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Understanding the catalytic performance and deactivation behaviour of second-promoter doped Pt/WO_(χ)/γ-Al_(2)O_(3) catalysts in the glycerol hydrogenolysis for selective and cleaner production of 1,3-propanediol

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Journal of Energy Chemistry 2024年第7期94卷 486-507页

作者： Rafik Rajjak Shaikh Sittichai Damruang rais ahmad khan Supareak Praserthdam Piyasan Praserthdam Center of Excellence on Catalysis and Catalytic Reaction Engineering(CECC) Department of Chemical EngineeringFaculty of EngineeringChulalongkorn UniversityBangkok 10330Thailand Department of Chemistry College of ScienceKing Saud UniversityP.O.Box 2455Riyadh 11451Saudi Arabia High-Performance Computing Unit(CECC-HCU) Centre of Excellence on Catalysis and Catalytic Reaction Engineering(CECC)Department of Chemical EngineeringFaculty of EngineeringChulalongkorn UniversityBangkok 10330Thailand

The selective aqueous-phase glycerol hydrogenolysis is a promising reaction to produce commercially useful 1,3-propanediol(1,3-PDO).The Pt-WOx bifunctional catalyst can catalyse the glycerol hydrogenol-ysis but the catalyst deactivation via sintering,metal leaching,and coking can predominantly occur in the aqueous phase *** this work,the effect of reaction temperature,pressure and second promoter(Cu,Fe,Rh,Mn,Re,Ru,Ir,Sn,B,and P)on catalytic performance and deactivation behaviour of Pt/WOx/-Al2O3 was *** doped with Rh,Mn,Re,Ru,Ir,B,and P,the second promoter boosts catalytic activity by promoting great dispersion of Pt on support and increasing Pt surface *** increased Bronsted acid sites lead to selective synthesis of 1,3-PDO than 1,2-propanediol(1,2-PDO).The characterization studies of fresh and spent catalysts reveal that the main cause of catalyst deactivation is the Pt sintering,as interpreted based on XRD,CO chemisorption,and TEM *** Pt sintering is affected depending on the second promoter that can either or reduce the interaction between Pt,WO_(χ)/γ and Al_(2)O_(3).As an electron acceptor of Pt in Pt/WO_(χ)/γ-Al_(2)O_(3),Re and Mn as second promoters resulted in increased Pt^(2+) on the catalytic surface,which strengthens the contact between Pt andγ-Al_(2)O_(3) and WO_(χ),resulting in a decrease in Pt *** metal leaching and coking are not affected by the presence of second *** catalyst modified with a second promoter possesses improved catalytic activity and 1,3-PDO production,however the stability continues to remain a *** present work unrav-elled the determining parameters of catalytic activity and deactivation,thus providing a promising pro-tocol toward effective catalysts for glycerol hydrogenolysis.

关键词： Glycerol hydrogenolysis 1,3-propanediol Metal-support interaction Second promoter Liquid phase Catalyst deactivation

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Outgrowth endothelial cells form a functional cerebral barrier and restore its integrity after damage

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Neural Regeneration Research 2020年第6期15卷 1071-1078页

作者： rais Reskiawan Abdulkadir Mansour Alwjwaj Othman ahmad Othman Kamini Rakkar Ulvi Bayraktutan Stroke Division of Clinical Neuroscience Clinical Sciences Building School of MedicineHucknall Road Nottingham NG5 1PB UK

Breakdown of blood-brain barrier,formed mainly by brain microvascular endothelial cells(BMECs),represents the major cause of mortality during early phases of ischemic ***,discovery of novel agents that can effectively replace dead or dying endothelial cells to restore blood-brain barrier integrity is of paramount importance in stroke *** endothelial progenitor cells(EPCs)represent one such agents,their rarity in peripheral blood severely limits their adequate isolation and therapeutic use for acute ischemic stroke which necessitate their ex vivo expansion and generate early EPCs and outgrowth endothelial cells(OECs)as a *** analyses of these cells,in the present study,demonstrated that only OECs endocytosed DiI-labelled acetylated low-density lipoprotein and formed tubules on matrigel,prominent endothelial cell and angiogenesis markers,*** analyses by flow cytometry demonstrated that OECs expressed specific markers for sternness(CD34),immaturity(CD133)and endothelial cells(CD31)but not for hematopoietic cells(CD45).Like BMECs,OECs established an equally tight in vitro model of human BBB with astrocytes and pericytes,suggesting their capacity to form tight *** injury mimicked by concurrent deprivation of oxygen and glucose(4 hours)or deprivation of oxygen and glucose followed by reperfusion(20 hours)affected both barrier integrity and function in a similar fashion as evidenced by decreases in transendothelial electrical resistance and increases in paracellular flux,*** scratch assays comparing the vasculoreparative capacity of cells revealed that,compared to BMECs,OECs possessed a greater proliferative and directional migratory *** a triple culture model of BBB established with astrocytes,pericytes and BMEC,exogenous addition of OECs effectively repaired the damage induced on endothelial layer in serum-free *** together,these data demonstrate that OECs may effect

关键词： cell-based therapy endothelial progenitor cells endothelium ischemic stroke neurodegeneration novel therapeutics outgrowth endothelial cells regenerative medicine stem cells translational medicine

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<i>H</i>(.,.)<i>- φ - η -</i>Accretive Operators and Generalized Variational-Like Inclusions

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American Journal of Operations Research 2011年第4期1卷 305-311页

作者： rais ahmad Mohammad Dilshad 不详

In this paper, we generalize H(.,.) accretive operator introduced by Zou and Huang [1] and we call it H(.,.)- φ - η - accretive operator. We define the resolvent operator associated with H(.,.)- φ - η - accretive operator and prove its Lipschitz continuity. By using these concepts an iterative algorithm is suggested to solve a generalized variational-like inclusion problem. Some examples are given to justify the definition of H(.,.)- φ - η - accretive operator.

关键词： H(. .)- φ - η - Accretive Operator Variational-Like Inclusion Resolvent Operator Algorithm Convergence

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Cylindrical Guided Wave Signals for Underground Pipe Inspection using Different Continuous Wavelet Mother Functions

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Journal of Civil Engineering and Architecture 2011年第12期5卷 1103-1110页

作者： rais ahmad Tribikram Kundu Department of Civil ＆ Environmental Engineering University of Connecticut USA Department of Civil Engineering ＆ Engineering Mechanics University of Arizona USA

Over the past decade, wavelets provided a powerful and flexible set of tools for handling fundamental problems in science and engineering. Wavelet analyses are being used for solving problems in different engineering areas like audio de-noising, signal compression, object detection, image decomposition, speech recognition etc. Wavelet analysis employs orthonormal as well as non-orthonornal functions. This research investigates the effectiveness of wavelet analysis in detecting defects in underground steel pipe networks. Continuous Wavelet Transforms （CWT） has been performed on the received signals of cylindrical guided waves. Cylindrical Guided waves are generated and propagated through the pipe wall boundaries in a pitch-catch system. Piezo-electric transducers are used to generate as well as receive guided waves. Several mother wavelet functions such as Daubechies, Symlet, Coiflet and Meyer have been used for the Continuous Wavelet Transform to investigate the most suitable function for defect detection. This research also investigates the effect of surrounding soil on wavelet transforms for different mother wavelet functions.

关键词： Wavelet analysis guided waves mother wavelet functions continuous wavelet transform.

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Intelligence Way from Eco-friendly Synthesis Strategy of New Heterocyclic Pyrazolic Carboxylic a-Amino Esters

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Chemical Research in Chinese Universities 2020年第6期36卷 1183-1189页

作者： EI Houssine MABROUK Nadia ARROUSSE Adil KORCHI Mohammed LACHGAR ahmad OUBAIR Abdelrhani ELACHQAR Mohamed JABHA Mohammed LACHKAR Fadoua El HAJJAJI Zakia rais Mustapha TALEB Laboratory of Materials Engineering for the Environment&Natural Resources Department of ChemistryFaculty of Sciences and TechnicsBP 509 BoutalamineErrachidiaMoulay Ismail University MeknesMorocco Laboratory of Engineering OrganometallicMolecular and Environment(LlMMOME)Faculty of SciencesUniversity Sidi Mohamed Ben AbdellahB.P.1796FezMorocco Faculty of Sciences and Technologies University Sidi Mohamed Ben AbdellahFezMorocco Department of Chemistry Faculty of Sciences Dhar El MahrazUniversity Sidi Mohamed Ben AbdellahB.P.1796FezMorocco Natural Resources and Environment Team(RN&E) Faculty of Sciences and TechnicsErrachidiaMoulay Ismail UniversityMorocco

The a-amino acid derivatives constitute a class of compounds of particular medicinal and synthetic attention and considerable interest has been devoted to their synthesis in recent *** the present work,we develop the computational study of the synthesis reaction of new pyrazolyl a-amino esters derivatives using the Gaussian 09based on the DET/B3LYP density functional theorv method,with the base 6-31G(d.p)to ensure the possibility of carrying out these reactions within the laboratory of ***,this research has encouraged us to establish an economical synthesis strategy of these products in overall vields of 73.5%to 87%to have access to new active biomolecule through the O-alkvlation reaction between methyl a-azidoglycinate N-benzoylated and primary pyrazole alcohols(3,5-dimethyl-1 H-pyrazol-1-yl)methanol,(1H-pyrazol-1-yl)methanol and(3-ethoxy-5-methyl-1H-pyrazol-1yl)methanoll under different operating *** structure of the prepared heterocyclic systems was characterized by conventional spectroscopic techniques,like H NMR.I3℃NMR,and *** results revealed that the experimental study is in good correlation with the computational one.

关键词： a-Pyrazolyl amino ester Methyl a-azido glycinate N-benzoylated O-Alkylation DFT/B3LYP/6-31G(d,p)

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