ترجمه مقاله با عنوان Fabrication, properties and application of porous metals with directional pores

اختصاصی از زد فایل ترجمه مقاله با عنوان Fabrication, properties and application of porous metals with directional pores دانلود با لینک مستقیم و پر سرعت .

متن کامل ترجمه مقاله ISI در elsevier در فایل word به فروش می رسد که ترجمه چکیده آن را به عنوان نمونه می توانید ملاحظه فرمایید.

Fabrication, properties and application of porous metals with directional pores

Abstract

This paper reviews the recent development of fabrication methods, various properties of porous metals with directional pores and its applications. This porous metals are fabricated by unidirectional solidification in pressurized gas atmosphere such as hydrogen, nitrogen and oxygen. The pores are evolved from insoluble gas when the melt metal dissolving the gas is solidified. The nucleation and growth mechanism of the directional pores in metals are discussed in comparison with a model experiment of carbon dioxide pores in ice. Three fabrication techniques, mold casting, continuous zone melting and continuous casting techniques, are introduced. The latter two techniques can control the solidification velocity and the last one possesses a merit for mass production. The porosity and pore size are able to be controlled by solidification velocity and ambient gas pressure, while the pore direction can be controlled by solidification direction. Not only metals and alloys but also intermetallic compounds, semiconductors and ceramics can be produced by this method. Anisotropy in the mechanical and physical properties is resulted from anisotropic pore morphology. The experimental results on the anisotropy in the elastic property and electrical conductivity are consistent with those calculated with an effective-mean-field theory. The anisotropic behaviors of tensile, compressive and fatigue strength are explained in terms of the dependence of stress concentration on the pore orientation. This porous metals exhibit good sound absorption and vibration–damping properties. Several possible applications are in progress for heat sink, golf putter, biomaterials and so on.

ساخت، خواص و کاربرد فلزات متخلخل با منافذ جهت دار

چکیده

در این مقاله توسعه های اخیر روشهای ساخت، خواص مختلف فلزات متخلخل با منافذ جهت دار و کاربردهای آن بررسی شده است. این فلزات متخلخل با انجماد یک سویه در اتمسفر گاز تحت فشار مانند هیدروژن، نیتروژن و اکسیژن ساخته شده است. در زمانی که فلز مذاب حل کننده گاز منجمد می­شود، منافذ از گاز غیر قابل حل متصاعد می­شوند. مکانیسم هسته زایی و رشد منافذ جهت دار در فلزات در مقایسه با یک مدل آزمایش منافذ دی اکسید کربن در یخ بحث شده است. سه تکنیک ساخت، ریخته گری شمش، ذوب منطقه پیوسته و تکنیک های ریخته گری پیوسته، ارائه می­شوند. دو روش دوم می­تواند سرعت انجماد را کنترل کند و روش آخر دارای شایستگی برای تولید انبوه است. تخلخل و اندازه منافذ توسط سرعت انجماد و فشار گاز محیط قادر به کنترل است، در حالی که جهت منافذ را می­توان با جهت انجماد کنترل کرد. نه تنها فلزات و آلیاژها بلکه ترکیبات بین فلزی، نیمه هادی ها و سرامیک ها را می­توان با این روش تولید کرد. ناهمسانگردی در خواص مکانیکی و فیزیکی از مورفولوژی منافذ ناهمسانگرد نتیجه می­شود. نتایج تجربی ناهمسانگردی در ویژگی الاستیکی و هدایت الکتریکی مطابق با آنهای محاسبه شده با نظریه میدان موثر متوسط است. رفتار ناهمسانگرد از مقاومت کششی، فشاری و مقاومت خستگی ها از نظر وابستگی تمرکز تنش در گرایش منافذ توضیح داده می­شود. این فلزات متخلخل، جذب صوت و خواص ارتعاش-میرایی خوبی نشان می­دهند. کاربردهای مختلفی ممکن است برای انباره حرارتی، چوب گلف، مواد زیستی و غیره در پیشرفت باشد.

CsI calorimeter with 3-D position resolution

اختصاصی از زد فایل CsI calorimeter with 3-D position resolution دانلود با لینک مستقیم و پر سرعت .

New gamma-ray calorimeter have been develop ed for the MEGA Compton camera.They consist of arrays of small CsI(Tl) scintillator bars read out by Silicon PIN- diodes and low noise, self triggering frontend electronics. The length of the bars (the thickness of the calorimeter) can b e varied for different applications to fit the stopping power needed and the light loss tolerable. In this paper we present calibration results from 2cm long bars with diodes on one side, and 8cm long bars with diodes on two opposite sides.

Doublesided readout gives 3-D information of interactions which will b e used to overcome the limited position resolution in Anger-cameras at high energies. Simpler detection devices like Anger-cameras might finally resolve only the center of gravity.

As events from gamma rays with energies of MeV do extend over several cm, it is a prerequisite for an imaging device to resolve the interaction structure in detail.

Combining CsI(Tl) scintillators, Silicon PIN-photo dio des and frontend electronics inside the housing results in a cheap rugged design. While the development in our institute is mainly done for the Compton camera prototyp e, many other applications are conceivable.

Details of In-Situ Foam Propagation Exposed With Magnetic Resonance Imaging

اختصاصی از زد فایل Details of In-Situ Foam Propagation Exposed With Magnetic Resonance Imaging دانلود با لینک مستقیم و پر سرعت .

مفاله spe 71300

Analyzing Flowing Production Data with Standard Pressure Transient Methods

اختصاصی از زد فایل Analyzing Flowing Production Data with Standard Pressure Transient Methods دانلود با لینک مستقیم و پر سرعت .

مقاله SPE شماره 71033

Patterns of Internet Use by Persons With Spinal Cord Injuries and Relationship to Health-Related Quality of Life

اختصاصی از زد فایل Patterns of Internet Use by Persons With Spinal Cord Injuries and Relationship to Health-Related Quality of Life دانلود با لینک مستقیم و پر سرعت .

Mari-Lynn Drainoni, PhD, Bethlyn Houlihan, MSW, MPH, Steve Williams, MD, Mark Vedrani, MPH,

ABSTRACT. Drainoni M-L, Houlihan B, Williams S, Vedrani
M, Esch D, Lee-Hood E, Weiner C. Patterns of Internet
use by persons with spinal cord injuries and relationship to
health-related quality of life. Arch Phys Med Rehabil 2004;85:
1872-9.
Objectives: To examine patterns of computer and Internet
use among persons with spinal cord injuries (SCI) and to assess
the relationship between Internet use and health-related quality
of life (HRQOL).
Design: Cross-sectional survey design.
Setting: National Model Spinal Cord Injury Systems.
Participants: People with SCI enrolled in a national
database.
Interventions: Not applicable.
Main Outcome Measures: Patterns of Internet use and
relationship to HRQOL indicators: self-perceived health status,
health status compared with 1 year ago, severity of depression,
social integration score, occupation score, contacts with
friends, business contacts, and satisfaction with life.
Results: Most subjects owned computers, had Internet access,
and used the Internet regularly—primarily for email,
disability and health information, and shopping. Bivariate analysis
revealed significant differences in Internet access based on
sociodemographics, particularly among subjects with less education
and among African Americans and Hispanics. In initial
univariate analysis, most HRQOL indicators were significantly
better for Internet users; once sociodemographic factors were
included, 4 indicators remained significant.
Conclusions: Complex factors contribute to Internet access
among people with SCI, with more barriers among specific
subgroups. A significant HRQOL benefit from Internet use is
suggested. Targeted interventions and studies of usage patterns
are recommended.
Key Words: Internet; Minority groups; Quality of life;
Rehabilitation; Spinal cord injuries.
© 2004 by the American Congress of Rehabilitation Medicine
and the American Academy of Physical Medicine and
RehabilitationDavid Esch, PhD, Elizabeth Lee-Hood, MS, MTS, Cheryl Weiner, MPH