检索结果-南通市图书馆

Green synthesis of bentonite-supported iron nanoparticles as a heterogeneous Fenton-like catalyst:Kinetics of decolorization of reactive blue 238 dye

在线全文

学校读者我要写书评

暂无评论

Water Science and Engineering 2020年第4期13卷 286-298页

作者： ahmed Khudhair Hassan Ghayda Yaseen al-Kindi Dalal Ghanim Environment and Water Directorate Ministry of Science and TechnologyBaghdad 10070Iraq Sanitary and Environmental Branch Civil Engineering DepartmentUniversity of TechnologyBaghdad 10009Iraq

This study aimed to synthesize green tea nano zero-valent iron(GT-NZVI)and bentonite-supported green tea nano zero-valent iron(BGT-NZVI)nanoparticles using green tea extracts in an environmentally sustainable *** was used as a support material because it disperses and stabilizes GT-NZVI,and it helps to reduce the cost,increase the adsorption capacity of GT-NZVI,and decrease the optimum amount of GT-NZVI used in Fenton-like oxidation.A scanning electron microscope,an atomic force microscope,and a Fourier transform infrared spectroscope were used to characterize GT-NZVI and B-GT-NZVI,while the zeta potential was measured to evaluate the stability of iron *** decolorization kinetics of reactive blue 238(RB 238)dye in the aqueous phase in the Fenton-like oxidation process were investigated as *** effects of various experimental conditions such as reaction time,dosages of catalysts,concentration of H2O2,temperature,addition of inorganic salts,and other parameters were *** results show that the oxidative degradation efficiencies of RB 238 dye catalyzed by GT-NZVI and B-GT-NZVI were 93.5%and 96.2%,respectively,at the optimum reaction conditions as follows:c(H2O2)¼5 mmol/L,r(GT-NZVI)¼0.5 g/L or r(B-GT-NZVI)¼0.5 g/L,c(RB 238 dye)¼0.05 mmol/L,and pH¼2.5 at 180 *** best catalytic performance was exhibited when B-GT-NZVI was *** kinetic models were employed,and the second-order model was found to be the best model representing the experimental kinetic data of RB 238 *** value of activation energy decreased from 38.22 kJ/mol for GT-NZVI to 14.13 kJ/mol for *** indicates that the effect of B-GT-NZVI in decreasing the energy barrier is more pronounced than that of the GT-NZVI catalyst,leading to improved Fenton-like oxidation processes.©2020 Hohai *** and hosting by Elsevier *** is an open access article under the CC BY-NC-ND license(http://***/licenses/by-nc-nd/4.0/).

关键词： Green synthesis Bentonite-supported iron nanoparticles Azo dye Fenton-like process Kinetics

Evaluation of extracts and essential oil from Callistemon viminalis leaves:Antibacterial and antioxidant activities,total phenolic and flavonoid contents

在线全文

学校读者我要写书评

暂无评论

Asian Pacific Journal of Tropical Medicine 2013年第10期6卷 785-791页

作者： Mohamed ZM salem Hayssam M ali Nader A El-Shanhorey ahmed Abdel-Megeed Forestry and Wood Technology Department Faculty of Agriculture(EL-Shatby)Alexandria University Botany and Microbiology Department College of ScienceKing Saud University Timber Trees Research Department Sabahia Horticulture Research StationHorticulture Research InstituteAgriculture Research Center Department of Botanical Gardens Research Horticultural Research Institute(ARC) Faculty of Agriculture(Saba Basha) Alexandria University

Objective:To investigate antioxidant and antibacterial activities of Callistemon viminalis(***)***:The essential oil of *** leaves obtained by hydrodistillation was analyzed by GC/*** extracts were tested for total phenolic and flavonoid contents and in vitro antioxidant(DPPH assay)and antibacterial(agar disc diffusion and 96-well micro-plates methods)***:Fourteen components were identified in the essential oil,representing 98.94%of the total *** major components were 1,8-cineole(64.53%)andα-pinene(9.69%).Leaf essential oil exhibited the highest antioxidant activity of(88.60±1.51)%comparable to gallic acid,a standard compound[(80.00±2.12)%].Additionally,the biggest zone of inhibitions against the studied bacterial strains was observed by the essential oil when compared to the standard antibiotic(tetracycline).The crude methanol extract and ethyl acetate fraction had a significant antibacterial activity against the tested bacterial ***:It can be suggested that *** is a great potential source of antibacterial and antioxidant compounds useful for new antimicrobial drugs from the natural *** present study revealed that the essential oil as well as the methanol extracts and ethyl acetate fraction of *** leaves exhibited highly significant antibacterial activity against the tested bacterial strains.

关键词： Callistemon viminalis Essential oil Antibacterial activity Antioxidant activity Phenolic content Flavonoid content

Hydromechanical behavior of unsaturated expansive clay under repetitive loading

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 Rock Mechanics and Geotechnical Engineering 2021年第5期13卷 1136-1146页

作者： ahmed M.al-Mahbashi Mosleh A.al-Shamrani Mohammad F.Abbas Bugshan Research Chair in Expansive Soils Department of Civil EngineeringKing Saud UniversityRiyadh11421Saudi Arabia Civil Engineering Department Prince Sattam bin Abdulaziz UniversityAl-Kharj11942Saudi Arabia Soil Mechanics and Geotechnical Engineering Research Institute Housing and Building National Research Center(HBRC)Giza11511Egypt

Compacted layers of expansive soils are used in different engineering projects,such as subgrades,engineered clay barriers,and buffers for radioactive waste *** layers are exposed to a variety of stresses and wetting conditions during field *** between hydraulic and mechanical repeated loading provides insight understanding to the induced progressive deformation of expansive *** study was conducted to investigate the hydromechanical behavior of unsaturated compacted expansive clay under repeated loadingeunloading(RLU)*** series of onedimensional(1D)oedometer tests were conducted under controlled matric suction up to 1500 kPa using the axis translation technique(Fredlund soil-water characteristic curve device,SWC-150).The first test series was carried out at different levels of controlled matric suction for non-repeated loading eunloading(NRLU)*** cycles were applied in the second test series at different repetitivestress levels and under different levels of matric *** results indicated increasing axial wetting strainε_(a)(s),axial swell pressure ss(s),compression index C_(c)(s),and swell index C_(s)(s)with suction *** estimated loadecollapse(LC)curves obtained from NRLU series(LCN)and RLU series(LCR)indicated increasing yield stress sy(s)with increasing *** is attributed to the developed apparent cohesion between soil particles,which in turn rigidifies the material *** repetitive loading induced a notable reduction of compression index C_(c)(s)at the same level of suction,whereas swell index C_(s)(s)seems to be independent of repetitive ***,repetitive loading exceeding initial yield stresses results in plastic hardening and,hence,enlargement of yield stress locus(*** curve).

关键词： Expansive clay Repetitive loading Suction Hydromechanical behavior Loadecollapse curve

Macrophage modulation with dipeptidyl peptidase-4 inhibitors:A new frontier for treating diabetic cardiomyopathy?

在线全文

学校读者我要写书评

暂无评论

World Journal of Diabetes 2024年第9期15卷 1847-1852页

作者： Saeed Mohammadi ahmed al-Harrasi Natural and Medical Sciences Research Center University of NizwaNizwa 616Oman Department of Biological Sciences and Chemistry University of NizwaNizwa 616Oman

This editorial introduces the potential of targeting macrophage function for diabetic cardiomyopathy(DCM)treatment by dipeptidyl peptidase-4(DPP-4)*** et al studied teneligliptin,a DPP-4 inhibitor used for diabetes management,and its potential cardioprotective effects in a diabetic mouse *** suggested teneligliptin administration may reverse established markers of DCM,including cardiac hypertrophy and compromised *** also inhibited the NLRP3 inflammasome and reduced inflammatory cytokine production in diabetic *** play crucial roles in DCM *** hyperglycemia disturbs the balance between pro-inflammatory(M1)and antiinflammatory(M2)macrophages,favoring a pro-inflammatory state contributing to heart ***,we highlight the potential of DPP-4 inhibitors to modulate macrophage function and promote an anti-inflammatory *** compounds may achieve this by elevating glucagon-like peptide-1 levels and potentially inhibiting the NLRP3 *** studies on teneligliptin in combination with other therapies targeting different aspects of DCM could be suggested for developing more effective treatment strategies to improve cardiovascular health in diabetic patients.

关键词： Diabetic cardiomyopathy Macrophage Dipeptidyl peptidase-4 inhibitor Teneligliptin NLRP3 inflammasome Glucagon-like peptide-1

Development of Machine Learning Regression Models for Predicting the Performance of Nanofibrous Scaffolds for Skin Tissue Engineering

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

生物组学研究杂志(英文) 2024年第3期7卷 97-104页

作者： salem Dina ahmed Moharam Mohamed Hussein Hashem Esraa Mamdouh Computer Engineering Department Misr University for Science and Technology (MUST University)th of October Egypt Communication Engineering Department Misr University for Science and Technology (MUST University)th of October Egypt Biomedical Engineering Department Misr University for Science and Technology (MUST University)th of October Egypt

Tissue engineering is a branch of regenerative medicine that harnesses biomaterials and stem cells to utilize the body’s natural healing responses to regenerate tissue and organs. Skin components can be rebuilt by safeguarding their structure and function with the help of advanced scaffold manufacturing techniques. It is important to combine medical concerns with the vast explosion of artificial intelligence concepts to preserve human life and improve health. Currently, machine learning can make reliable contributions to critical decision-making in a wide range of applications. Regression machine learning models rely on correlations, associations, and other relationships between a dependent variable and a group of features. The main objective of this research was to study the effects of applying machine learning techniques on the performance of nanoscaffolds. A regression tree, a random forest, AdaBoost, and a gradient boosting algorithm were applied to the dataset and clustering data. By comparing our proposed models with the relevant studies to verify each machine learning model’s optimal performance, the AdaBoost technique was shown to have the highest accuracy (98.58%, 99.6%, 98.51%, and 98.85%), with a mean absolute percentage error of 1.41% and anR2 value of 0.999, which indicates a strong correlation between the predicted and actual values for the whole dataset and all subgroups.

关键词：

Reforming of Methane by CO2 over Bimetallic Ni-Mn/γ-al2O3 Catalyst

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Physics 2014年第2期27卷 214-220,I0004页

作者： Anis Hamza Fakeeha Muhammad Awais Naeem Wasim Ullah Khan ahmed Elhag Abasaeed ahmed Sadeq al-Fatesh 沙特国王大学工程学院化学工程系利雅得11421

γ-al2O3 supported Ni-Mn bimetallic catalysts for CO2 reforming of methane were prepared by impregnation method. The reforming reactions were conducted at 500-700℃ and atmospheric pressure using CO2/CH4/N2 with feed ratio of 17/17/2, at total flow rate of 36 mL/min. The catalytic performance was assessed through CH4 and CO2 conversions, synthesis gas ratio （H2/CO） and long term stability. Catalytic activity and stability tests revealed that addition of Mn improved catalytic performance and led to higher stability of bimetallic catalysts which presented better coke suppression than monometallic catalyst. In this work, the optimum loading of Mn which exhibited the most stable performance and least coke deposition was 0.5wt%. The fresh and spent catalysts were characterized by various techniques such as Brunauer-Emmett-Teller, the temperature programmed desorption CO2- TPD, thermogravimetric analysis, X-ray diffraction, scanning electron microscope, EDX, and infrared spectroscopy.

关键词： CH4 CO2 Bimetallic Dry reforming Ni/γ-al2O3 Mn and H2/CO

Overview of the Global Electricity System in Oman Considering Energy Demand Model Forecast

在线全文

学校读者我要写书评

暂无评论

Energy Engineering 2023年第2期120卷 409-423页

作者： ahmed al-Abri Kenneth E.Okedu Department of Electrical and Communication Engineering National University of Science and TechnologyPC 111MuscatSultanate of Oman Department of Electrical and Electronic Engineering Nisantasi UniversityIstanbulTurkey

Lately,in modern smart power grids,energy demand for accurate forecast of electricity is gaining attention,with increased interest of *** is due to the fact that a good energy demand forecast would lead to proper responses for electricity *** addition,proper energy demand forecast would ensure efficient planning of the electricity industry and is critical in the scheduling of the power grid capacity and management of the entire power *** most power systems are been deregulated and with the rapid introduction and development of smart-metering technologies in Oman,new opportunities may arise considering the efficiency and reliability of the power system;like price-based demand response *** programs could either be a large scale for household,commercial or industrial ***,excellent demand forecasting models are crucial for the deployment of these smart metering in the power grid based on good knowledge of the electricity market ***,in this paper,an overview of the Oman regulatory regime,financial mechanism,price control,and distribution system security standard were *** so,the energy demand forecast in Oman was analysed,using the econometric model to forecasts its energy peak *** energy econometric analysis in this study describes the relationship between the growth of historical electricity consumption and macro-economic parameters(by region,and by tariff),considering a case study of Mazoon Electricity Distribution Company(MZEC),which is one of the major power distribution companies in Oman,for effective energy demand in the power grid.

关键词： Energy forecast energy demand load demand power grids electricity sector

Genetic Crossover Operators for the Capacitated Vehicle Routing Problem

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2023年第1期74卷 1575-1605页

作者： Zakir Hussain ahmed Naif al-Otaibi Abdullah al-Tameem Abdul Khader Jilani Saudagar Department of Mathematics and Statistics College of ScienceImam Mohammad Ibn Saud Islamic University(IMSIU)RiyadhSaudi Arabia Department of Information Systems College of Computer and Information SciencesImam Mohammad Ibn Saud Islamic University(IMSIU)RiyadhSaudi Arabia

We study the capacitated vehicle routing problem(CVRP)which is a well-known NP-hard combinatorial optimization problem(COP).The aim of the problem is to serve different customers by a convoy of vehicles starting from a depot so that sum of the routing costs under their capacity constraints is *** the problem is very complicated,solving the problem using exact methods is almost ***,one has to go for the heuristic/metaheuristic methods and genetic algorithm(GA)is broadly applied metaheuristic method to obtain near optimal solution to such ***,this paper studies GAs to find solution to the ***,to solve a COP,GAs start with a chromosome set named initial population,and then mainly three operators-selection,crossover andmutation,are *** these three operators,crossover is very crucial in designing and implementing GAs,and hence,numerous crossover operators were developed and applied to different *** are two major kinds of crossover operators-blind crossovers and distance-based *** intend to compare the performance of four blind crossover and four distance-based crossover operators to test the suitability of the operators to solve the *** operators were originally proposed for the standard travelling salesman problem(TSP).First,these eight crossovers are illustrated using same parent chromosomes for building offspring(s).Then eight GAs using these eight crossover operators without any mutation operator and another eight GAs using these eight crossover operators with a mutation operator are *** GAs are experimented on some benchmark asymmetric and symmetric instances of numerous sizes and various number of *** study revealed that the distance-based crossovers are much superior to the blind ***,we observed that the sequential constructive crossover with and without mutation operator is the best one for *** estimation is validated by Student’s t-test at 95%co

关键词： Vehicle routing problem NP-hard genetic algorithm sequential constructive crossover mutation

COVID-19 and Learning Styles: GCET as Case Study

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2021年第7期68卷 103-115页

作者： Mazhar Hussain Malik Sid ahmed Amjed Sulaiman al Hasani Department of Computing and Information Technology Global College of Engineering and TechnologyMuscatSultanate of Oman Department of Electrical and Electronics Engineering Global College of Engineering and TechnologyMuscatSultanate of Oman

The COVID-19 pandemic has caused higher educational institutions around the world to close campus-based activities and move to online *** aim of this paper is to present the case of Global College of Engineering and Technology(GCET)and how its practices including teaching,students/staff support,assessments,and exam policies were *** paper investigates the mediating role of no detriment policy impact on students’result along with the challenges faced by the higher educational institution,recommendations and *** investigation concludes that the strategies adopted for online delivery,student support,assessments and exam policies have helped students to effectively cope with the teaching and learning challenges posed by the COVID-19 pandemic without affecting their academic *** study shows that 99%of students were able to maintain the same or better level of performance during the 1st COVID-19 *** percent of students had shown a slight decrease in their performance(about 1%–2%)with respect to their overall marks *** no detriment policy has succoured those 1%of the students to maintain their overall performance to what it used to be pre-COVID-19 ***,the paper provides the list of challenges and suggestions for smooth conduction of online education.

关键词： Higher education learning styles COVID-19 challenges and strategies no detriment policy engineering and technology modules