检索结果-南通市图书馆

Effects of modified graphene oxide(GO) nanofluid on wettability and IFT changes: Experimental study for EOR applications

引用

Petroleum Science 2022年第4期19卷 1779-1792页

作者： Ehsan Jafarbeigi Farhad Salimi Ehsan Kamari Mohsen mansouri Department of Chemical Engineering Kermanshah BranchIslamic Azad UniversityKermanshahIran Department of Petroleum Engineering Research Institute of Petroleum IndustryTehranIran Department of Chemical Engineering llam UniversityllamIran

The application of nanoparticles(NPs) in enhanced oil recovery(EOR) offers a practical approach to resolving some surface-related problems encountered in contemporary technological processes. In this study, graphene oxide nanosheets(GONs) were synthesized by Hummer's method and, then, were subjected to surface modification by hexamethyldisilazane(HMDS) and diazonium sulfonic(DS) compounds. The new combination was known as GO-Su-HMDS. The potential stability of GO-Su-HMDS nanofluids(NFs) was investigated using the zeta(ζ) potential test. A comparative study of the effect of the synthesized NFs on wettability alteration of the reservoir rock was performed using interfacial tension(IFT) and contact angle experiments. According to the results of this study, the contact angle decreased from the initial value of 161.(oil wet) to 35.(water wet). In addition, IFT decreased from18.45 mN/m for deionized(DI) water to 8.8 mN/m for 500 ppm GO-Su-HMDS NF. Moreover, the results of flooding experiments showed that the NPs of a GO-Su-HMDS concentration of 400 and 500 ppm could increase the oil recovery by 20% and 19%, respectively. The experimental results showed that GO-SuHMDS NFs with a concentration of 500 ppm have the best efficiency in terms of altering the wettability of the rock from oil wet to water wet. Thus, it can be said that this nanofluid can reduce the contact angle and IFT and also increase the sweeping efficiency of oil.

关键词： Wettability alteration Graphene oxide Contact angle Interfacial tension Zeta potential

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effect of natural pozzolan content on the properties o engineered cementitious composites as repair material

引用

Frontiers of Structural and Civil Engineering 2018年第3期12卷 261-269页

作者： said CHOUCHA Amar BENYAHIA Mohamed GHRICI Mohamed said MANSOUR Geomaterials Laboratory Civil Engineering Department University Hassiba Benbouali of Chlef BP 151 Chief02000 Algeria

In order to determine the effect of Natural Pozzolan （NP） content on the mechanical properties and durability characteristics on Engineered Cementitious Composites （ECC） as repair material. This study focused on the evaluation of the most factors influencing compatibility between the repair material and the base concrete including mechanicals properties such as, compressive and flexural strengths, elastic modulus, capillary absorption and drying shrinkage. The experimental results showed that natural pozzolan reduces the compressive strength and the flexuraI strength of ECC at all ages. The elastic modulus of ECC was remarkably lower than that of normal-strength concrete. This lower ~oung＇s modulus is desirable for repair concrete, because it prevents the stresses induced by restrained shrinkage. In addition, the incorporation of high-volume natural pozzolan decreases significantly the coefficient of capillary absorption at long term and increases the drying shrinkage. Generally, based on the results obtained in the present experimental investigation, ECC can be used effectively as an overlay material over existing parent concrete.

关键词： natural pozzolan engineered cementitious composites mechanical strengths elastic modulus capillary absorption drying shrinkage

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Effects of Gibberellic Acid on Primary Terpenoids and △^9 -Tetrahydrocannabinol in Cannabis sativa at Flowering Stage

引用

Journal of Integrative Plant Biology 2009年第6期51卷 553-561页

作者： Hakimeh mansouri Zahra Asrar Mitra Mehrabani Faculty of Science Department of Biology Shahid Bahonar UniversityKerman Iran International Center for Science High Technology and Environmental Science(ICST)Kerman Iran Pharmacognosy Department Faculty of Pharmacy and Pharmaceutical Research Center Kerman University of Medical ScienceKerman Iran

Plants synthesize an astonishing diversity of isoprenoids, some of which play essential roles in photosynthesis, respiration, and the regulation of growth and development. Two independent pathways for the biosynthesis of isoprenoid precursors coexist within the plant cell： the cytosolic mevalonic acid （MVA） pathway and the plastidial methylerythritol phosphate （MEP） pathway. However, little is known about the effects of plant hormones on the regulation of these pathways. In the present study we investigated the effect of gibberellic acid （GA3） on changes in the amounts of many produced terpenoids and the activity of the key enzymes, 1-deoxy-D-xylulose 5-phosphate synthase （DXS） and 3-hydroxy-3-methylglutaryl coenzyme A reductase （HMGR）, in these pathways. Our results showed GA3 caused a decrease in DXS activity in both sexes that it was accompanied by a decrease in chlorophylls, carotenoids and Ag-tetrahydrocannabinol （THC） contents and an increase in α-tocopherol content. The treated plants with GA3 showed an increase in HMGR activity. This increase in HMGR activity was followed by accumulation of stigmasterol and β-sitosterol in male and female plants and campestrol in male plants. The pattern of the changes in the amounts of sterols was exactly similar to the changes in the HMGR activity. These data suggest that GA3 can probably influence the MEP and MVA pathways oppositely, with stimulatory and inhibitory effects on the produced primary terpenoids in MVA and DXS pathways, respectively.

关键词： α-tocopherol △^9 -tetrahydrocannabinol gibberellic acid phytosterols terpenoids.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Evaluation of sediment yield in PSIAC and MPSIAC models by using GIS at Toroq Watershed, Northeast of Iran

引用

Frontiers of Earth Science 2012年第1期6卷 83-94页

作者： Mohammad Reza mansouri Daneshvar Ali Bagherzadeh Department of Geography Mashhad Branch Islamic Azad University Mashhad Iran Department of Agriculture Mashhad Branch Islamic Azad University Mashhad Iran

Regarding the importance of watersheds in arid and semi-arid regions, it is necessary to better protect water supplies such as dam reservoirs. The most efficient way of conserving water sources is to apply proper management to decrease erosion and sedimentation. The first step of this process is to be aware of sediment yield （Qs）/production and identify erosive zones in upper reach of reservoirs. The present study aims to evaluate Qs and production in Pacific Southwest Inter-Agency Committee （PSIAC） and mod- ified PSIAC （MPSIAC） models by using satellite data, GIS analysis, and field observations. According to the results, the study area can be categorized into five erosive classes： very high, high, moderate, low and negligible. The east part of the watershed is slightly eroded due to its hard surface geology and relatively flat topography characteristics, while the northern and southern parts of the basin are highly eroded because of the high erodibility potential of soil and intensive cultivation of the area. A comparison of the output maps from PSIAC and MPSIAC models showed that the calculated Qs in most parts correspond well in both models and with field observa- tions. The results of regression between main determining factors （surface geology, soil, topography and land cover） and Qs derived from each model indicated moderate to strong correlation coefficient （R2 = 0.436-0.996 to 0.893- 0.998） after PSIAC and MPSIAC models, respec- tively.

关键词： evaluation of sediment yield (Qs) erodiblefactors Pacific Southwest Inter-Agency Committee(PSIAC) and modified PSIAC (MPSIAC) models sedimentproduction GIS Toroq Watershed Northeast of Iran

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Diabetic Macroangioapathy at the Internal Medicine Department of the Abass Ndao Hospital Center (About 359 Cases)

引用

Journal of Diabetes Mellitus 2024年第1期14卷 1-12页

作者： Sow Djiby Djiba Boundia Ndour Michel Assane Diedhiou Demba Dieng Mouhamed Diallo Ibrahima Mané Fall Ndiouga Gueye Khoudia Gadji Fatou Kiné Sarr Anna Diop said Nourou Ndour Mbaye Maimouna Department of Internal Medicine and Medical Specialties H&#244pital Abass Ndao Dakar Senegal

Introduction: Macroangiopathy plays an important role, with a high prevalence of morbidity and mortality in diabetic patients. The aim was to study the epidemiological, clinical, paraclinical, therapeutic and evolutionary profile of macroangiopathy in diabetic patients in the internal medicine department of the Abass Ndao hospital. Patients and methods: This was a descriptive and analytical cross-sectional study. Our investigations were recruited over a 7-year period (January 1, 2016 to December 31, 2022). Results: Three hundred and fifty-nine (359) patients (10.22%) were enrolled. The mean age was 62.83 years, with extremes ranging from 17 to 98 years. The [60 - 69] age group was more representative (37.32%). Women accounted for 180 cases (50.1%), with a sex ratio (m/f) of 0.99. The average duration of diabetes was 11.86 years. Average consultation time was 38.07 days, with extremes ranging from 1 to 368 days. Average hospital stay was 7.65 days. Inaugural diabetes was noted in 12 cases (3.34%). Type 2 diabetes accounted for 95.82% (n = 344) of patients. Hypertension was present in 150 patients (41.8%). Patients with 2 risk factors accounted for 173 cases (48.18%). Nineteen patients had already had a stroke (5.29% of cases). Fourteen (14) patients (4.2%) were amputees. Obliterative arteriopathy of the lower limbs (AOMI) was noted in 193 patients (54%). Stroke was noted in 101 patients (28%). Ischemic heart disease (IHD) was noted in 38 patients (11%). AOMI was more common in males (110 patients, 57%) than in females (43%). Seventy-three (73) patients (20.3%) died. Predictors of death were age over 60 and the existence of more than two cardiovascular risk factors. Conclusion: Diabetic macroangiopathy is a major cause of morbidity and mortality. The development and implementation of a prevention and management program is essential.

关键词： Macroangiopathy Diabetes Risk Factors Senegal

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

A Dynamic Management Scheme for Internet of Things(IoT)Environments:Simulation and Performance Evaluation

引用

Computer Modeling in Engineering & Sciences 2022年第12期133卷 673-695页

作者： Omar said Department of Information Technology College of Computers and Information TechnologyTaif UniversityP.O.Box 11099Taif21944Saudi Arabia

In recent years,the Internet of Things(IoT)technology has been considered one of the most attractive fields for researchers due to its aspirations and implications for society and life as a *** IoT environment contains vast numbers of devices,equipment,and heterogeneous users who generate massive amounts of ***,things’entry into and exit fromIoT systems occur dynamically,changing the topology and content of IoT networks very ***,managing IoT environments is among the most pressing *** paper proposes an adaptive and dynamic scheme for managing IoT environments is *** management scheme depends on the use of previous management methodologies,considering two main *** first factor is network status,which is determined in *** second factor is a management method’s suitability according to its desired *** test the proposed management scheme,a simulation environment is created using *** metrics used to measure the management scheme performance are bandwidth consumption,energy consumption,packet loss,throughput,delay,usage rate of individualmanagement techniques,and *** simulation results prove that the proposed management scheme outperformed the individual 6LowPANSNMP,CoAP,and LWM2M management schemes.

关键词： Internet of Things IoT management IoT simulation SNMP neural networks big data

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Hierarchical data replication strategy to improve performance in cloud computing

引用

Frontiers of Computer Science 2021年第2期15卷 63-79页

作者： Najme mansouri Mohammad Masoud JAVIDI Behnam Mohammad Hasani ZADE Department of Computer Science Shahid Bahonar University of KermanKerman76169-14111Iran Mahani Mathematical Research Center Shahid Bahonar University of KermanKerman76169-14111Iran

Cloud computing environment is getting more interesting as a new trend of data *** replication has been widely applied to improve data access in distributed systems such as Grid and ***,due to the finite storage capacity of each site,copies that are useful for future jobs can be wastefully deleted and replaced with less valuable ***,it is considerable to have appropriate replication strategy that can dynamically store the replicas while satisfying quality of service(QoS)requirements and storage capacity *** this paper,we present a dynamic replication algorithm,named hierarchical data replication strategy(HDRS).HDRS consists of the replica creation that can adaptively increase replicas based on exponential growth or decay rate,the replica placement according to the access load and labeling technique,and finally the replica replacement based on the value of file in the *** evaluate different dynamic data replication methods using CloudSim *** demonstrate that HDRS can reduce response time and bandwidth usage compared with other *** means that the HDRS can determine a popular file and replicates it to the best *** method avoids useless replications and decreases access latency by balancing the load of sites.

关键词： cloud computing data replication multi-tier architecture simulation load balance

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Spatial point-pattern analysis as a powerful tool in identifying pattern-process relationships in plant ecology: an updated review

引用

Ecological Processes 2021年第1期10卷 772-794页

作者： Mariem Ben-said Applied Biology and Pathology Laboratory Department of BiologyFaculty of SciencesAbdelmalek Essaadi UniversityTetouanMorocco

Background:Ecological processes such as seedling establishment,biotic interactions,and mortality can leave footprints on species spatial structure that can be detectable through spatial point-pattern analysis(SPPA).Being widely used in plant ecology,SPPA is increasingly carried out to describe biotic interactions and interpret patternprocess ***,some aspects are still subjected to a non-negligible debate such as required sample size(in terms of the number of points and plot area),the link between the low number of points and frequently observed random(or independent)patterns,and relating patterns to *** this paper,an overview of SPPA is given based on rich and updated literature providing guidance for ecologists(especially beginners)on summary statistics,uni-/bi-/multivariate analysis,unmarked/marked analysis,types of marks,*** ambiguities in SPPA are also ***:SPPA has a long history in plant ecology and is based on a large set of summary statistics aiming to describe species spatial *** mechanisms known to be responsible for species spatial patterns are actually investigated in different biomes and for different *** processes,plant environmental conditions,and human intervention are interrelated and are key drivers of plant spatial *** spite of being not recommended,small sample sizes are more common in *** some areas,periodic forest inventories and permanent plots are scarce although they are key tools for spatial data availability and plant dynamic ***:The spatial position of plants is an interesting source of information that helps to make hypotheses about processes responsible for plant spatial *** the continuous progress of SPPA,some ambiguities require further clarifications.

关键词： Spatial analysis Point-pattern Summary statistics Second-order characteristics Spatial structure Species interactions Competition Facilitation Positive association Negative association

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Development of Linearizing Feedback Control with a Variable Structure Observer for Continuous Stirred Tank Reactors

引用

Chinese Journal of Chemical Engineering 2012年第3期20卷 567-571页

作者： Bachir Daaou Abdellah mansouri Mohamed Bouhamida Mohammed Chenafa Department of Sciences and Technology Ibn-khaldoun University BP 78Zaaroura RoadTiaretAlgeria Department of Electrical Engineering E.N.S.E.T.OranLaboratory of Automatics and Systems Analysis(L.A.A.S) BP 1523 El' M'naouerOranAlgeria

This paper deals with the design of an observer-based nonlinear control for continuous stirred tank reactors(CSTR).A variable structure observer is constructed to estimate the whole process state *** observer is basically the conventional Luenberger observer with an additional switching term used to guarantee the robustness against modeling *** observer is coupled with a nonlinear controller,designed based on input-output linearization for controlling the reactor *** asymptotical stability of the closed-loop system is shown by the Lyapunov stability ***,computer simulations are developed for showing the performance of the proposed approach.

关键词： variable structure observer linearizing feedback global stability continuous stirred tank reactors

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Walk-off reduction,using an external optical plate and Bessel-Gaussian interaction

引用

Chinese Physics B 2015年第2期24卷 215-222页

作者： Masoume mansouri Mohsen Askarbioki Saeed Ghavami Sabouri Alireza Khorsandi Department of Physics University of Isfahan

To reduce the walk-off angle of the extraordinary third-harmonic ultraviolet wave at 355 nm generated by type ⅡKTiOPO4 and type I β-BaB2O4 optical crystals,and the Gaussian output beam of a Q-switched Nd：YAG laser,a simple theoretical model was developed based on a rotatable BK7 plate of variable *** rotating the plate up to 35°along the beam direction,we reduced the walk-off angle up to ~ 13%.The same phenomenon is predicted by the model,confirming the performance of the *** is found that,due to the walk-off effect,the intensity profile of the thirdharmonic generation beam is slightly *** compensate for the observed phenomena and further reduce the walkoff,we used a combination of a convex lens and an axicon to transform the beam profile of the interacting fundamental and second-harmonic generation waves to the zero-order Bessel-Gaussian *** a result,the walk-off is decreased to~ 48.81 mrad,providing ~ 30%relative *** using the same BK7 plate rotated up to 35° along the third-harmonic beam direction,the walk-off angle is further reduced to 38.9 ***,it is observed that the beam profile of the emerged Bessel-Gaussian third-harmonic generation beam remains unchanged with no degradation.

关键词： Bessel-Gaussian beam walk-off third-harmonic generation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：