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Performance improvement of solution-processed CdS/CdTe solar cells with a thin compact TiO_2 buffer layer

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Science Bulletin 2016年第1期61卷 86-91页

作者： Aashir waleed Qianpeng Zhang Mohammad Mahdi Tavakoli Siu-Fung Leung Leilei Gu Jin He Xiaoliang Mo Zhiyong Fan Department of Electronic and Computer Engineering The Hong Kong University of Science and Technology Peking University Shenzhen SOC Key Laboratory PKUHKUST Shenzhen-Hongkong Instituition Department of Materials Science Fudan University

The device performance of CdS/CdTe solar cells largely depends on not only the back ohmic contact, but also the conformality of Cd S window layer coating. In order to reduce the light absorption loss in Cd S, the Cd S thickness is usually less than 100 nm. However, pinholes in Cd S and non-conformal coverage of Cd S on transparent conducting oxide layer will cause shunting thus leading to device performance degradation and failure. In this paper, low-temperature and low-cost fabrication methods, i.e., chemical bath deposition and electrochemical deposition, were used to deposit Cd S and Cd Te, respectively. It was found that the yield of device was around 20 % due to shunting. In order to alleviate this problem, a compact layer of TiO2 was inserted between the fluorine-doped tin oxide and Cd S as a buffer layer. The thickness effect of TiO2 was studied and showed that devices with thin(20 nm thickness) TiO2 performed better than the counterparts with thick layers. It was discovered that device yield improved to 80 % and stability in air substantially improved with TiO2 layer.

关键词： Thin films Titanium dioxide Solarenergy Cadmium compounds

Hydrophobic epoxy resin coated proppants with ultra-high self-suspension ability and enhanced liquid conductivity

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Petroleum Science 2021年第6期18卷 1753-1759页

作者： Fan Fan Feng-Xia Li Shou-Ceng Tian Mao Sheng waleed Khan Ai-Ping Shi Yang Zhou Quan Xu State Key Laboratory of Shale Oil and Gas Enrichment Mechanisms and Effective Development National Energy Shale Oil Research and Development CenterHarvard SEAS-CUPB Joint Laboratory on Petroleum ScienceChina University of Petroleum(Beijing)Beijing102249China

Proppant is a key material for enhancing unconventional oil and gas production which requires a long distance of migration and efficient liquid conductivity paths within the hydraulic ***,it is difficult to find a proppant with both high self-suspension ability and liquid ***,a simple method is developed to coat epoxy resin onto the ceramic proppant and fabricate a novel coated proppant with high hydrophobicity,self-suspension,and liquid conductivity *** with uncoated ceramic proppants,the epoxy resin coated(ERC) proppant has a high self-suspension ability nearly 16 times that of the uncoated ***,the hydrophobic property and the liquid conductivity of the ERC proppant increased by 83.8% and 16.71%,respectively,compared with the uncoated *** summary,this novel ERC proppant provides new insights into the design of functional proppants,which are expected to be applied to oil and gas production.

关键词： Coated proppant Hydrophobic property Self-suspension Conductivity

Adaptive Fuzzy Logic Controller for Harmonics Mitigation Using Particle Swarm Optimization

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Computers, Materials & Continua 2022年第6期71卷 4275-4293页

作者： waleed Rafique Ayesha Khan Ahmad almogren Jehangir Arshad Adnan Yousaf Mujtaba Hussain Jaffery Ateeq Ur Rehman Muhammad Shafiq Department of Electrical&Computer Engineering COMSATS University Islamabad Lahore CampusLahore54000Pakistan Syed Babar ali School of Science and Engineering Lahore University of Management SciencesLahore54000Pakistan Department of Computer Science College of Computer and Information SciencesKing Saud UniversityRiyadh11633Saudi Arabia Department of Electrical Engineering Superior UniversityLahore54000Pakistan Department of Electrical Engineering Government College UniversityLahore54000Pakistan Department of Information and Communication Engineering Yeungnam UniversityGyeongsan38541Korea

An excessive use of non-linear devices in industry results in current harmonics that degrades the power quality with an unfavorable effect on power system *** this research,a novel control techniquebased Hybrid-Active Power-Filter(HAPF)is implemented for reactive power compensation and harmonic current component for balanced load by improving the Power-Factor(PF)and Total–Hormonic Distortion(THD)and the performance of a *** work proposed a soft-computing technique based on Particle Swarm-Optimization(PSO)and Adaptive Fuzzy technique to avoid the phase delays caused by conventional control ***,the control algorithms are implemented for an instantaneous reactive and active current(Id-Iq)and power theory(Pq0)in *** prevent the degradation effect of disturbances on the system’s performance,PS0-PI is applied in the inner loop which generate a required dc ***,a comparative analysis of both techniques has been presented to evaluate and validate the performance under balanced load *** presented result concludes that the Adaptive Fuzzy PI controller performs better due to the non-linearity and robustness of the ***,the gains taken from a tuning of the PSO based PI controller optimized with Fuzzy Logic Controller(FLC)are optimal that will detect reactive power and harmonics much faster and *** proposed hybrid technique minimizes distortion by selecting appropriate switching pulses for VSI(Voltage Source Inverter),and thus the simulation has been taken in SIMULINK/*** proposed technique gives better tracking performance and robustness for reactive power compensation and harmonics *** a result of the comparison,it can be concluded that the PSO-basedAdaptive Fuzzy PI system produces accurate results with the lower THD and a power factor closer to unity than other techniques.

关键词： Harmonics compensation soft computing technique hybrid fuzzy PSO based PI controller HSAPF power quality

An Intelligence Computational Approach for the Fractional 4D Chaotic Financial Model

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Computers, Materials & Continua 2023年第2期74卷 2711-2724页

作者： Wajaree Weera Thongchai Botmart Charuwat Chantawat Zulqurnain Sabir waleed Adel Muhammad Asif Zahoor Raja Muhammad Kristiawan Department of Mathematics Faculty of ScienceKhon Kaen UniversityKhon Kaen40002Thailand Department of Mathematics and Statistics Hazara UniversityMansehraPakistan Department of Mathematical Sciences United Arab Emirates UniversityP.O.Box 15551Al AinUAE Department of Mathematics and Engineering Physics Faculty of EngineeringMansoura UniversityEgypt UniversitéFrançaise D’Egypte Ismailia Desert RoadEl-ShoroukCairoEgypt Future Technology Research Center National Yunlin University of Science and Technology123 University RoadSection 3DouliouYunlin 64002Taiwan Science of Education Universitas BengkuluBengkulu CityIndonesia

The main purpose of the study is to present a numerical approach to investigate the numerical performances of the fractional 4-D chaotic financial system using a stochastic *** stochastic procedures mainly depend on the combination of the artificial neural network(ANNs)along with the Levenberg-Marquardt Backpropagation(LMB)i.e.,ANNs-LMB *** fractional-order term is defined in the Caputo sense and three cases are solved using the proposed technique for different values of the fractional orderα.The values of the fractional order derivatives to solve the fractional 4-D chaotic financial system are used between 0 and *** data proportion is applied as 73%,15%,and 12%for training,testing,and certification to solve the chaotic fractional *** acquired results are verified through the comparison of the reference solution,which indicates the proposed technique is efficient and *** 4-D chaotic model is numerically solved by using the ANNs-LMB technique to reduce the mean square error(MSE).To authenticate the exactness,and consistency of the technique,the obtained performances are plotted in the figures of correlation measures,error histograms,and *** these figures,it can be witnessed that the provided technique is effective for solving such models to give some new insight into the physical behavior of the model.

关键词： Financial model chaotic Levenberg-Marquardt Backpropagation fractional order artificial neural networks reference dataset

Endoscopic Assisted Microscopic Surgical Removal of Craniopharyngioma

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Open Journal of Modern Neurosurgery 2020年第4期10卷 475-482页

作者： waleed Abbass Amr Mohsen Department of Neurosurgery Faculty of Medicine Cairo University Giza Egypt

Background: Craniopharyngioma is a benign tumor which represents 2% - 3% of all intracranial tumors, there are two types: childhood type which affects children between 5 and 10 years and adulthood type which affects patients 50 - 60 years old. The presenting symptoms develop over years and include visual, endocrine, hypothalamic, neurological and neurophysiological manifestations. Surgery is the treatment of choice. Postoperative radiotherapy, gamma-knife and intra tumoral injection of chemotherapeutic drugs have been used as an adjuvant therapy in some cases. Objectives: In this study, we evaluated the role of endoscopy in assisting microscopic surgical removal of craniopharyngioma. Methods: Eleven patients were operated upon in Cairo University Hospitals, Egypt. all operations were done using microscope through the subfrontal approach. At the end of surgery, the endoscope was used to detect any residual tumor in the subchiasmatic and retrochiasmatic areas and to visualize the posterior part of the tumor which couldn’t be seen by the microscope to check if it was adherent to the hypothalamus and to evaluate whether to be removed or not. Results: The study included eleven cases, four of which were childhood type and seven adult type craniopharyngiomas. Total removal was achieved in six cases (five cases of adulthood type). Oumaya reservoir was inserted in five cases;ventriculoperitoneal shunt was needed in five cases. all cases suffered from temporary diabetes insipidus postoperatively, while only two cases developed permanent diabetes insipidus. Three cases presented preoperatively with pituitary hypofunction and two cases developed postoperative pituitary hypofunction, which necessitated hormone replacement therapy. Conclusion: Craniopharyngioma is one of the most difficult and challenging tumors for neurosurgeons due to its relation to optic nerve, hypothalamus and vascular syste

关键词： Craniopharyngiomas Endoscopy Microscopy Surgery

Functional Outcomes of Decompressive Hemicraniectomy for Treatment of Malignant Infarctions of the Middle Cerebral Artery

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Open Journal of Modern Neurosurgery 2020年第3期10卷 307-317页

作者： Amr Mohsen waleed Abbass Faculty of Medicine Cairo University Cairo Egypt

Introduction: Malignant middle cerebral artery (MCA) infarction is a devastating entity that is associated with up to 80% mortality. Decompressive Hemicraniectomy has been utilized to treat brain swelling and mass effect secondary to these infarctions in an attempt to improve functional outcome. Aim: To evaluate the functional outcome of decompressive hemicraniectomy in management of malignant MCA infarctions. Methods: The study included 30 patients with malignant MCA infarctions operated upon by decompressive hemicraniectomy and duroplasty with pericranium or fascia lata graft in the period from June 2016 to January 2019. Pre-operative neurological condition, associated morbidity, location and extent of the infarction were assessed. Surgery was performed within 48 hours of the onset of stroke or 12 hours within deterioration of conscious level. Pre-operative CT scan as well as sequential post-operative CT was done. Functional outcome was assessed by the modified Rankin Scale (mRS) at the time of discharge and 3 months following surgery. Results: The study included 18 males and 12 females with a mean age of 54.7 years. The pre-operative GCS was al outcome (mRS 0 - 3) was achieved in 13 (43.3%) cases while poor outcome (mRS 4 - 5) occurred in 8 (26.7%) cases and mortality (mRS 6) occurred in 9 (30%) cases. Conclusion: Decompressive hemicraniectomy improves functional outcome in cases of malignant MCA infarction. Pre-operative GCS, age, volume of infarction, degree of midline shift, timing of surgery and associated morbidity are the most important factors affecting the outcome.

关键词： Decompressive Hemicraniectomy Malignant MCA Infarction Functional Outcome Modified Rankin Scale

Outcomes of pancreaticoduodenectomy in elderly patients

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Hepatobiliary & Pancreatic Diseases International 2016年第4期15卷 419-427页

作者： Ayman El Nakeeb Ehab Atef Ehab El Hanafy ali Salem waleed Askar Helmy Ezzat Ahmed Shehta Mohamed Abdel Wahab Gastroenterology Surgical Center Mansoura University

BACKGROUND： although the mortality and morbidity of pancreaticoduodenectomy（PD） have improved significantly over the past years, the concerns for elderly patients undergoing PD are still present. Furthermore, the frequency of PD is increasing because of the increasing proportion of elderly patients and the increasing incidence of periampullary tumors. This study aimed to analyze the outcomes of PD in elderly ***： We studied all patients who had undergone PD in our center between January 1995 and February 2015. The patients were divided into three groups based on age： group I（patients aged 〈60 years）, group II（those aged 60 to 69 years） and group III（those aged ≥70 years）. The primary outcome was the rate of total postoperative complications. Secondary endpoint included total operative time, hospital mortality, length of postoperative hospital stay, delayed gastric emptying, re-exploration, and survival ***： A total of 828 patients who had undergone PD for resection of periampullary tumor were included in this study. There were 579（69.9%） patients in group I, 201（24.3%） in group II, and 48（5.8%） in group III. The overall incidence of complications was higher in elderly patients（25.9% in group I, 36.8% in group II, and 37.5% in group III; P=0.006）. There were more patients complicated with delayed gastric emptying in group II compared with the other two groups. There was no significant difference in the incidence of postoperative pancreatic fistula, biliary leakage, pancreatitis, pulmonary complications and hospital ***： PD can be performed safely in selected elderly patients. Advanced age alone should not be a contraindication for PD. The outcome of elderly patients who have undergone PD is similar to that of younger patients, and the increased rate of complications is due to the presence of associated comorbidities.

关键词： pancreaticoduodenectomy elderly pancreatic fistula delayed gastric emptying

Comparative study between bowel ultrasound and magnetic resonance enterography among Egyptian inflammatory bowel disease patients

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World Journal of Gastroenterology 2020年第38期26卷 5884-5895页

作者： Shimaa Kamel Mohamed Sakr waleed Hamed Mohamed Eltabbakh Safaa Askar Ahmed Bassuny Rasha Hussein Ahmed Elbaz Department of Tropical Medicine Gastroenterology and HepatologyAin Shams UniversityCairo 11566Egypt Department of Radiology Ain Shams University and MR Unit of Misr Radiology CenterCairo 11566Egypt

BACKGROUND Bowel ultrasound and magnetic resonance enterography(MRE)are decisive medical imaging modalities for diagnosing and locating bowel lesions with its extramural extent and *** assess the degree of activity,help clinicians to identify patients in need of surgery,and can be used for patient *** To compare the role of MRE and bowel ultrasound in diagnosis and follow-up of inflammatory bowel disease(IBD)patients in *** The study was conducted on 40 patients with *** patients were subjected to clinical assessment,laboratory investigations,bowel ultrasound,MRE,and colonoscopy up to the terminal ileum with biopsies for histopathological *** This study was conducted on 14 patients(35%)with ulcerative colitis and 26 patients(65%)with Crohn's disease;34(85%)of these patients had active *** ultrasound detected different bowel lesions with the following accuracies:ileum(85%),large bowel(70%),fistula(95%),stricture and proximal dilatation(95%)and abscesses(100%).also,it showed that statistically significance of bowel ultrasound in differentiation between remission and activity of IBD in comparison to MRE and *** In comparison to MRE,bowel ultrasound is a useful,non-invasive,and feasible bedside imaging tool for the detection of inflammation,detection of complications,and follow-up of IBD patients when performed by the attending physician.

关键词： Bowel ultrasound Colonoscopy Crohn's disease Magnetic resonance enterography Ulcerative colitis Inflammatory bowel disease

Magnusiomyces capitatus in Immune-Competent Patients with Pulmonary Haemorrhage and Systemic Lupus Erythematosus

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Case Reports in Clinical Medicine 2023年第10期12卷 408-417页

作者： waleed Amasaib Ahmed Angham Ahmed almakki Abeer Ahmed Bashinim Abdelgaffar A. Mohamed Amna al Kalkami Mohannad AbuRageila Department of Medicine Security Forces Hospital Makkah Saudi Arabia Department of Laboratory and Blood Bank Security Forces Hospital Makkah Saudi Arabia Department of Critical Care Security Forces Hospital Makkah Saudi Arabia

Invasive fungal infections have grown significantly over the last two decades, owing to an increase in immunocompromised hosts and geriatric patients. When the host’s defenses are compromised, such infections are associated with severe morbidity and mortality. Here, a rare case of fungal infection in a 61-year-old immunocompetent male patient from Saudi Arabia was reported, who suffered from pulmonary hemorrhage and Systemic Lupus Erythematous. Bronchoalveolar Lavage was used as a diagnostic tool to identify the fungus reported in the case. The pathogenic fungal specie identified as Magnusiomyces capitatus, in macroscopic and microscopic morphological characteristics of the colonies. Based on clinical evidence, liposomal amphotericin formulation was recommended for initial therapy against fungal infection. also, liposomal amphotericin B induced mycological eradication up to 70 percent in patients with proven Magnusiomyces capitatus infection. In addition to addressing suspected Systemic lupus erythematosus, the patient’s health has improved with no evidence of pulmonary bleeding and hemoptysis.

关键词： Magnusiomyces capitatus Fungal Infection Bronchoalveolar Lavage Pulmonary Haemorrhage SLE (Systemic Lupus Erythematosus) Amphotericin A Case Report