = 77.9%) is slightlylower than frequency ratio model (AUC = 78.8%). For the predictionrate, it was found that the index of entropy model (AUC = 74.9%)is slightly lower than the frequency ratio model (AUC = 76.7%). The landslide susceptibility maps produced from this study couldhelp decision makers, planners, engineers, and urban areas developersto make suitable decisions.

Genetic Markers for Adolescent Idiopathic Scoliosis on Chromosome 19p13.3 among Saudi Arabian Girls

Abdallah Ahmad Al-Othman,Mir Sadat-Ali,Ahmed Sh. Amer,Dakheel A. Al-Dakheel 대한척추외과학회 2017 Asian Spine Journal Vol.11 No.2

Study Design: Prospective case-controlled study. Purpose: This study aimed to assess genetic influence in Saudi Arabian children with adolescent idiopathic scoliosis (AIS). Overview of Literature: The genetic locus linked to chromosome 19p for idiopathic scoliosis has been described. A pilot study conducted at King Fahd Hospital of the University, Al-Khobar showed that three microsatellite markers (D19S216, D19S894, and DS1034) of chromosome 19p13.3 were significant in Saudi Arabian females compared with healthy subjects. Methods: A total of 100 unrelated Saudi Arabian girls treated for AIS, their parents, healthy siblings, and healthy subjects were recruited for genetic analysis of markers on chromosome 19p13.3. After informed consent was obtained from their parents, blood samples were collected and parametric and nonparametric linkage analyses were performed using GENEHUNTER ver. 2.1. Multipoint linkage analysis was used to specify an autosomal dominant trait with a gene frequency of 0.01 and an estimated penetrance of 80% at the genotypic and allelic levels. Results: Five hundred blood samples were collected and analyzed for microsatellite markers (D19S216, D19S894, and DS1034) of chromosome 19p13.3. Comparison among patients, family members, and healthy subjects revealed no significant association between markers and scoliosis at the genotypic level: D19S216 (p =0.21), D19S894 (p =0.37), and DS1034 (p =0.25). However, at the allelic level, a statistically significant association was observed for marker DS1034 (p =0.008), and marker D19S216 showed significance between fathers and patients (p <0.001) compared with patients and mothers. The other two markers, D19S216 (p =0.25) and D19S894 (p =0.17), showed no significant association between patients and mothers. Conclusions: At the allelic level, marker DS1034 was significantly associated with AIS patients and their fathers. This allelic marker on chromosome 19p13.3 appears to be important in AIS etiology.

Analysis and deep hydrodesulfurization reactivity of Saudi Arabian gas oils

김태곤,박주일,Syed Ahmed Ali,Khalid Alhooshani,Mohammed Al-Yami,윤성호,Isao Mochida 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.5

Gas oils obtained from Arabian Light (AL-GO), Arabian Medium (AM-GO) and Arabian Heavy (AH-GO)crude oils were subjected to detailed analysis in terms of reactive and refractory sulfur, nitrogen, as well as aromatic species. Deep hydrodesulfurization (HDS) of these gas oils over SiO2–Al2O3-supported CoMo and NiMo catalysts was studied using autoclave reactor either in one- or two-stage operations. AL-GO was easily and deeply desulfurized to 15 ppm over CoMo/Al2O3–SiO2 (catalyst X) at 340 8C and 5 MPa (H2) for 2 h. At the same conditions, AM-GO and AH-GO could be desulfurized to 70 and 78 ppm,respectively. Two-staged HDS, by combining CoMo and NiMo catalysts, in successive steps resulted in effective deep HDS. The replacement of hydrogen atmosphere after the first-stage (1 h) enhanced the AH-GO HDS during the second-stage (1 h) to 9 ppm. However, replacing the hydrogen in the secondstage with 5% H2S in hydrogen inhibited the HDS, resulting in product sulfur content of 15 ppm. Analysis of sulfur species indicate that significant fraction of reactive and refractory sulfur species were removed during the first-stage whereas the remaining refractory sulfur species were removed during the second-stage. Kinetic analysis indicates overwhelming influence of refractive sulfur species on the overall HDS. The results from this study show that two-stage scheme with optimum catalysts in series can be applied to overcome the difficulty to achieve deep HDS of AH-GO.

Leisure Time Physical Activity in Saudi Arabia: Prevalence, Pattern and Determining Factors

Amin, Tarek Tawfik,Al Khoudair, Ali Salah,Al Harbi, Mohammad Abdulwahab,Al Ali, Ahmed Radi Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.1

Background: Identification of reliable predictors of leisure time physical activity (LTPA) will enable healthcare providers to intervene and change the patterns of LTPA in the population to improve community health. Objectives: The objectives of this study were to determine prevalence and pattern of LTPA among adult Saudis aged 18-65 years, and to define the socio-demographic determinants that correlate with LTPA in Al-Hassa, Saudi Arabia. Subjects and Methods: A cross-sectional study of 2176 adult Saudis attending urban and rural primary health care centers were selected using a multistage proportionate sampling method. Participants were personally interviewed to gather information regarding socio-demographics, physical activity pattern using the Global Physical Activity Questionnaire (GPAQ). Physical activity (PA) in each domain was expressed in metabolic equivalents (METs). Results: The median total METs minutes/week for LTPA for both genders was 256, higher for men (636 METs minutes/week) compared to women (249METs minutes/week). Overall, only 19.8% of the total PA was derived from LTPA. Of the sampled population 50.0% reported doing no leisure activity. Using the cut off of 600 METs-minutes/day or 150 minutes of moderate intensity over 5 or more days/week, only 21.0% of the included sample were considered as being sufficiently active and 10.4% were in the high active category with beneficial health effects. Multivariate regression analysis showed that male, younger age (<35 years), absence of chronic disease conditions and moderate level of total PA were significant predictors for being active in the LTPA domain. Conclusion: The prevalence and intensity of LTPA among the included sample demonstrated low levels. Nearly 80% of the included sample population did not achieve the recommended LTPA level with beneficial health effects. Female gender, urban residence and associated chronic diseases correlated with a low LTPA.

Synergistic of a Coumarin Derivative with Potassium Iodide on the Corrosion Inhibition of Aluminum Alloy in 1.0 M H2SO4

Abu Bakar Mohamad,Abdul Amir H. Kadhum,Ahmed A. Al-Amiery,Lim Chai Ying,Ahmed Y. Musa 대한금속·재료학회 2014 METALS AND MATERIALS International Vol.20 No.3

Synergistic effects of the addition of KI on the corrosion inhibitive performance of a coumarin derivative on analuminum alloy in 1.0 M H2SO4 at different temperatures were studied using various electrochemicalmeasurements. Density functional theory was used to calculate the quantum chemical parameters of thecoumarin derivative. The experimental results showed that the coumarin derivative is considered as a mixedtypeinhibitor. The corrosion potential values were almost unchanged upon the addition of PBBC to the acidicsolution. The inhibition efficiency increases with increasing inhibitor concentration and increases further inthe presence of 6.02 mM KI but decreases significantly at higher temperature. The adsorption of PBBC obeyedthe Langmuir isotherm, and being chemically adsorbed at lower temperatures, while physical adsorption isfavoured at higher temperature. The theoretical results indicated that the coumarin derivative was adsorbedonto the surface of Al2024 through the sulfur, oxygen and nitrogen atoms.

A Bioactive Fraction from Streptomyces sp. Enhances Maize Tolerance against Drought Stress

Warrad Mona,Hassan Yasser M.,Mohamed Mahmoud S.M,Hagagy Nashwa,Al-Maghrabi Omar A,Selim Samy,Saleh Ahmed M.,AbdElgawad Hamada 한국미생물·생명공학회 2020 Journal of microbiology and biotechnology Vol.30 No.8

Drought stress is threatening the growth and productivity of many economical crops. Therefore, it is necessary to establish innovative and efficient approaches for improving crop growth and productivity. Here we investigated the potentials of the cell-free extract of Actinobacteria (Ac) isolated from a semi-arid habitat (Al-Jouf region, Saudi Arabia) to recover the reduction in maize growth and improve the physiological stress tolerance induced by drought. Three Ac isolates were screened for production of secondary metabolites, antioxidant and antimicrobial activities. The isolate Ac3 revealed the highest levels of flavonoids, antioxidant and antimicrobial activities in addition to having abilities to produce siderophores and phytohormones. Based on seed germination experiment, the selected bioactive fraction of Ac3 cell-free extract (F2.7, containing mainly isoquercetin), increased the growth and photosynthesis rate under drought stress. Moreover, F2.7 application significantly alleviated drought stress-induced increases in H2O2, lipid peroxidation (MDA) and protein oxidation (protein carbonyls). It also increased total antioxidant power and molecular antioxidant levels (total ascorbate, glutathione and tocopherols). F2.7 improved the primary metabolism of stressed maize plants; for example, it increased in several individuals of soluble carbohydrates, organic acids, amino acids, and fatty acids. Interestingly, to reduce stress impact, F2.7 accumulated some compatible solutes including total soluble sugars, sucrose and proline. Hence, this comprehensive assessment recommends the potentials of actinobacterial cell-free extract as an alternative ecofriendly approach to improve crop growth and quality under water deficit conditions.

First reported chloroplast genome sequence of Punica granatum (cultivar Helow) from Jabal Al-Akhdar, Oman: phylogenetic comparative assortment with Lagerstroemia

Khan, Abdul Latif,Asaf, Sajjad,Lee, In-Jung,Al-Harrasi, Ahmed,Al-Rawahi, Ahmed Springer-Verlag 2018 Genetica. Vol.146 No.6

Physical Activity and Cancer Prevention: Awareness and Meeting the Recommendations among Adult Saudis

Amin, Tarek Tawfik,Al-Hammam, Abudllah Mohammed,AlMulhim, Nasser Abdullah,Al-Hayan, Mohammed Ibrahim,Al-Mulhim, Mona Mohammed,Al-Mosabeh, Modhahir Jawad,Al-Subaie, Mohammed Ali,Al-Hmmad, Qassem Ahmed Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.6

Background: There is a scarcity of information about the proportion of the adult Saudi population that meet the recommended guidelines of physical activity (PA) to reduce cancer risk. Moreover, their awareness about the role of PA in cancer prevention is unclear. Objectives: This cross-sectional study aimed at estimating the proportion of adult Saudis meeting the PA guidelines, specifically those recommended by American Cancer Society (ACS) for cancer prevention, and to assess the public awareness about the role of PA in cancer prevention. Materials and Methods: Using a multistage sampling method, 2,127 adult Saudis of both genders were recruited from 6 urban and 4 rural primary health care centers in Al Hassa, Saudi Arabia. Participants were personally interviewed to gather information about their sociodemographic characteristics, searching activity about PA and cancer, and the time spent in leisure time PA (moderate and vigorous)/week using the Global Physical Activity Questionnaire with show cards. Finally, items about the role of PA in cancer risk reduction were inquired. Results: Of the included participants, 11.6% met the recommendations for cancer prevention (${\geq}45$ minutes of moderate-vigorous PA activity/${\geq}5$ days/week or 225 minutes/week). Multivariate regression showed that being male (AOR=1.49, CI=1.09-2.06), <20 years of age (AOR=3.11, CI=2.03-4.76), and unemployed (AOR=2.22, CI=1.57-3.18) were significant predictors for meeting PA recommendations for cancer prevention. Only 11.4% of the sample indicated correctly the frequency and duration of PA required for an average adult to be physically active and while >70% of them indicated the role of PA in prevention of hypertension, coronary heart disease and lowering elevated blood cholesterol, only 18.6% and 21.7% correctly mentioned the role of PA in reducing colon and breast cancer risk, respectively. Poor knowledge was found among those with less than college education and aged ${\geq}50$ years. The level of knowledge was significantly positively correlated with total leisure time PA of the participants. Conclusions: A minority of adult Saudis in Al Hassa was aware about the role of PA in cancer prevention and engaged in sufficient LTPA for cancer risk reduction benefits, highlighting the need for public health actions to include policies and programs that address factors deterring their participation in LTPA and increasing their awareness with remedies to manage the prevalent misconceptions.