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Experimental and Numerical Analysis of Oil-Water Flow with Drag Reducing Polymers in Horizontal Pipes

Fluid Dynamics & Materials Processing 2023年第10期19卷 2579-2595页

作者： Amer A.Abdulrahman Bashar J.Kadhim zainab y.shnain Hassan Sh.Majidi Asawer A.Alwaiti Farooq Al-Sheikh Adnan A.AbdulRazak Mohammed Shorbaz Mazin J.Shibeeb Chemical Engineering Department University of TechnologyBaghdadIraq Department of Chemical Engineering and Petroleum Industries Al-Mustaqbal University CollegeBabylonIraq East Baghdad Southern EBS PETROLEUM COMPANy BaghdadIraq

The well-known frictional effect related to liquid-liquid two-phaseﬂow in pipelines can be reduced using drag-reducing *** this study,such an effect has been investigated experimentally using a mixture of oil and ***,numerical simulations have been carried out using the COMSOL simulation *** mea-surements were taken in a horizontal pipe with the length and diameter equal to 3 and 0.125 m,***,Polyethylene oxide with 150 ppm was exploited to reduce the drag effect while considering different water-to-oil fractions(0.3,0.4,0.5,and 0.7)and a constant totalﬂow velocity of 2.3 m/*** made evident by the results,a signiﬁcant reduction can be obtained in terms of pressure drop,which becomes even more signiﬁcant as the water to oil fraction is *** maximum achieved drag reduction is 70%with a water fraction of *** results also show that the addition of polymer additives can also have an impact on theﬂow ***-parison of experimental and numerically determined pressure drop indicates that the error is smaller than 7%.

关键词： Two-phase flow drag reduction polymer COMSOL

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Therapeutic efficacy of voltage‑gated sodium channel inhibitors in epilepsy

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Acta Epileptologica 2023年第2期6卷 65-85页

作者： John Agbo zainab G.Ibrahim Shehu y.Magaji yahkub Babatunde Mutalub Philemon Paul Mshelia Daniel H.Mhyha Department of Clinical Pharmacology and Therapeutics Faculty of Basic Clinical SciencesCollege of Medical SciencesAbubakar Tafawa Balewa UniversityBauchi 740272Nigeria Department of Physiology Faculty of Basic Medical ScienceCollege of Medical SciencesAbubakar Tafawa Balewa UniversityBauchi 740272Nigeria Department of Medical Biochemistry Faculty of Basic Medical ScienceCollege of Medical SciencesAbubakar Tafawa Balewa UniversityBauchi 740272Nigeria

Epilepsy is a neurological disease characterized by excessive and abnormal hyper-synchrony of electrical discharges of the brain and a predisposition to generate epileptic seizures resulting in a broad spectrum of neurobiological insults,imposing psychological,cognitive,social and also economic burdens to the ***-gated sodium channels(VGSCs)are essential for the generation and propagation of action potentials throughout the central nervous *** of these channels has been implicated in the pathogenesis of *** inhibitors have been demonstrated to act as anticonvulsants to suppress the abnormal neuronal firing underlying epileptic seizures,and are used for the management and treatment of both genetic-idiopathic and acquired *** discuss the forms of idiopathic and acquired epilepsies caused by VGSC mutations and the therapeutic efficacy of VGSC blockers in idiopathic,acquired and pharmacoresistant forms of epilepsy in this *** conclude that there is a need for better alternative therapies that can be used alone or in combination with VGSC inhibitors in the management of *** current anti-seizure medications(ASMs)especially for pharmacoresistant epilepsies and some other types of epilepsy have not yielded expected therapeutic efficacy partly because they do not show subtype-selectivity in blocking sodium channels while also bringing side ***,there is a need to develop novel drug cocktails with enhanced selectivity for specific VGSC isoforms,to achieve better treatment of pharmacoresistant epilepsies and other types of epileptic seizures.

关键词： Epilepsy Voltage-gated sodium channels Idiopathic epilepsy Acquired epilepsy Anti-seizure medications Pharmacoresistant epilepsy

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New application of microbial fuel cell-based biosensor for monitoring the quality of actual potato chips’processing wastewater

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Waste Disposal and Sustainable Energy 2019年第3期1卷 227-235页

作者： Ahmed y.Radeef zainab Z.Ismail Department of Environmental Engineering University of BaghdadBaghdadIraq

In this study,a dual-chamber microbial fuel cell(MFC)fed with actual potato chips’processing wastewater(PCPW)was tested as a *** performance of MFC-based biosensor was evaluated in terms of the current measurement range,toxicity detection and sensitivity,and the operational *** results revealed that the MFC can simply be converted to an online biosensor unit to detect the harmful effect of suspended solids and acidic content in the actual PCPW on the anodic attached biofilm and the values of the generated current as well.A notable decrease in the current values was observed indicating the adverse effects of the harmful matters in the PCPW fed to the biosensor *** results proposed a competition between the harmful components and the favorable substrate in binding to the redox *** excellent fitting was obtained between the experimental and predicted results by I_(Km) model with determination coefficient(R^(2))and mean-square-error values of 0.927 and 0.363,***,a new approach was developed based on direct measurement of actual field data to replace the conventional statistical methods.

关键词： Microbial fuel cell Biosensor Modeling Potato chips processing wastewater Biodegradation

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Iodization of Village Water Supply in the Control of Endemic Iodine Deficiency in Rural Sarawak, Malaysia

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Biomedical and Environmental Sciences 1996年第2期9卷 236-241页

作者： L. C. FOO T. zainab S. y. GOH G. R. LETCHUMAN M. NAFIKUDIN P. DORAISINGAM AND BAK KHALIDA(Institute for Medical Research, Kuala Lumpur Sarawak Medical and Health Department, Kuching Department of Mechanical Engineering University of Malaya, Kuala Lumpu Institute for Medical Research Kuala Lumpur Malaysia.

A simple water iodizing system, which incorporates the Venturi principle in combination with the controlled release mechanism of a silicone-sodium iodide elastomer, for the iodization of rural piped-water supply in the control of endemic iodine deficiency has been developed and its effectiveness evaluated in three Iban longhouse villages in the iodinedeficient district of Lubok Antu, Sarawak. Urines were collected for iodine assays from women aged 15-40 years before and at 6 and 12 months after the connection of the iodinating device; goiter assessment was performed on the women at the start and end of the 1-year study. Water samples were collected for iodine assays at 2-weekly intervals. In all three villages, significant and sustained increases in median urinary iodine excretions,reaching levels recommended for an iodine-suffcient population, were observed; goitre prevalences were reduced in all the villages (by 22.6% to 35.8%). The iodine levels in the water ranged from 34 μg/l to 212 μg/L. In the control village, median urinary iodine excretions remained essentially unchanged but a small increase in goiter prevalence was observed. The iodized water was well received by the villagers and no adverse effects of water iodization were observed. The system functioned unattended throughout the one year period. The cost of providing supplemental iodine via the iodizing device is approximately 60 cents (U.S.) per family per year which is affordable by either the Government or the villagers. It is concluded that the iodizing system offers a new cost-effective strategy for the control of endemic iodine deficiency in Sarawak and may have applications in other areas with similar water sources

关键词： Malaysia Iodization of Village Water Supply in the Control of Endemic Iodine Deficiency in Rural Sarawak

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位图索引在数据仓库低基数值列中的研究

位图索引在数据仓库低基数值列中的研究

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作者：赛娜（zainab Qays Abdulhadi）中南大学

学位级别：硕士

在数据仓库和商业智能(BI)解决方案中加快查询处理是一个急需解决的问题。使用汇总表或索引等机制可以有效提高查询速度,其中预定义查询的汇总表已具有较好的性能,但需要预先花费额外的执行时间,而索引是一个更加高性能的且无需额外硬... 详细信息

在数据仓库和商业智能(BI)解决方案中加快查询处理是一个急需解决的问题。使用汇总表或索引等机制可以有效提高查询速度,其中预定义查询的汇总表已具有较好的性能,但需要预先花费额外的执行时间,而索引是一个更加高性能的且无需额外硬件的解决方案,但其中面临的挑战是如何找到一个合适各种数据集且都保持较高性能的索引类型。低基数数据在数据仓库中应用广泛,基数是一个数据集的列中值的个数。一般有大量重复值的列称作为低基数列,例如性别列,一般只有两个值：男性和女性,当然可以用其它的2个不同的符号来表示。B树是存储排序数据并允许以O(logn)的运行时间进行查找的树形数据结构,但B树索引应用于低基数值列时是一个非常低效的索引方法,在进行即席查询且数据量大时需要非常多I/O操作。因此一些关系型数据库管理系统采用新的索引技术,如位图索引,用以加快查询处理。位图索引有一个用于快速数据检索的特定结构,主要是利用二进制数(0或1)的字符串,以指示一个表中被索引的列是否为一个特定的值,也就是说,如果在一个索引列中一个特定的值存在,位图索引设置为'1',否则为'0'。与其它的索引技术相比,位图索引能大幅减少空间的使用,对于复杂逻辑的选择操作,可通过执行位的运算"AND","OR","NOT"等来快速地完成。位图索引的应用非常广泛,主要用于数据仓库系统和大型科学数据库。通过执行跨列位图间的快速逻辑运算,位图索引提供了一个更快的查询解决,而且能被被当代硬件广泛支持。很多商业的数据库系统都采用位图索引,如Oracle,从1995年开始就提供了位图索引,其它主要系统如DB2和Microsoft SQLServer没有采用。Microsoft SQL Server可能通过哈希连接生成位图,但不是通用的索引。DB2已经采用编码矢量索引,但是这基本上是一个编码投影索引,而不是一个位图索引。本论文的目的是通过实验的方式来证明在数据仓库中位图索引比B树索引更有效,尤其是对于低基数值列。在Oracle环境中,B树索引一般为默认的索引方式。我们通过3个典型的实验来测试在两个索引方式下复杂查询的执行时间,在每一个实验中我们分别测试3个条件、2个条件与1个条件的查询,并且测试4个不同的数据集,分别有100万条、80万条、60万条、30万条记录。我们首先在Oracle环境下设计并实现图形用户界面,采用Oracle Developer6i工具套件,这个套件由许多用于开发和编程项目的软件组成,这些软件以可视化的方式来处理数据仓库并操纵数据库。这意味着,使用可视化编程组件,如按钮、列表、标签、文本框、鼠标移动等等,无需复杂编程即可编写查询并以图形界面的方式呈现结果。我们使用Oracle lOg的数据库来创建表和索引。我们设计与实现的界面有2个主要部分即搜索使用位图索引、搜索使用B树索引,这2个部分具有相同的查询语句与数据集。我们在查询项目中的选择的参数选项有地区、学院、性别和年龄。当要执行查询时,我们首先确定搜索选项,即相当于在SQL语中复杂的“Where子句”条件,每个选项所代表的组合列表是通过鼠标左键点击下拉列表选择值进行组合。在每次实验中,我们对位图索引与B树索引的查询响应时间进行详细记录与比对,从而揭示在不同数据集与不同列值情形下两个索引方法的性能差别。实验主要包含以下三个方案：方案一：搜索表使用三个条件,其中有两个AND运算操作。搜索上分别做4组记录,30万条、60万条、80万条与100万条记录。方案二：搜索表使用两个条件,即一个AND运算操作,搜索上分别进行4组记录,30万条、60万条、80万条与100万条记录。方案三：搜索表使用一个条件,搜索记录4组,分别30万条、60万条、80万条与100万条记录。我们用许多不同的查询参数来测试不同SQL查询以获得更多的结果进行较为全面的分析。从三个实验方案进行观察发现,位图索引在对于低基数值列如“y”或“N”、“男”或“女”等比B树索引速度优势明显。但是位图索引只是方便静态表(无更新)的查询,如果查询的表不是只读的,则B树索引是一种相对有效的选择。位图索引对于决策支持系统、数据仓库、OLAP等数据相对静态的情形非常有效,而B树索引则对于OLTP环境更有效。已有相关研究将位图索引和B树索引的时间和空间复杂性计算规则进行了分析,数学计算表明位图索引的时间和空间复杂性比B树索引低,尤其是对于低基数值列。对于大型数据仓库来说,位图索引被认为是在当前和未来很有发展前途的索引,因此我们期待提出更有效的位图索引方法。我们的目标是通过采取新的方法来提高位图索引的性能,这个方法的主要思想是将基本的位图索引算法和基于值域编码算法进行有效结合,考虑不同的基数值列类型

关键词：数据仓库位图索引 B树索引索引基于值域编码基数

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