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Hot-pressed graphene nanoplatelets or/and zirconia reinforced hybrid alumina nanocomposites with improved toughness and mechanical characteristics

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Journal of materials Science & Technology 2020年第5期40卷 135-145页

作者： Iftikhar ahmad mohammad Islam Nuha al Habis Shahid Parvez Center of Excellence for Research in Engineering materials Deanship of Scientific ResearchKing Saud UniversityP.O.Box 800Riyadh 11421Saudi Arabia mechanical Engineering Department College of EngineeringKing Saud UniversityP.O.Box 800Riyadh 11421Saudi Arabia

This work explains the synergistic contribution of graphene nanoplatelets(GNP)and zirconia ceramic nanoparticles(ZrO2)on the microstructure,mechanical performance and ballistic properties of the alumina(al2O3)ceramic hybrid *** the benchmarked monolithic alumina,the hotpressed hybrid nanocomposite microstructure demonstrated 68%lower grain size due to grain pinning phenomenon by the homogenously distributed reinforcing GNP(0.5 wt%)and zirconia(4 wt%)***,the hybrid nanocomposite manifested 155%better fracture toughness(KIC)and 17%higher microhardness as well as 88%superior ballistic trait over the monolithic alumina,*** superior mechanical and ballistic performance of the hybrid nanocomposites was attributed to the combined role of zirconia nanoparticles and GNP nanomaterial in refining the microstructure and inducing idiosyncratic strengthening/toughening *** combined electron microscopy revealed complicated physical interlocking of the GNP into the microstructure as well as excellent bonding of the GNP with alumina at their interface in the hybrid *** also probed the efficiency of the pull-out and crack-bridging toughening mechanisms through proven quantitative *** on the information extracted from the in-depth SEm/TEm investigation,we outlined schematic models for understating the reinforcing ability as well as toughening mechanisms in the hybrid nanocomposites and meticulously *** hot-pressed hybrid nanocomposites owning high toughness and hardness may have applications in advanced armor technology.

关键词： Graphene alumina Zirconia Toughness Hybrid nanocomposites

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Analysis of the land suitability for paddy fields in Tanzania using a GIS-based analytical hierarchy process

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Geo-Spatial Information Science 2022年第2期25卷 212-228页

作者： ahmad al-Hanbali Kenichi Shibuta Bayan alsaaideh Yasuhiro Tawara Solution Department Geosphere Environmental Technology Corp..TokyoJapan Agriculture&Rural Development Department Nippon Koei Co.Ltd..TokyoJapan Independent Scholar ChibaJapan

The importance of irrigation development is considered a key factor for food security and poverty reduction because it improves crop productivity,and ensures stable expansion of agricultural ***,irrigation development requires understanding of the avail-able resources including the suitability of the land for *** this study,the land suitability for paddy fields was evaluated within the United Republic of Tanzania mainland by integrating the geographic information system(GIS)and analytical hierarchy process(AHP).In this study,11 criteria based on various sources(soil type,soil drainage,soil organic carbon,soil pH,soil depth,elevation,slope,land use,topographic wetness index,temperature,and precipitation)were *** criteria were used within the GIS-based AHP to identify the most suitable land for sustainable paddy field cultivation considering the preservation of the natural environment of forests and protected areas by examining two scenarios:rainfed condition and irrigation *** former ten criteria were assumed to be constant in both scenarios and were assigned the same scores,while the latter criterion(precipitation)was assigned different scores for varying amounts to plan new irrigation *** land represents 72.8%of the study area,reducing the potential agriculture land(Pal)appropriate for cultivation to 27.2%.In the rainfed condition scenario,the very high and high suitability classes represent 17.6%of the total land of the study area and 64.7%of the *** the irrigation priority scenario,the same classes represent 21.4%of the total land of the study area and 78.6%of the ***,the distribution of the land suitability for both scenarios was analyzed within eight administrative irrigation zones to determine the irrigation zone with the greatest potential for paddy field cultivation.

关键词： Paddy field agriculture land suitability Geographic Information System(GIS) Analytical Hierarchy Process(AHP) sustainable development Tanzania

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A genetic algorithm based lookup table approach for optimal stepping sequence of open-loop stepper motor systems

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控制理论与应用（英文版） 2013年第1期11卷 35-41页

作者： Suleiman BANIHANI Khalid al-WIDYAN ahmad al-JARRAH mohammad ABABNEH mechatronics Engineering Department The Hashemite University

Stepper motor driven systems are widely used in industrial applications. They are mainly used for their low cost open-loop high performance. However, as dynamic systems need to be increasingly faster and their motion more precise, it is important to have an open-loop system which is accurate and reliable. In this paper, we present a novel technique in which a genetic algorithm （GA） based lookup table approach is used to find the optimal stepping sequence of an open-loop stepper motor system. The optimal sequence objective is to minimize residual vibration and to accurately follow trajectory. A genetic algorithm is used to find the best stepping sequence which minimizes the error and improves the system performance. Numerical simulation has showed the effectiveness of our approach to improve the system performance for both position and velocity. The optimized system reduced the residual vibration and was able to follow the trajectory with minimal error.

关键词： Stepper motor Open-loop Genetic algorithm Optimal Stepping sequence Control

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Hepatitis B genotypes: Relation to clinical outcome in patients with chronic hepatitis B in Saudi Arabia

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World Journal of Gastroenterology 2006年第43期12卷 7019-7024页

作者： Ayman A Abdo Badr m.al-Jarallah Faisal m Sanai ahmad S Hersi Khalid al-Swat Nahla A Azzam manal al-Dukhayil Amira al-maarik Faleh Z al-Faleh Gastroenterology Division Faculty of Medicine King Saud University Riyadh Saudi Arabia Gastroenterology Unit Department of Medicine McGill University Montreal Canada Hepatology Division Department of Medicine Riyadh Military Hospital Riyadh Saudi Arabia

AIm： To identify the most common hepatitis B virus （HBV） genob/pe in Saudi Arabia, and correlate the prevailing genob/pes with the clinical outcome of patients. mETHODS： Patients were consecutively recruited from the hepatology clinics of two tertiary care referral centers. Patients were categorized into 4 different groups： group 1, patients with hepatitis B and normal liver enzymes; group 2, patients with hepatitis B and abnormal liver enzymes but without cirrhosis; group 3, patients with hepatitis B and liver cirrhosis; group 4, patients with hepatitis B and hepatocellular carcinoma. all patients had a positive hepatitis B surface antigen （HBsAg）. Genob/ping of HBV was performed by nested PCR-mediated amplification of the target sequence and hybridization with sequence-specific oligonucleotides. RESULTS： Seventy patients were enrolled in this study. They were predominantly male （72.9%） in their midforty＇s （mean age 47 years）. Forty-nine （70%） patients were hepatitis B envelope antigen （HBeAg） negative. The majority of patients （64%） acquired HBV through unknown risk factors. Hepatitis B genob/ping revealed that 57 patients （81.4%） were genob/pe D, 1 patient （1.4%） had genob/pe A, 1 patient （1.4%） had genotype C, and 4 patients （5.7%） had genob/pe E, while 7 patients （10%） had mixed genob/pe （4 patients ADG, 1 patient DE, 1 patient DF, and 1 patient ADFG）. Based on univariate analysis of genob/pe D patients, significant predictors of advanced liver disease were age, gender, aspartate transaminase, alanine transaminase, albumin,bilirubin, and alkaline phosphatase （all P 〈 0.001）. In multivariate analysis decreased hemoglobin （r = -0.05; 95% CI： -0.08 to -0.03; P = 0.001） and albumin levels （r = -0.004; 95% CI： -0.007 to -0.001; P = 0.002） were highly significant predictors of advanced liver disease. In patients with HBV genotype D, HBeAg negativity was found to increase across advancing stages of liver disease （P = 0.024）. CONCLUSION： This study highlights tha

关键词： Hepatitis B virus Genotype D Cirrhosis Hepatocellular carcinoma Saudi Arabia

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Red and yellow color aspects of compound 3-dicyclopropylmethylene-5-dicyanomethylene-4-diphenylmethylenetetrahydrofuran-2-one:Chromism effect

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Chinese Chemical Letters 2014年第4期25卷 609-612页

作者： Abdullah G.al-Sehemi ahmad Irfan Abdullah m.Asiri Department of Chemistry Faculty of ScienceKing Khalid University Unit of Science and Technology Faculty of ScienceKing Khalid University Center of Excellence for Advanced materials Research King Khalid University Chemistry Department Faculty of ScienceKing Abdulaziz University Center of Excellence for Advanced materials Research King Abdulaziz University

The title compound exists as yellow （1Y） and red （1R） crystals, but both gave red solutions. The intermolecular interactions between the CN parts of the crystals in IY are very weak. By the mechanical crushing as well as in solution 1Y again becomes red due to the absence of intermolecular interactions. We explain this color behavior by crystallochromism and solvation chromism.

关键词： lntermolecular interactions Crystallochromism Solvation chromism

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Validation of the Arabic version of the Ocular Surface Disease Index Questionnaire

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International Journal of Ophthalmology(English edition) 2021年第10期14卷 1595-1601页

作者： may m.Bakkar ahmad KEl-Sharif mohammad al Qadire Department of allied medical Sciences Faculty of Applied Medical SciencesJordan University of Science and TechnologyIrbid 22110Jordan Department of English Language and Literature Faculty of Arts and HumanitiesAl Al-Bayt UniversityMafraq 25113Jordan Department of Adult Health Faculty of NursingAl Al-Bayt UniversityMafraq 25113Jordan College of Nursing Sultan Qaboos UniversityMuscat 123Oman

AIm: To develop an Arabic version of the ocular surface disease index(OSDI) and to assess its reliability and ***: A cross sectional study was carried out to validate the Arabic version of the OSDI questionnaire. Initially, forward-backward translation was used to translate the English version of OSDI into Arabic. The translated questionnaire was tested for equivalence and cultural adaptability. Totally 200 subjects were then recruited from a non-clinical population and asked to complete the Arabic version of the OSDI(ARB-OSDI). The reliability of the questionnaire was assessed using Cronbach’s-α. A subgroup of 30 participants was asked to complete the questionnaire on two occasions to test the test-retest ***: A total of 200 participants were enrolled in the study. The average age of the study participants was 31.21±13.2 y and 57% were male. An acceptable internal consistency level for the ARB-OSDI questionnaire measured by Cronbach’s-α was revealed. all questions showed good internal consistency. Test-retest reliability analysis revealed good stability(interclass correlation coefficient, r=0.832, Palidity for the questionnaire was also ***: The ARB-OSDI questionnaire shows very good psychometric properties(acceptable internal consistency and test-retest reliability). That makes the questionnaire a valid potential tool to use in Arabic-speaking countries to monitor symptoms of dry eye disease in a larger population.

关键词： OSDI questionnaire dry eye disease Arabic validation psychometrics analysis Arabic version of the OSDI

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Design and Analysis of mEmS Based aluminum Nitride (alN), Lithium Niobate (LiNbO<sub>3</sub>) and Zinc Oxide (ZnO) Cantilever with Different Substrate materials for Piezoelectric Vibration Energy Harvesters Using COmSOL multiphysics Software

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Open Journal of Applied Sciences 2019年第4期9卷 181-197页

作者： ahmad m.alsaad ahmad A.ahmad Qais m.al-Bataineh Nermeen S.Daoud mais H.Khazaleh Department of Physical Sciences Jordan University of Science and TechnologyIrbidJordan Department of Physics Faculty of SciencesUniversity of Hafr Al-BatinHafr Al-BatinSaudi Arabia

Interest in energy harvesters has grown rapidly over the last decade. The cantilever shaped piezoelectric energy harvesting beam is one of the most employed designs, due to its simplicity and flexibility for further performance enhancement. The research effort in the mEmS Piezoelectric vibration energy harvester designed using three types of cantilever materials, Lithium Niobate (LiNbO3), aluminum Nitride (alN) and Zinc Oxide (ZnO) with different substrate materials: aluminum, steel and silicon using COmSOL multiphysics package were designed and analyzed. Voltage, mechanical power and electrical power versus frequency for different cantilever materials and substrates were modeled and simulated using Finite element method (FEm). The resonant frequencies of the LiNbO3/al, alN/al and ZnO/al systems were found to be 187.5 Hz, 279.5 Hz and 173.5 Hz, respectively. We found that ZnO/al system yields optimum voltage and electrical power values of 8.2 V and 2.8 mW, respectively. For ZnO cantilever on aluminum, steel and silicon substrates, we found the resonant frequencies to be 173.5 Hz, 170 Hz and 175 Hz, respectively. Interestingly, ZnO/steel yields optimal voltage and electrical power values of 9.83 V and 4.02 mW, respectively. Furthermore, all systems were studied at different differentiate frequencies. We found that voltage and electrical power have increased as the acceleration has increased.

关键词： mEmS Piezoelectric Energy Harvester Cantilever Lithium Niobate (LiNbO3) aluminum Nitride (alN) Zinc Oxide (ZnO) aluminium Substrate Steel Substrate Silicon Substrate COmSOL Finite Element method

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PtCu dendroframe octahedrons:Enhancing peroxidase-like activity and antibacterial efficiency through structural evolution

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Nano Research 2025年第1期18卷 100-106页

作者： Ri Feng Jiuyi Hu Liangjun Wang Jiayu Xu Jiajia Li Zeeshan ahmad Shaohui Zheng muhammad Farhan Farid Wenjing Liu Faisal Saleem Key Laboratory of Flexible Electronics(KLOFE) Institute of Advanced Materials(IAM)and School of Flexible Electronics(Future Technologies)Nanjing Tech UniversityNanjing 211816China

Nanozymes,which possess enzyme-like catalytic activity,are attractive alternatives to natural *** activity is largely dependent on the structure of the ***,challenges remain in optimizing the structure-activity *** work explores the synthesis and utilization of PtCu nanostructures(NSs),focusing on their peroxidase(POD)-like properties and their potential as antibacterial *** developed PtCu dendrites that transform into unique dendroframe octahedrons(DFOs)and subsequently stabilize into solid octahedrons with unusual growth *** intermediate DFO,showed higher POD-like activity in comparison to other shapes of PtCu *** DFOs also have the better ability to consume glutathione,thus enhancing their sterilization ***,we demonstrate the effectiveness of these PtCu DFOs as powerful antibacterial *** work provides valuable information on shape dependent activities of PtCu NSs in the field of biomedicine.

关键词： nanozymes antibacterials peroxidase PtCu dendroframe octahedrons dendrites

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Affective State Recognition Using Thermal-Based Imaging: A Survey

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Computer Systems Science & Engineering 2021年第4期37卷 47-62页

作者： mustafa m.m.al Qudah ahmad S.A.mohamed Syaheerah L.Lutfi School of Computer Sciences Universiti Sains MalaysiaPenang11800Malaysia

The thermal-based imaging technique has recently attracted the attention of researchers who are interested in the recognition of human affects dueto its ability to measure the facial transient temperature, which is correlated withhuman affects and robustness against illumination changes. Therefore, studieshave increasingly used the thermal imaging as a potential and supplemental solution to overcome the challenges of visual (RGB) imaging, such as the variation oflight conditions and revealing original human affect. moreover, the thermal-basedimaging has shown promising results in the detection of psychophysiological signals, such as pulse rate and respiration rate in a contactless and noninvasive *** paper presents a brief review on human affects and focuses on the advantages and challenges of the thermal imaging technique. In addition, this paper discusses the stages of thermal-based human affective state recognition, such asdataset type, preprocessing stage, region of interest (ROI), feature descriptors,and classification approaches with a brief performance analysis based on a number of works in the literature. This analysis could help beginners in the thermalimaging and affective recognition domain to explore numerous approaches usedby researchers to construct an affective state system based on thermal imaging.

关键词： Thermal-based imaging affective state recognition spontaneous emotion feature extraction and classification

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Sufficiency and Duality for Nonsmooth Interval-Valued Optimization Problems via Generalized Invex-Infine Functions

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Journal of the Operations Research Society of China 2023年第3期11卷 505-527页

作者： Izhar ahmad Krishna Kummari S.al-Homidan Department of mathematics and Statistics King Fahd University of Petroleum and MineralsDhahran31261Saudi Arabia Department of mathematics School of ScienceGITAMHyderabad CampusHyderabad502329India

In this paper,a new concept of generalized-affineness type of functions is *** class of functions is more general than some of the corresponding ones discussed in Chuong(Nonlinear Anal Theory methods Appl 75:5044–5052,2018),Sach et al.(J Global Optim 27:51–81,2003)and Nobakhtian(Comput math Appl 51:1385–1394,2006).These concepts are used to discuss the sufficient optimality conditions for the interval-valued programming problem in terms of the limiting/mordukhovich subdifferential of locally Lipschitz ***,two types of dual problems,namely mond–Weir type and mixed type duals are formulated for an interval-valued programming problem and usual duality theorems are *** results improve and generalize the results appeared in Kummari and ahmad(UPB Sci Bull Ser A 82(1):45–54,2020).

关键词： mordukhovich subdifferential Locally Lipschitz functions Generalized invex-infine function Interval-valued programming LU-optimal Constraint qualifications Duality

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