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small Hydropower Plants at Drops on Multi-Use Water Courses

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small Hydro Power News 2005年第82期22卷 2-8页

作者： s.Rangnekar M.A.National Inst. of Technology PKrishnamachar Bansal College of Engineering India

In arid regions of various countries in the world, multi-use water courses take off from storage reservoirs or diversion head works. The canals, running at very mild slopes to maintain maximum command negotiate steeper slopes of the terrain through drops at suitable intervals. The energy of flows at these falls, otherwise dissipated causing thermal pollution of the environment, can be utilized to generate hydropower by mini/micro hydro turbine generator. Canal drops are standardized, thus offering an excellent opportunity to standardize the small hydropower units, resulting in economy. The canals carry regulated and predictable flows free from debris. The flow-duration curves can be easily obtained with precision. The greatest advantage for hydropower generation at the canal drops is operation at maximum efficiency under constant head and discharge for a unit. A battery of hydro units can be installed to be successively started or stopped as the discharge and hence the water level in the upstream reach of the canal rises or falls. Bulb turbines with fixed guide vanes and runner blades in siphons placed directly over suitably modi- fied drop walls present the simplest and most economical solution as all civil works and complicated controls are avoided. Grid connected systems with induction generators will simplify controls. Prompted by the canal water level sensed, the control unit starts vacuum pump to prime a siphon and start a unit or de-prime the siphon by opening to the atmosphere a vent on the siphon hood and thus stop the unit. A number of units on various falls on a canal can remotely be controlled. The bulb units with hermitically sealed generators can be replaced through manholes for maintenance at a central workshop. A small traveling crane over the units and a cabinet for controls are all that are required as auxiliaries. The design case study of such a mini-micro hydropower station on a two meter drop on a canal is presented to exemplify.

关键词：小型水电站水资源涡轮水力发电

Preparation and Characterization of Flexible, Transparent and Thermally stable Aromatic Co-polyamides

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Chinese Journal of Polymer science 2019年第2期37卷 136-141页

作者： José Antonio Tec-sánchez Andrés Iván Oliva Arias Manuel Aguilar-Vega Juan Valerio Cauich-Rodríguez José Luis santiago-García Unidad de Materiales Centro de Investigación Científica de Yucatán A. C. Centro de Investigación y de Estudios Avanzados del IPN Unidad Mérida Departamento de Física Aplicada

Two aromatic co-polyamides were synthesized combining two diacid monomers containing bulky pendant groups, 5-(9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboximido)isophthalic acid(DEAIA) and 5-tert-butylisophthalic acid(TERT), with 4,4′-(hexafluoroisopropylidene)dianiline(HFA) or 2,3,5,6-tetramethyl-1,4-phenylenediamine(Durene) by direct polycondensation. The structures of the obtained aromatic co-polyamides were confirmed by FTIR, Raman and 1 H-NMR. The co-copolyamide films, DHTH and DDTD, exhibited rms-roughness values between 0.94 and 1.60 nm, respectively. Moreover, they presented good thermal stability up to300 °C. Young's moduli of the co-polyamide films were between 4.1 and 4.3 GPa. X-ray diffraction results showed that the co-polyamide films were amorphous due to the incorporation of both bulky pendant groups, tert-butyl and dibenzobarrelene. The combination of bulky pendant groups provided intrinsically transparent co-polyamide films with a transmittance higher than 88% in the range of 400-780 *** to these outstanding film and optical properties, they are suggested to be flexible substrates in applications for solar cell and other portable electronic devices.

关键词： Co-polyamides Flexible films Transmittance Thermal stability Polycondensation

Less common neoplasms of the pancreas

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World Journal of Gastroenterology 2006年第20期12卷 3180-3185页

作者： Abby L Mulkeen Peter s Yoo Charles Cha Department of surgery Yale University school of Medicine New HavenCT and the VACT Healthcare SystemWest HavenCT330 Cedar StreetLH 118PO Box 208062New HavenCT06520-8062United States

Recently, there has been an increased recognition of neoplasms of the pancreas other than ductal adenocarcinorna. Although not as well studied or characterized as pancreatic adenocarcinorna there are many distinct lesions which exhibit diverse biological behaviors and varying degrees of malignancy. These lesions include： endocrine neoplasms, cystic tumors, solid pseudopapillary tumors, acinar cell carcinoma, squamous cell carcinoma, primary lymphoma of the pancreas, and metastatic lesions to the pancreas. These less common neoplasms are being diagnosed more frequently as the number and sensitivity of diagnostic imaging studies increase. This review article discusses the clinical course, diagnosis, and treatment of these less common, but quite relevant, neoplasms of the pancreas.

关键词： Pancreas Neoplasms Ductal adenocarcinoma

Performance enhancement of futuristic airplanes by nature inspired biomimetic fish scale arrays--A design approach

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Biomimetic Intelligence & Robotics 2022年第2期2卷 32-47页

作者： Ganesh Natarajan s Bruce Ralphin Rose J Department of Mechanical Engineering Anna University Regional Campus TirunelveliTamilnaduIndia

Biomimetics has an immense potential to drive the next generation of technologies forward by propounding competent solutions from *** decades,the nonsmooth topography of most living creatures has been critical to their existence and *** to human-made smooth surfaces,when adapted for fluid flow applications,nonsmooth surfaces can enhance the overall aerodynamic performance by reducing the drag ***,the bioinspired scale structure of fish has been identified as a key biomimetic derivative for improving the aerodynamic efficiency in various cross-domain *** study investigates the aerodynamics of a fish scale array(FsA)NACA 0021 model at a specific Reynolds number(Re)of approximately 2.46×105 that is meant for laminar flow conditions using Computational Fluid Dynamics(CFD)tools and a subsonic wind tunnel facility.A 3D printed biomimetic FsA film is developed and affixed on the NACA 0021 wing profile for the experimental investigation,followed by flow visualization through the smoke tunnel *** proved qualitatively under specific aerodynamic conditions,the creation of velocity streaks has a major role in the drag reduction *** obtain a clear perspective of flow across the overlapping fish scale structures,the results are focused on the central and overlapping regions of the FsA *** experiment has proved the existence of a combined formation of low and high velocity streaks in central and overlapping *** FsA 0021 model showed a maximum drag reduction of 9.57%,which was attributed to the streak formation phenomenon observed in the overlapping FsA configuration.

关键词： Biomimetics Aerodynamics Fish scale arrays Drag reduction Bioinspired design

Exact solutions of Nonlinear Evolution Equations in Mathematical Physics Using the Modified simple Equation Method

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Chinese Physics Letters 2012年第6期29卷 1-4页

作者： E.M.E.Zayed s.A.Hoda Ibrahim Department of Mathematics Faculty of ScienceZagazig UniversityP.O.Box 44519ZagazigEgypt

The modified simple equation method is employed to construct the exact solutions involving parameters of nonlinear evolution equations via the (1+1)-dimensional modified KdV equation,and the (1+1)-dimensional reaction-diffusion *** these parameters are taken to be special values,the solitary wave solutions are derived from the exact *** is shown that the proposed method provides a more powerful mathematical tool for solving nonlinear evolution equations in mathematical physics.

关键词： equation. exact equation

Numerical study on rock failure around a tunnel destressed by a conceptualized notched technique

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Underground space 2022年第6期7卷 1086-1097页

作者： Amin Manouchehrian Pinnaduwa H.s.W.Kulatilake school of Resources and Environmental Engineering Jiangxi University of Science and TechnologyGanzhou 341000China

A destressing method for reducing the strainburst risk in burst-prone grounds is *** this method,the rock is destressed by cutting notches at the excavation ***,the concept of the proposed method is described both analytically and ***,the method is applied to a tunneling *** numerical models are built to study the destressing process and the failure mechanism around a circular *** show that when the notch is added to the model,the rock at the tunnel wall is destressed,and the stress concentration zones shift to a farther distance away from the ***,the analysis of the failure zone around the tunnel and the velocity of the failed elements show that the failure in the notched tunnel is less violent compared to that in the tunnel without the ***,a parametric study is conducted to investigate the influences of the notch dimensions on the stress distribution,deformation,and failures around the tunnel.

关键词： strainburst Destressing Deep excavation Notched tunnel Rock violent failure

Transporters Contributing to Iron Trafficking in Plants

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Molecular Plant 2011年第3期4卷 464-476页

作者： sarah s. Conte Elsbeth L. Walker University of Massachusetts Amherst Biology Department 611 No. Pleasant St Amherst MA 01002 USA

This review will discuss recent progress in understanding the many roles of transporters in the whole-plant physiological processes that maintain iron （Fe） homeostasis. These processes include uptake from the soil via roots, control of transport from roots to above-ground parts of the plant, unloading of Fe from the xylem in above-ground parts, loading of Fe into mitochondria and plastids, transport of Fe to reproductive parts of the plant, and Fe mobilization during seed germination. In addition, we will discuss the mechanisms that plants use to cope with an apparently unintended conse- quence of Fe acquisition： the uptake of toxic heavy metals via Fe transporters. Rapid progress has been made in under- standing the transport processes involved in each of these areas in the last 5 years and this review will focus on this recent progress. We will also highlight the key questions regarding transport steps that remain to be elucidated.

关键词： Nutrient and metal transport transporters gene regulation iron nicotianamine phytosiderophores.

Epstein-Barr virus and nasopharyngeal carcinoma

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Chinese Journal of Cancer 2014年第12期33卷 581-590页

作者： Lawrence s.Young Christopher W.Dawson Warwick Medical school The University of Warwick school of Cancer sciences University of Birmingham

since its discovery 50 years ago,Epstein-Barr virus(EBV)has been linked to the development of cancers originating from both lymphoid and epithelial *** 95%of the world’s population sustains an asymptomatic,life-long infection with *** virus persists in the memory B-cell pool of normal healthy individuals,and any disruption of this interaction results in virus-associated B-cell *** association of EBV with epithelial cell tumors,specifically nasopharyngeal carcinoma(NPC)and EBVpositive gastric carcinoma(EBV-GC),is less clear and is currently thought to be caused by the aberrant establishment of virus latency in epithelial cells that display premalignant genetic *** the precise role of EBV in the carcinogenic process is currently poorly understood,the presence of the virus in all tumor cells provides opportunities for developing novel therapeutic and diagnostic *** study of EBV and its role in carcinomas continues to provide insight into the carcinogenic process that is relevant to a broader understanding of tumor pathogenesis and to the development of targeted cancer therapies.

关键词： Epstein-Barr病毒鼻咽癌肿瘤细胞上皮细胞 EB病毒癌症治疗细胞起源世界人口

sonochemical degradation of organophosphorus pesticide in dilute aqueous solutions

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Journal of Environmental sciences 2003年第5期15卷 710-714页

作者： RobinaFarooq LINFeng-kai s.F.shaukat: HUANGJian-jun CollegeofResourcesandEnvironmentalEngineering EastChinaUniversityofS&TShanghai200237China DepartmentofPhysics GovernmentCollegeLahore.Pakistan

Ultrasonic irradiation was found to accelerate the rate of hydrolysis of omethoate in aqueous solution over the pH range of 2—12 Process parameters studied include pH, steady state temperature, concentration, and the type of gases. Greater than 96% hydrolysis was observed in 30 minutes through this process and the rate of destruction increased with the help of more soluble and low thermal inert gas. so with Krypton, omethoate was found to undergo rapid destruction as compared with Argon. In the presence of ultrasound, the observed first order rate of hydrolysis of omethoate is found to be independent of pH. The formation of transient supercritical water(sCW) appears to be an important factor in the acceleration of chemical reactions in the presence of ultrasound. A detailed chemical reaction mechanism for omethoate destruction in water was formulated. Experimental results and theoretical kinetic mechanism demonstrated that the most of the omethoate undergo destruction inside the cavitating holes. A very less effect of temperature on the degradation of omethoate within a temperature range of 20—70℃ proves that a small quantity of omethoate undergoes secondary destruction in the bulk liquid.

关键词： sonochemical degradation omethoate pesticide sonolysis role of inert gases