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Laboratory study on efficiency of three calcium carbonate scale inhibitors in the presence of EOR chemicals

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Petroleum 2018年第4期4卷 375-384页

作者： Qiwei Wang Feng Liang Waleed al-nasser Faez al-Dawood Tawfiq al-Shafai Hameed al-Badairy Shouwen Shen Hassan al-Ajwad Saudi Aramco Research&Development CenterP.O.Box 62Dhahran 31311Saudi Arabia Aramco Services Company Aramco Research Center e Houston16300 Park RowHoustonTX 77084USA

Chemical flooding has been widely used in the oil industry since the 1980s for enhanced oil recovery(EOR)*** studies have shown that the effectiveness of calcium carbonate scale inhibitors is affected by many factors,such as water composition,system pressure,temperature,production rates,pH *** breakthrough of the EOR chemicals in the production well could also affect scale formation process and interfere with the scale treatment program as ***,the studies on the impacts of injected EOR chemicals to scale inhibitor performances are very *** paper presents the comprehensive laboratory study on the impacts of the EOR chemicals on CaCO3 scale formation and prevention using static bottle and dynamic tube blocking *** EOR chemicals used in this study are a combination of surfactants and *** different types of inhibitors were evaluated:triphosphonate,penta-phosphonate,and polyacrylate based ***(%)from the bottle test and minimum effective dose(mED)based on the tube blocking method were determined for each inhibitor at 160*** precipitates from the bottle tests were also characterized for morphology and polymorphs using environmental scanning electron(ESEm)and X-ray diffraction(XRD)*** suggest that the performance of scale inhibitors could be substantially affected by the EOR *** dynamic tube blocking tests,the mED values of inhibitors were increased roughly 10 times with the EOR *** static bottle tests showed considerable changes under the test *** impact of EOR chemicals were also demonstrated by the remarkable ranges of crystal morphologies,changing from simple aragonite columns to nanorod,distorted spheroid,and flower-like superstructure in the presence of EOR chemicals and inhibitors.

关键词： Calcium carbonate Scaling Inhibitor Chemical flooding Enhanced oil recovery

A framework for an integrated unified modeling language

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Frontiers of Information Technology & Electronic Engineering 2016年第2期17卷 143-159页

作者： mohammad alSHAYEB nasser KHASHAN Sajjad mAHmOOD Information and Computer Science Department King Fahd University of Petroleum and Minerals

The unified modeling language(UmL) is one of the most commonly used modeling languages in the software *** simplifies the complex process of design by providing a set of graphical notations,which helps express the objectoriented analysis and design of software *** UmL is applicable to different types of systems,domains,methods,and processes,it cannot express certain problem domain ***,many extensions to UmL have been *** this paper,we propose a framework for integrating the UmL extensions and then use the framework to propose an integrated unified modeling language-graphical(iUmL-g) ***-g integrates the existing UmL extensions into one integrated *** includes an integrated diagram for UmL class,sequence,and use case *** proposed approach is evaluated using a case *** proposed iUmL-g is capable of modeling systems that use different domains.

关键词： Unified modeling language (UmL) Integration modeling System analysis and design

Optimal operation of energy at hydrothermal power plants by simultaneous minimization of pollution and costs using improved ABC algorithm

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Frontiers in Energy 2015年第4期9卷 426-432页

作者： Homayoun EBRAHImIAN Bahman TAHERI nasser YOUSEFI Department of Engineering Ardabil Branch Islamic Azad University Ardabil 0451 Iran Young Researchers and Elite Club Ardabil Branch Islamic Azad University Ardabil 0451 Iran

The aim of this paper is simultaneous mini- mization of hydrothermal units to reach the best solution by employing an improved artificial bee colony （ABC） algorithm in a multi-objective function consisting of economic dispatch （ED） considering the valve-point effect and pollution function in power systems in view of the hot water of the hydro system. In this type of optimization problem, all practical constraints of units were taken into account as much as possible in order to comply with the reality. These constraints include the maximum and minimum output power of units, the constraints caused by the balance between supply and demand, the impact of pollution, water balance, uneven production curve con- sidering the valve-point effect and system losses. The proposed algorithm is applied on the studied system, and the obtained results indifferent operating conditions are analyzed. To investigate in various operating conditions, different load profiles in 12 h are taken into account. The obtained results are compared with those of the other methods including the genetfc algorithm （GA）, the Basu technique, and the improved genetic algorithm. Fast convergence is one of this improved algorithm features.

关键词： practical constraints of units pollution func-tion inlet steam valve up-ramp rate of units improvedABC algorithm

Gas chromatography-mass spectrometry analysis of different organic crude extracts from the local medicinal plant of Thymus vulgaris L

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Asian Pacific Journal of Tropical Biomedicine 2013年第1期3卷 69-73页

作者： Laila Salim.al Hashmi mohammad Amzad Hossain Afaf mohammed Weli Qasim.al-Riyami Jamal nasser al-Sabahi School of Pharmacy College of Pharmacy and NursingUniversity of NizwaP.0.Box 33Postal Code 616NizwaSultanate of Oman Central Instrument Laboratory College of Agriculture and Marine SciencesSultan Qaboos UniversitySultanate of Oman

Objective:To isolate and analyze the chemical composition in different crude extracts of from the leaves of locally grown of Thymus vulgaris L(***)by gas chromatography-mass spectrometry(GC-mS).methods:The shade dried leaves powder was extracted with methanol by using Soxhlet *** crude extracts of *** and the derived fractions of hexane,chloroform,ethyl acetate and butanol were ***:Qualitative analyses of various organic crude extracts of *** by using GC-mS showed that there were different types of high and low molecular weight *** of the isolated and identified compounds by GC-mS in the crude extracts are basically biologically ***,the *** leaf possessed certain characteristics that can be ascribed to cultivation on a domestic *** crude extracts were prepared from the powder leaves of *** for respective compounds can be chosen on the basis of above GC-mS ***:all the major compounds were identified and characterized by spectroscopic method in different organic crude extracts of *** are biologically active *** the identification of a good number of compounds in various crude extracts of *** might have some ecological role.

关键词： Thymus vulgaris L Preparation crude extracts Soxhlet extractor GC-mS analyses

Application of a new SPA-SVm coupling method for QSPR study of electrophoretic mobilities of some organic and inorganic compounds

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Chinese Chemical Letters 2013年第10期24卷 904-908页

作者： nasser Goudarzi mohammad Goodarzi m.Arab Chamjangali m.H.Fatemi Faculty of Chemistry Shahrood University of Technology Department of Chemistry Faculty of SciencesYong Researchers ClubAzad University Faculty of Chemistry Mazandaran University

In this work, two chemometrics methods are applied for the modeling and prediction of electrophoretic mobilities of some organic and inorganic compounds. The successive projection algorithm, feature selection （SPA） strategy, is used as the descriptor selection and model development method. Then, the support vector machine （SVm） and multiple linear regression （mLR） model are utilized to construct the non-linear and linear quantitative structure-property relationship models. The results obtained using the SVm model are compared with those obtained using mLR reveal that the SVm model is of much better predictive value than the mLR one. The root-mean-square errors for the training set and the test set for the SVm model were 0.1911 and 0.2569, respectively, while by the mLR model, they were 0.4908 and 0.6494, respectively. The results show that the SVm model drastically enhances the ability of prediction in QSPR studies and is superior to the mLR model.

关键词： Quantitative structure-mobility relationship Support vector machine Electrophoretic mobility Successive projection algorithm multiple linear regression

Ionic Conductivity in Gelatin-Based Hybrid Solid Electrolytes:The Non-trivial Role of Nanoclay

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Journal of materials Science & Technology 2014年第11期30卷 1096-1102页

作者： ali Ghadami Nader Taheri Qazvini nasser Nikfarjam Polymer Division School of ChemistryCollege of ScienceUniversity of Tehran Biomaterials Research Center (BRC) University of Tehran

In this study, the ionic conductivity behavior in hybrid gelatin-based transparent electrolytes including various types of nanoclays with different size, shape and surface properties was characterized. The effects of nanoclay type and nanoclay concentration as well as different experimental conditions, e.g., pH, temperature and crosslinking were also investigated. In general, the impedance spectroscopy results suggested a non- trivial role for nanoclay. Regardless of the nanoclay type, the ionic conductivity slightly increased first and then decreased by increasing the nanoclay concentration. Furthermore, among sodium montmorillonite （Na＋mmT）, lithium montmorillonite （Li＋mmT）, laponite and hydrotalcite, the hybrid electrolytes prepared by Li＋mmT showed higher ionic conductivity. The results also showed that the chemical crosslinking along with sample preparation at optimum pH, where the gelatin chains might be efficiently adsorbed on exfoliated, negatively charged clay nanosheets, plays an important role. In comparison with the ionic conductivity of the neat sample at room temperature （～10-7 S cm-1）, a ten-fold increase was observed for the crosslinked sample containing 2 wt% of Li^＋mmT prepared at optimum pH 3.5. The conductivity behavior as a function of temperature revealed the obedience with the VogeI-Fulcher-Tammann （VFT） model for all samples, suggesting the important role of segmental motions in the ionic conductivity. Finally, a qualitative explanation was presented for the mechanism of the ionic conduction in gelatin-nanoclay hybrid electrolytes.

关键词： Gelatin Solid-state electrolytes Ionic conductivity montmorillonitc Laponite Impedance spectroscopy

Surgical management of acute pancreatitis: Historical perspectives, challenges, and current management approaches

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World Journal of Gastrointestinal Surgery 2023年第3期15卷 307-322页

作者： nasser alzerwi Department of Surgery Majmaah UniversityRiyadh 11952Saudi Arabia

Acute pancreatitis(AP)is a serious condition presenting catastrophic *** severe AP,the mortality rate is high,and some patients initially diagnosed with mild-to-moderate AP can progress to a life-threatening severe *** of AP has evolved over the *** was the first surgical procedure performed for AP;however,later,surgical approaches were replaced by more conservative approaches due to the availability of advanced medical care and improved understanding of the course of ***,surgery is used to manage several complications of AP,such as pseudocysts,pancreatic fistulas,and biliary tract *** who are unresponsive to conservative treatment or have complications are typically considered for surgical *** review focuses on the surgical approaches(endoscopic,percutaneous,and open)that have been established in recent studies to treat this acute condition and summarizes the common management guidelines for AP,discussing the relevant indications,significance,and *** is evident that despite their reduced involvement,surgeons lead the multidisciplinary care of patients with AP;however,given the gaps in existing knowledge,more research is required to standardize surgical protocols for AP.

关键词： Acute pancreatitis Surgery Endoscopic management Open surgery Necrosectomy

Effect of a chemical reaction on magnetohydrodynamic boundary layer flow of a maxwell fluid over a stretching sheet with nanoparticles

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Particuology 2016年第6期14卷 154-161页

作者： Ahmed A. Afify nasser S. Elgazery Department of mathematics Faculty of Science Helwan University Ain Helwan PO Box 11795 Cairo Egypt Department of mathematics Faculty of Education Ain Shams University Roxy Heliopolis Cairo Egypt

The influences of the convective boundary condition and heat generation/absorption on magnetohydro- dynamic boundary layer flow of a maxwell fluid over a stretching surface in the presence of nanoparticles have been numerically investigated. In the model, the physical mechanisms responsible for Brownian motion and thermophoresis with a chemical reaction are considered. Similarity equations are derived and then solved using the shooting method with the fourth-order Runge-Kutta integration scheme, The rates of heat and mass transfer are enhanced with a destructive chemical reaction and Blot number. The opposite influence is found with a generative chemical reaction in the presence of Brownian motion and the thermophoretic property.

关键词： magnetohydrodynamics Nanoparticle maxwell fluid Boundary layer flow Chemical reaction

Is there any correlation between vitamin D insufficiency and diabetic retinopathy?

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International Journal of Ophthalmology(English edition) 2015年第2期8卷 326-331页

作者： Shokoufeh Bonakdaran nasser Shoeibi Endocrine Research Center Mashhad University of Medical Sciences Ghaem Hospital Retina Research Center Mashhad University of Medical Sciences

AIm: To determine a relation between vitamin D level,which is an inhibitor of angiogenesis, and diabetic retinopathy and its risk factorsmETHODS: In a clinic-based cross sectional study two hundred and thirty-five type 2 diabetic patients older than 20 y were selected. Patients were classified according to ophthalmologic examination as following:no diabetic retinopathy(NDR)(n =153), non-proliferative diabetic retinopathy(NPDR)(n =64) and proliferative diabetic retinopathy(PDR)(n =18). Study subjects were tested for fasting blood glucose, glycated hemoglobin A1C(Hb A1C), lipid profile, microalbuminuria, Hs CRP,IGF1, insulin(in patients without history of insulin taking)and 25 hydroxy vitamin D [25(OH) D] levels. Vitamin D insufficiency was defined according to 25(OH) D level less than 30 ng/m L. The relationship between diabetic retinopathy and serum 25(OH) D insufficiency was ***: The prevalence of diabetic retinopathy was34.8% in our patients. Long duration of diabetes,hypertension, poor glycemic control, diabetic nephropathy, hyperinsulinemia and insulin resistance were risk factors for diabetic retinopathy but 25(OH) D level was not significant different between NDR, NPDR and PDR groups. Correlation between 25(OH) D level and other known risk factors of diabetic retinopathy was not ***: This study did not find any association between diabetic retinopathy and its severity and vitamin D insufficiency. Vitamin D insufficiency is not related to risk factors of diabetic retinopathy.

关键词： diabetes retinopathy vitamin D insulin resistance