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investigation on microstructure evolution of clayey soils: A review focusing on wetting/drying process

Journal of Rock Mechanics and Geotechnical Engineering 2023年第1期15卷 269-284页

作者： Chao-Sheng Tang Qing Cheng Xuepeng Gong Bin Shi hilary i.inyang School of Earth Sciences and Engineering Nanjing UniversityNanjing210023China Global Education and infrastructure Services inc. CharlotteUSA

Variability in moisture content is a common condition in natural *** influences soil properties significantly.A comprehensive understanding of the evolution of soil microstructure in wetting/drying process is of great significance for interpretation of soil macro hydro-mechanical *** this review paper,methods that are commonly used to study soil microstructure are *** them are scanning electron microscope(SEM),environmental SEM(ESEM),mercury intrusion porosimetry(MiP)and computed tomography(CT)***,progress in research on the soil microstructure evolution during drying,wetting and wetting/drying cycles is summarized based on reviews of a large body of research papers published in the past several *** compacted on the wet side of op-timum water content generally have a matrix-type structure with a monomodal pore size distribution(PSD),whereas soils compacted on the dry side of optimum water content display an aggregate structure that exhibits bimodal *** drying,decrease in soil volume is mainly caused by the shrinkage of inter-aggregate *** wetting,both the intra-and inter-aggregate pores increase gradually in number and *** in the characteristics of the soil pore structure significantly depend on stress state as the soil is subjected to *** wetting/drying cycles,soil structural change is not completely reversible,and the generated cumulative swelling/shrinkage deformation mainly derives from ***,based on this analysis and identified research needs,some important areas of research focus are proposed for future *** areas include innovative methods of sample preparation,new observation techniques,fast quantitative analysis of soil structure,integration of microstructural parameters into macro-mechanical models,and soil microstructure evolution charac-teristics under multi-field coupled conditions.

关键词： Soil microstructure Pore size distribution(PSD) Wetting/drying cycle Suction Volume change

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Mathematical Modelling and Design of Helical Coil Heat Exchanger for Production of Hot Air for Fluidized Bed Dryer

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Advances in Chemical Engineering and Science 2024年第3期14卷 125-136页

作者： iniubong James Uwa Uwem Ekwere inyang innocent Oseribho Oboh Department of Chemical Engineering Faculty of Engineering University of Uyo Uyo Nigeria

in global industrialization, efforts have been made to increase the rate of heat transfer in heat exchanger, minimizing the size of heat exchanger to reduce cost as well as increasing the effectiveness. Helical coil heat exchanger (HCHE) has been proven to be effective in improving heat transfer due to its large surface area. in this study, HCHE was designed to provide hot air needed for fluidized bed drying processes. The HCHE design model was fabricated and evaluated to study the efficiency of the hot air output for a laboratory fluidized bed dryer. The mathematical model for estimation of the final (output) temperature of air, Taf, passing through the HCHE was developed and validated experimentally. The drying of bitter kola particulates was carried out with a drying temperature of 50C 3C and a bed height-to-bed diameter ratio (H/D) of 1.5. The time taken to dry bitter kola particulates to 0.4% moisture content was 1 hour 45 minutes. Hence, HCHE is recommended for use in the production of hot for laboratory-scale fluidized bed dryers.

关键词： Helical Coil Heat Exchanger Fluidized Bed Dryer Heat Transfer Output Air Temperature

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Environmental issues from coal mining and their solutions

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Mining Science and Technology 2010年第2期20卷 215-223页

作者： BiAN, Zhengfu inyang, hilary i DANiELS, John L OTTO, Frank STRUTHERS, Sue institute of land resources china university of mining & technologyxuzhou 221008china global institute for energy and environmental systems university of north carolinacharlotte nc 28223usa global institute for energy and environmental systems university of north carolinacharlotte nc 28223usa natural science foundation of the usa arlington va 22230usa department of geoengineering and mining university of applied sciencebochum 44801germany skapa mining services orkney kw172sxuk

The environmental challenges from coal mining include coal mine accidents,land subsidence,damage to the water environment,mining waste disposal and air *** are either environmental pollution or landscape change.A conceptual framework for solving mine environmental issues is *** processes,or remediation measures,are designed to address environmental *** measures are proposed to handle landscape *** total methane drainage from 56 Chinese high methane concentration coal mines is about 101.94 million cubic *** this methane,19.32 million,35.58 million and 6.97 million cubic meters are utilized for electricity generation,civil fuel supplies and other industrial purposes,*** 39% of the methane is emitted into the *** production of coal mining wastes can be decreased 10% by reuse of mining wastes as underground fills,or by using the waste as fuel for power plants or for raw material to make bricks or other infrastructure *** proper use of mined land must be decided in terms of local physical and socio-economical *** European countries more than 50% of previously mined lands are reclaimed as forest or grass ***,in China more than 70% of the mined lands are reclaimed for agricultural purposes because the large population and a shortage of farmlands make this *** of rural communities or native residential improvement is one environmental problem arising from *** suggest two ways to reconstruct a farmer's house in China.

关键词： mine environment management of mining wastes reuse of mine gas mined land reclamation clean coal mining

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Soil micro-penetration resistance as an index of its infiltration processes during rainfall

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Journal of Rock Mechanics and Geotechnical Engineering 2022年第5期14卷 1580-1587页

作者： Chao-Sheng Tang Xue-Peng Gong Zhengtao Shen Qing Cheng hilary inyang Chao Lv Bin Shi School of Earth Sciences and Engineering Nanjing University163 Xianlin AvenueNanjing210023China Global institute for Sustainable Development CharlotteNCUSA

Rainfall infiltration is one of the most important driving factors of geological hazards, ecological environment problems, and engineering accidents. Understanding the principle of soil wetting during rainfall infiltration and its influence on soil mechanical properties is crucial for preventing geological hazards. in this study, micro-penetration tests coupled with moisture monitoring were performed to investigate the infiltration process during wetting through the measured change in mechanical characteristics. Results show that penetration resistance increases in the deep layer gradually. With increasing infiltration time,the wetting front keeps moving downward, and its range becomes wider. A slight increase of the penetration resistance in the shallow layer(d ≤ 17.5 mm) is observed. However, the penetration resistance in the middle layer(22.5 mm ≤ d ≤ 32.5 mm) decreases firstly before a slight increase. in the deep layer(d ≥ 37.5 mm), the penetration resistance decreases continuously during infiltration. Based on the measured water content profile during infiltration, it is found that the evolution of soil mechanical characteristics is fully responsible by the infiltration-induced re-distribution of water content along depth. Generally, the penetration resistance decreases exponentially with increasing water content in the soil. When the water content is low, wetting can weaken soil strength significantly, whereas this effect diminishes when the moisture surpasses a certain threshold. The results highlight that the penetration curves and water content profile show close inter-dependency and consistency, which verifies the feasibility of using micro-penetration to investigate rainfall infiltration and wetting process in surface soil layer or laboratory small-scale soil samples. This method enables fast, versatile and high-resolution measurements of infiltration process and moisture distribution in soil.

关键词： Micro-penetration test Soil wetting Rainfall infiltration Water content Hydro-mechanical behavior Microstructure

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Seropositivity of Chlamydophila pneumoniae immunoglobulin G antibody of HiV/AiDS patients in Abuja,Nigeria

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Asian Pacific Journal of Tropical Medicine 2010年第8期3卷 666-668页

作者： Yakubu Boyi Ngwai izebe KS ijele iG ishaleku D inyang US Microbiology Unit Nasarawa State UniversityP.M.B.1022KeffiNasarawa StateNigeria National institute for Pharmaceutical Research and Development P.M.B.21 GarkiAbujaNigeria

Objective:To detect igG antibody to Chlamydophila pneumoniae(CP) in sera of HiV/AiDS patients and provide rationale for inclusion of routine screening for anti-CP antibodies and anti-chlamydial agents in the Nigerian National H1V/AiDS Management ***:Serum samples from 34 consenting HiV/AiDS patients attended a Government-approved Antiretroviral Treatment Facility in Abuja were screened by enzyme-linked immunosorbent assay for anti-CP igG antibody using immunoComb? Chlamydia Bivalent igG Test kit(Orgenics,israel).Results: Anti-CP igG antibody was detected in 20(58.8%) of 34 patients *** detection rale was higher among the males(8/13:61.5%) than the females(12/21:57.1%).Patients of the age group 16-30 years had the highest(7/10:70%) detection of anti-CP igG ***:The result of the present study suggests the presence of anti-CP antibodies in sera of the HiV/AiDS patients,and reinforces the need for routine screening for anti-CP antibodies as a necessary intervention to reduce the burden of Chlamydophila pneumoniae(***) infections and to reduce HiV-positive morbidity in *** outcome of this study also provides justification for the possible inclusion of anti-chlamydial agents in the National HiV/AiDS Management Plan to provide prophylaxis against or treat active *** infections.

关键词： Chlamydophila pneumoniae Chlamydia Antibodies AiDS Nigeria

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PHYSiCO-CHEMiCAL DETERMiNANTS OF HARD SOiL AND SOFT ROCK CHARACTERiSTiCS

PHYSICO-CHEMICAL DETERMINANTS OF HARD SOIL AND SOFT ROCK CHA...

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岩石力学与环境岩土工程国际会议

作者： H.i.inyang J.L.Daniels Director DuPont Young ProfessorCenter for Environmental Engineering and Science Technologies(CEEST)and Dept.of Civil and Environmental EngineeringUniversity of MassachusettsOne University Ave.LowellMA 01854U.S.A. DuPont Graduate Fellow University of MassachusettsOne University Ave.LowellMA 01854U.S.A.

＜正＞Soil-water-environment interactions in some problematic hard soils such as stiff-fissured and overconsolidated clays,and soft rocks such as soil-like shales,weathering rocks,limestones and dolomite are *** textural heterogeneity of weathered rocks makes it difficult to design effective clean up systems for these *** this paper,further evaluations of mechanisms of fluid/solid interactions in these types of soil and rock are *** is hopedi that this additional information may lead to improved techniques for analysis and design of geoenvironmental projects.

关键词： Clay mineral Environmental geotechnology Geology Soil-rock properties Pollution Weathering

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Heat Transfer in Helical Coil Heat Exchanger

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Advances in Chemical Engineering and Science 2022年第1期12卷 26-39页

作者： Uwem Ekwere inyang iniubong James Uwa Department of Chemical and Petroleum Engineering Faculty of Engineering University of Uyo Uyo Nigeria

The research paper tends to review the effectiveness of helical coil in heat exchangers (HCHE). Heat exchanger is a device used in transferring thermal energy between two or more fluids or solid interfaces and a fluid, in solid particulates and a fluid at different temperatures and thermal contact. The author has concisely discussed the helical coil in heat exchanger at different shapes and conditions and compared the HCHE with straight tubes heat exchangers, and the factors affecting the performance and effectiveness of the helical coil heat exchanger such as the curvature ratio, and other heat exchangers. The author demonstrated that the HCHE provided more excellent heat transfer performance and effectiveness than straight tubes and other heat exchangers because of secondary flow development inside the helical tube, and heat transfer coefficient increased with an increase in the curvature ratio of HCHE for the same flow rates. The secondary flow and mass flow rates, advantages and disadvantagesily:Verdana;"> have also been reviewed. The authors back their findings with available theories. Suitable fluid should be searched for high efficiency in the helical coil.

关键词： Helical Coil Heat Transfer Heat Exchanger Boundary Conditions Temperature

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Prevalence of sexually transmitted diseases in pregnant women in ikot Ekpene, a rural community in Akwa ibom State, Nigeria

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Open Journal of Obstetrics and Gynecology 2012年第1期2卷 49-55页

作者： Etim inyang Ekanem Mbabel Ekott Atim Edet Udo Efiok Eyo Efiok Attah inyang-Out Department of Microbiology General Hospital Ikot Ekpene Nigeria Department of Obstetrics & Gynecology College of Medical Sciences University of Calabar Calabar Nigeria

Background: Sexually transmitted diseases are associated with adverse consequences in pregnancy and its outcome. However, early detections and effective treatments would prevent the associated complications. Objectives: The main aims of this study are to determine the prevalence of common sexually transmitted diseases and to assess the socio-demographic profile of the women. Subjects and Methods: Samples were collected from 560 pregnant women at the first antenatal visit in the hospital after they were counseled and informed consent obtained. Pre-tested questionnaires were used to assess their socio-economic and demographic characteristics. The samples were subjected to the relevant laboratory tests and analysis. Results: Out of the 562 pregnant women examined, 250 (44.5%) were infected with various etiologic agents. Genital candidasis was the highest infection encountered in 119 (21.1%) women followed by Bacterial vaginosis in 38 (6.8%) and Chalamydiae in 35 (6.2%). Others infections included Hepatitis 8 (1.4%);Trichomonasis 29 (5.2%);Human immunodeficiency virus infection 12 (2.1%), Syphilis 7 (1.2%) and 2 Gonococcal infections respectively. The mean parity of the women with infection was 3 ± 1.4 and majority was asymptomatic (57.1%). The prevalence rate of infection was inversely associated with increasing maternal age and advanced formal educational status. The mean gestational age was 19 weeks ± 4.2 and appeared highest with earlier gestational age. Conclusion: There is high prevalence of sexually transmitted diseases among our pregnant women with most of them being asymptomatic. Screening for and prophylactic treatment of the common treatable infection at booking may reduce the incidence of adverse maternal and perinatal outcome associated with these infections.

关键词： Pregnant Women STDs Diagnosis Maternal Morbidity

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pH-Dependence of Manganese (ii) Oxidation Reaction by Novel Wild-Type and Mutants Recombinant Phlebia radiata Manganese Peroxidase 3 (rPr-MnP3) Enzymes

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American Journal of Molecular Biology 2022年第2期12卷 67-84页

作者： Usenobong F. Ufot Monday i. Akpanabiatu Khasim Cali ifiok D. Uffia inyang Udosen Department of Genetics and Biotechnology Faculty of Biological Sciences Akwa Ibom State University Uyo Akwa Ibom State Nigeria Department of Biochemistry Faculty of Sciences University of Uyo Akwa Ibom State Uyo Akwa Ibom State Nigeria Department of Chemical Engineering and Analytical Science University of Manchester Manchester UK

The goal of this study was to determine whether mutation of the Mn-binding site of wild-type recombinant Phlebia radiata manganese peroxidase 3 affected the pH-dependence kinetic parameters. pH range investigated was 2.5 – 12.0. The catalytic efficiency of the mutant enzymes at high and low pH in comparison to the wild-type was investigated using standard rPr-MnP3 protocol. Wild-type recombinant Phlebia radiata MnP3 enzyme showed optimal activity with Mn (ii) as substrate at pH 5.0 and remained moderately active (approximately 40%) in the pH range of 6.0 - 9.0. The rPr-MnP3 mutants’ maximum activity ranged between 5.5 and 8.0. Wild-type and mutants rPr-MnP3 enzymes exhibited a similar pH profile with optimum pH of 3.0 for ABTS oxidation. Mutation has severely decreased the catalytic efficiency for Mn (ii) oxidation at pH 5.0. The rPr-MnP3 enzymes showed enhanced affinity for Mn (ii) at alkaline pH and a more alkaline range for catalysis than ever reported for any Manganese Peroxidase. This study reveals that at higher pH, rPr-MnP3 can function with alternative ligands in the Mn (ii) site and does not have an absolutely obligate requirement for an all carboxylate ligand set. These results further strongly confirm that Mn2+ binding site is the only productive catalytic site for Mn (ii) oxidation.

关键词： pH-Dependence Phlebia radiata Manganese Peroxidase Wild-Type Mutants Recombinant Enzyme

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广东沿海红树林区水质变化特征与富营养状态评估

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热带海洋学报 2022年第6期41卷 1-11页

作者： inyang Aniefiok ini 周月月王友绍热带海洋环境国家重点实验室(中国科学院南海海洋研究所) 广东广州510301 中国科学院大亚湾海洋生物综合试验站广东深圳518121 中国科学院南海生态环境工程创新研究院广东广州510301 中国科学院大学北京100049 南方海洋科学与工程广东省实验室(广州) 广东广州511458

调查了广东红树林区水质的时空变化,分别采集了红树林区表层水体水样旱季30个样点(2017年10月至2018年1月)和湿季20个样点(2018年7月至8月)进行分析。利用单一营养状态指数(TSi Chl a)评价红树林水质特征和营养状态,评价标准:0050为富营... 详细信息

调查了广东红树林区水质的时空变化,分别采集了红树林区表层水体水样旱季30个样点(2017年10月至2018年1月)和湿季20个样点(2018年7月至8月)进行分析。利用单一营养状态指数(TSi Chl a)评价红树林水质特征和营养状态,评价标准:0i≤30为贫营养,30i≤50为中营养,TSi>050为富营养,>70为高营养。红树林区环境参数的时空变化为:盐度(2.15‰~27.14‰)、p H(6.18~8.65)、电导率(10.87~90.52μs·cm)、浊度(0.0975~21.61FTU)、硝酸盐(0~127.2mg·L^(-1))、亚硝酸盐(0~12.0mg·L^(-1))、磷酸盐(0~34.5mg·L^(-1))、硅酸盐(1.22~2.88mg·L^(-1))和叶绿素a(0.19~38.08mg·m)。聚类分析表明,丰水期横跨雷州半岛右侧至广东沿海东部的水质相对较好,而左侧则处于中营养化状态。同时,在枯水期,红树林区水质较差,从雷州半岛周围的高中营养化状态,到广东沿海东部的富营养化状态。主成分分析表明,营养盐、盐度、p H、电导率(electrical conductivity,EC)和浊度对红树林区水质状况贡献显著,进而影响红树林生态系统中藻类群落的变化。

关键词：藻类丰度营养盐红树林营养状态广东沿海

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