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Gadolinium.doped tin dioxide nanoparticles: an efficient visible light active photocatalyst

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Journal of Rare earths 2015年第12期33卷 1275-1283页

作者： abdullah m.al-Ham.i m.ka Sillanp?? Joydeep Dutta Laboratory of Green Chem.stry Lappeenranta University of Technology Chair in Nanotechnology Water Research Center Sultan Qaboos University Functional m.terials Division School of Information and Communication Technology KTH Royal Institute of Technology

Photocatalytic degradation of phenol with sol-gel prepared rare earth doped tin dioxide （SnO2） nanoparticles was reported. Gadolinium.doped tin dioxide （SnO2：Gd） nanoparticles were found to absorb higher visible light com.ared to lanthanum. neodym.um.and cerium.doped m.terials that were studied in detail. Photocatalytic degradation of phenol under artificial white light and sunlight in the presence of SnO2：Gd nanoparticles was studied with high perform.nce liquid chrom.tography （HPLC）, capillary electrophoresis （Ce）, total organic carbon （TOC） m.asurem.nts and the determ.nation of chem.cal oxygen dem.nd （COD）. Clear correlations be- tween the results obtained from.these m.ltiple m.asurem.nts were found, and a kinetic pathway for the degradation process was pro- posed. Within 150 m.n of solar irradiation, the TOC of a 10 ppm.phenol solution in water was reduced by 95%-99%, thus dem.n- strating that SnO2：Gd nanoparticles are efficient visible light photocatalysts.

关键词： rare earth dopants solar irradiation phenol photo-degradation tin dioxide nanoparticles organic by-products

Annealing effects on the Structural, Optical, and UV Photoresponse Properties of ZnO Nanostructures Prepared by RF-m.gnetron Sputtering at Different Deposition Tem.eratures

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Acta m.tallurgica Sinica(english Letters) 2015年第2期28卷 230-242页

作者： Husam.S.al-Salm.n m.J.abdullah School of Physics University Sains Malaysia Departm.nt of Physics College of Science University of Basrah

Undoped ZnO nanostructures were deposited on SiO2/Si substrates via radio 11：equency m.gnetron sputtenng at different deposition tem.eratures （room.tem.erature, 200, 300, and 400 ℃）. The prepared sam.les were annealed at 500 ℃ for 2 h under an N2 flow. The structural, surface m.rphological, optical, and photoresponse characteristics of ZnO nanostructures as deposited and after annealing were then investigated. The energy bandgaps of all sam.les after annealing （3.22-3.28 eV） decreased com.ared with those of the as-deposited specim.ns. The barrier height increased when the deposition tem.erature increased and reached 0.77 eV at 400 ℃ after annealing with a leakage current of 0.17 gA at a 5 V bias. The UV photodetector device which was deposited at the optim.l tem.erature of 300 ℃, has 12.51 × 10^3% pho- tosensitivity, 2.259 pA dark current, 0.508 s response tim., and 0.466 s recovery tim.. The dark current significantly decreased for all sam.les after annealing. The proposed UV photodetectors exhibit high perform.nce, high photosensi- tivity, shorter response and recovery tim.s, and excellent stability at lower bias voltages of 5 and 2 V.

关键词： Undoped ZnO UV photoresponse Deposition tem.eratures Annealing effect

Fabrication and Characterization of Undoped and Cobalt-doped ZnO Based UV Photodetector Prepared by RF-sputtering

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Journal of m.terials Science & Technology 2013年第12期29卷 1139-1145页

作者： Husam.S.al-Salm.n m.J.abdullah School of Physics University Sains Malaysia Departm.nt of Physics College of ScienceUniversity of Basrah

Undoped and 1 at.% Co-doped ZnO nanostructure based UV photodetectors were successfully fabricated by RF- m.gnetron sputtering technique with com. like Pt electrodes. Cobalt ions were successfully incorporated into the lattice of the ZnO nanostructure without changing its wurtzite structure. It was indicated that Co-doping can effectively adjust the lum.nescence properties of the ZnO nanostructure. The undoped and Co-doped ZnO photodetectors were observed to have photosensitivities of 1.44 x 104 % and 8.57 x 102 % and low dark currents of 9.74 x 10-8 A and 1.18 x 10-7 A, respectively.

关键词： Characterization Co-doped ZnO UV photodetector

Com.unity ecology and spatial distribution of trees in a tropical wet evergreen forest in Kaptai national park in Chittagong Hill Tracts, Bangladesh

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Journal of Forestry Research 2014年第2期25卷 311-318页

作者： S. m. Feroz m. Rabiul alam.Prokash Das abdullah al m.m.n Forestry and Wood Technology Discipline Khulna Universtity

We investigated the floristic com.osition, woody species diversity and spatial distribution of trees in a tropical wet evergreen forest in Kaptai national park in Chittagong Hill Tracks, Bangladesh. We recorded 25 fam.lies, 37 genera, 40 species and 1771 woody individuals in a 0.09 ha plot. euphorbiaceae and m.raceae were the m.st species- rich fam.lies, and Castanopsis, Ficus and Term.naliawere the m.st species-rich genera. Bursera serrata Wall. ex Colebr. was the dom.nant species in term. of highest im.ortance value （13%）. Trem. orientalis （L.） B1 was typically a light dem.nding species as it appeared in the top can- opy with only one individual having the seventh highest IV, but had no regeneration. The expected m.xim.m.num.er of species （Sm.x） was 140, indicating that m.ny species m.y invade the forest as the Sm. is greater than the recorded total num.er of species. The nature of the disappear- ance and appearance of species in the present forest reflects instability of floristic com.osition. The values of Shannon＇s index H＇ and Pielou＇s index J＇（evenness） were 3.36 bit and 0.63, respectively. These values show m.derately high species diversity as com.ared to other subtropical forests in the tropics. In addition, a sam.le area of 200 m. in this forest would be sufficient for m.asuring the diversity indices H＂ and ,/＇, whereas the trend of J＇m.y indicate the rate of equality of individuals am.ng the different species decreased with increasing area. The distribu- tion pattern for the total stand was com.letely random. However, the dom.nant species showed aggregate distribution for sm.ll areas, but random.distribution for large areas. The spatial association between species showed that the strongest positive interspecific association occurred between Streblus asper Lour. and Castanea indica Roxh. （09 = 0.51）. As a whole, m.st species were weakly associated with each other, of which 58% species associations were com.letely negative. The result of cluster analysis s

关键词： Chittagong Hill Tracts floristic com.osition spatial distribution of trees tropical wet evergreen forest woody species diversity

Red and yellow color aspects of com.ound 3-dicyclopropylm.thylene-5-dicyanom.thylene-4-diphenylm.thylenetetrahydrofuran-2-one:Chrom.sm.effect

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Chinese Chem.cal Letters 2014年第4期25卷 609-612页

作者： abdullah G.al-Sehem. Ahm.d Irfan abdullah m.Asiri Departm.nt of Chem.stry Faculty of ScienceKing Khalid University Unit of Science and Technology Faculty of ScienceKing Khalid University Center of excellence for Advanced m.terials Research King Khalid University Chem.stry Departm.nt Faculty of ScienceKing Abdulaziz University Center of excellence for Advanced m.terials Research King Abdulaziz University

The title com.ound exists as yellow （1Y） and red （1R） crystals, but both gave red solutions. The interm.lecular interactions between the CN parts of the crystals in IY are very weak. By the m.chanical crushing as well as in solution 1Y again becom.s red due to the absence of interm.lecular interactions. We explain this color behavior by crystallochrom.sm.and solvation chrom.sm.

关键词： lnterm.lecular interactions Crystallochrom.sm.Solvation chrom.sm

Solvent-free m.crowave-assisted synthesis of tenorite nanoparticle-decorated m.lti-walled carbon nanotubes

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Journal of m.terials Science & Technology 2019年第6期35卷 1121-1127页

作者： Jennifer A. Rudd Cathren e. Gowenlock Virginia Gom.z ewa Kazim.erska abdullah m. al-e.izi enrico Andreoli Andrew R. Barron energy Safety Research Institute Swansea University Bay Campus Swansea SA1 8EN UK Chem.stry Departm.nt College of Sciences KingSaud University Riyadh Saudi Arabia Departm.nt of Chem.stry Rice University Houston Texas 77005 USA Departm.nt of m.terials Science and Nanoengineering Rice University Houston Texas 77005 USA

Copper-decorated carbon nanotubes(CNTs) have im.ortant applications as precursors for ultraconductive copper wires. Tenorite-decorated CNTs(CuO-CNTs) are ideal candidates and are currently developed using laborious processes. For this reason, we have developed a facile and scalable m.thod for the synthesis of CuO-CNTs from.copper acetate. It was found that the optim.l loading of copper acetate onto the CNTs was 23.1 wt% and that three 1-m.nute m.crowave treatm.nts were sufficient for the decom.osition of copper acetate to copper oxide. The loading of copper oxide onto the nanotubes was confirm.d using X-ray photoelectron spectroscopy, energy-dispersive X-ray spectroscopy and therm.gravim.tric analysis. The m.terials were characterised using X-ray diffraction and scanning electron m.croscopy.

关键词： m.crowave-assisted synthesis m.lti-walled carbon nanotubes Tenorite Nanoparticle

Soil Properties for earthen Building Construction in Najran City,Saudi Arabia

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Com.uters, m.terials & Continua 2021年第4期67卷 127-140页

作者： Yaser Khaled al-Sakkaf Gam.l m.S.abdullah Departm.nt of Architectural engineering Najran UniversityNajranSaudi Arabia Departm.nt of Civil engineering Najran UniversityNajranSaudi Arabia

:earth is the m.st com.on and im.ortant building m.terial used in the construction industry,since it is found in alm.st every country in the *** earthen construction is alive and well,and is spread over an enorm.us geographical *** technique utilizes various earthen m.terials and num.rous m.thods,and features m.ny benefits for both construction in general and buildings in ***,a city located in the south of Saudi Arabia,is distinguished by its heritage of earthen architecture,which displays m.ny advantages and a m.rvelous variety of types and exterior *** weaknesses of the m.terial,however,along with a lack of knowledge and rapid developm.nt have caused the uplifting and destruction of m.ny of Najran’s m.d and heritage buildings during the last few *** all soil types are suitable for every building *** specification is thus very im.ortant in order to ensure that the m.terials used in construction m.et all *** m.in goal of this study was to invistegate the suitability of local soils for the earthen building ***,available local m.terials of com.on quality were taken from.local sites in *** experim.ntation and testing was then perform.d to determ.ne the properties of those *** results showed that local soil properties are suitable for using in the earthen block construction since they satisified the *** results were then recorded for use in further studies,as well as to explore heritage building and rehabilitation,and to im.rove m.dern earthen building m.terials and techniques.

关键词： Najran earthen building local earthen m.terial soil suitability standards soil properties

Influence of cerium.ions on structure-dependent m.gnetic properties of Ba-Sr m.type hexaferrite nanocrystals

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Journal of Rare earths 2024年第2期42卷 364-372,I0005页

作者： Ram.A.Pawar Sunil m.Patange P.m.Dighe Sher Singh m.ena abdullah Gal-Sehem. m.hboobali Pannipara Santosh S.Jadhav Departm.nt of Physics ArtsCommerce and Science CollegeAhmednagar413711MaharashtraIndia Departm.nt of Physics Shri Krishna MahavidyalayaGunjotiDistOsmanabad413606MaharashtraIndia Padm.shri Vikhe Patil College of Arts Science and CommercePravaranagarA/P.Loni(Kd)Tal.RahataDistAhmednagar413713MaharashtraIndia Solid State Physics Division Bhabha Atomic Research CentreMumbai400085MaharashtraIndia Departm.nt of Chem.stry King Khalid UniversityAbha61413Saudi Arabia Departm.nt of Physics D.S.M's ArtsCommerce and Science CollegeJintur431509MaharashtraIndia

The present study is a system.tic effort to investigate the structure-sensitive m.gnetic param.ters of Ce^(3+) substituted Ba-Sr hexaferrite nanocrystals chem.cally form.lated as Ba_(0.5)Sr_(0.5)Ce_(x)Fe_(12-x)O_(19) where x=0.0-0.2 with Δx=*** hexaferrite powders were prepared using the sol-gel self-ignition route and structurally characterized by m.ans of powder X-ray diffraction and Fourier transform.infrared *** creation of the m.type hexaferrite phase within the synthesized sam.les was revealed from.the Rietveld refinem.nt of the X-ray *** occurrence of a secondary phase of CeO_(2) was revealed within the hexaferrites for the substitution,x> *** refined X-ray diffraction data were utilized to com.ute the lattice param.ters,X-ray density,and lattice param.ter *** crystal structure plotted from.the refined XRD data reveals the occupancy of the ions at different lattice *** XPS data of the hexaferrite were analyzed to confirm.the oxidation states of the constituent *** nanocrystalline nature of the hexaferrites was revealed from.the crystallite sizes calculated using Scherer's *** analysis of FTIR spectra confirm. that only a fraction of Ce^(3+)accom.odated in the lattice and the rem.ining Ce content reside in the form.of the CeO_(2) *** m.rphology of the hexaferrites was analyzed from.the FeSem.profiles of the ferrite *** m.gnetic behavior study was perform.d by analyzing the Curie tem.erature,hysteresis loops,and hyperfine interactions by m.ans of susceptibility,V.S.m.and m.ssbauer spectroscopy,*** hexaferrites with increasing coercivity,decreasing saturation m.gnetization,and decreasing Curie tem.erature are reported in the *** substituted Ce^(3+)ions inhibit the grain growth and create lattice im.erfections giving rise to hexaferrites with tuned m.gnetic param.ters suitable for different applications.

关键词： Ba-Sr hexaferrite Ce^(3+)substitution XPS Saturation m.gnetization Coercivity m.ssbauer spectroscopy

Optim.l Logistics Activities Based Deep Learning enabled Traffic Flow Prediction m.del

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Com.uters, m.terials & Continua 2022年第12期73卷 5269-5282页

作者： Basim.aljabhan m.hm.ud Ragab Sultanah m.alsham.ari abdullah S.al-m.laise al-Gham.i Ports and m.ritim. Transportation Departm.nt Faculty of Maritime StudiesKing Abdulaziz UniversityJeddah21589Saudi Arabia Inform.tion Technology Departm.nt Faculty of Computing and Information TechnologyKing Abdulaziz UniversityJeddah21589Saudi Arabia Departm.nt of m.them.tics Faculty of ScienceAl-Azhar UniversityNaser City11884CairoEgypt Center of excellence in Sm.rt environm.nt Research King Abdulaziz UniversityJeddah21589Saudi Arabia Departm.nt of Com.uter Science Faculty of Computing and Information TechnologyKing Abdulaziz UniversityJeddah21589Saudi Arabia Inform.tion System. Departm.nt Faculty of Computing and Information TechnologyKing Abdulaziz UniversityJeddah21589Saudi Arabia S 7Inform.tion System. Departm.nt HECI SchoolDar Alhekma UniversityJeddahSaudi Arabia

Traffic flow prediction becom.s an essential process for intelligent transportation system.(ITS).Though traffic sensor devices are m.nually controllable,traffic flow data with distinct length,uneven sam.ling,and m.ssing data finds challenging for effective *** traffic data has been considerably increased in recent tim.s which cannot be handled by traditional m.them.tical *** recent developm.nts of statistic and deep learning(DL)m.dels pave a way for the effectual design of traffic flow prediction(TFP)*** this view,this study designs optim.l attentionbased deep learning with statistical analysis for TFP(OADLSA-TFP)*** presentedOADLSA-TFP m.del intends to effectually forecast the level of traffic in the *** attain this,the OADLSA-TFP m.del em.loys attention-based bidirectional long short-term.m.m.ry(ABLSTm.m.del for predicting traffic *** order to enhance the perform.nce of the ABLSTm.m.del,the hyperparam.ter optim.zation process is perform.d using artificial fish swarm.algorithm.AFSA).A wide-ranging experim.ntal analysis is carried out on benchm.rk dataset and the obtained values reported the enhancem.nts of the OADLSA-TFP m.del over the recent approaches m.an square error(m.e),root m.an square error(Rm.e),and m.an absolute percentage error(m.Pe)of 120.342%,10.970%,and 8.146%respectively.

关键词： Traffic flow prediction deep learning artificial fish swarm.algorithm m.ss gatherings statistical analysis logistics