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Electrowinning of Copper Using Rotating Cylinder Electrode Utilizing Lead Anode

Engineering（科研） 2011年第4期3卷 340-358页

作者： hesham soliman Ahmed Abd El-Moneim 不详

The effect of lead anode, rotating cylinder electrode (RCE), amount of 1,2-dihydroxypropane (12-DHP), temperature and rotation on the electrowinning of copper from low concentration acidified copper sulphate solution has been investigated. Copper powder was electrodeposited onto RCE that made of pure copper. From cyclic voltammetry experiments, an empirical parameter called the departure percent, S, was obtained which may represent the stability of the organic additive in the given medium and under the experimental conditions. The inhibition percentage, P, was 0.00 - 89.91% depending on the experimental variables. P was affected by temperature and mole fraction of 12-DHP, while rotation did not show any influence on it. Values of activation energy of electrodeposition process, Ea, were found to be less than 28 kJ mol-1 indicating diffusion controlled process. The overall mass transfer correlations under the present conditions have been computed using the dimensional analysis method. The data were valid for 90 < Sh < 1098, 737 < Sc < 59284 and 271 < Re < 7046 and the results agreed with the previous studies of mass transfer to rotating cylinders in turbulent flow regimes. The effect of time, content of 12-DHP, temperature and the speed of rotation on the morphological changes of the electrodeposited copper powder as well as deposits composition and crystallite size have been studied. Various crystallite sizes ranged 7.1 nm - 250.6 nm were obtained and characterized by EDS and XRD. Different topographs proved that the rate of copper electrodeposition increased by increasing deposition time, temperature and the speed of rotation. Also, they proved that the deposition rate decreased by adding 12-DHP to the solution. Therefore, the results obtained by SEM supported those achieved by measuring the limiting current density and follow the normal manner when organic solvents were added to the electrodeposition bath.

关键词： Electrodeposition Electrowinning Lead Anode Rotating Cylinder Electrode (RCE) 1 2-Dihydroxypropane (12-DHP) Copper Powder

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The Management of Spontaneous Cerebrospinal Fluid Rhinorrhea in Patients at Risk for Increased Intracranial Tension

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Open Journal of Modern Neurosurgery 2020年第1期10卷 1-8页

作者： Ahmed Farahat hesham Elshitany Mohamed A. R. soliman Ear Nose and Throat Department Cairo University Giza Egypt Neurosurgery Department Cairo University Giza Egypt

Introduction: The exact pathophysiology of spontaneous CSF rhinorrhea is not always understood in some patients. Idiopathic intracranial hypertension (IIH) is now recognized as one of the causes of spontaneous CSF leak in the neurosurgical and ENT literature. Our aim was to set a management protocol for such cases according to the same setting intracranial tension (ICT). Methods: We prospectively managed patients with spontaneous CSF rhinorrhea who were admitted to our hospital between 1st of January 2014 and 31st of December 2017 with a prespecified treatment algorithm. Patients with a history of previous cranial or nasal surgery, trauma, skull base congenital malformations were excluded from the study. The patient’s demographics, clinical data, comorbidities, body mass index (BMI), first time or recurrent leakage and duration of the leak were collected. Results: 41 patients, 35 females and 6 males, presented with spontaneous CSF rhinorrhea with a mean BMI of 38 ± 4.16 Kg/m2. The mean pre-operative ICT manometry was 17.2 ± 5.9 cmH2O (range, 10 - 26 cmH2O). 43.9% of the patients were found to have an increased ICT (≥20 cmH2O) and underwent a permanent CSF diversion at the same setting of the endoscopic repair. None of the patients had a recurrence during the follow-up period. Conclusion: The prespecified treatment algorithm with measuring the ICT at the same setting of the endoscopic repair has a better result for control of spontaneous CSF rhinorrhea. This has led to no recurrence and decreased hospital stay.

关键词： Spontaneous Cerebrospinal (CSF) Rhinorrhea Cerebrospinal (CSF) Leak Endoscopic Repair Cerebrospinal (CSF) Diversion

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Electrochemical Deposition and Optimization of Thermoelectric Nanostructured Bismuth Telluride Thick Films

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Engineering（科研） 2011年第6期3卷 659-667页

作者： hesham M. A. soliman Abdel-Hady B. Kashyout 不详

Bismuth telluride thick films are suitable for thermoelectric (TE) devices covering large areas and operating at small-to-moderate temperature differences (20 - 200 K). High efficiency and high coefficient of performance (COP) are expected to be achieved by using thick films in some cooling applications. Bismuth telluride thick films fabrication have been achieved with Galvanostatic and Potentionstatic deposition. Stoichiometric bismuth telluride thick film was obtained by Galvanostatic deposition at current density of 3.1 mAcm-2. Bismuth telluride films with average growth rate of 10 μmh-1 and different composition were obtained. Effects of current density and composition of electrolyte in Galvanostatic deposition were studied. The current density affected the film compactness, where films deposited at lower current density were more compact than those deposited at higher current density. The morphology of the films did not depend on the current density, but chemical composition was observed when different composition of electrolyte was used. Effects of distance between electrodes, composition of electrolyte solution, and stirring in Potentionstatic deposition were studied. The shorter the distance between electrodes, the higher the electric field, thus the higher current density was applied and the deposited film was less compact. The current density increased more rapidly with stirring during electrodeposition which leads to less compact film. Through this study, films electrode-posited from solution containing 0.013 M Bi(NO3)3.5 H2O, 0.01 M TeO2 and 1 M HNO3 at 3.1 mA cm-2 for 6 hours without stirring and with interelectrode distance of 4.5 cm were free-standing with average film thickness of 60 μm and optimum film composition of Bi2Te3. The crystallite size of the later films was found to be around 4.3 nm using Scherrer’s equation from XRD patterns. Also, negative Seebeck coefficient for the same samples was revealed with an average value of -82 μV.K-1.

关键词： Bismuth Telluride Thermoelectric Electrodeposition Nanostructure Thick Film

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Influence of Nanocrystalline ZrO<sub>2</sub>Additives on the Fracture Toughness and Hardness of Spark Plasma Activated Sintered WC/ZrO<sub>2</sub>Nanocomposites Obtained by Mechanical Mixing Method

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Open Journal of Composite Materials 2012年第1期2卷 1-7页

作者： M. Sherif El-Eskandarany hesham M. A. soliman M. Omoric 不详

The present study reports the formation of ultrafine hard particles of nanocomposite WC with different additions of ZrO2 powders (0.5 - 20 vol.%). The initial mixed powders of WC with the desired ZrO2 concentrations were mechanically mixed for 360 ks (end-product) under argon gas atmosphere at room temperature, using high energy ball mill. The end-product consists of average grain size of about 17 nm in diameter. The obtained nanocomposite powders were consolidated into fully dense compact, using spark plasma sintering (SPS) technique in vacuum. The experimental results revealed that the consolidation step, which was conducted at 1673 K with uniaxial pressure ranging from 19.6 to 38.2 MPa for short time (0.18 ks), does not lead to dramatic grain growth in the powders so that the consolidated nanocomposite bulk objects maintain their nanocrystalline behavior, being fine grains with an average size of 63 nm in diameter. The relative densities of consolidated nanocomposite WC/ZrO2 materials increase from 99.1% for WC-0.5% ZrO2 to 99.93% for WC-20% ZrO2. The indentation fracture toughness of the composites can be tailored between 7.31 and 19.46 MPa/m1/2 by controlling the volume fraction of ZrO2 matrix from 0.5% to 20%. The results show that the Poisson’s ratio increased monotonically with increasing the ZrO2 concentrations to get a maximum value of 0.268 for WC-20% ZrO2. In the whole range of ZrO2 concentrations (0.5 - 20 vol.%), high hardness values (20.73 to 22.83 GPa) were achieved. The Young’s modulus tends to decrease with increasing the volume fraction of the ZrO2 matrix to reach a minimum value of 583.2 GPa for WC-20% ZrO2. These hard and tough WC/ZrO2 nanocomposites are proposed to be employed as higher abrasive-wear resistant materials.

关键词： Nanocomposite Tungsten Carbide Zirconia Spark Plasma Sintering Powder Metallurgy Mechanical Alloying Microstructure SEM HRTEM

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Fabrication of Congo Red/Oxidized Porous Silicon (CR/OPS) pH-Sensors

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Materials Sciences and Applications 2013年第8期4卷 79-87页

作者： Abdel-Hady Kashyout hesham M. A. soliman Marwa Nabil Ahmed A. Bishara Advanced Technology and New Materials Research Institute City for Scientific Research and Technology Applications New Borg El-Arab City Alexandria Egypt Physics Department Faculty of Science Alexandria University Alexandria Egypt

The fabrication of nano porous silicon, nPSi, using alkali etching process has been studied and carried out. The surface chemistry of anisotropic etching of n-type Si-wafer is reviewed and the anisotropic chemical etching of silicon in alkaline solution using wetting agents is discussed. Transformation of crystallographic plane of n-Si (211) to nPSi (100) has occurred on using n-propanol as wetting agent. The rate of pore formation was 0.02478 - 0.02827 μm/min, which was heavily dependent upon the concentration of the etchant containing wetting agents, allowing patterned porous silicon formation through selective doping of the substrate. A particle size of 15 nm for porous nano-silicon was calculated from the XRD data. Porosity of PS layers is about 10%. Pore diameter and porous layer thickness are 0.0614 nm and 16 μm, respectively. The energy gap of the produced porous silicon is 3.3 eV. Furthermore, the combination of PS with Congo Red, which are nanostructured due to their deposition within the porous matrix is discussed. Such nano compounds offer broad avenue of new and interesting properties depending on the involved materials as well as on their morphology. Chemical route was utilized as the host material to achieve pores filling. They were impregnated with Congo Red, which gave good results for the porous silicon as a promising pH sensor.

关键词： Nano Porous Silicon Anisotropic Etching Process Alkali Etching Congo Red PH Sensor

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Thoracoscopic internal mammary lymph nodes dissection: a staging tool for internal mammary lymph nodes in breast cancer

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The Chinese-German Journal of Clinical Oncology 2011年第10期10卷 580-583页

作者： Waheed Yousry Garee hesham Elsebaie Haytham Gareer Hytham Ahmed Mohamed Wafa Hussein soliman Surgical Oncology National Cancer InstituteCairo UniversityCairoEgypt Surgical Oncology Tanta University HospitalTantaEgypt

Objective： The aim of our study was to investigate the feasibility and safety of thoracoscopic internal mammary lymphadenectomy as a method to refine and thereby improve nodal staging in breast cancer. Methods： During the period from June 2004 to May 2007, 50 patients with operable breast cancer underwent modified radical mastectomy （MRM） or breast conserving surgery （BCS）, followed by thoracoscopic internal mammary lymphadenectomy, using 3 ports through the skin incision of the MRM or the BCS. Metal clips were used to mark precise site of lymphadenectomy. Results： of total number of 50 patients, the mean age of patients was 44 years （range, 27-60 years）. 40 （80%） had medio-central tumor, 10 （20%） had lateral tumor. 35 （70%） had clinically involved axillary nodes. 16 out of 50 patients received neo-adjuvant CTH. 44 patients underwent MRM and 6 patients underwent BCS. No intra-operative complications occurred. Atelectasis was the only postoperative complication that was encountered, which occurred in 12 cases, and was treated conservatively. The average chest drainage period was 1.2 day （range, 1-2 days）. The total number of IMN metastasis was 18 patients （36%）. The risk of IMN metastasis was higher; in younger patients （P = 0.03）, in medio-central tumors （P = 0.03）, in bigger tumors （P = 0.05）, with heavier metastasis of axillary LNs （P = 0.001）. But a correlation with the histological pattern of the lry tumor didn＇t exist （P = 1）. Knowing the IMN status helped in proper staging of patients, 7 patients showed evident stage migration after adding the IMN analysis to that of primary tumor and axillary LN. During the follow up period （the median, 22 months; range, 7 to 42 months）, no patient had pleural dissemination or port-site metastasis. Conclusion： Thoracoscopic IMN lymphadenectomy is a safe procedure, which can be done serious additional complications or cosmetic compromise. And allow proper nodal staging, which allow proper treatment planning.

关键词： breast cancer internal mammary lymph nodes lymphadenectomy thoracoscopic staging

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