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2008

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Articles 1 - 23 of 23

Full-Text Articles in Mechanical Engineering

A New Set-Up To Measure The Viscoelastic Properties Of Porous Media Using A Specific Electrodynamic Transducer, Dauchez Nicolas, Olivier Doutres Ph.D., Jean-Michel Génevaux, Guy Lemarquand Dec 2008

A New Set-Up To Measure The Viscoelastic Properties Of Porous Media Using A Specific Electrodynamic Transducer, Dauchez Nicolas, Olivier Doutres Ph.D., Jean-Michel Génevaux, Guy Lemarquand

Olivier Doutres Ph.D.

A new method for measuring viscoelastic properties of sound absorbing materials is presented. This method is derived from the quasistatic method using a loudspeaker as actuator and sensor. Previous results carried out with a traditional electrodynamic loudspeaker were limited to 100 Hz because of transducer nonlinearities. In this paper, viscoelastic properties are determined up to 500 Hz due to the design of a specific loudspeaker devoid of the main nonlinearities.


تعيين عرض تختال در ورودي كوره هاي پيش گرم ناحيه نورد گرم مجتمع فولاد مباركه با استفاده از پردازش ديجيتال تصاوير, Eaman Alibeigi, Rasoul Amirfattahi, Masoud Harooni, Hamid Montazerolghaem Nov 2008

تعيين عرض تختال در ورودي كوره هاي پيش گرم ناحيه نورد گرم مجتمع فولاد مباركه با استفاده از پردازش ديجيتال تصاوير, Eaman Alibeigi, Rasoul Amirfattahi, Masoud Harooni, Hamid Montazerolghaem

Masoud Harooni

هر يك از تختال هاي توليد شده در بخش ريخته گري مداوم ناحيه فولاد سازي، پس از مارك زني و تعيين مشتري به يكي از دو صورت هوايي يا سيالي خنك شده و در زمان مقرر به وسيله غلطك هايي وارد كوره پيش گرم مي شوند. در اين مرحله، 1/6 mm تختال تا حرارت 1100 درجه سانتيگراد گرم شده و عمليات نورد گرم بر روي آن به منظور تهيه ورق فولاد با ضخامت صورت مي گيرد. تعيين دقيق مشخصات ابعادي تختال ها از جمله طول، عرض و ضخامت آنها قبل از ورود به كوره هاي پيش گرم و تطبيق ...


Gtaw ايجادشده با روش جوشکاری Tini-Tic و Tini بررسی ريزساختاری پوشش, Masoud Harooni, Morteza Shamanian, Alireza Fadaei Tehrani Oct 2008

Gtaw ايجادشده با روش جوشکاری Tini-Tic و Tini بررسی ريزساختاری پوشش, Masoud Harooni, Morteza Shamanian, Alireza Fadaei Tehrani

Masoud Harooni

هدف از انجام اين پژوهش بهبود سختي سطحي و ريزساختار فولاد ساده کربنی از نوع 52 و مقايسه ريز ساختار اين دو با هم GTAW ايجاد شده به روش جوشکاری TiNi-TiC و TiNi پوششی از بترتيب با نسبت استوکيومتری مساوي و نسبت ۲۰ Ti-Ni-C و Ti-Ni است. بدين منظور مخلوط پودری به طور جداگانه توسط روش فعال سازی مکانيکی فعال شد و سپس بر سطح TiC درصد تقويت کننده به ضخامت ۱ ميليمتر پيش نشانده شده با استفاده از روش جوشکاری قوسی St نمونه های فولادی 52 تنگستن- گاز ذوب و با فلز پايه امتزاج يافته است. جهت بررسي نوع ...


European Climate Policy And The Position Of Cyprus, Theodoros Zachariadis Oct 2008

European Climate Policy And The Position Of Cyprus, Theodoros Zachariadis

Theodoros Zachariadis

No abstract provided.


Thermal Stability Of Electrodeposited Liga Ni-W Alloys For High Temperature Mems Applications, Haseeb Asma Oct 2008

Thermal Stability Of Electrodeposited Liga Ni-W Alloys For High Temperature Mems Applications, Haseeb Asma

Haseeb ASMA

For thermally stable LIGA materials for high temperature MEMS applications LIGA Ni-W layers and micro testing samples with different compositions (15 and 5 at% W) were electrodeposited. In order to investigate the thermal stability the Ni-W layers were annealed at different temperatures (300-700 degrees C) and for different durations (1, 4, 16 h). Their microstructure and micro-hardness were than analysed after annealing and compared with those of as-deposited states. The observed microstructures show, in comparison to pure LIGA nickel, a small grain growth and a relatively stable structure up to 700 degrees C. The micro-hardness values of the LIGA Ni-W ...


The Dependence Of Measured Modulation Error Ratio On Phase Noise, Ron D. Katznelson Aug 2008

The Dependence Of Measured Modulation Error Ratio On Phase Noise, Ron D. Katznelson

Ron D. Katznelson

This paper reviews the algorithms used by Vector Signal Analyzers to measure Modulation Error Ratio (MER) and derives the explicit functional dependence of measured MER on phase noise of digital transmitters. The modulation error model is introduced and the analytical expression for key estimated parameters required to obtain MER measure are derived. The essential elements of algorithms employed by MER measurement instruments to estimate amplitude scale, frequency offset, and initial phase intercept and the resulting MER are identified. The frequency response of the effective phase-noise rejection filtering action associated with a given measurement epoch is derived. It is shown that ...


Moving From Low Income Housing Toward Affordable Quality Housing, B Bakhtyar Jul 2008

Moving From Low Income Housing Toward Affordable Quality Housing, B Bakhtyar

B Bakhtyar

Smart growth development entails retracting the city, hence attempting to house low-income residents at new affordable housing facilities within a metropolitan area. This paper introduces the Low Income Housing Tax credit (LIHTC) as an alternative funding source for developing affordable housing projects. In this article, we present the affordable housing and smart growth elements in two selected tax credit programs in the United States. We compared these elements with the Malaysian commitments in Agenda 21 and recommend how we could move forward in utilizing these elements to develop the Malaysian LIHTC point system that supports both affordable housing and smart ...


Fuel Taxation And Social Policy, Theodoros Zachariadis Jun 2008

Fuel Taxation And Social Policy, Theodoros Zachariadis

Theodoros Zachariadis

No abstract provided.


6 - مدلسازي و تحليل پاسخ حرارتي بدن انسان در برابر تابشهاي شدت بالا, Alireza Zolfaghari, Mehdi Maerefat, Amir Omidvar Apr 2008

6 - مدلسازي و تحليل پاسخ حرارتي بدن انسان در برابر تابشهاي شدت بالا, Alireza Zolfaghari, Mehdi Maerefat, Amir Omidvar

Dr Alireza Zolfaghari

No abstract provided.


Proceedings From Scientific Conference On Green Energy And It, Dr. Erik Dahlquist Mar 2008

Proceedings From Scientific Conference On Green Energy And It, Dr. Erik Dahlquist

Dr. Erik Dahlquist

This conference is part of the annual Energitinget, a national arena for energy in Sweden, with some 2500 participants. The focus with this session is to give a forum for researchers to present scientific results, and also to discuss these with other researchers. It contains papers in the area of Energy and IT as well as Green energy generally


Liga Fabrication Of Nanocrystalline Ni-Walloy Micro Specimens From Ammonia-Citrate Bath, Haseeb Asma Mar 2008

Liga Fabrication Of Nanocrystalline Ni-Walloy Micro Specimens From Ammonia-Citrate Bath, Haseeb Asma

Haseeb ASMA

Ammonia-citrate bath has been investigated for the deposition of nano crystalline Ni - W alloy micro components using the LIGA process. First the bath stability and deposit characteristics were studied. Fabrication of micro specimens were then carried out on silicon substrates covered with novolac as well as thick PMMA resist for LIGA. Effects of different parameters like current density, nickel ion and tungsten ion concentration in the bath, deposition time etc. on the deposit characteristics and current efficiency were studied. The deposited Ni - W samples were characterized by scanning electron microscopy, energy depressive X-ray spectroscopy, light optical microscopy and X-ray diffraction ...


5 - تأثير فرش کردن کف اتاق با قالي و يا برخي پوششهاي سنتي- تزييني مشابه بر عملکرد سيستمهاي گرمايش از کف هيدرونيک, Amir Omidvar, Alireza Zolfaghari, Mehdi Maerefat Feb 2008

5 - تأثير فرش کردن کف اتاق با قالي و يا برخي پوششهاي سنتي- تزييني مشابه بر عملکرد سيستمهاي گرمايش از کف هيدرونيک, Amir Omidvar, Alireza Zolfaghari, Mehdi Maerefat

Dr Alireza Zolfaghari

No abstract provided.


4 - تأثير نوع شيشة پنجره بر مصرف انرژي و شرايط آسايش حرارتي در سيستم سرمايش تابشي سقفي, Alireza Zolfaghari, Amir Omidvar, Mehdi Maerefat Feb 2008

4 - تأثير نوع شيشة پنجره بر مصرف انرژي و شرايط آسايش حرارتي در سيستم سرمايش تابشي سقفي, Alireza Zolfaghari, Amir Omidvar, Mehdi Maerefat

Dr Alireza Zolfaghari

No abstract provided.


3 - مدلسازي و تحليل پاسخ حرارتي بدن تحت تأثير صرف غذاي سرد يا گرم, Alireza Zolfaghari, Amir Omidvar, Mehdi Maerefat Feb 2008

3 - مدلسازي و تحليل پاسخ حرارتي بدن تحت تأثير صرف غذاي سرد يا گرم, Alireza Zolfaghari, Amir Omidvar, Mehdi Maerefat

Dr Alireza Zolfaghari

No abstract provided.


A Preliminary Assessment Of The State Of Harvest And Collection Technology For Forest Residues, Erin G. Wilkerson, D. Brad Blackwelder, Robert D. Perlack, David J. Muth, J. Richard Hess Feb 2008

A Preliminary Assessment Of The State Of Harvest And Collection Technology For Forest Residues, Erin G. Wilkerson, D. Brad Blackwelder, Robert D. Perlack, David J. Muth, J. Richard Hess

David J. Muth

To meet the “Twenty in Ten Initiative” goals set in the 2007 State of the Union address, forest resources will be needed as feedstocks for lignocellulosic ethanol production. It has been estimated that 368 million dry tons can be produced annually in the U.S. from logging residues and fuel treatment thinnings. Currently, very little of this woody biomass is used for energy production due to the costs and difficulty in collecting and transporting this material. However, minimizing biomass costs (including harvest, handling, transport, storage, and processing costs) delivered to the refinery is necessary to develop a sustainable cellulosic ethanol ...


Friction And Wear Characteristics Of Electrodeposited Nanocrystalline Nickel-Tungsten Alloy Films Jan 2008

Friction And Wear Characteristics Of Electrodeposited Nanocrystalline Nickel-Tungsten Alloy Films

A.S. Md Abdul Haseeb

Electrodeposited nanocrystalline nickel-tungsten alloys are being investigated as an attractive alternative to electrodeposited nickel for applications involving fabrication of micro electro mechanical systems (MEMS). Ni-W alloys are also being considered as an environmentally friendly alternative to hard chrome plating in some cases. In applications involving sliding contacts such as in micro-gears in MEMS, mould inserts, etc., tribological properties of Ni-W alloys would be of relevance. In this work, the sliding friction and wear characteristics of Ni-W alloys with different tungsten contents were investigated and compared with that of nickel film deposited from sulphamate bath commonly used in microfabrication. For wear ...


Liga Fabrication Of Nanocrystalline Ni-W Alloy Micro Specimens From Ammonia-Citrate Bath Jan 2008

Liga Fabrication Of Nanocrystalline Ni-W Alloy Micro Specimens From Ammonia-Citrate Bath

A.S. Md Abdul Haseeb

Ammonia-citrate bath has been investigated for the deposition of nano crystalline Ni-W alloy micro components using the LIGA process. First the bath stability and deposit characteristics were studied. Fabrication of micro specimens were then carried out on silicon substrates covered with novolac as well as thick PMMA resist for LIGA. Effects of different parameters like current density, nickel ion and tungsten ion concentration in the bath, deposition time etc. on the deposit characteristics and current efficiency were studied. The deposited Ni-W samples were characterized by scanning electron microscopy, energy depressive X-ray spectroscopy, light optical microscopy and X-ray diffraction. Results show ...


Liga Fabrication Of Nanocrystalline Ni-W Alloy Micro Specimens From Ammonia-Citrate Bath Jan 2008

Liga Fabrication Of Nanocrystalline Ni-W Alloy Micro Specimens From Ammonia-Citrate Bath

A.S. Md Abdul Haseeb

Ammonia-citrate bath has been investigated for the deposition of nano crystalline Ni-W alloy micro components using the LIGA process. First the bath stability and deposit characteristics were studied. Fabrication of micro specimens were then carried out on silicon substrates covered with novolac as well as thick PMMA resist for LIGA. Effects of different parameters like current density, nickel ion and tungsten ion concentration in the bath, deposition time etc. on the deposit characteristics and current efficiency were studied. The deposited Ni-W samples were characterized by scanning electron microscopy, energy depressive X-ray spectroscopy, light optical microscopy and X-ray diffraction. Results show ...


Thermal Stability Of Electrodeposited Liga Ni-W Alloys For High Temperature Mems Applications Jan 2008

Thermal Stability Of Electrodeposited Liga Ni-W Alloys For High Temperature Mems Applications

A.S. Md Abdul Haseeb

For thermally stable LIGA materials for high temperature MEMS applications LIGA Ni-W layers and micro testing samples with different compositions (15 and 5 at% W) were electrodeposited. In order to investigate the thermal stability the Ni-W layers were annealed at different temperatures (300-700°C) and for different durations (1, 4, 16 h). Their microstructure and micro-hardness were than analysed after annealing and compared with those of as-deposited states. The observed microstructures show, in comparison to pure LIGA nickel, a small grain growth and a relatively stable structure up to 700°C. The micro-hardness values of the LIGA Ni-W layers are ...


Friction And Wear Characteristics Of Electrodeposited Nanocrystalline Nickel-Tungsten Alloy Films, Haseeb Asma Jan 2008

Friction And Wear Characteristics Of Electrodeposited Nanocrystalline Nickel-Tungsten Alloy Films, Haseeb Asma

Haseeb ASMA

Electrodeposited nanocrystalline nickel-tungsten alloys are being investigated as an attractive alternative to electrodeposited nickel for applications involving fabrication of micro electro mechanical systems (MEMS). Ni-W alloys are also being considered as an environmentally friendly alternative to hard chrome plating in some cases. In applications involving sliding contacts such as in micro-gears in MEMS, mould inserts, etc., tribological properties of Ni-W alloys would be of relevance. In this work, the sliding friction and wear characteristics of Ni-W alloys with different tungsten contents were investigated and compared with that of nickel film deposited from sulphamate bath commonly used in microfabrication. For wear ...


Modeling Of Dispersed Phase By Lagrangian Approach In Fluent - 2d Exercise, Kari Myöhänen Jan 2008

Modeling Of Dispersed Phase By Lagrangian Approach In Fluent - 2d Exercise, Kari Myöhänen

Kari Myöhänen

This shows an example calculation applying DPM model in Fluent. This is related to the other DPM presentation and was prepared for the course 'Theory and simulation of dispersed-phase multiphase flows" by Dr. Payman Jalali, Lappeenranta University of Technology.


Modeling Of Dispersed Phase By Lagrangian Approach In Fluent, Kari Myöhänen Jan 2008

Modeling Of Dispersed Phase By Lagrangian Approach In Fluent, Kari Myöhänen

Kari Myöhänen

This is a seminar work prepared for a course 'Theory and simulation of dispersed-phase multiphase flows' by Dr. Payman Jalali, Lappeenranta University of Technology


Use Of Modeling And Simulation In Pulp And, Dr. Erik Dahlquist Jan 2008

Use Of Modeling And Simulation In Pulp And, Dr. Erik Dahlquist

Dr. Erik Dahlquist

The book is a handbook for operators and process engineers in primarily pulp and paper industry, but also other process industries about how to utilise simulation as a tool for enhanced process operations. The book has been written as part of a EU COST action on Process Simulation, with 14 countries and 50 researchers and process industry representatives involved.