检索结果-南通市图书馆

Performance evaluation of up-flow anaerobic sludge blanket(UASb) reactor for treatment of paper mill wastewater

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2004年第2期16卷 194-198页

作者： m. mahadevaswamy b.m. Sadashiva murthy A.r. Girijamma Department of Environmental Engineering S.J.College of EngineeringDepartment of Environmental EngineeringS.J.College of EngineeringDepartment of Environmental EngineeringS.J.College of Engineering Mysore-570 006Karnataka StateIndiaMysore-570 006Karnataka StateIndiaMysore-570 006Karnataka StateIndia

The present study deals with the performance evaluation of the UASb reactor under varied organic loading rate(OLr) for the treatment of paper mill wastewater. The sludge granulation process started after 120 days from the start-up period. Sludge granules size was found to be 0 8 mm at OLr of 1 72 kgCOD/(m 3·d), which reached maximum size of about 1 0 to 1 2 mm at OLr of 2 1 kgCOD/(m 3·d). At the end of initial OLr of 1 0 kgCOD/(m 3·d) the VSS concentration was 12 86 gVSS/L, which got increased to 38 05 gVSS/L at the end of an OLr 2 1 kgCOD/(m 3·d). most of the times VFA recorded were well within the limit of VFA reported in anaerobic fermentation process. many times the pH observed was between 6 5 and 7 8, which is more favorable for any anaerobic process. It is also found that pH within the reactor increases along with the height of reactor. The total maximum biogas production was found to be 0 40 L/gCOD removals at OLr of 2 1 kgCOD/(m 3·d) and the maximum bOD removal at this stage was observed to be 90%.

关键词： UASb biogas anaerobic digestion sludge loading rate organic loading rate

Influence of surface roughness on flotation kinetics of quartz

在线全文

学校读者我要写书评

暂无评论

Journal of Central South University 2012年第5期19卷 1206-1211页

作者： m.rahimi m.r.Aslani b.rezai Department of mining and metallurgical Engineering Amirkabir University of TechnologyTehranIran Department of mining Engineering Science and Research BranchIslamic Azad UniversityTehranIran

Surface roughness of quartz particles was determined by measuring the specific surface area of *** wettability characteristics of particles were determined by measuring the flotation rate using a laboratory flotation *** results show that the rod mill product has higher roughness than the ball mill *** the particles with larger surface roughness,the flotation kinetics constant is also ***,empirical relationships between surface roughness(r) and the flotation kinetics constant(k) of quartz particles as k=A+br+Cr0.5lnr+D/lnr+E/r and k=A+br are presented,in which A,b,C,D and E are constants related to experimental conditions and mineralogical properties of mineral.

关键词： grinding flotation kinetics surface roughness ball mill rod mill

The method of Fundamental Solutions for Two-Dimensional Elastostatic Problems with Stress Concentration and Highly Anisotropic materials

在线全文

学校读者我要写书评

暂无评论

Computer modeling in Engineering & Sciences 2022年第3期130卷 1349-1369页

作者： m.r.Hematiyan b.Jamshidi m.mohammadi Department of mechanical Engineering Shiraz UniversityShiraz71936Iran Department of mechanical Engineering College of EngineeringShiraz BranchIslamic Azad UniversityShiraz71993Iran

The method of fundamental solutions(mFS)is a boundary-type and truly meshfree method,which is recognized as an efficient numerical tool for solving boundary value *** geometrical shape,boundary conditions,and applied loads can be easily modeled in the *** capability makes the mFS particularly suitable for shape optimization,moving load,and inverse ***,it is observed that the standard mFS lead to inaccurate solutions for some elastostatic problems with stress concentration and/or highly anisotropic *** thiswork,by a numerical study,the important parameters,which have significant influence on the accuracy of the mFS for the analysis of two-dimensional anisotropic elastostatic problems,are *** studied parameters are the degree of anisotropy of the problem,the ratio of the number of collocation points to the number of source points,and the distance between main and pseudo *** is observed that as the anisotropy of the material increases,there will be more errors in the *** is also observed that for simple problems,increasing the distance between main and pseudo boundaries enhances the accuracy of the results;however,it is not the case for complicated ***,it is concluded that more collocation points than source points can significantly improve the accuracy of the results.

关键词： meshfree method degree of anisotropy location of source points anisotropic elasticity least squares mFS

Stellar structure model in hydrostatic equilibrium in the context of f(r)-gravity

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

research in Astronomy and Astrophysics 2017年第12期17卷 31-40页

作者： raíla Andr Gilberto m.Kremer Departamento de Fisica Universidade Federal do Parana81531-980 CuritibaBrazil manipal Centre for Natural Sciences Manipal UniversityManipal 576104India

In this work we present a stellar structure model from the f（r）-gravity point of view capable of describing some classes of stars（white dwarfs, brown dwarfs, neutron stars, red giants and the Sun）. This model is based on f（r）-gravity field equations for f（r） = r ＋ f2r2, hydrostatic equilibrium equation and a polytropic equation of state. We compare the results obtained with those found by Newtonian theory. It has been observed that in these systems, where high curvature regimes emerge,stellar structure equations undergo modifications. Despite the simplicity of this model, the results are satisfactory. The estimated values of pressure, density and temperature of the stars are within those determined by observations. This f（r）-gravity model has proved to be necessary to describe stars with strong fields such as white dwarfs, neutron stars and brown dwarfs, while stars with weaker fields, such as red giants and the Sun, are best described by Newtonian theory.

关键词： cosmology:theory stars:general massive brown dwarfs white dwarfs neutron

Effects of Tillage and Crop residue management on maize Yields and Net returns in the Central mexican Highlands Under Drought Conditions

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2014年第4期24卷 476-486页

作者： r.rOmErO-PErEZGrOVAS N.VErHULST D.DE la rOSA V.HErNáNDEZ m.mAErTENS J.DECKErS b.GOVAErTS International maize and Wheat Improvement Center(CImmYT) P.O.Box 6-641Mexico D.F.06600(Mexico) Department of Earth and Environmental Sciences University of LeuvenCelestijnenlaan 200 ELeuven 3001(Belgium) mathematics research Center(CImAT) Jalisco S/NValencianaGuanajuatoMexico CP 36240(Mexico)

In the subtropical highlands of Central mexico, where the main crop is maize （Zea mays）, the conventional practice （CP） involves tillage, monoculture and residue removal, leading to soil degradation and unsustainable use of natural resources and agricultural inputs. Conservation agriculture （CA） has been proposed as a viable alternative in the region, based on reduction in tillage, retention of adequate levels of crop residues and soil surface cover and use of crop rotation. This study began in 2009 when the highlands of Central mexico suffered from a prolonged drought during vegetative maize growth in July-August, providing an opportunity for the on-farm comparison of CA with CP under severe drought conditions which 21 climate change models projected to become more frequent. Under dry conditions, CA resulted in higher yields and net returns per hectare as early as the first and second years after adoption by farmers. As an average of 27 plots under farmers＇ management in 2009, the maize yields were 26% higher under CA （6.3 t ha-1） than under CP （5.0 t ha-l）. 2010 was close to a normal year in terms of rainfall so yields were higher than in 2009 for both practices; in addition, the yield difference between the practices was reduced to 19% （6.8 t ha-1 for CA vs. 5.7 t ha-1 for CP）. When all the 2009 and 2010 observations were analyzed in a modified stability analysis, CA had an overall positive effect of 3 838 mexican Pesos ha-1 （320 $US ha-1） on net return and 1.3 t ha-1 on yield. After only one to two years of adoption by farmers on their fields, CA had higher yields and net returns under dry conditions that were even drier than those predicted by the analyzed 21 climate change models under a climate change scenario, emission scenario A2.

关键词： climate change conservation agriculture conventional practice emission scenario modified stability analysis

A Note on Tropical Triangles in the Plane

在线全文

学校读者我要写书评

暂无评论

Acta mathematica Sinica,English Series 2009年第11期25卷 1775-1786页

作者： m.ANSOla m.J.de la PUENTE Departamento de Algebra Facultad de matemáticas Universidad Complutense

We define transversal tropical triangles （affine and projective） and characterize them via six inequalities to be satisfied by the coordinates of the vertices. We prove that the vertices of a transversal tropical triangle are tropically independent and they tropically span a classical hexagon whose sides have slopes ∞, 0, 1. Using this classical hexagon, we determine a parameter space for transversal tropical triangles. The coordinates of the vertices of a transversal tropical triangle determine a tropically regular matrix. Triangulations of the tropical plane are obtained.

关键词： tropical triangles tropical triangulation linear inequalities convexity tropical semi-field

Solidification, microstructure, and mechanical properties of the as-cast ZrE1 magnesium alloy with different praseodymium contents

在线全文

学校读者我要写书评

暂无评论

International Journal of minerals,metallurgy and materials 2017年第11期24卷 1306-1320页

作者： Z.m.Sheggaf r.Ahmad m.b.A.Asmael A.m.m.Elaswad Department of manufacturing and Industrial Engineering Faculty of Mechanical and Manufacturing Engineering Universiti Tun Hussein Onn Malaysia Parit Raja86400 BatuPahat Johor Malaysia Department of mechanical Engineering Eastern Mediterranean University North Cyprus Gazimagsa TRNC Mersin 10 Turkey

The influence of praseodymium(Pr) content on the solidification characteristics, microstructure, and mechanical properties of ZrE1 magnesium(mg) cast alloy was investigated. The obtained solidification parameters showed that Pr strongly affected the solidification time, leading to refinement of the microstructure of the alloys. When the freezing time was reduced to approximately 52 s, the grain size decreased by 12%. mg_(12)Zn(Ce,Pr) was formed as a new phase upon the addition of Pr and was detected via X-ray diffraction analysis. The addition of Pr led to a substantial improvement in mechanical properties, which was attributed to the formation of intermetallic compounds; the ultimate tensile strength and yield strength increased by approximately 10% and 13%, respectively. Pr addition also refined the microstructure, and the hardness was recovered. The results herein demonstrate that the mechanical properties of mg alloys are strongly influenced by their microstructure characteristics, including the grain size, volume fraction, and distribution of intermetallic phases.

关键词： metal solidification microstructure mechanical properties magnesium alloys intermetallics

mitochondria–cGAS–STING axis is a potential therapeutic target for senescence-dependent inflammaging-associated neurodegeneration

在线全文

学校读者我要写书评

暂无评论

Neural regeneration research 2025年第3期20卷 805-807页

作者： Josém.Izquierdo Centro de biología molecular Severo Ochoa(Cbm) Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid(CSIC-UAM)MadridSpain

The word “senescence” comes from the latin senescens, meaning “to begin to age”, and is characterized by a long-lasting but reversible block in proliferation, resulting from stress-induced cell cycle arrest of pre... 详细信息

关键词： latin potential lasting

Solid-state synthesis of lnOCl/ln_2O_3(ln=Eu, Nd) by using chitosan and PS-co-P4VP as polymeric supports

在线全文

学校读者我要写书评

暂无评论

Journal of rare Earths 2018年第12期36卷 1326-1332页

作者： C.Diaz D.Carrillo r.de la Campa A.Presa Soto m.L.Valenzuela Departamento de Quimica Facultad de Quimica Universidad de Chile Departamento de Quimica Organica e Inorganica (IUQOEm) Facultad de Quimica Universidad de Oviedo Universidad Autonoma de Chile Facultad de Ingenieria Instituto de Ciendas Quimicas Aplicadas Inorganic Chemistry and Molecular Material Center

A series of lanthanide materials of type lnOCl or ln2O3(ln = Eu, Nd) were successfully prepared via a convenient and straightforward two-step procedure. Firstly, and by using chitosan and PS-co-P4 VP as polymeric supports, macromolecular complexes of type chitosan ·lnCl3and PS-co-P4 VP·lnCl3 were prepared. These macro molecular complexes were treated in solid state at 800 ℃ under air, leading to the corresponding lnOCl or ln2O3materials(ln = Eu, Nd) with moderate to good yields. The nature of the asprepared lanthanide materials(lnOCl and/or ln2O3) is strongly influenced by the polymeric template(i.e.,chitosan or PS-co-P4 VP), the lanthanide salt precursor, and the polymer/lanthanide molar ratio. Thus, when chitosan · EuCl3and PS-co-P4 VP·EuCl3are used as macromolecular precursors, a mixture of crystalline phases of both EuOCl and Eu2O3are obtained. However, when chitosan· NdCl3and PS-co-P4 VP· NdCl3are used, a sole pure crystalline phase of NdOCl is obtained. The nano structured lanthanide materials were characterized by means of XrD(X-ray diffraction of powder), SEm, EDS, TEm, and HrTEm. The luminescent spectra of the asprepared EuOCI/Eu2O3mixture materials show an emission pattern whose intensity is strongly influenced by the nature of the polymeric precursor, as well as on the metal/polymer molar ratios.

关键词： EuOCl/Eu_2O_3 NdOCl Solventless method Luminescence lanthanides rare earths