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New Development of Acid Regeneration in Steel Pickling Plants

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Journal of Iron and Steel Research International 2008年第4期15卷 1-6页

作者： W f Kladnig ICC Chemical Consulting Vienna A-1193 Austria

for acid pickling heat treated mild steel and steel products, up to the middle of the last century, sulfuric acid was primarily in use, which has been replaced stepwise by hydrochloric acid since the sixties. During this time, the pickling of high alloyed steel with hydrofluoric acid or mixtures for hydrofluoric acid together with nitric acid has also been applied on industrial scale. The technologies used by several plant contractors hereby show considerable differences in their engineering. The study provides a survey of the progress in the state of art of regeneration technology as well as the use of different *** media in the form of a review on existing technologies as well as improvements done within the recent years in the area.

关键词： pickling mild steel high alloyed steel acid recycling technology global emission standard treatment of stack gas

AXISYMMETRIC fLOW THROUGH A PERMEABLE NEAR-SPHERE

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Applied Mathematics and Mechanics(English Edition) 2005年第10期26卷 1319-1331页

作者： f.Ayaz Department of Mathematics Faculty of Science and Arts Gazi University 06500 Teknikokullar Ankara Turkey

An analytical approach is described for the axisymmetric flow through a permeable near-sphere with a modification to boundary conditions in order to account permeability. The Stokes equation was solved by a regular perturbation technique up to the second order correction in epsilon representing the deviation from the radius of nondeformed sphere. The drag and the flow rate were calculated and the results were evaluated from the point of geometry and the permeability of the surface. An attempt also was made to apply the theory to the filter feeding problem. The filter appendages of small ecologically important aquatic organisms were modeled as axisymmetric permeable bodies, therefore a rough model for this problem was considered here as an oblate spheroid or near-sphere.

关键词： Stokes flow perturbation technique filter feeding

Damper placement for seismic control of super-long-span suspension bridges based on the first-order optimization method

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Science China(Technological Sciences) 2010年第7期53卷 2008-2014页

作者： Billie f SPENCER Department of Civil and Environmental Engineering University of Illinois at Urbana-Champaign

To ensure the anti-earthquake performances of super-long-span suspension bridges, effective devices should be employed to control the seismic response of key sections. In this paper, four kinds of assessment functions for seismic response control effect are formulated based on the mechanism of seismic response control with dampers and the seismic response characteristics of long-span suspension bridges. A new optimal placement method of dampers using penalty function and first-order optimization theory is then proposed. Runyang suspension bridge (RSB) with a main span of 1490 m is then taken as an example. After seismic response time-history analyses on RSB using different placements of dampers, the analysis results are optimized by employing the optimal placement method and the optimal placements of dampers with the four assessment functions are then achieved respectively. Comparison of the four optimal control effects show that different assessment functions can lead to different optimal placements when the number of dampers is certain, but all placements of dampers can reduce the seismic response of RSB significantly. The selection of assessment functions and damper optimal placement should be determined by the structural characteristics and by what is considered in the structures. Results also show that the first-order optimization is an effective method on determining the optimal placement of dampers.

关键词： suspension bridge seismic control damper placement control effect assessment first-order optimization method

Effect of thermal conductivity on heat transfer for a power-law non-Newtonian fluid over a continuous stretched surface with various injection parameters

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Applied Mathematics and Mechanics(English Edition) 2010年第8期31卷 963-968页

作者： f.A.SALAMA Department of Mathematics Faculty of Science Suez Canal University

The two-dimensional non-Newtonian steady flow on a power-law stretched surface with suction or injection is studied. Thermal conductivity is assumed to vary as a linear function of temperature. The transformed governing equations in the present study are solved numerically using the Runge-Kutta method. Through a comparison, results for a special case of the problem show excellent agreement with those in a previous work. Two cases are considered, one corresponding to a cooled surface temperature and the other to a uniform surface temperature. Numerical results show that the thermal conductivity variation parameter, the injection parameter, and the power-law index have significant influences on the temperature profiles and the Nusselt number.

关键词： non-Newtonian fluid thermal conductivity power-law fluid heat transfer

Serum testosterone levels and excessive erythrocytosis during the process of adaptation to high altitudes

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Asian Journal of Andrology 2013年第3期15卷 368-374页

作者： Gustavo f Gonzales High Altitude Research Institute and Department of Biological and Physiological Sciences Faculty of Sciences and Philosophy Universidad Peruana Cayetano Heredia Lima 31 Peru

Populations living at high altitudes （HAs）, particularly in the Peruvian Andes, are characterized by a mixture of subjects with erythrocytosis （16 g dl-1〈haemoglobin （Hb）≤21 gdl-1） and others with excessive erythrocytosis （EE）（Hb〉21 g dl-1）. Elevated haemoglobin values （EE） are associated with chronic mountain sickness, a condition reflecting the lack of adaptation to HA. According to current data, native men from regions of HA are not adequately adapted to live at such altitudes if they have elevated serum testosterone levels. This seems to be due to an increased conversion of dehydroepiandrosterone sulphate （DH EAS） to testosterone. Men with erythrocytosis at HAs show higher serum androstenedione levels and a lower testosterone/androstenedione ratio than men with EE, suggesting reduced 17beta-hydroxysteroid dehydrogenase （17beta-HSD） activity. Lower 17beta-HSD activity via A4-steroid production in men with erythrocytosis at HA may protect against elevated serum testosterone levels, thus preventing EE. The higher conversion of DHEAS to testosterone in subjects with EE indicates increased 17beta-HSD activity via the A5-pathway. Currently, there are various situations in which people live （human biodiversity） with low or high haemoglobin levels at HA. Antiquity could be an important adaptation component for life at HA, and testosterone seems to participate in this process.

关键词： chronic mountain sickness DHEA haemoglobin high altitudes men oestradiol women

Effects of radiation upon gastrointestinal motility

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World Journal of Gastroenterology 2007年第19期13卷 2684-2692页

作者： Mary f Otterson Departments of Surgery and Physiology Cancer Center and Digestive Diseases Center Medical College of Wisconsin and Zablocki Veterans Affairs Medical Center Milwaukee Wisconsin 4-4-2007 United States

Whether due to therapeutic or belligerent exposure, the gastrointestinal effects of irradiation produce symptoms dreaded by a majority of the population. Nausea, vomiting, diarrhea and abdominal cramping are hallmarks of the prodromal phase of radiation sickness, occurring hours to days following radiation exposure. The prodromal phase is distinct from acute radiation sickness in that the absorptive, secretory and anatomic changes associated with radiation damage are not easily identifi able. It is during this phase of radiation sickness that gastrointestinal motility significantly changes. In addition, there is evidence that motor activity of the gut contributes to some of the acute and chronic effects of radiation.

关键词： Electrical control activity Retrograde giant contraction Giant migrating contraction Migrating motor Complex Radiation therapy

Molecular nature of sulfhydryl modification by hydrogen peroxide on type 1 ryanodine receptor

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Acta Pharmacologica Sinica 2006年第7期27卷 888-894页

作者： Anthony f LAI Cardiff Cf14 4XN Cardiff University UK Wales Heart Research Institute Wales College of Medicine

Aim:To elucidate the molecular nature of sulfhydryl modification by hydrogenperoxide on type 1 ryanodine receptor(RyR1).Methods:Rabbit skeletal musclesarcoplasmic reticulum was treated with hydrogen peroxide,then RyR1 complexwas *** proteins in the complex were analysed by electrophoresis,Western blot and electron ***:(1)Hydrogen peroxide inducesinter-subunit cross-linking within the tetrameric RyR1 molecule;(2)in parallel tointer-subunit cross-linking,the RyR1 molecule changes morphology;(3)the chemi-cal and morphological changes are reversible:upon reduction by reducing agents,the RyR1 molecule regains its original ***:These findings suggestthat the molecular mechanism of RyR1 channel activity in sarcoplasmic reticulumregulated by hydrogen peroxide is through inter-subunit cross-linking within thetetrameric RyR1 molecule,which in turn induces structural changes of RyR1.

关键词： Ca2+ release channel/ryanodine receptor hydrogen peroxide reactive oxygen redoxsensitive ion channel

Modelling ballistic impact on military helmets:The relevance of projectile plasticity

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Defence Technology（防务技术） 2021年第5期17卷 1699-1711页

作者： A.Caçoilo R.Mourao f.Teixeira-Dias A.Azevedo f.Coghe R.A.f.Valente School of Engineering The University of EdinburghEdinburghEH93FGUK Dept.Weapon Systems and Ballistics Royal Military AcademyBrusselsBelgium Centre for Mechanical Technology and Automation Department of Mechanical EngineeringUniversity of AveiroPortugal

The need to develop armour systems to protect against attacks from various sources is increasingly a matter of personal,social and national *** develop innovative armour systems it is necessary to monitor developments being made on the type,technology and performance of the threats(weapons,projectiles,explosives,etc.) Specifically,the use of high protection level helmets on the battlefield is *** development of evaluation methods that can predict injuries and trauma is therefore of major ***,the risk of injuries or trauma that can arise from induced accelerations is an additional *** develop new materials and layouts for helmets it is necessary to study the effects caused by ballistic impacts in the human head on various *** use of numerical simulation is a fundamental tool in this *** work here presented focuses on the use of numerical simulation(finite elements analysis) to predict the consequences of bullet impacts on military helmets on human *** main objectives are to assess the level and probability of head trauma using the Head Injury Criterion,caused by the impact of a 9 mm NATO projectile on a PASGT helmet and to quantify the relevance of projectile plasticity on the whole modelling *** accelerations derived from the impact phenomenon and the deformations caused on the helmet are evaluated using fully three-dimensional models of the helmet,head,neck and *** studies are done at impact angles ranging from 0 to 75°.Results are presented and discussed in terms of HIC and probability of acceleration induced trauma *** comparison analyses are done using a rigid and a deformable projectile and it is observed that plastic deformation of the projectile is a significant energy dissipation mechanism in the whole impact process.

关键词： Ballistic impact Helmet impact Plasticity finite element analysis Injury Trauma HIC

The theoretical study of the efficiency of diffusion deposition of nanoaerosols in the extended range of the Peclet numbers

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Particuology 2023年第6期77卷 47-55页

作者： R.f.Mardanov S.K.Zaripov V.f.Sharafutdinov N.I.Lobachevskii Institute of Mathematics and Mechanics Kazan(Volga Region)Federal UniversityKremlevskaya ul.18KazanTatarstan420008Russia

The efficiencies of the diffusion deposition of nanoaerosols for a single fiber for the models of aerosol filter and wire mesh screen are studied numerically in the extended range of the Peclet number *** rectangular periodic cell model for fluid flow and convective-diffusive transport of small aerosol particles is *** of the previous theoretical and experimental studies of single fiber diffusion deposition efficiency were for the case of Pe>*** array with uniform square or chess grid of fibers and of a row of circular cylindrical fibers are considered as the filter and wire mesh screen *** flow and particles transport equations are solved numerically using the Boundary Element *** obtained numerical data are used to derive the approximate formulas for the deposition efficiency in the entire range of the Peclet number for the various porosities of the filter medium or distances between fibers in a wire mesh *** derived dependencies take into account nonlinearity of the deposition efficiency at the low Peclet *** obtained analytical dependencies compare well with the numerical and experimental data.

关键词： Arrayof fibers Row of fibers Periodic cell model Convection-diffusion equation Single fiber efficiency