检索结果-南通市图书馆

Corrosion behavior of cold-rolled and post heat-treated 316L stainless steel in 0.9wt%NaCl solution

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2021年第3期28卷 440-449页

作者： k.Bin Tayyab A.Farooq A.ahmed Alvi A.Basit Nadeem k.M.Deen Corrosion Control Research Cell Department of Metallurgy and Materials EngineeringUniversity of the PunjabLahorePakistan Department of Materials Engineering The University of British ColumbiaVancouverV6T 1Z4BCCanada

The effect of cold rolling and post-rolling heat treatment on the microstructural and electrochemical properties of the 316L stainless steel was ***-pass and four-pass cold-rolled stainless steel specimens were heat-treated by annealing at 900℃followed by quenching in *** the cold rolling,the microstructure of the as-received specimen transformed from austenite to strain-inducedα′-martensite due to significant plastic deformation that also resulted in significant grain elongation(i.e.,~33%and 223%increases in the grain elongation after two and four rolling passes,respectively).The hardness of the heat-treated as-received specimen decreased from HV 190 to 146 due to the recovery and recrystallization of the austenite grain *** cyclic polarization scans of the as-rolled and heat-treated specimens were obtained in 0.9wt%NaCl *** pitting potential of the four-pass rolled specimen was significantly increased from 322.3 to 930.5 mV after post-rolling heat *** beneficial effect of the heat treatment process was evident from~10-times-lower corrosion current density and two-orders-of-magnitude-lower passive current density of the heat-treated specimens compared with those of the as-rolled ***,appreciably lower corrosion rate(3.302×10^(−4)mm/a)and higher pitting resistance(1115.5 mV)were exhibited by the postrolled heat-treated specimens compared with the as-rolled 316L stainless steel specimens.

关键词： cold rolling quenching cyclic polarization re-passivation tendency

Walking experience:Exploring the trilateral interrelation of walkability,temporal perception,and urban ambiance

在线全文

学校读者我要写书评

暂无评论

Frontiers of Architectural Research 2021年第3期10卷 516-539页

作者： Doaa k.Hassan ahmed Elkhateeb Department of Architecture Faculty of EngineeringAin Shams UniversityCairoEgypt

Walking experience through urban spaces is a frequent daily ***,planning and designing for walkability become crucial for building up quality of *** daily walks around the city are affected by fulfilling the needed psychological contentment that is in turn measured unconsciously by our temporal *** contentment is inherent in what we experience in accordance with urban ambiance that goes beyond the spatial attributes of spaces to include their social and sensorial ***,the question here is how walkability of urban routes is affected by urban ambiance and therefore perceived in terms of ***,this study aims to understate the trilateral interrelation of walkability,temporal perception,and urban ambiance in walkable routes for daily routine *** work depends on an experimental study where participants are asked to walk along two selected ***-gathering tools rely on documenting the lived experience of the target group via reporting their trips and answering a *** analysis demonstrates this trilateral interrelation to clarify the *** study concludes specific qualities of walkable routes for routine use that reduce sense of time,which is highly crucial to be realized in such daily walk journeys.

关键词： Walkability Urban ambiance Temporal perception People’s needs in open spaces

Escherichia coli-host macrophage interactions in the pathogenesis of inflammatory bowel disease

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2014年第27期20卷 8751-8763页

作者： ahmed Tawfik Paul k Flanagan Barry J Campbell Department of Gastroenterology Institute of Translational Medicine University of Liverpool

Multiple studies have demonstrated alterations in the intestinal microbial community (termed the microbiome) in Crohn’s disease (CD) and several lines of evidence suggest these changes may have a significant role in disease pathogenesis. In active and quiescent disease, both the faecal and mucosa-associated microbiome are discordant with matched controls with reduced biodiversity, changes in dominant organisms and increased temporal variation described. Mucosa-associated adherent, invasive Escherichia coli (E. coli) (AIEC), pro-inflammatory and resistant to killing by mucosal macrophages, appear to be particularly important. AIEC possess several virulence factors which may confer pathogenic potential in CD. Type-1 pili (FimH) allow adherence to intestinal cells via cell-surface carcinoembryonic antigen-related cell adhesion molecules and possession of long polar fimbrae promotes translocation across the intestinal mucosa via microfold (M)-cells of the follicle-associated epithelium. Resistance to stress genes (htrA, dsbA and hfq) and tolerance of an acidic pH may contribute to survival within the phagolysosomal environment. Here we review the current understanding of the role of mucosa-associated E. coli in Crohn’s pathogenesis, the role of the innate immune system, factors which may contribute to prolonged bacterial survival and therapeutic strategies to target intracellular E. coli.

关键词： Crohn's disease Inflammatory bowel disease Escherichia coli Intra-macrophage survival and replication Phagolysosome Autophagy

Effect of partial blockage of air duct outlet on performance of OWC device

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Central South University 2012年第3期19卷 748-754页

作者： S.Patel k.Ram M.Rafiuddin ahmed Renewable Energy Research Group University of the South Pacific

The use of a Savonius rotor as turbine for an oscillating water column(OWC) is *** effect of tuning the OWC using turbine duct blockage is also studied for different wave conditions.A horizontal turbine section OWC employing a Savonius rotor was tested by varying the opening of OWC exit(0%,25%,50%,75% and 100%) to study the behavior and performance of the *** OWC model was tested at water depth of 0.29 m at frequencies of 0.8,0.9 and 1.0 Hz while the exit openings are *** static pressure,dynamic pressure,rotational speed of the Savonius rotor and the coefficient of power are presented as *** OWC with exit opening of 25% showed greater performance in terms of rotational speed and CP compared to OWC with other exit opening *** proves the ability of the OWC to be tuned by regulating flow in the turbine duct.

关键词： oscillating water column wave energy converter wells turbine impulse turbine Savonius rotor

A STUDY OF A FULLY COUPLED TWO-PARAMETER SYSTEM OF SEQUENTIAL FRACTIONAL INTEGRO-DIFFERENTIAL EQUATIONS WITH NONLOCAL INTEGRO-MULTIPOINT BOUNDARY CONDITIONS

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2019年第4期39卷 927-944页

作者： ahmed ALSAEDI Bashir AHMAD Shorog ALJOUDI Sotiris k. NTOUYAS Nonlinear Analysis and Applied Mathematics (NA AM)-Research Group Department of Mathematics Faculty of Science King Abdulaziz UniversityP.O. Box 80203 Jeddah 21589 Saudi Arabia Department of Mathematics University of Ioannina 451 10 Ioannina Greece Nonlinear Analysis and Applied Mathematics (NA AM)-Research Group Department of Mathematics Faculty of Science King Abdulaziz UniversityP. O. Box 80203 Jeddah 21589 Saudi Arabia

In this article, we discuss the existence and uniqueness of solutions for a coupled two-parameter system of sequential fractional integro-differential equations supplemented with nonlocal integro-multipoint boundary conditions. The standard tools of the fixed-point theory are employed to obtain the main results. We emphasize that our results are not only new in the given configuration, but also correspond to several new special cases for specific values of the parameters involved in the problem at hand.

关键词： Coupled system sequential fractional derivative multi-point integral boundary conditions existence

Composite Solid Rocket Propellant Based on GAP Polyurethane Matrix with Different Binder Contents

在线全文

学校读者我要写书评

暂无评论

火炸药学报 2020年第4期43卷 362-367页

作者： Islam kBoshra ahmed Elbeih GUO Lin Mohamed GZaki School of Chemistry and Environment Beihang UniversityBeijing 100191China Military Technical College Kobry ElkobbahCairoEgypt

Different GAP-based CSRP samples with different binder contents were prepared and compared with that of conventional HTPB *** crosslinker mixture of trimethylol propane(TMP)and butane diol(BD)was used in the GAP matrix beside the addition of dibutyltin dilaurate(DBTDL)to ensure cross-linking and curing completion of the prepared *** viscosity and hardness of all prepared formulations were monitored continuously during the curing *** mechanical characteristics of cured samples were *** burning rate at operating pressure and specific impulse were measured,while the theoretical specific impulse(I sp)was calculated by ICT code and compared with the measured *** to the results,DOA was found to be a suitable plasticizer for GAP when using in *** mechanical properties of CSRP with 25%GAP can produce the optimum mechanical behavior,which is close to that of HTPB-based *** optimum GAP-based formulation is one candidate to replace the traditional HTPB-based CSRP with high burning rate for some applications.

关键词： physical chemistry glycidyl azide polymer(GAP) hydroxyl terminated polybutadiene(HTPB) cross-linker mechanical properties

Effect of Three Different Growth Media on Yield and Oil Constituents of Rosemary （Rosmarinus officinalis L.） under Protected Agriculture Conditions

在线全文

学校读者我要写书评

暂无评论

Journal of Agricultural Science and Technology(A) 2014年第5期4卷 395-403页

作者： kholod F. Abou Seedo ahmed A. Salih ahmed A. taha Arid Zones Sciences Programme Graduate College Arabian Gulf University Manama Kingdom of Bahrain Department of Chemistry Faculty of Science University of Bahrain Manama Kingdom of Bahrain

Medicinal plants provide an important source of cure since ancient time. Poor soil resources, scarce and saline water and the harsh environment limited the production of plants in the Arabian Gulf countries. This study aimed to investigate the production potential of rosemary （Rosmarinus officinalis L.） grown on different growth media under greenhouse conditions. Three growth media agricultural soil, compost and hydroponic system were used, whereas tuff （inert volcanic material） was used as substrate. The result indicated that the high salinity of the agricultural soil limited growth and oil yield in rosemary. Shoot height increased in 11 weeks, by 62%, 65% and 114% in plants grown in agricultural soil, hydroponic system and compost, respectively. Na content in plants grown in agricultural soil was significantly higher than in plants grown in the other treatment. Essential oil yield in plants grown in compost exceeded those in agricultural soil by 114%. Essential oil content （0.66%-1.5% w/w） and chemical constituents concentrations did not change significantly with growth media. The main constituents, more or less, are comparable to essential oils constituents reported from other countries. In comparison, better yields are obtained for individual components of the oils of plants grown under our green house conditions. This study demonstrated the great potential of commercial production of rosemary in the greenhouse without compromising the oil quality and oil yield.

关键词： Rosemary oil content chemical composition nutrients greenhouse conditions growth media hydroponic compost.

Transference Principles for the Series of Semigroups with a Theorem of Peller

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Pure Mathematics 2019年第2期9卷 164-204页

作者： Simon Joseph ahmed Sufyan Hala taha Ranya Tahir Department of Mathematics College of Education Dr. John Garang Memorial University of Science and Technology Bor South Sudan Department of Mathematics Ministry of Education Muscat Sultanate of Oman Department of Mathematics College of Science Princess Nourah bint Abdulrahman University Al-Riyadh KSA Department of Mathematics Faculty of Science Jazan University Jazan KSA

A general approach to transference principles for discrete and continuous sequence of operators (semi) groups is described. This allows one to recover the classical transference results of Calderon, Coifman and Weiss and of Berkson, Gilleppie and Muhly and the more recent one of the author. The method is applied to derive a new transference principle for (discrete and continuous) the sequence of operators semigroups that need not be grouped. As an application, functional calculus estimates for bounded sequence of operators with at most polynomially growing powers are derived, leading to a new proof of classical results by Peller from 1982. The method allows for a generalization of his results away from Hilbert spaces to -spaces and—involving the concept of γ-boundedness—to general spaces. Analogous results for strongly-continuous one-parameter (semi) groups are presented as well by Markus Haase [1]. Finally, an application is given to singular integrals for one-parameter semigroups.

关键词： Transference Operator Semigroup Functional Calculus Analytic Besov Peller γ-Boundedness γ-Radonifying γ-Summing Power-Bounded Operator

Covid-19 Detection Using Deep Correlation-Grey Wolf Optimizer

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computer Systems Science & Engineering 2023年第9期46卷 2933-2945页

作者： k.S.Bhuvaneshwari ahmed Najat ahmed Mehedi Masud Samah H.Alajmani Mohamed Abouhawwash Department of Computer Science and Engineering Karpagam College of EngineeringCoimbatore641032India Department of Computer Engineering Lebanese French UniversityErbil44001Iraq Department of Computer Science College of Computers and Information TechnologyTaif UniversityP.O.Box 11099Taif21944Saudi Arabia Department of Information Technology College of Computer and Information TechnologyTaif UniversityPO Box 11099Taif21994Saudi Arabia Department of Mathematics Faculty of ScienceMansoura UniversityMansoura35516Egypt Department of Computational Mathematics Scienceand Engineering(CMSE)Michigan State UniversityEast Lansing48824MIUSA

The immediate and quick spread of the coronavirus has become a life-threatening disease around the *** widespread illness has dramatically changed almost all sectors,moving from offline to online,resulting in a new normal lifestyle for *** impact of coronavirus is tremendous in the healthcare sector,which has experienced a decline in the first quarter of *** pandemic has created an urge to use computer-aided diagnosis techniques for classifying the Covid-19 dataset to reduce the burden of clinical *** current situation motivated me to choose correlationbased development called correlation-based grey wolf optimizer to perform accurate classification.A proposed multistage model helps to identify Covid from Computed Tomography(CT)scan *** first process uses a convolutional neural network(CNN)for extracting the feature from the CT *** Pearson coefficient filter method is applied to remove redundant and irrelevant ***,theGrey wolf optimizer is used to choose optimal *** analysis proves that this determines the optimal characteristics to detect the deadly *** proposed model’s accuracy is 14%higher than the krill herd and bacterial foraging optimization for severe accurate respiratory syndrome image(SARS-CoV-2 CT)*** COVID CT image dataset is 22%higher than the existing krill herd and bacterial foraging optimization *** proposed techniques help to increase the classification accuracy of the algorithm in most cases,which marks the stability of the stated *** analysis reveals that the proposed classification technique to predict COVID-19 withmaximumaccuracy of 98%outperforms other competitive approaches.

关键词： COVID-19 feature selection CT image classification features extraction