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strength-ductility synergy in a 1.4 GPa austenitic steel with a heterogeneous lamellar microstructure

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Journal of Materials science & Technology 2022年第11期106卷 133-138页

作者： Gang Niu hatem s.Zurob R.D.K.Misra Huibin Wu Yu Zou Department of Materials science and Engineering University of TorontoTorontoONM5S 3E4Canada Collaborative Innovation Center of Steel TechnologyUniversity of Science and Technology BeijingBeijing 100083China Department of Materials science and Engineering McMaster UniversityHamiltonONL8S 4L7Canada Department of Metallurgical Materials and Biomedical EngineeringUniversity of Texas at El PasoEl PasoTX 79968USA Collaborative Innovation Center of steel Technology University of Science and Technology BeijingBeijing 100083China Department of Materials science and Engineering University of TorontoTorontoONM5S 3E4Canada

*** Advanced high-strength steels with good ductility are essen-tial to the manufacturing,structural safety,and light-weighting of load-bearing structures in many industries[1-3].Austenitic stain-less steel(Ass)exhibits high ductility due to the TRIP and/or TWIP effect that can alleviate stress concentration,prevent void nucle-ation,enhance work hardening,and postpone necking[4-6].The yield strength of conventional Ass is generally low(∼200-500 MPa),and their deformation resistance is insufficient for many load-bearing applications[6].Previous studies reported the in-creased yield strength in various austenitic steels through grain refinement,dislocation strengthening,precipitation strengthening,and heterogeneous hardening[7-14].A single strengthening mech-anism,however,is typically insufficient to obtain ultrahigh yield strength over 1 GPa in austenitic steel[12].

关键词： steel ductility austenitic

Congestion pricing strategies to investigate the potential of route diversion on toll facilities using en-route guidance

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Journal of Traffic and Transportation Engineering(English Edition) 2016年第1期3卷 59-70页

作者： hatem Abou-senna Center for Advanced Transportation systems simulations (CATss) Department of Civil Environmental and Construction Engineering (CECE) University of Central Florida

The application of intelligent transportation systems （ITs） technologies to facilitate the traffic mobility requires dynamic routing decisions. This study examines the effectiveness of Paramics, a microscopic traffic simulation model that uses a link-to-link shortest path algorithm to consider both updated link travel times and incident conditions detected through different traffic assignment techniques. This paper describes modeling of an urban highway network＇s traffic conditions to investigate potential route diversion through congestion pricing strategies on toll facilities in Orlando, Florida using Paramics. The experimental design included a multi-level factorial design with three qualitative variables and four response quantitative variables. The experiment＇s objective was to investigate different scenarios for reducing tolls on less congested roads （sR528 and sR417） and increasing tolls on more congested roads （sR408） to determine the impact on travelers＇ route choices and overall congestion in the network. The simulation results demonstrate that the Dynamic Feedback Assignment （DFB） led to a reduction in the average queuing delay and average travel time when compared to results from the stochastic Assignment （sA）. DFB significantly affected the percentage of diversion in the network. Drivers saved 10%-16% of travel time when DFB information was provided. Results also show that percentages of route diversion vary from one route to another and depending on the travel cost between specific origin-destination pairs. While drivers incorporate real time guidance information to maximize their own utility, not all drivers gain the same benefit. This was attributed to the limited extra capacity of the alternative routes and the longer travel distance. Combining congestion pricing strategies with traffic information maximize travel time benefits.

关键词： ParamicsCongestion pricingToll roadRoute diversionDynamic assignmentIntelligent transportation systems

Hordatines as a Potential Inhibitor of COVID-19 Main Protease and RNA Polymerase: An In-silico Approach

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Natural Products and Bioprospecting 2020年第6期10卷 453-462页

作者： Mohammed ADahab Mostafa M.Hegazy hatem s.Abbass Department of Pharmaceutical Medicinal Chemistry and Drug Design Faculty of PharmacyAl-Azhar University(Boys)Cairo 11884Egypt Department of Pharmacognosy Faculty of PharmacyAl-Azhar University(Boys)Cairo 11884Egypt Department of Pharmacognosy Faculty of PharmacySinai UniversityKantara 41636Egypt

Total 40 natural compounds were selected to perform the molecular docking studies to screen and identify the potent antiviral agents specifically for severe Acute Respiratory syndrome Coronavirus 2 that causes coronavirus disease 2019(COVID-19).The key targets of COVID-19,protease(PDB ID:7BQY)and RNA polymerase(PDB ID:7bV2)were used to dock our target compounds by Molecular Operating Environment(MOE)version *** used 3 different conformations of protease target(6M0K,6Y2F and 7BQY)and two different score functions to strengthen the probability of inhibitors *** an extensive screening analysis,20 compounds exhibit good binding affinities to one or both COVID-19 targets.7 out of 20 compounds were predicted to overcome the activity of both *** top 7 hits are,flacourticin(3),sagerinic acid(16),hordatine A(23),hordatine B(24),N-feruloyl tyramine dimer(25),bisavenanthramides B-5(29)and vulnibactins(40).According to our results,all these top hits was found to have a better binding scores than remdesivir,the native ligand in RNA polymerase target(PDB ID:7bV2).Hordatines are phenolic compounds present in barley,were found to exhibit the highest binding affinity to both protease and polymerase through forming strong hydrogen bonds with the catalytic residues,as well as significant interactions with other receptor-binding *** results probably provided an excellent lead candidate for the development of therapeutic drugs against ***,animal experiment and accurate clinical trials are needed to confirm the preventive potentials of these compounds.

关键词： Barley COVID-19 Docking Hordatine Protease RNA polymerase MOE

six Minute Walk Test to assess functional capacity in chronic liver disease patients

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World Journal of Gastroenterology 2007年第29期13卷 3996-4001页

作者： hatem F Alameri Faisal M sanai Manal Al Dukhayil Nahla A Azzam Khalid A Al-swat Ahmad s Hersi Ayman A Abdo Unit of Pulmonary Medicine Department of Medicine King Saud University Riyadh Saudi Arabia Hepatology Division Department of Medicine Riyadh Military Hospital Riyadh Saudi Arabia Unit of Gastroenterology Department of Medicine King Saud University Riyadh Saudi Arabia

AIM: To examine the utility of six Minute Walk Test (6MWT) in patients with chronic liver disease (CLD). METHODs: Two hundred and fifty subjects between the ages of 18 and 80 (mean 47) years performed 6MWT and the six Minute Walk Distance (6MWD) was measured. REsULTs: The subjects were categorized into four groups. Group A (n = 45) healthy subjects (control); group B (n = 49) chronic hepatitis B patients; group C (n = 54) chronic hepatitis C patients; group D (n = 98) liver cirrhosis patients. The four groups differed in terms of 6MWDs (P st distance walked was 421 ± 47 m by group A, then group B (390 ± 53 m), group C (357 ± 72 m) and group D (306 ± 111 m). The 6MWD correlated with age (r = -0.482, P s. The Child-Pugh classification was negatively correlated with the 6MWD in cirrhosis (group D) patients (r = -0.328, P sis patients had died from disease complications. The 6MWD for the surviving cirrhotic patients was longer than for non-survivors (317 ± 101 vs 245 ± 145 m, P = 0.021; 95% CI 11-132). The 6MWD was found to be an independent predictor of survival (P = 0.024). CONCLUsION: 6MWT is a useful tool for assessing physical function in CLD patients. We suggest that 6MWD may serve as a prognostic indicator in patients with liver cirrhosis.

关键词： six Minute Walk Test Chronic liver disease Functional capacity

Application of AVO attributes for gas channels identification, West offshore Nile Delta, Egypt

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Petroleum Research 2020年第2期5卷 112-123页

作者： Amir Ismail hatem Farouk Ewida Mohammad Galal Al-Ibiary Aldo Zollo Department of Physics“E.Pancini” University of Naples‘Federico II’Italy Department of Geology Faculty of ScienceHelwan UniversityCairoEgypt Exploration General Manager PERENCO North Sinai Petroleum CompanyCairoEgypt

The offshore part of the Nile Delta is considered one of the most prolific provinces for gas production andfor future petroleum exploration. Amplitude Variation with Offset (AVO) analysis supported by composite logs considered as one of the best-advanced techniques enables the interpreter to understand theseismic data. It is used to generate a new view of the output results, especially for the identification of gaszones as gas channels by using pre-stack AVO attributes that based on the intercept product gradient(A*B) and the scaled Poisson’s Ratio Change. Free gas, regardless of the percentage show obvious AVOanomaly. Well log data, including gamma-ray, resistivity, and Vp sonic logs are used in the seismic data towell tie and in the generation of the synthetic seismogram. seismic data conditioning processes withcheck-shot correction is performed to improve the resolution of the reflection events and signal to noiseratio. AVO attributes technique, as a direct hydrocarbon indicator, including AVO gradient analysis andAVO crossplot separate the gas levels in the sand-shale sequences. The identified gas-bearing zonesconsistent with well log data responses. As the main conclusion, we show the visual evidence for the gasbearing zones by interpreting different AVO responses due to the changes in fluid and rock types.

关键词： AVO attributes Offshore Nile Delta Gas channels Gas bearing sand zones AVO crossplots

Isolation Enhancement in a Compact Four-Element MIMO Antenna for Ultra-Wideband Applications

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Computers, Materials & Continua 2023年第4期75卷 911-925页

作者： Awais Khan shahid Bashir salman Ghafoor hatem Rmili Jawad Mirza Ammar Ahmad Department of Electrical Engineering University of Engineering and TechnologyPeshawar25000Pakistan Department of Electrical Engineering University of Science and TechnologyBannu28100Pakistan school of Electrical Engineering and Computer science(sEECs) National University of Sciences and Technology(NUST)Islamabad44000Pakistan Electrical and Computer Engineering Department Faculty of EngineeringKing Abdulaziz UniversityJeddahSaudi Arabia K.A.CARE Energy Research and Innovation Center King Abdulaziz UniversityJeddah21589Saudi Arabia sEECs Photonic Research Group National University of Sciences and TechnologyIslamabad44000Pakistan

Mutual coupling reduction or isolation enhancement in antenna arrays is an important area of research as it severely affects the performance of an *** this paper,a new type of compact and highly isolated Multiple-Input-Multiple-Output(MIMO)antenna for ultra-wideband(UWB)applications is *** design consists of four radiators that are orthogonally positioned and confined to a compact 40×40×0.8 mm3 *** final antenna design uses an inverted L shape partial ground to produce an acceptable reflection coefficient(s11solation has also been enhanced to>20 db for majority of the UWB *** antenna was fabricated and tested with the vector network analyzer(VNA)and in an anechoic chamber for scattering parameters and radiation ***,different MIMO diversity performance metrics are also measured to validate the proposed *** simulation results and the experimental results from the constructed model agree quite *** proposed antenna is compared with similar designs in recently published literature for various performance *** of its low envelope correlation coefficient(ECCsity gain(DG>9.99 dB),peak gain of 4.6 dB,reduced channel capacity loss(CCLs/Hz),and average radiation efficiency of over 85%,the proposed MIMO antenna is ideally suited for practical UWB applications.

关键词： Multiple input multiple output antennas envelope correlation coefficient defected ground structure ultra wide band diversity gain

Evaluating germinability of eight desert halophytes under long-term seed storage: Implications for conservation

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Plant Diversity 2019年第4期41卷 229-236页

作者： sanjay Gairola hatem A. shabana Tamer Mahmoud Ali El-Keblawy Andrea santo sharjah seed Bank and Herbarium Sharjah Research AcademyP.O.Box 60999SharjahUnited Arab Emirates Department of Applied Biology College of SciencesUniversity of SharjahP.O.Box 27272SharjahUnited Arab Emirates Independent Researcher SelargiusCagliariItaly

Ex situ conservation in seed banks is a potential complementary conservation strategy for native plant *** is well established that ex situ seed banking of native wild plants prolongs seed viability and thereby preserves genetic and species diversity for future *** evaluated ex situ storage potential of eight halophytic species from deserts in the United Arab Emirates(UAE)by studying seed ***,we examined the germinability of freshly collected seeds and seeds stored for three years in a seed *** also examined the effect of light conditions on fresh and stored seed *** seeds of seven of the eight species tested had a higher germination rates under 12/12 h light/dark fluctuations than did those exposed to total *** reduced light sensitivity in Halocnemum strobilaceum,suaeda aegyptiaca,salsola drummondii and salsola imbricata,but increased the requirement for light in Arthrocnemum *** Anabasis setifera,storage decreased germination percentage when there was a 12-hour light/dark fluctuation,but increased germination rate when exposed to the dark *** significantly reduced germination in both the light/dark and dark treatments in suaeda vermiculata and *** speed also responded differently to storage;whereas Timson's index significantly increased in *** and ***,it significantly decreased for ***,*** and *** of these species at a range of temperatures requires further testing;additionally,we strongly suggest that these laboratory findings be complemented by field studies.

关键词： Ex situ conservation Halophytes seed bank collection seed germination salt tolerance ssBH

Load Balancing Based on Multi-Agent Framework to Enhance Cloud Environment

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Computers, Materials & Continua 2023年第2期74卷 3015-3028页

作者： shrouk H.Hessen hatem M.Abdul-kader Ayman E.Khedr Rashed K.salem Information systems Department Faculty of Computers and InformationMenoufia UniversityShebin ElkomEgypt Information systems Department Faculty of Computers and Artificial IntelligenceSouth Valley UniversityHurghadaEgypt Information systems Department Faculty of Computers and Information TechnologyFuture University in Egypt(FUE)CairoEgypt

According to the advances in users’service requirements,physical hardware accessibility,and speed of resource delivery,Cloud Computing(CC)is an essential technology to be used in many ***,the Internet of Things(IoT)is employed for more communication flexibility and richness that are required to obtain fruitful services.A multi-agent system might be a proper solution to control the load balancing of interaction and communication among *** paper proposes a multi-agent load balancing framework that consists of two phases to optimize the workload among different servers with large-scale CC power with various utilities and a significant number of IoT devices with low *** agents are integrated based on relevant features of behavioral interaction using classification techniques to balance the *** balancing algorithm is developed to serve users’requests to improve the solution of workload problems with an efficient *** activity task from IoT devices has been classified by feature selection methods in the preparatory phase to optimize the scalability ***,the server’s availability is checked and the classified task is assigned to its suitable server in the main phase to enhance the cloud environment ***-agent load balancing framework is succeeded to cope with the importance of using large-scale requirements of CC and(low resources and large number)of IoT.

关键词： Cloud computing IoT multi-agent system load balancing algorithm server utilities

Experimental Investigation of Natural Fiber Reinforced Polymers

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Materials sciences and Applications 2012年第2期3卷 59-66页

作者： Irene s. Fahim salah M. Elhaggar hatem Elayat 不详

The potential usage of virgin Low density polyethelyne (LDPE) reinforced with different concentrations (2%, 5% and 6% by weight) of treated rice straw with different lengths (2 mm, 4 mm and 6 mm) is investigated to produce high value products that have technical and environmental demand. The two treatment methods used for rice straw are alkali and acidic treatments of rice straw. The removal of impurities and waxy substances from fiber surface avoid creation of rougher topography after treatment and improves the quality of fiber, also content of hemi cellulose and lignin decrease so increase effectiveness of fiber due to dispersing of fiber in matrix. The reinforcing material is embedded in the matrix material to enhance tensile and flexural behaviors of the synthesized composite. The result of investigating these two mechanical properties, using statistical analysis & design of experiments, showed an enhancement in the mechaniccal properties of the virgin polymer composite compared to the virgin polymer. The flexural stress of the composite increased three times the virgin flexural stress, while the tensile stress increased eight times the original tensile stress.

关键词： Polymers-Matrix Composites (PMCs) Fiber Reinforced Plastic (FRP) Natural Fibers Low Density Polyethylene (LDPE)