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Simultaneous removal of trihalomethanes by bimetallic Ag/Zn:kinetics study

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Frontiers of Chemical Science and Engineering 2010年第3期4卷 322-327页

作者： ahmed h A dabwan Satoshi KANECO hideyuki KATSUMATA Tohru SUZUKI Kiyoyuki EGUSA Kiyohisa OhTA Faculty of Chemical Engineering Technology Tati University CollegeJalan PanchorTeluk Kalong24000 KemamanTerengganuMalaysia Department of Chemistry for Materials Graduate School of EngineeringMie UniversityMie 514-8507Japan Environmental Preservation Center Mie UniversityMie 514-8507Japan

In the present work,bimetallic silver/zinc was applied into the degradation of trihalomethanes,ThMs:ChCl_(3),ChBrCl_(2),ChBr_(2)Cl,and ChBr_(3).The kinetics reaction rates and removal efficiencies of the ThM compound mixtures,in the aqueous solutions,were *** experiments were conducted under mild conditions,ambient temperature,and *** primary degradation reaction followed a pseudo-first-order kinetic *** first-order rate constants and the degradation efficiencies followed the decreasing order of ChBr_(3)>ChBr_(2)Cl>ChBrCl_(2)>ChCl_(3).The bond dissociation energy and hydrophilic/hydrophobic characteristics of the ThM compounds may become the most important parameters affecting the degradation kinetics and efficiency by bimetallic Ag/Zn.

关键词： degradation trihalomethanes bimetallic silver/zinc halogenated pollutants kinetics

Influence of temperature on the properties of one-dimensional piezoelectric phononic crystals

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Chinese Physics B 2018年第9期27卷 342-345页

作者： ahmed Nagaty ahmed Mehaney Arafa h Aly Physics Department Faculty of Sciences Beni-Suef University

The current study investigates the influence of temperature on a one-dimensional piezoelectric phononic crystal using tunable resonant frequencies. Analytical and numerical examples are introduced to emphasize the influence of temperature on the piezoelectric phononic crystals. It was observed that the transmission spectrum of a one-dimensional phononic crystal containing a piezoelectric material（0.7 PMN-0.3 PT） can be changed drastically by an increase in *** resonant peak can be shifted toward high or low frequencies by an increase or decrease in temperature, ***, we deduced that temperature can exhibit a large tuning in the phononic band gaps and in the local resonant frequencies depending on the presence of a piezoelectric material. Such result can enhance the harvesting energy from piezoelectric materials, especially those that are confined in a phononic crystal.

关键词： phononic crystals resonant modes piezoelectric material thermal properties and temperature

Low band gap frequencies and multiplexing properties in 1D and 2D mass spring structures

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Chinese Physics B 2016年第11期25卷 333-339页

作者： Arafa h Aly ahmed Mehaney Physics Department Faculty of Sciences Beni-Suef University

This study reports on the propagation of elastic waves in 1D and 2D mass spring *** analytical and computation model is presented for the 1D and 2D mass spring systems with different *** enhancement in the band gap values was obtained by modeling the structures to obtain low frequency band gaps at small ***,the evolution of the band gap as a function of mass value is *** attention is devoted to the local resonance property in frequency ranges within the gaps in the band structure for the corresponding infinite periodic lattice in the 1D and 2D mass spring system.A linear defect formed of a row of specific masses produces an elastic waveguide that transmits at the narrow pass band *** frequency of the waveguides can be selected by adjusting the mass and stiffness coefficients of the materials constituting the ***,we pay more attention to analyze the wave multiplexer and DE-multiplexer in the 2D mass spring *** show that two of these tunable waveguides with alternating materials can be employed to filter and separate specific frequencies from a broad band input *** presented simulation data is validated through comparison with the published research,and can be extended in the development of resonators and MEMS verification.

关键词： multiplexing waveguide tunable separate dimensions devoted verification stiffness validated infinite

Nonalcoholic fatty liver disease and COVID-19:An epidemic that begets pandemic

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World Journal of Clinical Cases 2021年第17期9卷 4133-4142页

作者： Musaab ahmed Mohamed h ahmed College of Medicine Ajman UniversityAjman 346United Arab Emirates Department of Medicine and hIV Metabolic Clinic Milton Keynes University Hospital NHS Foundation TrustMilton Keynes MK56LDUnited Kingdom

Coronavirus disease 2019(COVID-19)caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has become a global pandemic,affecting all the individuals across the ***-19 has gained significant attention due to its high prevalence among individuals with diabetes,nonalcoholic fatty liver disease(NAFLD),and metabolic *** is the hepatic manifestation of metabolic syndrome and can be associated with a high risk of developing type 2 *** association of COVID-19 and NAFLD has also gained more attention because NAFLD is highly associated with the epidemic of *** is a potential risk factor for SARS-CoV-2 infection and severe COVID-19,independent of metabolic ***,it is not yet clear whether the epidemics of obesity and NAFLD have perpetuated the current pandemic of *** research is urgently needed to assess the following:(1)Whether NAFLD is a high risk factor for SARS-CoV-2 infection;(2)Whether NAFLD is associated with the severe form of COVID-19;and(3)Whether the presence of NAFLD can explain the racial variation in the morbidity and mortality associated with *** review summarizes the interactions between COVID-19 and NAFLD,mechanism of liver injury by COVID-19,and effect of lockdown due to COVID-19 on patients with NAFLD.

关键词： Fatty liver COVID-19 Diabetes Obesity Pandemic

Exploring tree diversity and stand structure of savanna woodlands in southeastern Sudan

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Journal of Arid Land 2020年第4期12卷 609-617页

作者： ahmed M M hASOBA ahmed A h SIDDIG Yousif E YAGOUB Faculty of Forest Sciences and Technology University of GeziraMadani 22212Sudan Faculty of Forestry University of KhartoumKhartoum North 13314Sudan Department of Environmental Conservation University of Massachusetts AmherstAmherst 01003USA

Savanna woodlands in Sudan host great biodiversity, provide a plethora of ecosystem goods and services to local communities, and sustain numerous ecological functions. Although the importance of the Acacia trees in these areas is well known, up-to-date information about these woodlands' diversity is limited and changes in their woody vegetation composition, density, diversity and relative frequency are not monitored over time. This study explored tree diversity and stand stage structure in Nuara Reserved Forest, a typical savanna woodland ecosystem in southeastern Sudan. A total of 638 circular sample plots(1000 m^2 for each) were established using a systematic sampling grid method. The distance between plots was 200 m. In each plot, all living trees with diameter at breast height(DBh) ≥5.00 cm were identified and counted, and their DBh values were recorded. From these data, tree composition, diversity, density and stage structure were assessed. There were 12,259 individual trees representing four species(Acacia seyal, Balanites aegyptiaca, Acacia Senegal and Acacia mellifera) that belong to two families. The dominant species was Acacia seyal. Average tree density was 191 trees/hm^2 and the Shannon-Weiner index for trees diversity was 0.204. Overall, young trees comprised 86.30% of the forest. The state of tree richness and density in the study area was low compared to other similar environments in the region and around the world. We recommended adoption of a proper management system that includes monitoring of woody vegetation diversity in this forest, and management actions to enhance tree diversity and sustain ecosystem services to local communities. In addition to care for the dominant Acacia seyal stands, more attention and conservation should be devoted to reestablishing Acacia senegal and Acacia mellifera trees because of their high ecological and economic values for local communities.

关键词： species diversity stand structure savanna woodland ecosystem forest monitoring forest management ecosystem services Nuara Reserved Forest

Optimization of Conditions for the Photocatalytic Degradation of EDTA in Aqueous Solution with Fe-Doped Titanium Dioxide

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Open Journal of Inorganic Non 2014年第3期4卷 28-34页

作者： Tomoki Sugiyama ahmed h. A. dabwan hideyuki Katsumata Tohru Suzuki Satoshi Kaneco Department of Chemistry for Materials Graduate School of Engineering Mie University Mie Japan Mie Global Environment Center for Education & Research Mie University Mie Japan Research Center of Process for Environmental Load Reduction Mie University Mie Japan Department of Chemistry for Materials Graduate School of Engineering Mie University Mie Japan Research Center of Process for Environmental Load Reduction Mie University Mie Japan Gifu University Gifu Japan Mie Global Environment Center for Education & Research Mie University Mie Japan Research Center of Process for Environmental Load Reduction Mie University Mie Japan Research Management Center Tati University College Kemaman Terengganu Malaysia

The conditions for photocatalytic degradation of ethylenediaminetetraacetic acid (EDTA) in aqueous solution with Fe-doped titanium dioxide (TiO2) were optimized. The degradation efficiencies with Fe-doped TiO2 were better, compared with those obtained with bare TiO2 and Pt-doped TiO2. The effect of various experimental factors, such as photocatalytic dosage, temperature, solution ph and light intensity on the photocatalytic degradation of EDTA by Fe-doped TiO2 was investigated. The photocatalytic degradation treatment for the wastewater containing EDTA is simple, easy handling and low cost.

关键词： EDTA Fe-Doped TioEDTA Fe-Doped TiO2 Photocatalytic Degradation Wastewater Treatment Radioactive Liquid Waste

Obstructive sleep apnea syndrome and fatty liver: Association or causal link?

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World Journal of Gastroenterology 2010年第34期16卷 4243-4252页

作者： Mohamed h ahmed Christopher D Byrne Chemical Pathology Department Southampton University Hospital NHS Trust Southampton SO16 6YD United Kingdom Endocrinology and Metabolism DOHaD Division University of Southampton and Southampton University Hospitals Trust Southampton SO16 6YD United Kingdom

Obstructive sleep apnea (OSA) is a complex disorder that consists of upper airway obstruction, chronic intermittent hypoxia and sleep fragmentation. OSA is well known to be associated with hypoxia, insulin resistance and glucose intolerance, and these factors can occur in the presence or absence of obesity and metabolic syndrome. Although it is well established that insulin resistance, glucose intolerance and obesity occur frequently with non-alcoholic fatty liver disease (NAFLD), it is now becoming apparent that hypoxia might also be important in the development of NAFLD, and it is recognized that there is increased risk of NAFLD with OSA. This review discusses the association between OSA, NAFLD and cardiovascular disease, and describes the potential role of hypoxia in the development of NAFLD with OSA.

关键词： Sleep apnea syndrome hyperlipidemia Non-alcoholic fatty liver disease Insulin resistance

Analyzing the effect of earthquakes on OpenStreetMap contribution patterns and tweeting activities

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Geo-Spatial Information Science 2018年第3期21卷 195-212页

作者： ahmed Ahmouda hartwig h.hochmair Sreten Cvetojevic Geomatics Program Fort Lauderdale Research and Education CenterUniversity of FloridaFloridaFort LauderdaleUSA

Natural disasters,such as wildfires,earthquakes,landslides,or floods,lead to an increase in topical information shared on social media and in increased mapping activities in volunteered geographic information(VGI)*** earthquakes in Nepal and Central Italy as case studies,this research analyzes the effects of natural disasters on short-term(weeks)and longer-term(half year)changes in OpenStreetMap(OSM)mapping behavior and tweet activities in the affected *** increase of activities in OSM during the events can be partially attributed to those focused OSM mapping campaigns,for example,through the humanitarian OSM Team(hOT).Using source tags in OSM change-sets,it was found that only a small portion of external mappers actually travels to the affected regions,whereas the majority of external mappers relies on desktop mapping ***,the study analyzes the spatio-temporal sequence of posted tweets together with keyword filters to identify a subset of users who most likely traveled to the affected regions for support and rescue *** also explores where,geographically,earthquake information spreads within social networks.

关键词： Volunteered geographic information(VGI) OpenStreetMap(OSM) Twitter natural disaster human dynamics

Oilfield produced water treatment in internal-loop airlift reactor using electrocoagulation/flotation technique

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Chinese Journal of Chemical Engineering 2018年第4期26卷 879-885页

作者： Saad h.Ammar ahmed S.Akbar Department of Chemical engineering AL-Nahrain University

Oilfield produced water is large quantities of salty water trapped in underground formations and subsisted under high temperatures and pressures that are brought to the surface along with oil during production. Produced water(PW) contains a lot of pollutants such as hydrocarbons and metals, this water must be treated before disposal. Therefore, different techniques are being used to treat produced water. Electrocoagulation is an efficient treatment technique involving the dissolution of anodes and formation of electro-coagulants, while the simultaneous generation of h_2 bubbles at the cathode leads to the pollutant removal by flotation. Electrocoagulation(EC)method is one of the most promising and widely used processes to treat oilfield produced water. In the present work, a conventional internal-loop(draught tube) airlift reactor was utilized as electrocoagulation/flotation cell for PW treatment by inserting two aluminum electrodes in the riser section of the airlift reactor. The EC airlift reactor was operated in a batch mode for the liquid phase. Different experimental parameters were studied on the oil and turbidity removal efficiencies such as current density, initial ph, electrocoagulation time, and air *** experimental results showed that mixing of the oil droplets in the PW was accomplished using only the liquid recirculation resulted by h_2 microbubbles generated by EC process which enhanced the oil removal. The experimental results further showed that the EC time required achieving ≥ 90% oil removal efficiency decreases from 46 to 15 min when operating current density increases from 6.8 to 45.5 mA·cm^(-2). This reactor type was found to be highly efficient and less energy consuming compared to conventional existing electrochemical cells which used mechanical agitation.

关键词： Produced water Wastewater treatment Electrocoagulation/flotation Internal loop Airlift reactor