检索结果-南通市图书馆

Journal of Environmental Protection 2019年第10期10卷 1262-1277页

作者： mohamed A. Shreadah Omnia Gamal Abdel Hamid Amr A. Yakout Ramadan H. El-Sokkary National Institute of Oceanography and Fisheries Alexandria Egypt ChemistryDepartment Faculty of Science University of Jeddah Jeddah KSA Chemistry Department Faculty of Science Alexandria University Alexandria Egypt.

The present study is aimed to examine the adsorption characteristics of Cu(II) by using the novel cellulose acetate composite and to apply it for the removal of Cu(II) from real wastewater samples. In order to achieve this objective, ethylenediamine, diethylenetriamine, triethylenetetramine and te-traethylenepentanene were used for immobilization of grafted cellulose acetate-nanoscale manganese dioxide. Cellulose was extracted from mangrove species Avicennia marina and converted to cellulose acetate then it was formed composite with nano-manganese dioxide via precipitation of nano-manganese dioxide on it. The composite was grafted with acrylamide monomer before immobilization. The synthesized compounds were used for adsorption of Cu(II) and characterized by FT-IR, TGA and SEM. The adsorption characteristics of synthesized sorbents were optimized. Langmuir and Freundlich models were used to establish sorption equilibria. The analytical applications of these modified materials were applied successfully for the removal of Cu(II).

关键词： Manganese Oxide Coated Zeolite Removal of Copper(II) Ions Seawater

Characterization and Adsorption Study of Thymol on Pillared Bentonite

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Physical Chemistry 2014年第3期4卷 98-116页

作者： mohamed El Miz Samira Salhi Ikrame Chraibi Ali El Bachiri Marie-Laure Fauconnier Abdesselam Tahani Département de Géologie Faculté des Sciences Université Mohamed 1er Oujda Morocco LACPRENE Faculté des Sciences Université Mohamed 1er Oujda Morocco Unité de Chimie Générale et Organique Gembloux Agro-Bio Tech Université de Liège Gembloux Belgique

Pillared clay (PILC) was prepared from Moroccan clay and characterized, and its aqueous thymol adsorption capacities were studied using a batch equilibrium technique. So, we tested the encapsulation of thymol by aluminum pillared clay (PILC). The PILCs displayed a total surface area of 270 m2/g, a total pore volume of 0.246 cm3/g and an average pore diameter of 8.9 A, which corresponds to the size of Al13 forming the pillars between the clay layers. The adsorption capacity shown by the PILCs for thymol from water is close to 319 mg?g-1 for low solid/liquid ratio (0.2%). This result suggests that the PILCs have both hydrophobic and hydrophilic characteristics, as a result of the presence of silanol and siloxane groups formed during the pillaring and calcination of the PILCs. The experimental data were analyzed by the Freundlich and the Langmuir isotherm types for low values of equilibrium concentration. The rise of the isotherm in this range of concentrations was related to the affinity of thymol for clay sites, and the equilibrium data fitted well with the Freundlich model with maximum adsorption capacity of 319.51 mg/g for a ratio RS/L = 0.2%. Pseudo-first and pseudo-second-order kinetic models were tested with the experimental data and pseudo-first order kinetics was the best for the adsorption of thymol with coefficients of correlation R2 ≥0.986, and the adsorption was rapid with 90% of the thymol adsorbed within the first 20 min.

关键词： Clays Bentonite Thymol Adsorption Desorption Kinetics Pillared Clay

Intersection Curves of Implicit and Parametric Surfaces in R<sup>3</sup>

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Applied Mathematics 2011年第8期2卷 1019-1026页

作者： mohamed Abdel-Latif Soliman Nassar Hassan Abdel-All Soad Ali Hassan Sayed Abdel-Naeim Badr 不详

We present algorithms for computing the differential geometry properties of Frenet apparatus {t,n,b,κ,τ} and higher-order derivatives of intersection curves of implicit and parametric surfaces in R3 for transversal and tangential intersection. This work is considered as a continuation to Ye and Maekawa [1]. We obtain a classification of the singularities on the intersection curve. Some examples are given and plotted.

关键词： Geometric Properties Frenet Frame Frenet Apparatus Frenet-Serret Formulas Surface-Surface Intersection Transversal Intersection Tangential Intersection Dupin Indicatrices

Outcome of percutaneous drainage for septic complications coexisted with COVID-19

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Radiology 2022年第4期14卷 91-103页

作者： mohamed A Deif Ahmad M Mounir Sherif A Abo-Hedibah Ahmed M Abdel Khalek Ali H Elmokadem Department of Radiology National Liver InstituteMenoufia UniversityShibin Al Kawm 32521Egypt Department of Radiology Mansoura UniversityMansoura 35516Egypt Department of Radiology Cairo universityCairo 12613Egypt

BACKGROUND The resulting tissue hypoxia and increased inflammation secondary to severe coronavirus disease 2019(COVID-19)combined with viral load,and other baseline risk factors contribute to an increased risk of severe sepsis or co-existed septic condition *** To describe the clinical,radiological,and laboratory characteristics of a small cohort of patients infected by severe acute respiratory syndrome coronavirus 2 who underwent percutaneous drainage for septic complications and their postprocedural *** This retrospective study consisted of 11 patients who were confirmed to have COVID-19 by RT-PCR test and required drain placement for septic *** mean age±SD of the patients was 48.5±14 years(range 30-72 years).Three patients underwent cholecystostomy for acute acalculous *** drainage was performed in seven patients;two peripancreatic collections;two infected leaks after hepatic resection;one recurrent hepatic abscess,one psoas abscess and one lumbar *** patient underwent a percutaneous nephrostomy for acute *** Technical success was achieved in 100%of patients,while clinical success was achieved in 4 out of 11 patients(36.3%).Six patients(54.5%)died despite proper percutaneous drainage and adequate antibiotic *** patient(9%)needed operative *** patients(18.2%)had two drainage procedures to drain multiple fluid *** patients(18.2%)had repeat drainage procedures due to recurrent fluid *** average volume of the drained fluid immediately after tube insertion was 85 ***-up scans show a reduction of the retained content and associated inflammatory changes after tube insertion in all *** was no significant statistical difference(P=0.6 and 0.4)between the mean of WBCs and neutrophils count before drainage and seven days after *** lymphocyte count shows significant increased seven days after drainage(P=0.03).CONCLUS

关键词： COVID-19 SARS-CoV-2 Coronavirus Sepsis Drainage Abscess

Determination of Thermal Conductivity and Porosity of Building Stone from Ultrasonic Velocity Measurements

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Geomaterials 2013年第4期3卷 138-144页

作者： Abderrahim Boulanouar Abdelaali Rahmouni mohamed Boukalouch Abderrahim Samaouali Yves Géraud Mimoun Harnafi Jamal Sebbani Department of Earth Science Scientific Institute Mohamed V University Rabat Morocco Laboratory of Thermodynamics Department of Physics Faculty of Science Mohammed V University Rabat Morocco University of Strasbourg EOST Institute of Global Physics Strasbourg France

Ultrasonic velocity measurement, a non-destructive and easy method to apply in both field and laboratory conditions, has increasingly been conducted to determine the physical properties of rock materials. This paper presents an experimental study of the measurement of P-wave velocity, thermal conductivity and porosity of several types of sedimentary, metamorphic, and magmatic rocks. The aim of this study is to predict the rocks properties including their thermal conductivity and porosity using P-wave velocity. For this purpose, the physical properties are determined in the laboratory to obtain correlations between P-wave velocity and physical properties. Consequently, good linear relationships are found between all the determined physical properties and the P-wave velocity measurements.

关键词： Building Stone Thermal Conductivity P-Wave Velocity Porosity Optical Scanning

Adsorption of Cu(II) on maghnite from aqueous solution: Effects of pH, initial concentration, interaction time and temperature

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Natural Science 2012年第11期4卷 856-868页

作者： mohamed Amine Zenasni Said Benfarhi André Merlin Stéphane Molina Béatrice George Bahia Meroufel Institute of Sciences and Technology Department of Sciences Bechar University Bechar Algeria Istitute of Sciences Department of Chemistry Batna University Batna Algeria Laboratory of Studies and Research on Material Wood (LERMAB) University of Lorraine Nancy France nstitute of Sciences and Technology Department of Sciences Bechar University Bechar Algeria

The adsorption behaviour of Cu2+ onto maghnite was conducted under batch conditions. The effect of time, pH of the dispersion, temperature and initial metal concentration on the adsorption of Cu2+ onto maghnite was investigated. In this study, 94% of Cu(II), was adsorbed on the maghnite clay when the equilibrium was reached at 120 min. The adsorption of Cu2+ was a fast process that followed the pseudo-second-order kinetics. This process could be described by the Langmuir model and gave a maximum Cu2+ adsorption capacity of 21.78 mg/g at 293 K. The thermodynamic parameters such as variation of enthalpy ΔH, variation of entropy ΔS and variation of Gibbs free energy ΔG were calculated from the slope and intercept of lnKd vs. 1/T plots. The adsorption was endothermic reaction. The adsorption process for this natural maghnite is more spontaneous because the values of ΔG are less negative. The results suggested that natural maghnite was suitable as sorbent material for the recovery and adsorption of metal ion from aqueous solutions.

关键词： Adsorption Isotherms Natural Maghnite Heavy Metal Cu(II)

Development of a Novel Hybrid Aluminum-Based Sol-Gel Materials: Application to the Protection of AA2024-T3 Alloys in Alkaline Environment

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Materials Physics and Chemistry 2014年第5期4卷 75-84页

作者： mohamed Oubaha Padinchare Covilakath Rajath Varma Brendan Duffy Zuhair Mattoug Gasem Steven J. Hinder Centre for Research Excellence in Corrosion King Fahd University of Petroleum and Minerals Dhahran KSA Centre for Research in Engineering Surface Technology (CREST) FOCAS Institute Dublin Institute of Technology Dublin Ireland The Surface Analysis Laboratory Faculty of Engineering and Physical Sciences University of SurreyGuildford UK

Extensive research on environmentally complaint sol-gel coatings is currently underway for a wide range of applications. Sol-gel technology combines the synergistic properties of inorganic and organic components to design nanostructured coating materials with advanced physical properties. Through a judicious choice of precursors and additives improved performances, such as chemical resistance or pH stability, it can be achieved. This is of particular interest for copper rich AA 2024-T3 aluminium alloys used on aircraft, where increase in local pH occurs at corrosion sites. This work focuses on improving the alkaline stability and anticorrosion properties of such a sol-gel coatings on AA2024-T3 by incorporating aluminium functionality into hybrid materials prepared from hydrolysis and condensation of 3-methacryloxypropyltrimethoxysilane, zirconium n-propoxide and zirconium/alkoxide precursors. Dynamic light scattering technique was used to study the particle size nature of the sol-gel materials in colloidal form. X-ray photoelectron spectroscopy was used to study the oxidation state of the aluminium and zirconium at the sol-gel coating surface. Field emission scanning electrochemical microscopy coupled with energy dispersive spectroscopy was used to assess the microstructural features. Electrochemical characterisations employing potentiodynamic scanning and electrochemical impedance spectroscopy were performed to investigate the anticorrosion performance of the hybrid sol-gel coatings. The best anti-corrosive protection of AA2024-T3 in an alkaline saline solution (pH = 10) was achieved with materials containing 10 mol% and 15 mol% aluminium doped sol-gel coatings. This study shows that presence of aluminium has a positive effect on alkaline stability of the coatings and is a potential green candidate for the protective coatings on aerospace alloys.

关键词： Sol-Gel Aluminium Zirconium Corrosion Coatings Hybrid: Organo-Silane

Kinetic spectrophotometric determination of certain cephalosporins using iodate/iodide mixture

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Natural Science 2010年第5期2卷 432-443页

作者： Salwa R. El-Shaboury Fardous A. mohamed Gamal A. Saleh Azza H. Rageh 不详

A simple, precise and accurate kinetic spectro-photometric method for determination of ce-fradine anhydrous, cefaclor monohydrate, ce-fadroxil monohydrate, cefalexin anhydrous and cefixime in bulk and in pharmaceutical formula-tions has been developed. The method based on a kinetic investigation of the reaction of the free carboxylic acid group of the drug with a mixture of potassium iodate and potassium iodide at room temperature to form yellow coloured triiodide ions. The reaction was followed up spectrophotometrically by measuring the increase in absorbance at 352 nm as a function of time. The initial rate, fixed time, variable time and rate-constant methods were adopted for constructing the calibration curves but fixed time method has been found to be more applicable. The analytical performance of the method, in terms of accuracy and precision, was statistically validated;the results were satisfactory. The method has been successfully applied to the determination of the studied drugs in commercial pharmaceutical formulations. Statistical comparison of the results with a well established reported method showed excellent ag- reement and proved that there is no significant difference in the accuracy and precision.

关键词： Cephalosporins Kinetic Spectrophotometry Lodate/Lodide Mixture Pharmaceutical Analysis

Bronchospasm Diagnosis in Motorcycle Taxi Drivers Exposed to Automotive Pollutants in Porto-Novo

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Open Journal of Respiratory Diseases 2013年第1期3卷 13-20页

作者： Folly Messan mohamed Lawani Barnabé Akplogan Pierre Dansou Daouda Mama Rodrigue Hounkponou Rodrigue A. Dagnitché Laboratory of Applied Hydrology Faculty of Sciences and Technics University of Abomey-Calavi Cotonou Republic of Benin Laboratory of Biomechanics and Performance (LABIOP) National Institute of Youth Physical Education and Sport (INJEPS) University of Abomey-Calavi Cotonou Republic of Benin Laboratory of PSA and Motricity National Institute of Youth Physical Education and Sport (INJEPS) University of Abomey-Calavi Cotonou Republic of Benin

Background: In African cities, chronic exposure to pollutants is the most common public health problem faced daily by motorcycle taxi drivers. In Benin, studies conducted on motorcycle drivers, have shown the presence of nitrogen oxides, carbon monoxide, sulfur dioxide, volatile organic compounds and particulate matter in ambient air, which may affect lung function. Aims: This study aims to diagnose potential respiratory problems among 48 motorcycle taxi drivers (47.02 ± 8.75 years) compared to a control group made up of 52 people (46.38 ± 8.81 years) in Porto-Novo, Benin. Methods: A questionnaire, two exploration pulmonary function tests and two 6-minute walk tests were used to identify symptoms and changes in respiratory variables that reveal the existence of bronchospasm. Results: The frequency of respiratory symptoms noted among motorcycle taxi drivers is higher than that recorded among members of the control group. We observed that motorcycle drivers at rest and after physical effort have significantly lower respiratory variables (FVC, FEV1, PEF, FEF25-75, FEF50 and FEF25) (p < 0.05) than those recoded in control group. Conclusion: It can therefore be concluded that, because of the relatively long duration of exposure among motorcycle taxi drivers, the inhalation of automobile pollutants, may cause respiratory problems in this population.

关键词： Automobile Pollution Asthma Bronchospasm Urban Pollution Motorcycle-Taxi Drivers Benin

Moroccan Taxi Drivers Fatigue Using Pichot Questionnaire： A Cross-Sectional Survey

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Health Science 2017年第2期5卷 114-120页

作者： Nadia Benaicha Abdessalam Diarra Oussmane Desire Diakite Oussamne S.Y Adil Najdi mohamed AmineBerraho Department of Epidemiology and Community Health Faculty of Medicine University Sidi Mohamed Benabdellah Fez Morocco

Studies conducted in many countries the world has shown that fatigued driving contributes to approximately 3%-30% of road accidents. We conducted this study to estimate the prevalence of fatigue among taxi drivers and to assess the determinant of fatigue among taxi drivers. In this cross-sectional study, 300 urban and rural taxi drivers from Fez, Morocco were enrolled from January to May 2013. The mean score of Pichot scale was 13.59 ± 8.23. The mean duration of sleep was 6.78 ±1.47 h per day. The mean rate of accident was 2.78 ± 1.12 per year. At the final model of the multiple linear regression we found an association statistically significant between Pichot scale and income, cardiovascular disorders, tobacco use, problems with colleagues, regularity of sleep and sleeping at the wheel. This study opened the door to many discussions about the professional drivers＇ conditions of work and we can argue that we should ameliorate the professional drivers conditions of work in Morocco.

关键词： Fatigue Pichot scale taxi drivers Morocco.