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NEWTONIAN FLOW IN CONVERGING-DIVERGING CAPILLARIES

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International Journal of Modeling, Simulation, and Scientific Computing 2013年第3期4卷 84-96页

作者： taha SOCHI Imaging Sciences&Biomedical Engineering King’s College London The Rayne Institute St Thomas’HospitalLondonSE17EHUK

The one-dimensional Navier–Stokes equations are used to derive analytical expressions for the relation between pressure and volumetric flow rate in capillaries of five different converging-diverging axisymmetric geometries for Newtonian *** results are compared to previously derived expressions for the same geometries using the lubrication *** results of the one-dimensional Navier–Stokes are identical to those obtained from the lubrication approximation within a nondimensional numerical *** derived flow expressions have also been validated by comparison to numerical solutions obtained from discretization with numerical ***,they have been certified by testing the convergence of solutions as the converging-diverging geometries approach the limiting straight geometry.

关键词： Fluid dynamics one-dimensional Navier-Stokes converging-diverging capillaries Newtonian fluids.

Crystal Structure, Vibrational Studies, Optical Properties and TG-DTA Investigations of a New Chlorocadmate Templated by 1-Methylimidazolium

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Chemical Research in Chinese Universities 2016年第2期32卷 253-260页

作者： Melek HAJJI taha GUERFEL Laboratory of Electrochemistry Materials and Environment Preparatory Institute for Engineering Studies Kairouan University 3100 Kairouan Tunisia

Chemical preparation, X-ray single crystal diffraction, thermal analysis, electrochemical measurements, IR, Raman and UV spectroscopic investigations of a novel organic-inorganic hybrid material（CaH7N2）CdCl3（H2O）（1） were described. 1-Methylimidazolium aquapentachlorocadmate（II） crystallized in the monoclinic system with P2 1/n space group. Its structure provided a new interesting example of infinite inorganic layers of [CdCl3（H2O）]n n- centered by （-101） planes. The [CdCl5（H2O）]- anions were interconnected by O-H...Cl hydrogen bonds. Acidic protons of the chloride group were transferred to the organic molecule, giving the singly-protonated cations. The ability of ions to form a spontaneous three-dimensional structure through O-H…Cl and N-H…Cl hydrogen bonds was fully utilized. These hydrogen bonds induced notable vibrational effects. IR and Raman spectra were reported and discussed on the basis of group theoretical analysis and on quantum chemical density theory（DFT） calculation. The molecular HOMO-LUMO compositions and their respective energy gaps were also drawn to explain the activity of our compound. The role of the intermolecular interaction in this crystal was analyzed. The optical study was also investigated by UV-Vis absorption spectrum. Thermal analysis reveals the hydrous character of the compound. Cyclic voltammetry was studied to evaluate the spectral and structural changes accompanying electron transfer.

关键词： Chlorocadmate(II) X-Ray diffraction Thermal analysis(TG-DTA) Vibrational study Density functional theory calculation Cyclic voltammetry

A review on zero energy buildings-Pros and cons

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Energy and Built Environment 2023年第1期4卷 25-38页

作者： Tabbi Wilberforce A.G.Olabi Enas taha Sayed Khaled Elsaid Hussein M.Maghrabie mohammad Ali Abdelkareem Mechanical Engineering and Design Aston UniversitySchool of Engineering and Applied ScienceAston TriangleBirmingham B47ETUK Department of Sustainable and Renewable Energy Engineering University of SharjahP.O.Box 27272SharjahUnited Arab Emirates Center for Advanced Materials Research University of SharjahPO Box 27272SharjahUnited Arab Emirates Chemical Engineering Department Minia UniversityElminiaEgypt Chemical Engineering Department Texas A&M UniversityTX 77843-3122College StationTXUSA Department of Mechanical Engineering Faculty of EngineeringSouth Valley UniversityQena 83521Egypt

Enhancing the energy efficiency of structures has been a staple of energy *** key goal is to slash elec-tricity usage in order to minimize the footprint of *** goal is sought by putting restrictions on the design specifications with respect to the properties of the raw materials and components as well as the exploitation of sustainable sources of *** facts for the basis for zero-energy building(ZEB)being *** novel technology has faced several obstacles impeding its commercialization and future *** inves-tigation therefore holistically explored and evaluated the state of zero energy building and factors impeding their *** review further proposed some suggestion in terms of technology that can be considered by the sector to augment existing ***,the investigation touched on the effect of occupant’s character in zero energy *** in terms of government subsidies and tax rebates were recommended to encourage more investors into the ***,the perception of zero energy building being more expensive compared to the traditional structures can equally be curbed via efficient and effective public sensitization.

关键词： Zero energy buildings Policies Renewable energy Construction industry

Evaluation of the microstructure,thermal and mechanical properties of Cu/SiC nanocomposites fabricated by mechanical alloying

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International Journal of Minerals,Metallurgy and Materials 2021年第3期28卷 475-486页

作者： Essam B.Moustafa Mohammed A.taha Mechanical Engineering Departments Faculty of EngineeringKing Abdulaziz UniversityJeddah 21589Saudi Arabia Solid State Physics Department National Research CentreEl Buhouth St.Dokki12622 GizaEgypt

Nano-sized silicon carbide(SiC:0wt%,1wt%,2wt%,4wt%,and 8wt%)reinforced copper(Cu)matrix nanocomposites were manufactured,pressed,and sintered at 775 and 875℃in an argon atmosphere.X-ray diffraction(XRD)and scanning electron microscopy were performed to characterize the microstructural *** density,thermal expansion,mechanical,and electrical properties were *** analyses showed that with increasing SiC content,the microstrain and dislocation density increased,while the crystal size *** coefficient of thermal expansion(CTE)of the nanocomposites was less than that of the Cu *** improvement in the CTE with increasing sintering temperature may be because of densification of the ***,the mechanical properties of these nanocomposites showed noticeable enhancements with the addition of SiC and sintering temperatures,where the microhardness and apparent strengthening efficiency of nanocomposites containing 8wt%SiC and sintered at 875℃were 958.7 MPa and 1.07 vol%^(−1),*** electrical conductivity of the sample slightly decreased with additional SiC and increased with sintering *** prepared Cu/SiC nanocomposites possessed good electrical conductivity,high thermal stability,and excellent mechanical properties.

关键词： copper matrix nanocomposites silicon carbide coefficient of thermal expansion elastic moduli electrical conductivity mechanical alloying

PREPARATION AND PROPERTIES OF FUMED SILICA/CYANATE ESTER NANOCOMPOSITES

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Chinese Journal of Polymer Science 2012年第4期30卷 530-536页

作者： Elhussein A.taha 吴俊涛郭林 Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry ofEducation School of Chemistry and EnvironmentBeihang University Key Laboratory of Bio-InspiredSmart Interfacial Science and Technology of Ministry of Education School of Chemistry and EnvironmentBeihang University

Fumed silica/bisphenol A dicyanate ester （BADCy） nanocomposites were prepared by introducing different contents of nano-sized fumed SiO2 into the BADCy matrix. Two different average primary particle diameters of 12 and 40 nm were chosen. Dibutyltindilaurate （DBTDL） catalyst was chosen to catalyze the cyanate ester group into triazine group via cyclotrimerization reaction. The SEM micrographs indicated that the fumed SiO2 particles were homogeneously dispersed in the poly（bisphenol A dicyanate） matrix by means of ultrasonic treatment and the addition of a coupling agent. The FTIR spectroscopy shows that, not only DBTDL catalyzes the polymerization reaction but also --OH groups of the SiO2 particles surface help the catalyst for the complete polymerization of BADCy monomer. The thermal stability of the cured BADCy can be improved by adequate addition of fumed SiO2. A slight increase in the dielectric constant and dielectric loss values were identified by testing the dielectric properties of the prepared nanocomposite samples. By increasing the SiO2 content, there was a slight increasing in the thermal conductivity values of the tested samples. The obtained results proved that the fumed silica/BADCy nanocomposites had good thermal and dielectrieal properties and can be used in many applications such as in the thermal insulation field.

关键词： Cyanate ester Fumed silica Nanocomposites Thermal conductivity Dielectric properties.

Progress in plant-based bioelectrochemical systems and their connection with sustainable development goals

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Carbon Resources Conversion 2021年第1期4卷 169-183页

作者： Enas taha Sayed mohammad Ali Abdelkareem Khaled Obaideen Khaled Elsaid Tabbi Wilberforce Hussein M.Maghrabie A.G.Olabi Center for Advanced Materials Research University of SharjahPO Box 27272SharjahUnited Arab Emirates Chemical Engineering Department Minia UniversityElminiaEgypt Dept.of Sustainable and Renewable Energy Engineering University of SharjahP.O.Box 27272SharjahUnited Arab Emirates Chemical Engineering Department Texas A&M UniversityCollege StationTX 77843-3122TXUSA Mechanical Engineering and Design Aston UniversitySchool of Engineering and Applied ScienceAston TriangleBirmingham B47ETUK Department of Mechanical Engineering Faculty of EngineeringSouth Valley UniversityQena 83521Egypt

Living organisms’energy conversion is considered as an essential and sustainable green energy source and future bio-hybrid ***,plants were used after harvesting as biomass in bio-fermentation as an energy *** bio-electrochemical systems,microorganisms work with plants to generate electricity,hydrogen,or *** work discusses the simultaneous pollutant removal and electricity generation in plant-based bio-electrochemical systems(P-BES).Factors affecting the P-BES performance and the removal efficiencies of the different organic and inorganic pollutants were ***,the plant-based bioelectrochemical systems’role in achieving the sustainable development goals(SDGs)was *** SDGs contribution of plant-based bioelectrochemical systems were presented and discussed to evaluate such systems’ability to achieve the three pillars of sustainable development,i.e.,economic,environmental,and social.

关键词： Plant Bioelectrochemical systems Sustainable development goals,pollutant removal Power generation

Safety and effi cacy of hepatitis A vaccine in children with chronic liver diseas

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World Journal of Gastroenterology 2006年第45期12卷 7337-7340页

作者： Hanaa Mostafa El-Karaksy Manal Ismail El-Hawary Nehal mohammad El-Koofy Rokaya El-Sayed Mona Al-Saeed El-Raziky Samah Asaad Mansour Gamal mohammad taha Fatma El-Mougy Department of Pediatrics Cairo University Egypt Department of Pediatrics Fayoum University Egypt Department of Pediatrics Beni-Swaif University Egypt Department of Chemical Pathology Cairo University Egypt

AIM： To study the safety and efficacy of hepatitis A vaccine （HAV） in children with chronic liver disease of various etiologies. METHODS： Eleven children with chronic liver disease and thirteen age- and sex-matched controls negative for HAV antibodies were vaccinated against hepatitis A after they gave their informed consent. Children with uncontrolled coagulopathy or signs of hepatic decompensation were excluded. The vaccine （Havrix： 720 ELISA units in 0.5 mL, from GlaxoSmithKline Biologicals） was given intramuscularly in the deltoid in 2 doses 6 mo apart. Children were tested for HAV antibodies one and six months after the ist dose and one month after the 2^nd dose. Total serum bilirubin, alanine aminotransferase （ALT）, and aspartate aminotransferase （AST） were determined immediately before and after one month of the 1st dose of the vaccine. RESULTS： Only 7 out of the 11 patients were positive for HAV antibodies after the 1^st dose of the vaccine, as compared to 100% of the controls. One month after the 2nd dose, all patients tested were positive for HAV antibodies. No deterioration in liver functions of patients was noted after vaccination. No adverse events, immediate or late, were reported by the mothers after each dose of the vaccine. CONCLUSION： Hepatitis A vaccine is both safe and effective in this small studied group of children with chronic liver disease. Given the high seroconversion rate, post-vaccination testing for HAV antibodies is not needed.

关键词： Children Chronic liver disease Hepatitis A Hepatitis A vaccine

Central choroidal thickness in children and adolescents with anxiety disorders:enhanced depth imaging optical coherence tomography findings

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International Journal of Ophthalmology(English edition) 2020年第10期13卷 1580-1585页

作者： Didem Ayyildiz taha Ayyildiz Child and Adolescent Psychiatry Department Bursa Dortcelik Child HospitalBursa 16120Turkey Ophthalmology Department Bursa City HospitalBursa 16110Turkey

AIM:To measure the central choroidal thickness(ChT)in children and adolescents with anxiety ***:Totally 41 anxiety patients(8-16 y)and 35 healthy controls(age-matched)were *** ophthalmic examination was *** criteria were best corrected visual acuity≥20/20,normal intraocular pressure(IOP;10-21 mm Hg),and no systemic or ocular diseases according to *** diagnosis of psychiatric disorders was determined using Schedule for Affective Disorders and Schizophrenia for School Aged Children Present-Lifetime Version(K-SADS-PL).Enhanced depth imaging optical coherence tomography(EDI-OCT)was used to measure the central ***:The mean age was 12.18±3.24 y in the patient group and 12.86±3.15 y in the control *** and gender distribution of the two groups was *** ChT mean value was 353.26±31.9μm in anxiety patients while 318.75±60.9μm in the control *** central ChT was statistically significantly higher in the children and adolescents with anxiety disorders than healthy controls(P=0.002).CONCLUSION:The children and adolescents with anxiety disorders have significantly thicker central ChT than *** the larger sample,longitudinal studies will contribute to the use of choroidal differences as a clinical marker for monitoring anxiety disorders.

关键词： anxiety disorders choroidal thickness spectral optical coherence tomography children adolescent

A Hybrid Meta-Classifier of Fuzzy Clustering and Logistic Regression for Diabetes Prediction

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Computers, Materials & Continua 2022年第6期71卷 6089-6105页

作者： Altyeb Altaher taha Sharaf Jameel Malebary Department of Information Technology Faculty of Computing and Information Technology in RabighKing Abdulaziz UniversityJeddahSaudi Arabia

Diabetes is a chronic health condition that impairs the body’s ability to convert food to energy,recognized by persistently high levels of blood *** diabetes can cause many complications,including retinopathy,nephropathy,neuropathy,and other vascular *** learning methods can be very useful for disease identification,prediction,and *** paper proposes a new ensemble learning approach for type 2 diabetes prediction based on a hybrid meta-classifier of fuzzy clustering and logistic *** proposed approach consists of two ***,a baselearner comprising six machine learning algorithms is utilized for predicting ***,a hybrid meta-learner that combines fuzzy clustering and logistic regression is employed to appropriately integrate predictions from the base-learners and provide an accurate prediction of *** hybrid metalearner employs the Fuzzy C-means Clustering(FCM)algorithm to generate highly significant clusters of predictions from *** predictions of base-learners and their fuzzy clusters are then employed as inputs to the Logistic Regression(LR)algorithm,which generates the final diabetes prediction *** were conducted using two publicly available datasets,the Pima Indians Diabetes Database(PIDD)and the Schorling Diabetes Dataset(SDD)to demonstrate the efficacy of the proposed method for predicting *** compared with other models,the proposed approach outperformed them and obtained the highest prediction accuracies of 99.00%and 95.20%using the PIDD and SDD datasets,respectively.

关键词： Ensemble learning fuzzy clustering diabetes prediction machine learning