Investigation of electrical properties (ac and dc) of organic zinc phthalocyanine, ZnPc, semiconductor thin films

A.M.Saleh,A.O.Abu-Hilal,R.D.Gould 한국물리학회 2003 Current Applied Physics Vol.3 No.4

We report measurements on the electrical properties of thermally evaporated zinc phthalocyanine, ZnPc, semiconductor thinlms. Aluminum and gold metal electrodes were used and both proved to act as ohmic contacts. A relative permittivity,er, of 1.56was estimated from the dependence of capacitance on lm thickness. The room temperature current densityvoltage measurementsindicated an ohmic conduction at low voltages, while a spacecharge-limited conduction at higher voltages. An average value of athermally generated hole concentration of the order 1013 m. 3 was estimated at room temperature.The ac conductivity, capacitance and loss tangent were measured over a wide range of temperature (from 170 to 430 K) andfrequency (between 0.1 and 20 kHz). The ac conductivity of ZnPc lms was observed to be proportional toxs, wherex is theangular frequency, and the indexs is a temperature and frequency-dependent constant. At low temperatures and for higher fre-temperature and frequency, but was constant for all frequencies at low temperatures. Such dependences were accounted for theequivalent-circuit model consisting of inherent capacitance in parallel with a temperature dependent resistive element.. 2002 Elsevier Science B.V. All rights reserved.

Temporal analysis of 16 STR loci in human blood drawn from two culicid mosquitoes cultured at different temperatures

Ahmed M.A. Ibrahim,Lamia A. ALRAKAN,Saleh Ahmed ALAIFAN 한국곤충학회 2015 Entomological Research Vol.45 No.5

Female mosquitoes feed on human blood, which can be collected to analyze human short tandem repeat (STR) sequences; these are specific to each human individual. Analysis of STRs might help in identification of a person found near a crime scene. Aedes aegypti and Culex pipiens mosquitoes fed on human blood were cultured at 18°C or 40°C (median temperature for summer and winter time in Riyadh governorate, Saudi Arabia) for 3, 6, 12, 24, 48 and 72 h. In A. aegypti, human DNA concentration was reduced with time at both temperatures. At 18°C, we obtained full STR profiles up to 48 h post feeding on human blood while none of the 16 loci were obtained at 72 h. At 40°C, we missed six sites at 12 h after blood sucking, 12 at 24 h, and 15 at 48 h and 72 h. In C. pipiens cultured at 18°C, full profiles were developed up to 48 h following blood feeding while we could not amplify five sites at 72 h. At 40°C, mortality among females was 50% at 24 h and 100% at both 48 h and 72 h; however, we had full profiles in all samples including dead insects. This research addressed the possibility of using mosquitoes in forensic research by DNA genotyping by changing the mosquito culturing temperature and mosquito genus. Our findings proved that different types of mosquito change the temporal pattern of STR analysis and showed that the mosquito culturing temperature affects the integrity of DNA for STR analysis.

Microwave-assisted synthesis of novel porous organic polymers for effective selective capture of CO2

Ahmed M. Alloush,Hamza Abdulghani,Hassan A. Amasha,Tawfik A. Saleh,Othman Charles S. Al Hamouz 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.113 No.-

Performing carbon dioxide (CO2) capture in an environmentally benign and cost-effective way is challengingowing to several factors including selectivity. Thus, the development of polymers that providehigh capacity and selectivity for the removal of CO2 gas is important. N-based porous polymers arepromising for CO2 capture due to their abundant porosity, variable surface characteristics, and great stability. Herein, porous organic polymers were synthesized by microwave-assisted Freidel-Crafts alkylationof 2,20-bipyridine and pyrrole with dimethoxymethane as a cross-linker. The synthesized polymers werecharacterized by Fourier transform infrared, nuclear magnetic resonance, thermogravimetric analyzers,and surface analyzers based on Brunauer–Emmett–Teller theory (BET). The porous polymers exhibitedhigh surface areas of 580 – 930 m2/g. The polymers showed high ideal adsorbed solution theory (IAST)selectivity of 53 – 63 toward CO2 over N2 at 1 bar and 298 K under flue gas composition. Whereas theselectivity toward CO2 over CH4 at 1 bar and 298 K under natural gas composition was 12 – 18. The synthesizedpolymers achieved exceptional H2O adsorption capacity at P/P0 = 0.9 and 293 K of 35 – 45 mmol/g. The results reveal the polymers provide promising candidates for the CO2 capture from various mixtures,such as flue gas and natural gas.

Allelic variation of melanocortin-1 receptor locus in Saudi indigenous sheep exhibiting different color coats

Mahmoud, Ahmed H.,Mashaly, Ashraf M.,Rady, Ahmed M.,Al-Anazi, Khalid M.,Saleh, Amgad A. Asian Australasian Association of Animal Productio 2017 Animal Bioscience Vol.30 No.2

Objective: This study was designed to characterize the DNA polymorphisms of the melanocortin-1 receptor (MC1R) gene in indigenous Saudi Arabian sheep breeds exhibiting different color coats, along with individuals of the Sawaknee breed, an exotic sheep imported from Sudan. Methods: The complete coding region of MC1R gene including parts of 3' and 5' untranslated regions was amplified and sequenced from three the indigenous Saudi sheep; Najdi (generally black, n = 41), Naeimi (generally white with brown faces, n = 36) and Herri (generally white, n = 18), in addition to 13 Sawaknee sheep. Results: Five single nucleotide polymorphisms (SNPs) were detected in the MC1R gene: two led to nonsynonymous mutations (c.218 T>A, p.73 Met>Lys and c.361 G>A, p.121 Asp>Asn) and three led to synonymous mutations (c.429 C>T, p.143 Tyr>Tyr; c.600 T>G, p.200 Leu>Leu, and c.735 C>T, p.245 Ile>Ile). Based on these five SNPs, eight haplotypes representing MC1R $E^d$ and $E^+$ alleles were identified among the studied sheep breeds. The most common haplotype (H3) of the dominant $E^d$ allele was associated with either black or brown coat color in Najdi and Sawaknee sheep, respectively. Two other haplotypes (H6 and H7) of $E^d$ allele, with only the nonsynonymous mutation A218T, were detected for the first time in Saudi indigenous sheep. Conclusion: In addition to investigating the MC1R allelic variation in Saudi indigenous sheep populations, the present study supports the assumption that the two independent nonsynonymous Met73Lys and Asp121Asn mutations in MC1R gene are associated with black or red coat colors in sheep breeds.

Insights into the Incidence of Watermelon chlorotic stunt virus Causing Yellowing Disease of Watermelon in Western and Southwestern Regions of Saudi Arabia

M. H. Ahmad,M. T. Shakeel,I. M. Al-Shahwan,M. A. Al-Saleh,M. A. Amer 한국식물병리학회 2018 Plant Pathology Journal Vol.34 No.5

During the spring season of 2014, a total of 148 melon and watermelon leaf samples were collected from symptomatic and asymptomatic plants in the western and southwestern regions of Saudi Arabia and were tested for the presence of Watermelon chlorotic stunt virus (WmCSV) and other suspected cucurbit viruses by double antibody sandwich enzyme-linked immunosorbent assays. Ninety-eight samples were found to be positive for the presence of WmCSV, nine samples were positive for the presence of Cucurbit yellow stunting disorder virus (CYSDV), and 22 showed a mixed infection with both WmCSV and CYSDV. No other cucurbit viruses were detected in any of the samples. Host range experiments revealed that eight out of fourteen tested plant species were susceptible to WmCSV. PCR products of approximately 1.2 kb were obtained after amplification using primers specifically targeting the coat protein region of WmCSV. Positive PCR results were confirmed by dot blot hybridization. Coat protein gene sequences from eleven WmCSV isolates indicated that the highest identity was between the 104WMA-SA isolate from the Wadi Baish location and a previously reported isolate from the AL-Lith location in Saudi Arabia. The lowest identity was observed between the 42WMA-SA isolate and an isolate from Palestine.

RRSEB: A Reliable Routing Scheme For Energy-Balancing Using A Self-Adaptive Method In Wireless Sensor Networks

( Ahmed M. Shamsan Saleh ),( Borhanuddin Mohd. Ali ),( Hafizal Mohamad ),( Mohd Fadlee A. Rasid ),( Alyani Ismail ) 한국인터넷정보학회 2013 KSII Transactions on Internet and Information Syst Vol.7 No.7

Over recent years, enormous amounts of research in wireless sensor networks (WSNs) have been conducted, due to its multifarious applications such as in environmental monitoring, object tracking, disaster management, manufacturing, monitoring and control. In some of WSN applications dependent the energy-efficient and link reliability are demanded. Hence, this paper presents a routing protocol that considers these two criteria. We propose a new mechanism called Reliable Routing Scheme for Energy-Balanced (RRSEB) to reduce the packets dropped during the data communications. It is based on Swarm Intelligence (SI) using the Ant Colony Optimization (ACO) method. The RRSEB is a self-adaptive method to ensure the high routing reliability in WSNs, if the failures occur due to the movement of the sensor nodes or sensor node`s energy depletion. This is done by introducing a new method to create alternative paths together with the data routing obtained during the path discovery stage. The goal of this operation is to update and offer new routing information in order to construct the multiple paths resulting in an increased reliability of the sensor network. From the simulation, we have seen that the proposed method shows better results in terms of packet delivery ratio and energy efficiency.

Insights into the Incidence of Watermelon chlorotic stunt virus Causing Yellowing Disease of Watermelon in Western and Southwestern Regions of Saudi Arabia

Ahmad, M.H.,Shakeel, M.T.,Al-Shahwan, I.M.,Al-Saleh, M.A.,Amer, M.A. The Korean Society of Plant Pathology 2018 Plant Pathology Journal Vol.34 No.5

During the spring season of 2014, a total of 148 melon and watermelon leaf samples were collected from symptomatic and asymptomatic plants in the western and southwestern regions of Saudi Arabia and were tested for the presence of Watermelon chlorotic stunt virus (WmCSV) and other suspected cucurbit viruses by double antibody sandwich enzyme-linked immunosorbent assays. Ninety-eight samples were found to be positive for the presence of WmCSV, nine samples were positive for the presence of Cucurbit yellow stunting disorder virus (CYSDV), and 22 showed a mixed infection with both WmCSV and CYSDV. No other cucurbit viruses were detected in any of the samples. Host range experiments revealed that eight out of fourteen tested plant species were susceptible to WmCSV. PCR products of approximately 1.2 kb were obtained after amplification using primers specifically targeting the coat protein region of WmCSV. Positive PCR results were confirmed by dot blot hybridization. Coat protein gene sequences from eleven WmCSV isolates indicated that the highest identity was between the 104WMA-SA isolate from the Wadi Baish location and a previously reported isolate from the AL-Lith location in Saudi Arabia. The lowest identity was observed between the 42WMA-SA isolate and an isolate from Palestine.

Synthesis, Pharmacological Activity Evaluation and Molecular Modeling of New Polynuclear Heterocyclic Compounds Containing Benzimidazole Derivatives

Fatma A. Bassyouni,Tamer S. Saleh,Mahmoud M. ElHefnawi,Sherein I. Abd El-Moez,Waled M. El-Senousy,Mohamed E. Abdel-Rehim 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.12

Novel heterocyclic compounds containing benzimidazole derivatives were synthesized from 2-(1Hbenzimidazol-2-yl) acetonitrile (1) and arylhydrazononitrile derivative 2 was obtained via coupling of 1 with 4-methyl phenyldiazonium salt, which was then reacted with hydroxylamine hydrochloride to give amidooxime derivative 3. This product was cyclized into the corresponding oxadiazole derivative 4 upon reflux in acetic anhydride. Compound 4 was refluxed in DMF in the presence of triethylamine to give the corresponding 5-(1H-benzimidazol-2-yl)-2-p-tolyl-2H-1,2,3-triazol-4-amine 6. Treatment of compound 6 with ethyl chloroformate afforded 2,6-dihydro-2-(4-methylphenyl)-1,2,3-triazolo[4'',5''-4',5']pyrimido[1,6-a]benzimidazole-5(4H)-one (8). 1,2-bis(2-cyanomethyl-1H-benzimidazol-1-yl)ethane-1,2-dione (10) was synthesized via the condensation reaction of 2-(1H-benzimidazol-2-yl) acetonitrile (1) and diethyloxalate. The reactivity of compound 10 towards some diamine reagents was studied. The in vitro antimicrobial activity of the synthesized compounds was investigated against several pathogenic bacterial strains such as Escherichia coli O157, Salmonella typhimurium, E. coli O119, S. paratyphi, Pseudomonas aeruginosa, Staphylococcus aureus, Listeria monocytogenes and Bacillus cereus. The results of MIC revealed that compounds 12a-c showed the most effective antimicrobial activity against tested strains. On the other hand, compounds 12a, b exhibited high activity against rotavirus Wa strain while compounds 12b, c exhibited high activity against adenovirus type 7. In silico target prediction, docking and validation of the compounds 12a-c were performed. The dialkylglycine decarboxylase bacterial enzyme was predicted as a potential bacterial target receptor using pharmacophorebased correspondence with previous leads; giving the highest normalized scores and a high correlation docking score with mean inhibition concentrations. A novel binding mechanism was predicted after docking using the MOE software and its validation.

Investigation of photon, neutron and proton shielding features of H₃BO₃-ZnO-Na₂O-BaO glass system

Mhareb, M.H.A.,Alajerami, Y.S.M.,Dwaikat, Nidal,Al-Buriahi, M.S.,Alqahtani, Muna,Alshahri, Fatimh,Saleh, Noha,Alonizan, N.,Saleh, M.A.,Sayyed, M.I. Korean Nuclear Society 2021 Nuclear Engineering and Technology Vol.53 No.3

The current study aims to explore the shielding properties of multi-component borate-based glass series. Seven glass-samples with composition of (80-y)H₃BO₃-10ZnO-10Na₂O-yBaO where (y = 0, 5, 10, 15, 20, 25 and 30 mol.%) were synthesized by melt-quench method. Various shielding features for photons, neutrons, and protons were determined for all prepared samples. XCOM, Phy-X program, and SRIM code were performed to determine and explain several shielding properties such as equivalent atomic number, exposure build-up factor, specific gamma-ray constants, effective removal cross-section (Σ_R), neutron scattering and absorption, Mass Stopping Power (MSP) and projected range. The energy ranges for photons and protons were 0.015-15 MeV and 0.01-10 MeV, respectively. The mass attenuation coefficient (μ/ρ) was also determined experimentally by utilizing two radioactive sources (¹⁶⁶Ho and ¹³⁷Cs). Consistent results were obtained between experimental and XCOM values in determining μ/ρ of the new glasses. The addition of BaO to the glass matrix led to enhance the μ/ρ and specific gamma-ray constants of glasses. Whereas the remarkable reductions in Σ_R, MSP, and projected range values were reported with increasing BaO concentrations. The acquired results nominate the use of these glasses in different radiation shielding purposes.

The Difference of Invariance, Reliability of The Student Engagement Scale (ESE) In Distance-Learning During Covid-19 Pandemic in Light of Some Students' Characteristics

Almaleki, Deyab A.,Alzahrani, Abdulrahman J.,Alkhairi, Mohammed A.,Albalawi, Farhan A.,Albogami, Hosin A.,Alhajory, Easa S.,Readi, Wadea A.,Idrees, Mohammed A.,Alshamrani, Saleh M.,Alwusaidi, Osama A. International Journal of Computer ScienceNetwork S 2022 International journal of computer science and netw Vol.22 No.8

This study aimed to test the factor structure of the measure of student participation in distance education. The study population consisted of all teachers in public education and faculty members in higher education in the Kingdom of Saudi Arabia by applying it to a sample of bachelor's and graduate students at the college of Education at umm al-Qura University. The (ESE) was applied to a random sample representing the study population consisting of (216) respondents. The results of the study showed that the scale consists of three main factors, with showed a high degree of construct validity through fit indices of the confirmatory factor analysis. The results have shown a gradual consistency of the measure's invariance that reaches the high level of the Measurement Invariance across the gender and study groups variables.