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Progress in Natural Science:Materials International 2013年第1期23卷 23-35页

作者： Ramzi Chalghaf walid oueslati Marwa Ammar Hafsia Ben Rhaiem Abdesslem Ben Haj Amara UR05/13-01:Physique des Matériaux Lamellaires et Nanomatériaux Hybrides(PMLNMH) Facultédes Sciences de BizerteZarzouna 7021Tunisia

This work aims at investigating the strain effect,created by varying pH solution and continuous heating cycle,on the cation exchange process in the case of Na-rich montmorillonite sample in contact with bi-ionic solution with variable concentration,saturated respectively by Co2+ and Cu2+ *** ionic exchange process is characterized using XRD analysis obtained through the comparison of experimental XRD patterns with calculated ones,which allowed us to determine several structural parameters related to the nature,abundance,size,position and organization of exchangeable cation and water molecule in the interlamellar space along the ***,the proposed theoretical models,for the stressed samples,show that the structure presents an interstratified hydration character and proves the coexistence of more than two ''crystallite'' specie in the *** perturbation types have an obvious effect on the selective exchange process for all stressed samples,where the interlayer space is characterized by the coexistence of more one exchangeable cation.

关键词： Geological membrane Soil decontamination Alkaline strain Thermal stress Quantitative XRD analysis Ionic exchange process

Effect of Alkali-NaOH Solution on the Nature of Synthesized Zeolite from 2：1 Tunisian Clays： XRD and MAS-NMR Investigation

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Journal of Chemistry and Chemical Engineering 2011年第3期5卷 246-249页

作者： Mahdi Meftah walid oueslati Abdesslem Ben HajAmara Laboratoire de Physique des Matdriaux Lamellaires et Nanomat~riaux Hybrides UR05/13-O I （PMLNMH） Facult~ des Sciencesde Bizerte 7021 Zarzouna Tunisia Faculte des Scienees de Gafsa Ddpartement de Physique Campus Universiatire Sidi Ahmed Zarrouk 2112 Gafsa Tunisia

This work focuses the effect of alkali-NaOH solution on the nature of synthesized zeolite from 2：1 Tunisian clays. This study was achieved using correlation between results obtained from X-ray diffraction （XRD） and MAS-NMR analysis. Preliminary treatment was adopted to prepare the starting sample that is placed in contact with NaOH solution at variable concentration. A specific hydrothermal reactor, allowing the control ofpH 〉 9, temperature and a continuous stirring of the sample in the NaOH solution; was used to achieve these syntheses. The obtained results showed that, for concentration value ~IN, the final complex presented characteristic XRD and MAS-NMR line of zeolite P. For 3N solution concentration we obtained zeolite HS. All synthesize process are controlled by XRD and MAS-NMR investigation.

关键词： Alkali-NaOH solution bydrothermal reactor zeolite P HS.

Relation Between Mechanical Constraints and The Hydration Behaviour in the Case of Na-Montmorillonite:Structural Analysis and Elastics Properties

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矿物学报 2013年第S1期33卷 95-95页

作者： walid oueslati Hafsia Ben Rhaiem Abdesslem Ben Haj Amara SUR05/13-01 Physique des Matériaux Lamellaires et Nanomatériaux Hybrides (PMLNMH) Faculté des Sciences de BizerteZarzouna 7021Tunisia

The experimental prediction of the mechanical properties of minerals remains difficult because of their small particle size (typically < 2 micrometers). This work aims at examining, the effect of an applied mechanical constraint on the hydration behaviour in the case of Na rich-montmorillonite and its relation with the elastic properties. The mechanical constraint is created, at the laboratory scale, by applying a monoaxial pressure for unstressed host material (i.e. Na rich montmorillonite). The structural analysis before and after stress is achieved using an XRD profile modeling approach. This investigation allowed us to determine several structural parameters related to the nature, abundance, size, position and organization of exchangeable cation and water molecule in the interlamellar space along the c* axis. In order to evaluate the affected elastic properties, the GULP code have been used to study the structure and the interlamellar organization. Indeed, the bulk modulus and elastic constants of montmorilonite have been calculated from first principles within density functional theory (DFT). The obtained Young’s modulus for Na-montmorillonite interlayer varies from 5 GPa to 16 GPa. According to the interlamellar space configuration the calculated elastic constant tensors indicate that the a direction is slightly more flexible than the b direction. The calculated elastic constant tensor along c is much lower than the constants calculated along a and b.

关键词： Na rich-montmorillonite hydration behavior GULP code elastic properies

Assessment of vegetation cover changes and the contributing factors in the Al-Ahsa Oasis using Normalized Difference Vegetation Index(NDVI)

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Regional Sustainability 2024年第1期5卷 42-53页

作者： walid CHOUARI Department of Geography College of ArtsKing Faisal UniversityAl-Ahsa31982Saudi Arabia Laboratory Syfacte Faculty of Arts and Humanities of SfaxUniversity of SfaxSfax1168-3000Tunisia

The abandonment of date palm grove of the former Al-Ahsa Oasis in the eastern region of Saudi Arabia has resulted in the conversion of delicate agricultural area into urban *** current state of the oasis is influenced by both expansion and degradation ***,it is important to study the spatiotemporal variation of vegetation cover for the sustainable management of oasis *** study used Landsat satellite images in 1987,2002,and 2021 to monitor the spatiotemporal variation of vegetation cover in the Al-Ahsa Oasis,applied multi-temporal Normalized Difference Vegetation Index(NDVI)data spanning from 1987 to 2021 to assess environmental and spatiotemporal variations that have occurred in the Al-Ahsa Oasis,and investigated the factors influencing these *** study reveals that there is a significant improvement in the ecological environment of the oasis during 1987–2021,with increase of NDVI values being higher than *** 2021,the highest NDVI value is generally above 0.70,while the lowest value remains largely ***,there is a remarkable increase in NDVI values between 0.20 and *** area of low NDVI values(0.00–0.20)has remained almost stable,but the region with high NDVI values(above 0.70)expands during 1987–***,this study finds that in 1987–2002,the increase of vegetation cover is most notable in the northern region of the study area,whereas from 2002 to 2021,the increase of vegetation cover is mainly concentrated in the northern and southern regions of the study *** 1987 to 2021,NDVI values exhibit the most pronounced variation,with a significant increase in the“green”zone(characterized by NDVI values exceeding 0.40),indicating a substantial enhancement in the ecological environment of the *** NDVI classification is validated through 50 ground validation points in the study area,demonstrating a mean accuracy of 92.00%in the detection of vegetation *** general,both the user’s and produce

关键词： Normalized Difference Vegetation Index(NDVI) Vegetation cover Ecological environment Land use and land cover(LULC) Urban expansion Al-Ahsa Oasis

Steam reforming of acetic acid over Ni/biochar of low metal-loading:Involvement of biochar in tailoring reaction intermediates renders superior catalytic performance

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Chinese Journal of Chemical Engineering 2024年第4期68卷 241-252页

作者： Yunyu Guo Yiran Wang Shu Zhang Yi Wang Song Hu Jun Xiang walid Nabgan Xun Hu School of Material Science and Engineering University of JinanJinan 250022China Joint International Research Laboratory of Biomass Energy and Materials College of Materials Science and EngineeringNanjing Forestry UniversityNanjing 210037China State Key Laboratory of Coal Combustion Huazhong University of Science and TechnologyWuhan 430074China Departament d'Enginyeria Química Universitat Rovira i VirgiliTarragona 43007Spain

Biochar is a reactive carrier as it may be partially gasified with steam in steam reforming,which could influence the formation of reaction intermediates and modify catalytic ***,the Ni/biochar as well as two comparative catalysts,Ni/Al_(2)O_(3) and Ni/SiO_(2),with low nickel loading(2%(mass))was conducted to probe involvement of the varied carriers in the steam *** results indicated that the Ni/biochar performed excellent catalytic activity than Ni/SiO_(2) and Ni/Al_(2)O_(3),as the biochar carrier facilitated quick conversion of the -OH from dissociation of steam to gasify the oxygen-rich carbonaceous intermediates like C=O and C-O-C,resulting in low coverage while high exposure of nickel species for maintaining the superior catalytic *** converse,strong adsorption of aliphatic intermediates over Ni/Al_(2)O_(3) and Ni/SiO_(2) induced serious coking with polymeric coke as the main type(21.5%and 32.1%,respectively),which was significantly higher than that over Ni/biochar(3.9%).The coke over Ni/biochar was mainly aromatic or catalytic type with nanotube morphology and high *** high resistivity of Ni/biochar towards coking was due to the balance between formation of coke and gasification of coke and partially biochar with steam,which created developed mesopores in spent Ni/biochar while the coke blocked pores in Ni/Al_(2)O_(3) and Ni/SiO_(2) catalysts.

关键词： Steam reforming Acetic acid Ni/biochar catalyst Property of coke Reaction intermediates

Soil erosion susceptibility mapping of Hangu Region,Kohat Plateau of Pakistan using GIS and RS-based models

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Journal of Mountain Science 2024年第8期21卷 2547-2561页

作者： Fakhrul ISLAM Liaqat Ali WASEEM Tehmina BIBI Waqar AHMAD Muhammad SADIQ Matee ULLAH walid SOUFAN Aqil TARIQ Department of Geology Khushal Khan Khattak UniversityKarak 27200Pakistan Department of Geography Government College University FaisalabadPunjab 38000Pakistan Institute of Geology The University of Azad Jammu&KashmirMuzaffarabad 13100Pakistan Department of Earth Sciences Changan UniversityXi’an 710003China NCEG University of PeshawarPeshawar 25120Pakistan Faculty of Earth Sciences Geography and AstronomyUniversity of ViennaVienna 1090Austria Plant Production Department College of Food and Agriculture SciencesKing Saud UniversityRiyadh 11451Saudi Arabia Department of Wildlife Fisheries and AquacultureCollege of Forest ResourcesMississippi State UniversityMS 39762USA

Soil erosion is a crucial geo-environmental hazard worldwide that affects water quality and agriculture,decreases reservoir storage capacity due to sedimentation,and increases the danger of flooding and ***,this study uses geospatial modeling to produce soil erosion susceptibility maps(SESM)for the Hangu region,Khyber Pakhtunkhwa(KPK),*** Hangu region,located in the Kohat Plateau of KPK,Pakistan,is particularly susceptible to soil erosion due to its unique geomorphological and climatic ***,the Hangu region is characterized by a combination of steep slopes,variable rainfall patterns,diverse land use,and distinct soil types,all of which contribute to the complexity and severity of soil erosion *** factors necessitate a detailed and region-specific study to develop effective soil conservation *** this research,we detected and mapped 1013 soil erosion points and prepared 12 predisposing factors(elevation,aspect,slope,Normalized Differentiate Vegetation Index(NDVI),drainage network,curvature,Land Use Land Cover(LULC),rainfall,lithology,contour,soil texture,and road network)of soil erosion using GIS ***,GIS-based statistical models like the weight of evidence(WOE)and frequency ratio(FR)were applied to produce the SESM for the study *** SESM was reclassified into four classes,i.e.,low,medium,high,and very high *** results of WOE for SESM show that 16.39%,33.02%,29.27%,and 21.30%of areas are covered by low,medium,high,and very high zones,*** contrast,the FR results revealed that 16.50%,24.33%,35.55%,and 23.59%of the areas are occupied by low,medium,high,and very high ***,the reliability of applied models was evaluated using the Area Under Curve(AUC)*** validation results utilizing the area under curve showed that the success rate curve(SRC)and predicted rate curve(PRC)for WOE are 82%and 86%,respectively,while SRC and PRC for FR are 85%and 96%,res

关键词： Soil erosion Geospatial technology Statistical models Hangu Pakistan

Hierarchical CoFe@N-Doped Carbon Decorated Wood Carbon as Bifunctional Cathode in Wearable Zn-Air Battery

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Energy & Environmental Materials 2024年第1期7卷 42-50页

作者： Kelong Ao Xiangyang Zhang Renat R.Nazmutdinov Di Wang Jihong Shi Xian Yue Jianguo Sun Wolfgang Schmickler walid A.Daoud Department of Mechanical Engineering City University of Hong KongHong Kong 999077China Kazan National Research Technological University 420015 KazanRussian Federation School of Textile and Garment Anhui Polytechnic UniversityWuhu 241000China Wood Materials Science Institute for Building MaterialsETH Zürich8093 ZürichSwitzerland Am Sandhaken 18 D-89069 UlmGermany

Rechargeable Zn-air batteries(ZAB)have drawn extensive attention due to their eco-friendliness and ***,the lack of high-performance and low-cost oxygen redox reactions(OER and ORR)catalysts has become one of the main stumbling blocks in their ***,we successfully fabricate a CoFe nanobubble encapsulated in nitrogen-doped carbon nanocage on wood carbon support(CoFe@NC/WC)via pyrolysis of a novel Prussian blue analog(PBA)/spruce *** hierarchical CoFe@NC/WC catalyst exhibits an excellent potential difference of 0.74 V between the OER potential at 10 mA cm^(-2)and half-wave potential of ORR in 0.1 M KOH,comparable to recently reported preeminent ***,CoFe@NC/WC shows outstanding electrochemical performance in liquid ZAB,with a peak power density of 138.9 mW cm^(-2)and a specific capacity of 763.5 mAh g^(-1).More importantly,a bacterial cellulose nanofiber reinforced polyacrylic acid(BC-PAA)hydrogel electrolyte shows ultrahigh tensile-breaking stress of 1.58 *** conjunction with the as-prepared CoFe@NC/WC catalyst,BC-PAA-based wearable ZAB displays impressive rechargeability and foldability,and can power portable electronics,such as electronic timer and mobile phone,in bent *** work provides a new approach toward high-activity and low-cost catalysts for ZAB.

关键词： biomass-based catalyst DFT computation hydrogel electrolyte oxygen redox reactions wearable Zn-air battery

Comparison of QT Correction Methods in the Pediatric Population of a Community Hospital: A Retrospective Study

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Congenital Heart Disease 2024年第1期19卷 107-121页

作者： Koren Hyogene Kwag Ibrahim Kak Ying Li walid Khass Alec McKechnie Oksana Nulman Brande Brown Manoj Chhabra Department of Pediatrics New York Presbyterian Brooklyn Methodist HospitalBrooklyn11215USA Department of Population Health Sciences Division of BiostatisticsWeill Cornell MedicineNew York10065USA

Objective:Accurate measurement of QT interval,the ventricular action potential from depolarization to repolarization,is important for the early detection of Long QT *** most effective QT correction(QTc)formula has yet to be determined in the pediatric population,although it has intrinsically greater extremes in heart rate(HR)and is more susceptible to errors in *** authors of this study compare six dif-ferent QTc methods(Bazett,Fridericia,Framingham,Hodges,Rautaharju,and a computer algorithm utilizing the Bazett formula)for consistency against variations in HR and RR ***:Descriptive Retrospective *** included participants from a pediatric cardiology practice of a community hospital who had an ECG performed in *** participants were healthy patients with no past medical history and no regular ***:ECGs from 95 participants from one month to 21 years of age(mean 9.7 years)were included with a mean HR of 91 beats per minute(bpm).The two-sample paired t-test or Wilcoxon signed-rank test assessed for any difference between QTc methods.A statistically signiﬁcant difference was observed between every combination of two QTc *** Spearman’s rank correlation analysis explored the QTc/HR and QTc/RR relationships for each *** method was most independent of HR and RR with the lowest absolute value of correlation coefﬁ*** and Computer had moderate correlations,while Framingham and Rautaharju exhibited strong *** were positive for Bazett and Computer,reﬂecting results from prior studies demonstrating an over-correction of Bazett at higher *** the linear QTc/HR regression analysis,Bazett had the slope closest to zero,although Computer,Hodges,and Fridericia had comparable ***,Fridericia had the linear QTc/RR regression coefﬁcient closest to *** Bland-Altman method assessed for bias and the limits of agreement between correction *** an

关键词： Corrected QT interval QT prolongation long QT syndrome electrocardiogram retrospective study bazett fridericia framingham hodges rautaharju computer algorithm

Factors and Cut-Off Predicting Stone Passage under Medical Expulsive Therapy (MET)

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Open Journal of Urology 2024年第8期14卷 423-434页

作者： Nazih Rahhal Ali Ismail walid Alame Faculty of Medical Sciences Lebanese University Beirut Lebanon Faculty of Medical Sciences Neuroscience Research Centre Lebanese University Beirut Lebanon Division of Urology Sahel General Hospital-FAUMC Beirut Lebanon Division of Urology Faculty of Medical Sciences Lebanese University Beirut Lebanon

Background: Ureteral stones are the most common leading cause of acute flank pain. This study aimed to identify sociodemographic and clinical variables predicting spontaneous ureteral stone passage and determine the optimal size cut-off for predicting such passage. Method: We conducted a retrospective evaluation of patients presenting with acute renal colic at a urology outpatient clinic. Patients with ureteral stones ≤ 10 mm and no surgical intervention post-initial diagnosis, who attended follow-up visits, were included. Exclusion criteria comprised stone size > 1 cm, fever due to obstructive pyelonephritis, acute kidney injury, single kidney status, or bilateral ureteral obstruction. Results: Of 124 included patients, the spontaneous stone passage rate was 57.3%, with a mean passage time of 11.1 (SD 6.25) days. Bivariate analysis revealed that factors predicting spontaneous passage were stone size (p Conclusions: Stone size < 7 mm, UVJ or distal ureter location, emerged as key predictors of stone passage in nephrolithiasis, and stone size below 6.85 mm is a reasonable cut off to initiate MET rather than 10 mm.

关键词： Ureteral Stones Nephrolithiasis Spontaneous Stone Passage

A Hybrid Cybersecurity Algorithm for Digital Image Transmission over Advanced Communication Channel Models

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Computers, Materials & Continua 2024年第4期79卷 201-241页

作者： Naglaa F.Soliman Fatma E.Fadl-Allah walid El-Shafai Mahmoud I.Aly Maali Alabdulhafith Fathi E.Abd El-Samie Department of Information Technology College of Computer and Information SciencesPrincess Nourah bint Abdulrahman UniversityP.O.Box 84428Riyadh11671Saudi Arabia Department of Electronics and Communications Faculty of EngineeringZagazig UniversityZagazig44519Egypt Security Engineering Lab Computer Science DepartmentPrince Sultan UniversityRiyadh11586Saudi Arabia Department of Electronics and Electrical Communications Engineering Faculty of Electronic EngineeringMenoufia UniversityMenouf32952Egypt

The efficient transmission of images,which plays a large role inwireless communication systems,poses a significant challenge in the growth of multimedia ***-quality images require well-tuned communication *** Single Carrier Frequency Division Multiple Access(SC-FDMA)is adopted for broadband wireless communications,because of its low sensitivity to carrier frequency offsets and low Peak-to-Average Power Ratio(PAPR).Data transmission through open-channel networks requires much concentration on security,reliability,and *** data need a space away fromunauthorized access,modification,or *** requirements are to be fulfilled by digital image watermarking and *** paper ismainly concerned with secure image communication over the wireless SC-FDMA systemas an adopted communication *** introduces a robust image communication framework over SC-FDMA that comprises digital image watermarking and encryption to improve image security,while maintaining a high-quality reconstruction of images at the receiver *** proposed framework allows image watermarking based on the Discrete Cosine Transform(DCT)merged with the Singular Value Decomposition(SVD)in the so-called DCT-SVD *** addition,image encryption is implemented based on chaos and DNA *** encrypted watermarked images are then transmitted through the wireless SC-FDMA *** linearMinimumMean Square Error(MMSE)equalizer is investigated in this paper to mitigate the effect of channel fading and noise on the transmitted *** subcarrier mapping schemes,namely localized and interleaved schemes,are compared in this *** study depends on different channelmodels,namely PedestrianAandVehicularA,with a modulation technique namedQuadratureAmplitude Modulation(QAM).Extensive simulation experiments are conducted and introduced in this paper for efficient transmission of encrypted watermarked *** addition,different variants of SC-FDMA bas

关键词： Cybersecurity applications image transmission channel models modulation techniques watermarking and encryption