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Modeling, analysis, and optimization of dimensional accuracy of FDM-fabricated parts using definitive screening design and deep learning feedforward artificial neural network

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Advances in Manufacturing 2021年第1期9卷 115-129页

作者： Omar ahmed mohamed Syed Hasan Masood Jahar Lal Bhowmik School of Engineering Deakin UniversityGeelongAustralia Department of Mechanical Engineering Higher Institute of Engineering TechnologyBani WalidLibya Department of Mechanical and Product Design Engineering Swinburne University of TechnologyHawthornVIC 3122Australia Department of Health Science and Biostatistics Swinburne University of TechnologyHawthornVIC 3122Australia

Additive manufacturing(AM)technologies such as fused deposition modeling(FDM)rely on the quality of manufactured products and the process ***,the dimensional accuracy and stability of any AM process is essential for ensuring that customer specifications are satisfied at the highest standard,and variations are controlled without significantly affecting the functioning of processes,machines,and product *** study aims to investigate the effects of FDM fabrication conditions on the dimensional accuracy of cylindrical *** this study,a new class of experimental design techniques for integrated second-order definitive screening design(DSD)and an artificial neural network(ANN)are proposed for designing experiments to evaluate and predict the effects of six important operating *** determining the optimum fabrication conditions to obtain better dimensional accuracies for cylindrical parts,the time consumption and number of complex experiments are reduced considerably in this *** optimum fabrication conditions generated through a second-order DSD are verified with experimental *** results indicate that the slice thickness,part print direction,and number of perimeters significantly affect the percentage of length difference,whereas the percentage of diameter difference is significantly affected by the raster-to-raster air gap,bead width,number of perimeters,and part print ***,the results demonstrate that a second-order DSD integrated with an ANN is a more attractive and promising methodology for AM applications.

关键词： Artificial neural network(ANN) OptimizationDefinitive screening design(DSD) Analysis of variance(ANOVA) Fused deposition modeling(FDM) Dimensional accuracy

Response of slope surface roughness to wave-induced erosion during water level fluctuating

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Journal of Mountain Science 2020年第4期17卷 871-883页

作者： GU Ju LIU Gang ABD ELBASIT mohamed ahmed mohamed SHI Hong-qiang State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau Institute of Soil and Water ConservationNorthwest A&F UniversityYangling 712100China Institute of Soil and Water Conservation Chinese Academy of Sciences and Ministry of Water ResourcesYangling 712100China Agricultural Research Council Institute for SoilClimate&WaterPrivate Bag X79Pretoria 0001South Africa

The bank slopes in hydro-fluctuation areas of reservoirs or lakes suffer from severe erosion due to an absence of protection. Waves are one of the important external forces that cause bank erosion and slope failures. However, the processes and quantified impacts of wave-induced erosion on slopes remain unclear under different water level-fluctuation conditions. This paper focuses on the characteristics of wave-induced slope erosion under three conditions: water level dropping(WLD), fixed(WLF) and rising(WLR). A steel tank with glass pane was used to simulate the wave-induced slope erosion in the three treatments. The slope elevation data were collected by using the method of the pin meter for every 15 minutes from the beginning to the end, a total of 5 times during all treatments. These data were processed by using software(SURFER 9.0) to get the slope micro-topography and the erosion volume. Then the temporal and spatial change of slope erosion was analysed according to the erosion amount or erosion rate calculated based on bulk density of slope soil. The results demonstrated that the soil erosion rates for different water level changing treatments are in the following order: WLR>WLD>WLF. For the erosion spatial variation, the middle part of the slope was the major source of sediment in the WLD. The upper part of the slope was the major source of the sediment for the other two treatments. Compared with the standard deviation(SD), the coefficient of variation(CV) based on the SD is more representative of variations in the soil surface roughness(SSR). Furthermore, the good fit between the SSR and soil erosion rate have the potential to be used to predict soil erosion. Above all, the injection angle of the wave determined the rate of erosion to some extent, and the fall-back flow of the wave could also influence the extent of erosion, deposition, and bank morphology. It is vital to choose the appropriate index(SD or CV) in the three water levels to improve the predict

关键词： Bank erosion Erosion rate Micro topography Soil surface roughness Breaking point

Techniques for colorectal anastomosis

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World Journal of Gastroenterology 2010年第13期16卷 1610-1621页

作者： Yik-Hong Ho mohamed ahmed Tawfi k Ashour Discipline of Surgery School of Medicine James Cook University

Colorectal anastomotic leak remains one of the most feared post-operative complications, particularly after anterior resection of the rectum with, the shift from abdomino-peritoneal resections to total mesorectal excision and primary anastomosis. The literature fails to demonstrate superiority of stapled over hand-sewn techniques in colorectal anastomosis, regardless of the level of anastomosis, although a high stricture rate was noted in the former technique. Thus, improvements in safety aspects of anastomosis and alternatives to handsewn and stapled techniques are being sought. Here, we review alternative anastomotic techniques used to fashion bowel anastomosis. Compression anastomosis using compression anastomotic clips, endoluminal compression anastomotic rings, AKA-2, biofragmental anastomotic rings, or Magnamosis all involve the concept of creating a sutureless end-to-end anastomosis by compressing two bowel ends together, leading to a simultaneous necrosis and healing process that joins the two lumens. Staple line reinforcement is a new approach that reduce the drawbacks of staplers used in colorectal practice, i.e. leakage, bleeding, misfi ring, and inadequate tissue approximation. Various nonabsorbable, semi or fully absorbable materials are now available. Two other techniques can provide alternative anastomotic support to the suture line: a colorectal drain and a polyester stent, which can be utilized in ultra-low rectal excision and can negate the formation of a defunctioning stoma. Doxycycline coated sutures have been used to overcome the post-operative weakness in anastomosis secondary to rapid matrix degradation mediated by matrix metalloproteinase. Another novel technique, the electric welding system, showed promising results in construction of a safe, neat, smooth sutureless bowel anastomosis. Various anastomotic techniques have been shown to be comparable to the standard techniques of suturing and stapling. However, most of these alternatives need t

关键词： Alternative anastomosis Compression anastomotic clip Compression anastomotic ring Biofragmental anastomotic ring AKA-2 Magnamosis (magnetic anastomosis) Matrix metallo-proteinase Sutureless

Unsteady Operation of New Type Turbofan Engine with Aerodynamic Torque Converter Reducing Front Fan Speed

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Journal of Thermal Science 2005年第3期14卷 206-210页

作者： Toshiaki KANEMOTO Seita SEKI Kazunori IDENO ahmed mohamed GALAL Kyushu Institute of Technology Sensui 1-1 Tobata Kitakyushu 804-8550 Japan ProfessorKyushu Institute of Technology Sensui 1-1 Tobata Kitakyushu 804-8550 JapanKyushu Institute of Technology Sensui 1-1 Tobata Kitakyushu 804-8550 JapanKyushu Institute of Technology Sensui 1-1 Tobata Kitakyushu 804-8550 Japan

It is desired to increase the rotational speed of the core engine of the turbofan so as to get the best efficiency for the next leap of engine technology. The conventional mechanism in which the front fan is directly connected to the output shaft of a core engine, have a limit of increasing the spool speed, because the fan diameter is very large. The authors have proposed a new driving system in which the front fan is driven through the aerodynamic torque converter. The front fan can work at the best performance at slower speed while the core engine runs more efficiently at higher speed. Continuously, this paper discusses the response of the front fan in the unsteady operation of the core engine, accompanying with the internal flow. The system has the acceptable responsibility in the unsteady operation which is very important for the aircrafts.

关键词： turbofan engine front fan torque converter rotational speed

Derivation of travel demand forecasting models for low population areas:the case of Port Said Governorate,North East Egypt

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Journal of Traffic and Transportation Engineering(English Edition) 2014年第3期1卷 196-208页

作者： ahmed mohamed Semeida Department of Civil Engineering Faculty of EngineeringPort Said UniversityPort SaidEgypt

In the last decades, there has been substantial development in modeling techniques of travel demand estimation. For low population areas the external trip estimation is important but usually neglected in travel demand modeling process. In Egypt, the researches in this field are scarce due to lack of data. Accordingly, this paper aims to identify and estimate the main variables that affect the travel demand in low population areas, and to develop models to predict them. The study focused on the Port Said Govemorate in North East Egypt. A special questionnaire had been prepared in 2010 depending on interviews of passengers at basic taxi terminals in Port Said. And 2211 filled questionnaires were offering for research. To analyze the data, two modeling procedures were used. One is the multiple linear regression and the other is the generalized linear modeling （GLM） applying normal distributions. It is found that GLM procedure offers more suitable and accurate approach than the linear regression for developing number of trips. The final demand models have statistics within the acceptable regions and, also, they are conceptually reasonable. These results are so important for Egyptian highway authorities to improve the efficiency of highway transportation system in Egypt.

关键词： travel demand linear regression generalized linear modeling low population areas Port Said

Application of artificial neural networks for operating speed prediction at horizontal curves: a case study in Egypt

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Journal of Modern Transportation 2014年第1期22卷 20-29页

作者： ahmed mohamed Semeida Civil Engineering Department Specialization of Transportation and Traffic Engineering Faculty of Engineering Port Said University

Horizontal alignment greatly affects the speedof vehicles at rural roads. Therefore, it is necessary toanalyze and predict vehicles speed on curve *** studies took rural two-lane as research subjectsand provided models for predicting operating ***, less attention has been paid to multi-lane highwaysespecially in Egypt. In this research, field operatingspeed data of both cars and trucks on 78 curve sections offour multi-lane highways is collected. With the data, correlationbetween operating speed （V85） and alignment isanalyzed. The paper includes two separate relevant *** first analysis uses the regression models toinvestigate the relationships between V85 as dependentvariable, and horizontal alignment and roadway factors asindependent variables. This analysis proposes two predictingmodels for cars and trucks. The second analysisuses the artificial neural networks （ANNs） to explore theprevious relationships. It is found that the ANN modelinggives the best prediction model. The most influential variableon V85 for cars is the radius of curve. Also, for V85 fortrucks, the most influential variable is the median ***, the derived models have statistics within theacceptable regions and they are conceptually reasonable.

关键词： Artificial neural networks Horizontal curve Multi-lane highways Operating speed Prediction models Regression models Roadway factors

Maximizing the Benefit of Rate Transient Analysis for Gas Condensate Reservoirs

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Energy Engineering 2021年第5期118卷 1411-1423页

作者： Mahmoud Abdo Tantawy ahmed A.M.Elgibaly ahmed mohamed Farag Faculty of Petroleum and Mining Engineering Suez UniversitySuezEgypt Abu Qir Petroleum Company AlexandriaEgypt

In recent years,many trials have been made to use the Rate Transient Analysis(RTA)techniques as a method to describe the gas condensate *** problem with using these techniques is the multi-phase behavior of the gas condensate ***,the Pressure Transient Analysis(PTA)is commonly used in this case to analyze the reservoir *** this paper,we are going to compare the results of both PTA and RTA of three wells in gas condensate *** comparison showed a great match between the results of the two mentioned techniques for the first time using a reference GOR of 75,000 SCF/***,we concluded that we could depend on RTA instead of PTA to spare the cost associated with the PTA in the gas condensate reservoirs.

关键词： Rate transient analysis production data analysis well testing permeability skin factor gas condensate

Induction of sub-G0 arrest and apoptosis by seed extract of Moringa peregrina（Forssk.） Fiori in cervical and prostate cancer cell lines

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Journal of Integrative Medicine 2019年第6期17卷 410-422页

作者： Maged mohamed Maher Abou-Hashem Dina mohamed Abo-elmatty Noha Mostafa Mesbah ahmed mohamed Abd EL-Mawgoud Faculty of Pharmacy Pharmacognosy DepartmentZagazig UniversityZagazig 44511Egypt Faculty of Pharmacy Biochemistry DepartmentSuez Canal UniversityIsmailia 41522Egypt Egyptian International Pharmaceuticals Industries Company Tenth of Ramadan City 44629Egypt

Objective: This study investigated cytotoxicity and induction of apoptosis in human cervical cancer cells(HELA) and prostate cancer cells(PC-3) using the most active fraction of Moringa peregrina seed ***: Dried and powdered seeds were extracted using 95% ethanol. The total ethanolic extract was further dissolved in distilled water and separated into petroleum ether, chloroform, ethyl acetate and aqueous extracts. Based on the results of in vitro anticancer studies of all extracts, the most highly active extract was selected for evaluation of apoptosis induction and cell cycle analysis on HELA and PC-3 cells at its half maximal inhibitory concentration using flow cytometry;DNA fragmentation by agarose gel electrophoresis and the expression of protein were measured by Western ***: The chloroform fraction from the ethanolic extract of M. peregrina(CFEE) was the most active antitumor fraction. The selectivity index, determined using the normal Vero cell line, indicated that CFEE had a high degree of selectivity against HELA and PC-3 cells. CFEE induced apoptosis, confirmed by cell cycle arrest at sub-G0 phase and DNA fragmentation. CFEE induced an increase in mRNA expression of caspase-3, a decrease in Bcl-2 mRNA expression, and decreased ATP levels. CFEE increased protein expression of caspase-3 and decreased protein expression of poly-ADP-ribose polymerase-1(PARP-1).Flow cytometric analysis showed an appreciable increase in the number of cells in the early apoptotic stage in CFEE-treated HELA and PC-3 cells. CFEE treatment significantly increased lipid peroxidation(malondialdehyde level) in HELA and PC-3 ***: Seed extract of M. peregrina displayed a significant antitumor effect through apoptosis induction in HELA and PC-3 cells.

关键词： Moringa peregrina Fractionation Antiproliferation Apoptosis

Problem of living liver donation in the absence of deceased liver transplantation program:Mansoura experience

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World Journal of Gastroenterology 2014年第37期20卷 13607-13614页

作者： mohamed Abdel Wahab Hosam Hamed Tarek Salah Waleed Elsarraf mohamed Elshobary ahmed mohamed Sultan ahmed Shehta Omar Fathy Helmy Ezzat Amr Yassen mohamed Elmorshedi mohamed Elsaadany Usama Shiha Gatrointestinal Surgery Liver Transplantation Unit Gastrointestinal Surgical Center Mansoura University Daqahlia 35516 Egypt Anesthesia Intensive Care Department Gastrointestinal Surgical Center Mansoura Faculty of Medicine Mansoura University Daqahlia 35516 Egypt Internal Medicine Department Mansoura Faculty of Medicine Mansoura University Daqahlia 35516 Egypt Radiology Department Gastrointestinal Surgical Center Mansoura University Daqahlia 35516 Egypt

We report our experience with potential donors for living donor liver transplantation(LDLT), which is the first report from an area where there is no legalized deceased donation program. This is a single center retrospective analysis of potential living donors(n = 1004) between May 2004 and December 2012. This report focuses on the analysis of causes, duration, cost, and various implications of donor exclusion(n = 792).Most of the transplant candidates(82.3%) had an experience with more than one excluded donor(median = 3). Some recipients travelled abroad for a deceased donor transplant(n = 12) and some died before finding a suitable donor(n = 14). The evaluation of an excluded donor is a time-consuming process(median = 3 d, range 1 d to 47 d). It is also a costly process with a median cost of approximately 70 USD(range 35 USD to 885 USD). From these results, living donor exclusion has negative implications on the patients and transplant program with ethical dilemmas and an economic impact. Many strategies are adopted by other centers to expand the donor pool; however, they are not all applicable in our locality. We conclude that an active legalized deceased donor transplantation program is necessary to overcome the shortage of available liver grafts in Egypt.

关键词： Living donor Liver transplantation Excluded donors Deceased donor Liver disease