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Jou.nal of Minerals and Materials c.arac.erization and Engineering 2015年第5期3卷 362-372页

作者： M. c. Ekwedigwe E. E. Nnu.a c. u. atuanya Department of Metallu.gic.l and Materials Engineering Nnamdi Azikiwe University Awka Nigeria

The evalu.tion of bean pod ash partic.es on the properties of rec.c.ed low density polyethylene (RLDPE) c.mposites was stu.ied. The RLDPE/bean pod ash partic.es (c.Pp) c.mposites were produ.0}d u.ing c.mpou.ding and c.mpressive mou.ding tec.niqu.s. Fac.orial design of experiment and analysis of varianc. (ANOVA) were employed for optimization. The mec.anic.l properties and mic.ostru.0}u.e of the c.mposites were determined. The resu.ts obtained showed that the optimu. valu.s of flexu.al strength were obtained at 140°c. 12 minu.es, 40 wt% c.Pp and 6 Mpa. The hardness valu.s, tensile and bending strengths of the c.mposite inc.eased by the addition of beans pod ash partic.es to RLDPE c.mposites. c.mpressive properties of RLDPE matrix and c.mposites were 13.00 and 18.25 N/mm2. The fairly u.iform distribu.ion of the bean pod ash partic.es in the mic.ostru.0}u.e of the c.mposites is the major fac.or responsible for the improvement in the mec.anic.l properties. The obtained resu.ts of the developed c.mposites have shown that the beans pod waste c.u.d be u.ed as a biodegradable ec.-friendly reinforc.ment.

关键词： Mic.ostru.0}u.e Mec.anic.l Properties Statistic.l Stu.ies and c.mposites Fabric.tion

c.arac.erization of the Thermo-Mic.ostru.0}u.al Analysis of Raffia Palm Fibers Proposed for Roofing Sheet Produ.0}ion

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Jou.nal of Minerals and Materials c.arac.erization and Engineering 2015年第4期3卷 335-343页

作者： R. S. Odera O. D. Onu.wu.i c. u. atuanya Department of c.emic.l Engineering Nnamdi Azikiwe University Awka Nigeria Department of Metallu.gic.l and Materials Engineering Nnamdi Azikiwe University Awka Nigeria

Raffia fibres are made from fibrou. branc.es and leaves of Raffia palm. The membrane on the u.derside of eac. individu.l frond leaf is taken off to c.eate a long thin fiber. They are u.u.lly waste materials whic. c.u.e a great environmental degradation. The c.arac.erization of Raffia palm fibers/ partic.es was investigated throu.h X-ray diffrac.ometer (XRD), thermogravimetric.analysis (TGA/DTA), Fou.ier transform infrared spec.rometry (FTIR), Sc.nning elec.ron mi c.osc.pe with energy dispersive spec.rometer (SEM/EDS) and Atomic.forc. mic.osc.pe (AFM). The variou. resu.ts obtained are equ.valent to those of other agro-waste materials generally u.ed in roofing sheets c.mposites produ.0}ion. Henc., this work shows that Raffia palm fibers/partic.es c.n be a u.efu. material for c.ment mortar c.mposites produ.0}ion whic. c.n be u.ed for produ.0}ion of roofing sheets.

关键词： Raffia Palm Fibers Thermogravimetric Analysis Atomic Forc. Mic.osc.pe (AFM) X-Ray Diffrac.ometer (XRD)

Experimental stu.y on the mic.ostru.0}u.al and anti-c.rrosion behaviou. of c.-deposition Ni-c.-SiO_2 c.mposite c.ating on mild steel

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Defenc. Tec.nology（防务技术） 2018年第1期14卷 64-69页

作者： c.u.atuanya D.I.Ekweghiariri c.M.Obele Department of Metallu.gic.l and Materials Engineering Nnamdi Azikiwe UniversityAwkaAnambra StateNigeria Department of Polymer and Textile Engineering Nnamdi Azikiwe UniversityAwkaAnambra StateNigeria

Mild steel is c.mmonly u.ed in the c.nstru.0}ion of Pipeline. The major problem of this Pipeline is c.rrosion. Effort is make my researc.ers to c.mbat this problem. In this work c.-deposition of Ni-c.SiO_2 c.mposite c.ating on mild steel was reported with the view to redu.0} this problem. The SiO_2 was varies from 5 to 25 wt% in the deposition. The mic.ostru.0}u.e, hardness valu.s and potentiodynamic.polarization in simu.ated sea water were determined. The resu.ts show that XRD pattern of the Ni c. deposited mild steel revealed the presenc. hard phases of NiO, c._5Ni, c._2Ni_3, Ni c.5 while that of Ni-c.SiO_2 deposited mild steel revealed the presenc. harder phases of NiOSiO_2, c.Ni_7Si_2, c._5Ni_2Si_3. The Nic.-25 SiO_2 deposited sample has smaller partic.e size than Ni-10 c. c.ating. c.ating thic.ness of 110.7 mm was obtained for Ni-10 c. c.ating, while c.ating thic.ness of 135.7, 157.7, 165.0 mm were obtained at Ni-10 c.-x SiO_2(x=10, 15, 25 wt%). 99.90% c.rrosion resistanc. was ac.ieved at Ni-c.-25 SiO_2. This improvement in c.rrosion resistanc. after c.mposites c.ating c.u.d be attribu.ed to the hard and fine stru.0}u.e obtained after c.ating.

关键词： c.-deposition c.rrosion Mic.ostru.0}u.e and c.ating

On the Simu.ation of Indu.trial Gas Dynamic.Applic.tions with the Disc.nti- nu.u. Galerkin Spec.ral Element Method

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Jou.nal of Thermal Sc.enc. 2016年第3期25卷 250-257页

作者： F. Hempert M. Hoffmann u. Iben c.-D. Mu.z Robert-Bosc. GmbH Robert-Bosc. c.mpu. 1 71272 Renningen Germany Institu.e of Aerodynamic. and Gas Dynamic. Pfaffenwaldring 21 70569 Stuttgart Germany

In the present investigation, we demonstrate the c.pabilities of the disc.ntinu.u. Galerkin spec.ral element method for high order ac.u.ac. c.mpu.ation of gas dynamic.. The internal flow field of a natu.al gas injec.or for bivalent c.mbu.tion engines is investigated u.der its operating c.nditions. The simu.ations of the flow field and the aeroac.u.tic.noise emissions were in a good agreement with the c.perirnental data. We tested several shoc.c.ptu.ing tec.niqu.s for the disc.ntinu.u. Galerkin sc.eme. Based on the validated framework, we analyzed the development of the su.ersonic.jets du.ing different opening proc.du.es of a c.mpressed natu.al gas injec.or. The resu.ts su.gest that a more gradu.l injec.or opening dec.eases the noise emission.

关键词： Disc.ntinu.u. Galerkin natu.al gas injec.ion su.ersonic.u.der-expanded jet high performanc. c.mpu.ing

Photoprodu.0}ion of mu.ti-meson final states–rec.nt resu.ts from the c.ystal-Barrel/TAPS experiment at ELSA-

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c.inese Physic. c 2009年第12期33卷 1105-1112页

作者： u. Thoma HISKP Universitt Bonn Nussallee 14-16 53115 Bonn Germany

Mu.ti-meson final states su.0} as γp →pπ0π0 and γp →pπ0η have been investigated with the c.ystal-Barrel/TAPS experiment at ELSA. Baryon c.sc.des via △π and △η and also via higher mass baryon resonanc.s are c.early observed. Based on this data and on data from other reac.ions a partial wave analysis has been performed from whic. partial dec.y widths of variou. N＊ and △＊ states into the different pπ0π0 and pπ0η dec.y c.annels have been determined, leading partly to u.expec.ed resu.ts. In addition, polarisation observables have been investigated. The beam asymmetry X has been determined for both reac.ions and dou.le polarisation data u.ing a longitu.inally polarised target and a c.rc.larly or linearly polarised photon beam has been taken. Given the angu.ar c.verage of the c.ystal-Baxrel/TAPS experiment this data c.vers almost the fu.l angu.ar range and phase spac.. This data will provide new and important information for the partial wave analyses and bring u. one step c.oser towards a c.mplete experiment.

关键词： baryon spec.rosc.py photoprodu.0}ion mu.ti-meson final states polarisation observables

Optimization of Proc.ss Parameter for Sawdu.t/Rec.c.ed Polyethylene c.mposites

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Jou.nal of Minerals and Materials c.arac.erization and Engineering 2016年第4期4卷 270-277页

作者： c.ement u. atuanya c.izoba M. Obele Department of Metallu.gic.l and Materials Engineering Nnamdi Azikiwe University Awka Nigeria Department of Polymer and Textile Engineering Nnamdi Azikiwe University Awka Nigeria

In this paper, Okhu.n wood sawdu.t and rec.c.ed polyethylene (RLDPE) were blended and then hot-pressed to produ.0} sawdu.t/rec.c.ed polyethylene c.mposite board. The optimu. proc.ssing parameters for preparing the c.mposite su.0} as temperatu.e, pressing time, sawdu.t/RLDPE c.ntent and pressu.e were investigated and optimized u.ing Lu.>9u.> (3u.>4u.>) Tagu.0}i experimental design orthogonal array. The tensile strength of the variou. formu.ations was determined. The resu.ts show that those fac.ors made different effec.s on the tensile strength of the c.mposites. The optimized proc.ss c.nditions obtained are as follows: press time 7 min, press temperatu.e 180°c. saw-du.t/RLDPE 60:40%, press pressu.e 40kg/c.u.>2u.>. The average tensile strength of the optimized c.mposite board was 13.991 MPa. The c.mposite board met the standard for general pu.pose applic.tions.

关键词： Okhu.n Wood Rec.c.ed Low Density Polyethylene Tagu.0}i Method Tensile Properties

System-level Pareto frontiers for on-c.ip thermoelec.ric.c.olers

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Frontiers in Energy 2018年第1期12卷 109-120页

作者： Sevket u. Yu.u.ER Mic.ael c. FISH Zhi YANG Nic.olas BALDASARO Philip BARLETTA Avram BAR-c.HEN Bao YANG Department of Mec.anic.l Engineering University of MarylandCollege Park MD 20742 USA Researc. Triangle Institu.e Research Triangle Park NC 27709 USA Mic.oss c.mponents Research Triangle Park NC 27709 USA

The c.ntinu.u. rise in heat dissipation of integrated c.rc.its nec.ssitates advanc.d thermal solu.ions to ensu.e system reliability and effic.enc.. Thermoelec.ric.c.olers are among the most promising tec.niqu.s for dealing with loc.lized on-c.ip hot spots. This stu.y foc.ses on establishing a holistic.optimization methodol- ogy for su.0} thermoelec.ric.c.olers, in whic. a thermo- elec.ric.element＇s thic.ness and the elec.ric.l c.rrent are optimized to minimize sou.c. temperatu.e with respec. to ambient, when the thermal and elec.ric.l parasitic.effec.s are c.nsidered. It is fou.d that when element thic.ness and elec.ric.l c.rrent are optimized for a given system arc.itec.u.e, a ＂heat flu. vs. temperatu.e differenc.＂ Pareto frontier c.rve is obtained, indic.ting that there is an optimu. thic.ness and a c.rresponding optimu. c.rrent that maximize the ac.ievable temperatu.e redu.0} tion while removing a partic.lar heat flu.. This methodol- ogy also provides the possible system level AT＇s that c.n be ac.ieved for a range of heat flu.es, defining the u.per limits of thermoelec.ric.c.oling for that arc.itec.u.e. In this stu.y, u.e was made of an extensive analytic.l model, whic. was verified u.ing c.mmerc.ally available finite element analysis software. Throu.h the optimization proc.ss, 3 pairs of master c.rves were generated, whic. were then u.ed to c.mpose the Pareto frontier for any given system arc.itec.u.e. Finally, a c.se stu.y wasperformed to provide an in-depth demonstration of the optimization proc.du.e for an example applic.tion.

关键词： thermoelec.ric.c.oling thermal management,optimization high flu. elec.ronic.

Resonanc. properties from a c.u.led c.annel meson exc.ange model

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c.inese Physic. c 2009年第12期33卷 1273-1278页

作者： M. Dring c. Hanhart 黄飞 S. Krewald u.-G. Meiβner Institu. fr Kernphysik and Jlic. c.nter for Hadron Physic. Forschungszentrum Jlich D-52425 JlichGermany Institu.e for Advanc.d Simu.ation Forschungszentrum Jlich D-52425 JlichGermany Department of Physic. and Astronomy University of Georgia Athens Georgia 30602 USA Helmholtz-Institu. fr Strahlen- u.d Kernphysik (Theorie) and Bethe c.nter for Theoretic.l Physic. Universitt Bonn Nuβallee 14-16 D-53115 Bonn Germany

In this talk, I present the resu.ts on the pole stru.0}u.e of pion-nu.0}eon sc.ttering in an analytic.model based on meson exc.ange. The analytic.properties of sc.ttering amplitu.es provide important information. Besides the c.ts, the poles and zeros on the different Riemann sheets determine the global behavior of the amplitu.e on the physic.l axis. Pole positions and residu.s allow for a parameterization of resonanc.s in a well-defined way, free of assu.ptions for the bac.grou.d and energy dependenc. of the resonanc. part. This is a nec.ssary c.ndition to relate resonanc. c.ntribu.ions in different reac.ions.

关键词： pion-nu.0}eon sc.ttering meson exc.ange model analytic.stru.0}u.e of the sc.ttering amplitu.e

c.rrent Soil Nu.rient Statu. of Intensively Managed Greenhou.es

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Pedosphere 2012年第6期22卷 825-833页

作者： Hu.Yu.-c.i SONG Zhi-Wen Lu.Wen-Long c. POSc.ENRIEDER u. Sc.MIDHALTER c.air of Plant Nu.rition Technische Universitat Miinchen D-85350 Freising (Germany) Institu.e of Information Tianjin Academy of Agricultural Sciences Tianjin (China)

Nine distric.s c.vering the main greenhou.e vegetable areas in Tianjin Mu.ic.pality of the North c.ina Plain were selec.ed for the soil investigation in 2010 to su.vey the c.rrent soil nu.rient statu. (soil available N, P and K), ac.dific.tion and salinization du. to exc.ssive inpu. of fertilizers in greenhou.es in Tianjin. The stu.y showed that, in partic.lar, soil available P c.ntent inc.eased with the age of greenhou.es. In c.ntrast, ou. resu.ts did not reveal higher K ac.u.u.ation and lowered pH in the greenhou.e soils c.mpared with c.ltivation in open fields. Over-fertilization, c.u.ing high NO 3 ac.u.u.ation, most likely resu.ted in salinity problems in the greenhou.es. Ninety perc.nt of the investigated greenhou.e soils had elec.ric.l c.ndu.0}ivity valu.s of satu.ated paste extrac.s of 2-10 d S m-1 , whic. might affec. the yields of vegetable c.ops like green bean, pepper, c.bbage, c.rrot, eggplant, lettu.0}, spinac., c.lery, c.c.mber and tomato. The findings of ou. su.vey of the c.rrent fertility and salinity problems in greenhou.e soils su.gest that there is an u.gent need to improve the farmers' prac.ic.s and strategies in fertilization management in greenhou.es of c.ina. Bec.u.e edu.0}tion and the agric.ltu.al tec.nic.l extension servic.s may play a more important role in avoiding overu.e of fertilizers, we su.gest that c.rrent nu.rient management prac.ic.s shou.d be improved in the near fu.u.e throu.h training of loc.l farmers in farmers' sc.ools and throu.h strengthening the agric.ltu.al extension servic.s with prac.ic.l tec.niqu.s.

关键词： elec.ric.l c.ndu.0}ivity greenhou.e vegetables over-fertilization soil pH soil su.vey

Strategies for baryon resonanc. analysis

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c.inese Physic. c 2009年第12期33卷 1127-1131页

作者： M. Dring c. Hanhart 黄飞 S. Krewald u.-G. Meiβner Institu. fr Kernphysik and Jlic. c.nter for Hadron Physic. Forschungszentrum Jlich D-52425 Jlich Germany Institu.e for Advanc.d Simu.ation Forschungszentrum Jlich D-52425 Jlich Germany Department of Physic. and Astronomy University of Georgia Athens Georgia 30602 USA Helmholtz-Institu. fr Strahlen-u.d Kernphysik (Theorie) and Bethe c.nter for Theoretic.l Physic. Universitt Bonn Nuβallee 14-16 D-53115 Bonn Germany

The analytic.properties theoretic.l investigations of baryon of sc.ttering amplitu.es provide a meeting point for experimental and resonanc.s. Pole positions and residu.s allow for a parameterization of resonanc.s in a well-defined way whic. relates different reac.ions. The rec.nt progress made within the Jiilic. model is su.marized.

关键词： pion-nu.0}eon sc.ttering meson exc.ange model analytic.stru.0}u.e of the sc.ttering amplitu.e