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Preliminary performance analysis and optimization based on 1D neutronics model for Indian DEmO HccB blanket

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Plasma Science and Technology 2020年第8期22卷 184-191页

作者： D AGGARWAL c DANANI m Z YOUSSEF Institute for Plasma Research GandhinagarGujarat 382428India Homi Bhabha National Institute(HBNI) AnushaktinagarMumbai 400094India University of california-Los Angeles Los AngelesCA 90095United States of America

India,under its breeding blanket R&D program for DEmO,is focusing on the development of two tritium breeding blanket concepts;namely the lead-lithium-cooled ceramic breeder and the helium-cooled ceramic breeder(HccB).The study presented in this paper focuses on the neutronic design analysis and optimization from the tritium breeding perspective of the HccB *** Indian concept has an edge-on configuration and is one of the variants of the helium-cooled solid breeder blanket concepts proposed by several partner countries in *** Indian HccB blanket having lithium titanate(Li2TiO3)as the tritium breeder and beryllium(Be)as the neutron multiplier with reduced-activation ferritic/martensitic steel structure aims at utilizing the low-energy neutrons at the rear part of the *** aim of the optimization study is to minimize the radial blanket thickness while ensuring tritium self-sufficiency and provide data for further neutronic design and thermal-hydraulic layout of the HccB *** is found that inboard and outboard blanket thicknesses of 40 cm and 60 cm,respectively,can give a tritium breeding ratio(TBR)>1.3,with 60%6Li enrichment,which is assumed to be sufficient to cover potential tritium losses and associated *** results also demonstrated that the Be packing fraction(PF)has a more profound impact on the TBR as compared to 6Li enrichment and the PF of Li2TiO3.

关键词： DEmO helium-cooled ceramic breeder blanket neutronic optimization study tritium breeding ratio

Hot cracking in AZ31 and AZ61 magnesium Alloy

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Journal of materials Science & Technology 2011年第7期27卷 633-640页

作者： c.J. Huang c.m. cheng c.P. chou F.H. chen Department of mechanical Engineering National Chiao Tung University Hsinchu 300 Taiwan China Department of Industrial Education National Taiwan Normal University Taipei 106 Taiwan China

This paper examined the impact of the number of thermal cycles and augmented strain on hot cracking in AZ31 and AZ61 magnesium alloy. Statistical analyses were performed. Following observation using a scanning electron microscope （SEm）, an energy dispersive spectrometer （EDS） was used for component analysis. Results showed that Al content in magnesium alloy has an effect on hot cracking susceptibility. In addition, the nonequilibrium solidification process produced segregation in Al content, causing higher liquid mg-alloy rich Al content at grain boundaries, and resulting into liquefied grain boundaries of partially melted zone （PmZ）. In summary, under multiple thermal cycles AZ61 produced serious liquation cracking. AZ61 has higher （6 wt%） Al content and produced much liquefied mg17Al12 at grain boundaries under multiple thermal cycles. The liquefied mg17Al12 were pulled apart and hot cracks formed at weld metal HAZ due to the augmented strain. Since AZ31 had half the Al content of AZ61, its hot-cracking susceptibility was lower than AZ61. In addition, AZ61 showed longer total crack length （TcL） in one thermal cycle compared to that in three thermal cycles. This phenomenon was possibly due to high-temperature gasification of Al during the welding process, which resulted in lower overall Al content. consequently, shorter hot cracks exhibited in three thermal cycles. It was found the Al content of AZ31 and AZ61 can be used to assess the hot-cracking susceptibility.

关键词： Varestraint test Thermal cycles Hot-cracking susceptibility Gas tungsten arc welding (GTAW) AZ31 AZ61

Experimental study on the microstructural and anti-corrosion behaviour of co-deposition Ni-co-SiO_2 composite coating on mild steel

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Defence Technology（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 metallurgical and materials Engineering Nnamdi Azikiwe UniversityAwkaAnambra StateNigeria Department of Polymer and Textile Engineering Nnamdi Azikiwe UniversityAwkaAnambra StateNigeria

mild steel is commonly used in the construction of Pipeline. The major problem of this Pipeline is corrosion. Effort is make my researchers to combat this problem. In this work co-deposition of Ni-coSiO_2 composite coating on mild steel was reported with the view to reduce this problem. The SiO_2 was varies from 5 to 25 wt% in the deposition. The microstructure, hardness values and potentiodynamic polarization in simulated sea water were determined. The results show that XRD pattern of the Ni co deposited mild steel revealed the presence hard phases of NiO, co_5Ni, co_2Ni_3, Ni co5 while that of Ni-coSiO_2 deposited mild steel revealed the presence harder phases of NiOSiO_2, coNi_7Si_2, co_5Ni_2Si_3. The Nico-25 SiO_2 deposited sample has smaller particle size than Ni-10 co coating. coating thickness of 110.7 mm was obtained for Ni-10 co coating, while coating thickness of 135.7, 157.7, 165.0 mm were obtained at Ni-10 co-x SiO_2(x=10, 15, 25 wt%). 99.90% corrosion resistance was achieved at Ni-co-25 SiO_2. This improvement in corrosion resistance after composites coating could be attributed to the hard and fine structure obtained after coating.

关键词： co-deposition corrosion microstructure and coating

Heavy metals and PAHs in Sewage Sludge from Twelve Wastewater Treatment Plants in Zhejiang Province

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Biomedical and Environmental Sciences 2008年第4期21卷 345-352页

作者： c. m. TIENTcHEN college of Environmental and Resource Sciences Zhejiang University

Objective To investigate the heavy metals （Hms） and polycyclic aromatic hydrocarbons （PAHs） in sludge of twelve wastewater treatment plants （WWTPs） in Zhejiang province of china, and to assess their potential for land application. methods Sludge was collected from 12 WWTPs within the province. Gc-mS and AAS were used to measure PAHs and Hms contents in sludge. Results concentrations of Hms in most of the sludge samples were below the regulatory limits for the sludge to be used in agriculture in china with the exception of Zn in 2 sludge samples and cd in 1 sample. All 16 PAHs, targeted by the USEPA agency, were found in the sludge from the twelve plants with a total concentration ranging from 33.73 mg kg^-1 to 82.58 mg kg^-1 （dry weight, d.w.）. The levels of Σ9 PAHs varied from 13.87 mg kg^-1 to 61.86 mg kg^-1 （d.w.） in the sludge, far exceeding the limitation value recommended by the Europe Union. The concentration and composition of PAHs in sewage sludge varied and depended mainly on the quantity and type of industrial wastewater accepted by the WWTPs. A significant relationship between the proportion of industrial wastewater received by WWTPs and the total content of 16 PAHs in the sludge was observed. conclusion PAHs have become one of the primary pollutants in sludge of Zhejiang WWTPs instead of Hms. It is, therefore, essential to reduce the contents of PAHs before the sludge can be used in agriculture through proper treatment.

关键词： Sludge Heavy metal chemical Fractions Polycyclic aromatic hydrocarbons contribution

Nonlinear forced vibration in a subcritical regime of a porous functionally graded pipe conveying fluid with a retaining clip

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Applied mathematics and mechanics(English Edition) 2025年第1期46卷 101-122页

作者： m.GHOLAmI m.EFTEKHARI Department of mechanical Engineering Shahid Bahonar University of Kerman

This study examines the nonlinear behaviors of a clamped-clamped porous pipe made of a functionally graded material(FGm) that conveys fluids and is equipped with a retaining clip, focusing on primary resonance and subcritical dynamics. The nonlinear governing equations for the FGm pipe are derived by the extended Hamilton's principle, and subsequently discretized through the application of the Galerkin *** direct method of multi-scales is then used to solve the derived equations. A thorough analysis of various parameters, including the clip stiffness, the power-law index, the porosity, and the clip location, is conducted to gain a comprehensive understanding of the system's nonlinear dynamics. Through the analysis of the first natural frequency, the study highlights the influence of the flow velocity and the clip stiffness, while the comparisons with metallic pipes emphasize the role of FGm composition. The examination of the forced response curves reveals saddle-node bifurcations and their dependence on parameters such as the detuning parameter and the power-law index, offering valuable insights into the system's nonlinear resonant behavior. Furthermore, the frequency-response curves illustrate the hardening nonlinearities influenced by factors such as the porosity and the clip stiffness, revealing nuanced effects on the system response and resonance characteristics. This comprehensive analysis enhances the understanding of nonlinear behaviors in FGm porous pipes with a retaining clip, providing key insights for practical engineering applications in system design and optimization.

关键词： Galerkin methods

Visualising data distributions with kernel density estimation and reduced chi-squared statistic

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Geoscience Frontiers 2017年第6期8卷 1247-1252页

作者： c.J.Spencer c.Yakymchuk m.Ghaznavi Earth Dynamics Research Group The Institute of Geoscience ResearchDepartment of Applied GeologyCurtin UniversityPerthAustralia Department of Earth and Environmental Sciences University of WaterlooWaterlooCanada David R.cheriton School of computer Science University of WaterlooWaterlooCanada

The application of frequency distribution statistics to data provides objective means to assess the nature of the data distribution and viability of numerical models that are used to visualize and interpret *** commonly used tools are the kernel density estimation and reduced chi-squared statistic used in combination with a weighted *** to the wide applicability of these tools,we present a Java-based computer application called KDX to facilitate the visualization of data and the utilization of these numerical tools.

关键词： Data visualisation Kernel density estimation Reduced chi-squared statistic mean square weighted deviation Geostatistics

SURFAcE FINITE ELEmENTS FOR PARABOLIc EQUATIONS

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Journal of computational mathematics 2007年第4期25卷 385-407页

作者： G. Dziuk c.m. Elliott Abteilung für Angewandte mathematik University of Freiburg Hermann-Herder-Straβe 10 D-79104Freiburg i. BrGermany Department of mathematics University of Sussex Falmer Brighton BN1 9RF United Kingdom

In this article we define a surface finite element method （SFEm） for the numerical solution of parabolic partial differential equations on hypersurfaces F in R^n＋1. The key idea is based on the approximation of F by a polyhedral surface Гh consisting of a union of simplices （triangles for n = 2, intervals for n = 1） with vertices on Г. A finite element space of functions is then defined by taking the continuous functions on Гh which are linear affine on each simplex of the polygonal surface. We use surface gradients to define weak forms of elliptic operators and naturally generate weak formulations of elliptic and parabolic equations on Г. Our finite element method is applied to weak forms of the equations. The computation of the mass and element stiffness matrices are simple and straightforward. We give an example of error bounds in the case of semi-discretization in space for a fourth order linear problem. Numerical experiments are described for several linear and nonlinear partial differential equations. In particular the power of the method is demorrstrated by employing it to solve highly nonlinear second and fourth order problems such as surface Allen-cahn and cahn-Hilliard equations and surface level set equations for geodesic mean curvature flow.

关键词： Surface partial differential equations Surface finite element method Geodesic curvature Triangulated surface.

Analysis of Differences in Productivity,Profitability and Soil Fertility Between Organic and conventional cropping Systems in the Tropics and Sub-tropics

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Journal of Integrative Agriculture 2014年第10期13卷 2299-2310页

作者： Te Pas c m Rees R m School of GeoSciences University of Edinburgh carbon management centre Scotland's Rural College

Organic farming aims to stimulate soil fertility by avoiding the use of synthetic fertiliser inputs, relying instead on locally available natural resources. It is regarded by many as a sustainable alternative to conventional fanning because it ensures higher biodiversity, restricts environmental pollution, prevents land degradation and is easy to apply for smallholder and subsistence farmers. Although widely practiced and studied in temperate regions, little is known about the potential overall benefits of organic farming in the tropics and subtropics. This paper addresses this gap by undertaking an analysis of the differences between organic and conventional agriculture in the tropics and sub-tropics based on an extensive literature review including 88 papers with 458 data pairs. The comparison is based on three main indicators： yield, gross margin and soil organic carbon （SOc）. The differences between the organic and conventional systems for each of these main indicators is represented by the ratio of the value of the indicator in the organic system divided by the corresponding value in the conventional system. This was initially calculated for each data pair individually, and grouped by a variety of explanatory factors, such as precipitation, human development level, soil texture, crop type, organic input type, time after conversion and certification. The results demonstrate that under organic management, yields were on average 26% higher, gross margins 51% higher and soil organic carbon 53% higher than under conventional management. The highest yield increases in organic cropping systems were achieved in the least developed countries, in arid regions and on coarse soils. For gross margins, certification was the main reason for differences between organic and conventional systems. certified farmers, mostly located in developed countries, receive significantly higher prices. Furthermore, organic farming in the driest regions results in higher profits than in other

关键词： organic farming conventional fanning tropics subtropics carbon sequestration yield soil quality soil organic carbon

modelling mechanical Properties in Native and Biomimetically Formed Vascular Grafts

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Journal of Bionic Engineering 2009年第4期6卷 371-377页

作者： m.mandru c.Ionescu m.chirita University of medicine and Pharmacy Faculty of Biomedical EngineeringUniversity street 16700115 IasiRomania Ghent University Department of Electrical energySystems and AutomationTechnologiepark 913B9052GentBelgium

The paper presents a detailed analysis of experimental data in order to characterize the elastic properties of *** analysis would provide a good basis for evaluation of biomimetic vascular *** the latter needs to exhibit similar properties of native tissue,it is important to accurately characterize the biomimetic sample in a large range of applied stresses. The stress-strain properties vary according to the specific pathology(***,aneurism)and the tissue graft must be chosen *** models are proposed in this paper on the stress-strain *** extension for frequency-domain analysis is provided for one of the *** comparison between vascular grafts and native tissue for carotid and thoracic arteries in pigs are in good agreement with results from *** proposed experimental method offers suitable parameters for identifying models which characterize both elasticity and stiffness properties of the analyzed tissues(stress-strain).The proposed models show good performance in characterizing the intrinsic material properties.

关键词： biomimetic biomaterials vascular graft native and artificial tissues stress-strain modeling