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The effect of optimism bias and governmental action on siltation management within Japanese reservoirs surveyed via artificial neural network

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Big Earth Data 2020年第1期4卷 68-89页

作者： Tobias Landwehr sameh ahmed kantoush Claudia Pahl-Wostl Tetsuya Sumi Mitsuteru Irie Institute for Environmental Systems Research Osnabrück UniversityOsnabrückGermany Water Resources Research Center Disaster Prevention Research InstituteKyoto UniversityKyotoJapan Department of Civil and Environmental Engineering Faculty of EngineeringMiyazaki UniversityMiyazakiJapan

Reservoirs are installed as long-term assets to guarantee water and energy security for decades,if not ***,the effect of siltation undermines reservoirs’sustainability because it significantly reduces the reservoirs’original *** present paper attempts to evaluate the global reservoir siltation problem with the optimism bias theorem introduced by Kahneman and Tversky and applied to infrastructural mega-projects by Flyvbjerg and Ansar using artificial neural networks(ANNs)algorithms for large Japanese *** possesses suitable long-term data and a legal directive concerning the sediment capacity siltation duration,which serves as a valid guide to check whether,over the past 100 years,engineers,planners and managers were capable of judging the sediment input *** ANN models were established to emulate Japanese reservoir siltation *** networks demonstrate that reservoirs in Japan suffer from optimism *** contrast to the law,the dead storage volume of an average dam is supposed to reach capacity after 52 *** finding joins the overall observation that mega-projects generally and globally suffer from optimism *** emulations were subsequently screened for a presumed influence of governance actions,namely,indicating plus monitoring and the change in the market competition *** reservoir siltation appears to continue regardless of the level of competition in public procurement,monitoring directives appear to have a considerable impact on improved siltation management,which demonstrates that dedicated governance action can significantly strengthen the sustainable behavior of key infrastructure elements such as reservoirs.

关键词： Neural networks optimism bias governance Japan sustainability reservoirs sedimentation infrastructure

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Experimental study on the effect of bottomless structure in front of a bottom outlet on a sediment ?ushing cone

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International Journal of Sediment Research 2021年第3期36卷 335-347页

作者： Hadi Haghjouei Majid Rahimpour Kourosh Qaderi sameh A.kantoush Department of Water Engineering Shahid Bahonar University of Kerman

One of the main problems in reservoirs is sedimentation which reduces the operating life of dams if a proper plan and analysis method are not in *** techniques to manage sediment in reservoirs include several sustainable management techniques that route sediment through or around the *** of the main economical methods in arid and semi-arid regions is pressurized flushing using moderate drawdown of the water level of the reservoir to evacuate sediment deposited behind *** the current study,the effect of a new structure called a dendritic bottomless extended （DBE） outlet structure at three angles of 30°,45°,and 60° on pressurized flushing efficiency was ***,45 experiments were designed for three discharge rates （Q;） ,three sediment levels （H;）,four types of structure,and a no-structure condition （reference test）.The results indicated that the DBE structure with a 30° angle between the branches,a sedimentary dimensionless index of ■,and a flow dimensionless index of ■（where g is the acceleration of gravity and Do is the diameter of the bottom outlet） lead to 10-fold increase in the sediment flushing cone dimensions and sediment removal efficiency compared to the results of the reference ***,according to a statistical analysis of the results,a dimensionless equation for calculating the sediment flushing cone dimensions was developed for the tested sediment characteristics.

关键词： Reservoir Sediment removal efficiency Sediment flushing cone Bottom outlet Dendritic bottomless extended structure

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Experimental and numerical modelling of sedimentation in a rectangular shallow basin

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International Journal of Sediment Research 2008年第3期23卷 212-232页

作者： sameh A. kantoush Erik BOLLAERT Anton J. SCHLEISS Ecole Polytechnique Fédérale de Lausanne (EPFL) Laboratory of Hydraulic Constructions (LCH) Station 18 CH -1015 Lausanne SwitzerlandDr. Ecole Polytechnique Fédérale de Lausanne (EPFL) Laboratory of Hydraulic Constructions (LCH) Station 18 CH -1015 Lausanne SwitzerlandProf.

Numerical simulation of flows in shallow reservoirs has to be checked for its consistency in predicting real flow conditions and sedimentation patterns. Typical flow patterns may exhibit flow separation at the inlet, accompanied by several recirculation and stagnation areas all over the reservoir surface. The aim of the present research project is to study the influence of the geometry of a reservoir on sediment transport and deposition numerically and experimentally, focusing on a prototype reservoir depth between 5 and 15 m as well as suspended sediment transport. A series of numerical simulations is presented and compared with scaled laboratory experiments, with the objective of testing the sensitivity to different flow and sediment parameters and different turbulence closure schemes. Different scenarios are analyzed and a detailed comparison of preliminary laboratory tests and some selected simulations are presented. The laboratory experiments show that suspended sediment transport and deposition are determined by the initial flow pattern and by the upstream and downstream boundary conditions. In the experiments, deposition in the rectangular basin systematically developed along the left bank, although inflow and outflow were positioned symmetrically along the centre of the basin. Three major horizontal eddies developed influencing the sediment deposition pattern. Although asymmetric flow patterns are privileged, a symmetric pattern can appear from time to time. This particular behaviour could also be reproduced by a two-dimensional depth-averaged flow and sediment transport model (CCHE2D). The paper presents numerical simulations using different turbulence closure schemes (k-ε and eddy viscosity models). In spite of the symmetric setup, these generally produced an asymmetric flow pattern that can easily switch sides depending on the assumptions made for the initial and boundary conditions. When using the laboratory experiment as a reference, the most reliable n

关键词： Shallow reservoir sedimentation and morphology Suspended sediment Reservoir geometry influence Numerical simulations Scaled physical modelling

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Application of an impact plate-Bedload transport measuring system for high-speed flows

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International Journal of Sediment Research 2018年第1期33卷 35-46页

作者： Takahiro Koshiba Christian Auel Daizo Tsutsumi sameh A.kantoush Tetsuya Sumi Water Resources Research Center Disaster Prevention Research Institute Kyoto University ILF Consulting Engineers Hodaka Sedimentation Observatory Research Center for Fluvial and Coastal Disasters Disaster Prevention Research Institute Kyoto University

To achieve the sustainable use of dams, the development of methods for sediment management in reservoirs is required. One such method includes the use of Sediment Bypass Tunnels(SBTs) to divert sediment around a dam, thereby preventing sedimentation in the reservoir. However, SBTs are prone to severe invert abrasion caused by the high sediment flux. Therefore, it is necessary to establish a measurement system of the sediment transport rate in these tunnels. One system to measure sediment transport in rivers is the Swiss plate geophone, which can register plate vibrations caused by particle impact. In Japan, the Japanese pipe microphone is used, and sediment transport is measured based on the sound emitted by the particle impact. In this study an attempt was made to optimize the advantages of both systems by fixing a microphone and an acceleration sensor to a steel plate. The results of calibration experiments with this new system are presented and compared with the existing methods. It was found that the acceleration sensor can detect sediment particles larger than 2 mm in ***, a new parameter, referred to as the detection rate, was introduced to describe the correlation between the actual amount of sediment and the registered output. Finally, two parameters-the saturation rate and hit rate-are introduced and exhibit strong correlation with the detection rate.(?) 2018 International Research and Training Centre on Erosion and Sedimentation/the World Association

关键词： Sediment Bypass Tunnel Bedload Acoustic measurement Geophone Hydrophone High-speed flow

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Peristaltic Flow of Dusty Nanofluids in Curved Channels

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Computers, Materials & Continua 2021年第1期66卷 1011-1026页

作者： Z.Z.Rashed sameh E.ahmed mathematics department jouf universityqurayyatsaudi arabia department of mathematics king khalid universityabhasaudi arabia

In this paper,numerical investigations for peristaltic motion of dusty nanofluids in a curved channel are *** systems of partial differential equations are presented for the nanofluid and dusty phases and then the approximations of the long wave length and low Reynolds number are *** physical domain is transformed to a rectangular computational model using suitable grid *** resulting systems are solved numerically using shooting method and mathematical forms for the pressure distributions are *** controlling parameters in this study are the thermal buoyancy parameter G_(r),the concentration buoyancy parameter Gc,the amplitude ratio,the Eckert number Ec,the thermophoresis parameter N_(t) and the Brownian motion parameter Nb and the dusty parameters D_(s);α_(s).The obtained results revealed that an increase in the Eckert number enhances the temperature of the fluid and dusty particles while the nanoparticle volume fraction is ***,both of the temperature and nanoparticles volume fraction are supported by the growing of the Brownian motion parameter.

关键词： Peristaltic motion dusty particles nanofluid curved channels

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Impact of composition ratio on the structure and optical properties of(1-x)MnFe_(2)O_4/(x)ZnMn_(2)O_4 nanocomposite

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Chinese Physics B 2022年第7期31卷 481-489页

作者： Zein K.Heiba Mohamed Bakr Mohamed Ali A.Alkathiri sameh I.ahmed A A Alhazime Department of Physics Faculty of ScienceAin shams UniversityCairo 11566Egypt Physics Department Faculty of ScienceTaibah UniversityAl-Madina al MunawarahSaudi Arabia Depatment of Physics College of ScienceTaif UniversityP.O.Box 11099Taif 21944Saudi Arabia

(1-x)MnFe_(2)O_(4)(MFO)/xZnMn_(2)O_(4)(ZMO)(x=0,0.2,0.5,0.8,and 1.0)nanocomposite samples were prepared using co-precipitation *** phase percentage,cell parameters,and crystallite size of MFO and ZMO phases in each nanocomposite sample were calculated using Rietveld refinement *** x-ray diffraction(XRD)analysis and Fourier-transform infrared spectroscopy techniques established the variation in the lattice parameters of each phase are due to permutation of all cations among the octahedral and tetrahedral sites of MFO and *** different oxidation states of different ions in all samples were determined using x-ray photoelectron spectroscopy(XPS)*** variation in absorbance of the nanocomposite samples with composition parameter(x)is dependent on the wavelength *** optical bandgap of the nanocomposite samples is decreased as the content of ZMO phase *** effect of alloying on the refractive index,extinction coefficient,dielectric constant,optical conductivity,and the nonlinear optical behaviors of all samples were studied in *** nanocomposite sample x=0.5 disclosed upgraded optical parameters with the highest refractive index,optical conductivity,and PL intensity,which nominate it to be functional in various application fields.

关键词： MFO and ZMO composite XPS structure optical

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Literature review of the outcome of and methods used to improve transperineal repair of rectocele

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World Journal of Gastrointestinal Surgery 2021年第9期13卷 1063-1078页

作者： Mohammad Fathy ahmed Hossam Elfallal sameh Hany Emile General Surgery Mansoura University Faculty of MedicineMansoura 35516Egypt

BACKGROUND Rectocele is commonly seen in parous women and sometimes associated with symptoms of obstructed defecation syndrome(ODS).AIM To assess the current literature in regard to the outcome of the classical transperineal repair(TPR)of rectocele and its technical *** An organized literature search for studies that assessed the outcome of TPR of rectocele was ***/Medline and Google Scholar were queried in the period of January 1991 through December *** main outcome measures were improvement in ODS symptoms,improvement in sexual functions and continence,changes in manometric parameters,and quality of *** After screening of 306 studies,24 articles were found eligible for inclusion to the *** studies(301 patients)assessed the classical TPR of *** median rate of postoperative improvement in ODS symptoms was 72.7%(range,45.8%-83.3%)and reduction in rectocele size ranged from 41.4%-95.0%.Modifications of the classical repair entailed omission of levatorplasty,addition of implant,concomitant lateral internal sphincterotomy,changing the direction of plication of rectovaginal septum,and site-specific *** The transperineal repair of rectocele is associated with satisfactory,yet variable,improvement in ODS symptoms with parallel increase in quality-of-life *** modifications of the classical TPR were *** modifications include omission of levatorplasty,insertion of implants,performing lateral sphincterotomy,changing the direction of classical plication,and site-specific *** indications for these modifications are not yet fully clear and need further prospective studies to help tailor the technique to rectocele patients.

关键词： Transperineal repair Rectocele Review Modifications Outcome

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Nanofluid Flows Within Porous Enclosures Using Non-Linear Boussinesq Approximation

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Computers, Materials & Continua 2021年第3期66卷 3195-3213页

作者： sameh E.ahmed Dalal Alrowaili Ehab Mahmoud Mohamed Abdelraheem M.Aly Department of Mathematics College of ScienceKing Khalid UniversityAbha62529Saudi Arabia Department of Mathematics South Valley UniversityQena83523Egypt Mathematics Department College of ScienceJouf UniversitySakakaSaudi Arabia Electrical Engineering Department College of EngineeringPrince Sattam Bin Abdulaziz UniversityWadi Addwasir11991Saudi Arabia Electrical Engineering Department Aswan UniversityAswan81542Egypt

In this paper,the Galerkin finite element method(FEM)together with the characteristic-based split(CBS)scheme are applied to study the case of the non-linear Boussinesq approximation within sinusoidal heating inclined enclosures filled with a non-Darcy porous media and *** enclosure has an inclination angle and its side-walls have varying sinusoidal temperature *** working fluid is a nanofluid that is consisting of water as a based nanofluid and Al2O3 as *** porous medium is modeled using the Brinkman Forchheimer extended Darcy *** obtained results are analyzed over wide ranges of the non-linear Boussinesq parameter 0≤ζ≤1,the phase deviation 00≤Φ≤1800,the inclination angle 00≤γ≤900,the nanoparticles volume fraction 0%≤φ≤4%,the amplitude ratio 0≤a≤1 and the Rayleigh number 104≤Ra≤*** results revealed that the average Nusselt number is enhanced by 0.73%,26.46%and 35.42%at Ra=104,105 and 106,respectively,when the non-linearBoussinesq parameter is varied from 0 to *** addition,rate of heat transfer in the case of a non-uniformly heating is higher than that of a uniformly ***-linear Boussinesq parameter rises the flow speed and heat transfer in an *** deviation makes clear changes on the isotherms and heat transfer rate on the right wall of an *** inclination angle varies the flow speed and it has a slight effect on heat transfer in an enclosure.

关键词： CBS scheme non-linear Boussinesq approximation nonuniformly heating non-darcy flow nanofluid

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Cystic pancreatic lesions,the endless dilemma

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World Journal of Gastroenterology 2021年第21期27卷 2664-2680页

作者： Hussein Hassan Okasha Abeer Awad ahmed El-meligui Reem Ezzat Ashraf Aboubakr sameh AbouElenin Ramy El-Husseiny ahmed Alzamzamy Department of Internal Medicine and Gastroenterology Hepatology UnitKasr Al-Aini HospitalsCairo UniversityCairo 11562Egypt Department of Internal Medicine and Gastroenterology Hepatology UnitAssuit UniversityAssuit 71515Egypt Department of Gastroenterology and Hepatology Maadi Armed Forces Medical ComplexMilitary Medical AcademyCairo 11441Egypt Department of Gastroenterology and Hepatology Military Medical AcademyCairo 11441Egypt Department of Hepatology and Tropical Medicine National Hepatology and Tropical Medicine Research Institute(NHTMRI)Cairo 11441Egypt

Cystic pancreatic lesions involve a wide variety of pathological entities that include neoplastic and non-neoplastic *** proper diagnosis,differentiation,and staging of these cystic lesions are considered a crucial issue in planning further *** are great challenges for their diagnostic *** our time,new emerging methods for this diagnosis have been *** ultrasonography-guided fine-needle aspiration cytology with chemical and molecular analysis of cyst fluid and EUS-guided fine needlebased confocal laser endomicroscopy,through the needle microforceps biopsy,and single-operator cho-langioscopy/pancreatoscopy are promising methods that have been used in the diagnosis of cystic pancreatic *** we discuss the diagnosis of cystic pancreatic lesions and the benefits of various diagnostic models.

关键词： Pancreatic cystic lesion Endoscopic diagnosis Endoscopic ultrasonography Cyst fluid markers Endoscopic ultrasonography-guided fine needle-based confocal laser endomicroscopy Through the needle microforceps biopsy Single operator cholangioscopy/pancreatoscopy

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Two-stage procedure in the management of selected cases of keratoconus: clear lens extraction with aspherical IOL implantation followed by WFG-PRK

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International Journal of Ophthalmology(English edition) 2018年第11期11卷 1761-1767页

作者： Waleed Abou Samra Tharwat Mokbel Mohammed Elwan sameh Saleh ahmed Elwehidy Mohammed Iqbal Adel Ellayeh Department of Ophthalmology Faculty of Medicine Mansoura University Department of Ophthalmology Faculty of Medicine Sohag University

AIM： To assess the objective and subjective results of a two-stage procedure for management of keratoconus： clear lensectomy with aspherical intraocular lens（IOL） implantation followed by wave front-guided photorefractive keratotomy（WFG-PRK）.METHODS： This prospective interventional non-randomized study included patients aged 35 years old or more with grade I and II stable keratoconus, a clear visual axis, minimal corneal thickness（MCT） 420 μm or more and average keratometric reading（K） less than 54 diopter（D）. Refraction of all selected eyes should be-8.00 D sphere or more with less than-6.00 D cylinder and could be corrected two lines or more with spectacles or contact lenses. All studied eyes underwent a two-stage approach treatment： first refractive lens exchange and aspherical IOL implantation followed, after at least 3 mo, by WFGPRK. Pre and postoperative complete ophthalmological examination were performed. Topographical, visual and aberrometric results were recorded and evaluated during 6 mo follow up period. Moreover, patient satisfaction and other subjective outcomes were also ***： The 13 eyes of 11 patients diagnosed with stable keratoconus and aged from 39 to 49 y（42.4±6.2 y） were enrolled in the study. At baseline, 8 eyes had grade I and 5 eyes had grade II keratoconus. The manifest sphere was-10.3±4.2 D（ranged from-8.0 to-14.0 D） and the manifest cylinder was-4.2±1.2 D（ranged from-1.75 to-5.50 D）. After the two-stage procedure, sphere and cylinder reduced significantly to-0.43±0.22 D and-1.3±0.72 D respectively（P〈0.001）. There was also a highly significant improvement in the mean uncorrected distance visual acuity（UDVA） from logMAR 1.41±0.49 preoperatively to 0.51±0.16 postoperatively（P〈0.001） and the mean corrected distance visual acuity（CDVA） from 0.76±0.24 preoperatively to 0.49±0.13 after the operation（P〈0.001）. All aberrometric and mesopic vision parameters and most of the topographical indices demonstrated highly significant improveme

关键词： keratoconus clear lensectomy wave front guided photorefractive keratotomy

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