Open Access. Powered by Scholars. Published by Universities.®

Digital Commons Network

Open Access. Powered by Scholars. Published by Universities.®

PDF

Mechanical Engineering

Selected Works

2008

Institution
Keyword
Publication

Articles 1 - 30 of 58

Full-Text Articles in Entire DC Network

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.


Edge-Stress Induced Warping Of Graphene Sheets And Nanoribbons, Ashwin Ramasubramaniam, Y. W. Zhang, C. D. Reddy, V. B. Shenoy Nov 2008

Edge-Stress Induced Warping Of Graphene Sheets And Nanoribbons, Ashwin Ramasubramaniam, Y. W. Zhang, C. D. Reddy, V. B. Shenoy

Ashwin Ramasubramaniam

We show that edge stresses introduce intrinsic ripples in freestanding graphene sheets even in the absence of any thermal effects. Compressive edge stresses along zigzag and armchair edges of the sheet cause out-of-plane warping to attain several degenerate mode shapes. Based on elastic plate theory, we identify scaling laws for the amplitude and penetration depth of edge ripples as a function of wavelength. We also demonstrate that edge stresses can lead to twisting and scrolling of nanoribbons as seen in experiments. Our results underscore the importance of accounting for edge stresses in thermal theories and electronic structure calculations for freestanding ...


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 ...


Homogeneous Dbd In N2: 1) Lif, Talif And Electrical Measurements, N. Gherardi, Et. Es-Sebbar, C. Sarra-Bourret, N. Naudé, F. Massines Oct 2008

Homogeneous Dbd In N2: 1) Lif, Talif And Electrical Measurements, N. Gherardi, Et. Es-Sebbar, C. Sarra-Bourret, N. Naudé, F. Massines

Dr. Et-touhami Es-sebbar

In this paper we compare two different discharges that can be obtained in a DBD configuration, that is to say the filamentary discharge (usual regime in atmospheric DBD) with the Atmospheric Pressure Townsend Discharge (APTD), which is a homogeneous regime obtained in nitrogen atmosphere. The aim is to help in the understanding of the processes which control the transition from one regime to the other. To do so, the discharge is characterized through electrical measurements, coupled with optical diagnostics among which Laser Induced Fluorescence (LIF) for radical density measurements. The influence of the addition of small quantities of additives on ...


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 ...


Unsteady Nanoscale Thermal Transport Across A Solid-Fluid Interface, Ganesh Balasubramanian, Soumik Banerjee, Ishwar K. Puri Sep 2008

Unsteady Nanoscale Thermal Transport Across A Solid-Fluid Interface, Ganesh Balasubramanian, Soumik Banerjee, Ishwar K. Puri

Ganesh Balasubramanian

We simulate unsteady nanoscale thermal transport at a solid-fluidinterface by placing cooler liquid-vapor Ar mixtures adjacent to warmer Fe walls. The equilibration of the system towards a uniform overall temperature is investigated using nonequilibrium molecular dynamics simulations from which the heat flux is also determined explicitly. The Ar–Fe intermolecular interactions induce the migration of fluid atoms into quasicrystallineinterfacial layers adjacent to the walls, creating vacancies at the migration sites. This induces temperature discontinuities between the solidlikeinterfaces and their neighboring fluid molecules. The interfacial temperature difference and thus the heat flux decrease as the system equilibrates over time. The averaged ...


Active Species Generation Of Homogeneous Dbd In N2: Experiment And Modelling, N. Gherardi, Et. Es-Sebbar, C. Sarra-Bourret, N. Naudé, F. Massines, D. Tzyganov, P. Ségur, S. Pancheshnyi Sep 2008

Active Species Generation Of Homogeneous Dbd In N2: Experiment And Modelling, N. Gherardi, Et. Es-Sebbar, C. Sarra-Bourret, N. Naudé, F. Massines, D. Tzyganov, P. Ségur, S. Pancheshnyi

Dr. Et-touhami Es-sebbar

No abstract provided.


A Heuristic Scheduling Scheme In Multiuser Ofdma Networks, Zheng Sun, Zhiqiang He, Ruochen Wang, Kai Niu Aug 2008

A Heuristic Scheduling Scheme In Multiuser Ofdma Networks, Zheng Sun, Zhiqiang He, Ruochen Wang, Kai Niu

Zheng Sun

Conventional heterogeneous-traffic scheduling schemes utilize zero-delay constraint for real-time services, which aims to minimize the average packet delay among real-time users. However, in light or moderate load networks this strategy is unnecessary and leads to low data throughput for non-real-time users. In this paper, we propose a heuristic scheduling scheme to solve this problem. The scheme measures and assigns scheduling priorities to both real-time and non-real-time users, and schedules the radio resources for the two user classes simultaneously. Simulation results show that the proposed scheme efficiently handles the heterogeneous-traffic scheduling with diverse QoS requirements and alleviates the unfairness between real-time ...


Production And Purification Of Zircon Opacifier From Zircon Found In The Coastal Area Of Bangladesh, Haseeb Asma Aug 2008

Production And Purification Of Zircon Opacifier From Zircon Found In The Coastal Area Of Bangladesh, Haseeb Asma

Haseeb ASMA

In this study the potentiality of Bangladesh zircon as a raw material for opacifier was examined. Preparation of zircon flour was done by both wet and dry ball milling. Wet milling of zircon was found to be much efficient than dry milling. Zircon flour of peak size 8 mu m obtained by wet milling was purified by leaching in concentrated H(2)SO(4) acid. Leaching time was varied from 2 to 20 h and sulphuric acid concentration ranged from 10 to 80 ml/l. Both un-purified and purified Bangladesh zircon flour were tested for their performance as opacifier in ...


Production And Purification Of Zircon Opacifier From Zircon Found In The Coastal Area Of Bangladesh Aug 2008

Production And Purification Of Zircon Opacifier From Zircon Found In The Coastal Area Of Bangladesh

A.S. Md Abdul Haseeb

In this study the potentiality of Bangladesh zircon as a raw material for opacifier was examined. Preparation of zircon flour was done by both wet and dry ball milling. Wet milling of zircon was found to be much efficient than dry milling. Zircon flour of peak size 8 μm obtained by wet milling was purified by leaching in concentrated H2SO4 acid. Leaching time was varied from 2 to 20 h and sulphuric acid concentration ranged from 10 to 80 ml/l. Both un-purified and purified Bangladesh zircon flour were tested for their performance as opacifier in a couple of local ...


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 ...


Sum Frequency Generation Vibrational Spectroscopy Of Pyridine Hydrogenation On Platinum Nanoparticles, Kaitlin M. Bratlie, Kyriakos Komvopoulos, Gabor A. Somorjai Aug 2008

Sum Frequency Generation Vibrational Spectroscopy Of Pyridine Hydrogenation On Platinum Nanoparticles, Kaitlin M. Bratlie, Kyriakos Komvopoulos, Gabor A. Somorjai

Kaitlin M. Bratlie

Pyridine hydrogenation in the presence of a surface monolayer consisting of cubic Pt nanoparticles stabilized by tetradecyltrimethylammonium bromide (TTAB) was investigated by sum frequency generation (SFG) vibrational spectroscopy using total internal reflection (TIR) geometry. TIR-SFG spectra analysis revealed that a pyridinium cation (C5H5NH+) forms during pyridine hydrogenation on the Pt nanoparticle surface, and the NH group in the C5H5NH+ cation becomes more hydrogen bound with the increase of the temperature. In addition, the surface coverage of the cation decreases with the increase of the temperature. An important contribution of this study is the in situ identification of reaction intermediates adsorbed ...


Uncertainty Analysis In Mcp-Based Wind Resource Assessment And Energy Production Estimation, Matthew Lackner, Anthony L. Rogers, James F. Manwell Aug 2008

Uncertainty Analysis In Mcp-Based Wind Resource Assessment And Energy Production Estimation, Matthew Lackner, Anthony L. Rogers, James F. Manwell

Matthew Lackner

This paper presents a mathematical framework to properly account for uncertainty in wind resource assessment and wind energy production estimation. A meteorological tower based wind measurement campaign is considered exclusively, in which measurecorrelate- predict is used to estimate the long-term wind resource. The evaluation of a wind resource and the subsequent estimation of the annual energy production (AEP) is a highly uncertain process. Uncertainty arises at all points in the process, from measuring the wind speed to the uncertainty in a power curve. A proper assessment of uncertainty is critical for judging the feasibility and risk of a potential wind ...


Surface Ion-Electron Recombination As The Main Source Of Atoms In Flowing N2 Dbd, D. Tsyganov, Et. Es-Sebbar, S. Pancheshnyi, N. Gherardi, P. Ségur, F. Massines Jul 2008

Surface Ion-Electron Recombination As The Main Source Of Atoms In Flowing N2 Dbd, D. Tsyganov, Et. Es-Sebbar, S. Pancheshnyi, N. Gherardi, P. Ségur, F. Massines

Dr. Et-touhami Es-sebbar

No abstract provided.


Talif Quantification Of Nitrogen Atoms Applied To Experimental Simulation Of Titan’S Atmosphere, Et. Es-Sebbar, Y. Benilan, E. Arzoumanian, M.-C. Gazeau Jul 2008

Talif Quantification Of Nitrogen Atoms Applied To Experimental Simulation Of Titan’S Atmosphere, Et. Es-Sebbar, Y. Benilan, E. Arzoumanian, M.-C. Gazeau

Dr. Et-touhami Es-sebbar

No abstract provided.


S.E.T.U.P., A New Program Of Representative Simulations Of Titan’S Atmosphere: Current Status, M-C. Gazeau, E. Arzoumanian, Y. Benilan, Et. Es-Sebbar, A. Jolly, S. Perrier, C. Romanzin Jul 2008

S.E.T.U.P., A New Program Of Representative Simulations Of Titan’S Atmosphere: Current Status, M-C. Gazeau, E. Arzoumanian, Y. Benilan, Et. Es-Sebbar, A. Jolly, S. Perrier, C. Romanzin

Dr. Et-touhami Es-sebbar

No abstract provided.


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 ...


Comparison Of Townsend Dielectric Barrier Discharge In N2, N2/O2 And N2/N2o: Behavior And Density Of Radicals, F. Massines, Et. Es-Sebbar, N. Gherardi, N. Naudé, D. Tsyganov, P. Ségur, S. Pancheshnyi Jun 2008

Comparison Of Townsend Dielectric Barrier Discharge In N2, N2/O2 And N2/N2o: Behavior And Density Of Radicals, F. Massines, Et. Es-Sebbar, N. Gherardi, N. Naudé, D. Tsyganov, P. Ségur, S. Pancheshnyi

Dr. Et-touhami Es-sebbar

No abstract provided.


Dual Beam Actuation Of Piezoelectric Aln Rf Mems Switches Integrated With Aln Contour-Mode Resonators, Nipun Sinha, Rashed Mahamameed, Chengjie Zuo, Marcelo B. Pisani, Carlos R. Perez, Gianluca Piazza Jun 2008

Dual Beam Actuation Of Piezoelectric Aln Rf Mems Switches Integrated With Aln Contour-Mode Resonators, Nipun Sinha, Rashed Mahamameed, Chengjie Zuo, Marcelo B. Pisani, Carlos R. Perez, Gianluca Piazza

Nipun Sinha

This work reports on piezoelectric Aluminum Nitride (AlN) based dual-beam RF MEMS switches that have been monolithically integrated with AlN contour-mode resonators. The dual-beam switch design presented in this paper intrinsically compensates for the residual stress in the deposited films, requires low actuation voltage (5-20 V), facilitates active pull-off to open the switch and fast switching times (1 to 2 µsec). This work also presents the combined response (cascaded S-parameters) of a resonator and a switch that were co-fabricated on the same substrate. The response shows that the resonator can be effectively turned on and off by the switch. A ...


Dual Beam Actuation Of Piezoelectric Aln Rf Mems Switches Integrated With Aln Contour-Mode Resonators, Nipun Sinha, Rashed Mahamameed, Chengjie Zuo, Marcelo B. Pisani, Carlos R. Perez, Gianluca Piazza Jun 2008

Dual Beam Actuation Of Piezoelectric Aln Rf Mems Switches Integrated With Aln Contour-Mode Resonators, Nipun Sinha, Rashed Mahamameed, Chengjie Zuo, Marcelo B. Pisani, Carlos R. Perez, Gianluca Piazza

Marcelo B Pisani

This work reports on piezoelectric Aluminum Nitride (AlN) based dual-beam RF MEMS switches that have been monolithically integrated with AlN contour-mode resonators. The dual-beam switch design presented in this paper intrinsically compensates for the residual stress in the deposited films, requires low actuation voltage (5-20 V), facilitates active pull-off to open the switch and fast switching times (1 to 2 µsec). This work also presents the combined response (cascaded S-parameters) of a resonator and a switch that were co-fabricated on the same substrate. The response shows that the resonator can be effectively turned on and off by the switch. A ...


Fuel Taxation And Social Policy, Theodoros Zachariadis Jun 2008

Fuel Taxation And Social Policy, Theodoros Zachariadis

Theodoros Zachariadis

No abstract provided.


Writing Research Proposal: Literature Review And Database Search, Mamoudou H. Dicko Prof. May 2008

Writing Research Proposal: Literature Review And Database Search, Mamoudou H. Dicko Prof.

Pr. Mamoudou H. DICKO, PhD

The maiden proposed research project should demonstrate that the present study will add a significant knowledge on the subject. The main objective of the literature research is to allow that the statement of the research need will clearly establish the objective of the new study.


Criteria On Utility Designing Of Convex Optimization In Fdma Networks, Zheng Sun, Wenjun Xu, Zhiqiang He, Kai Niu Apr 2008

Criteria On Utility Designing Of Convex Optimization In Fdma Networks, Zheng Sun, Wenjun Xu, Zhiqiang He, Kai Niu

Zheng Sun

In this paper, we investigate the network utility maximization problem in FDMA systems. We summarize with a suite of criteria on designing utility functions so as to achieve the global optimization convex. After proposing the general form of the utility functions, we present examples of commonly used utility function forms that are consistent with the criteria proposed in this paper, which include the well-known proportional fairness function and the sigmoidal-like functions. In the second part of this paper, we use numerical results to demonstrate a case study based on the criteria mentioned above, which deals with the subcarrier scheduling problem ...


Measurement And Analysis Of Vitiation Of Secondary Air In Air Distribution Systems (Rp-1276), David P. Yuill, Grenville K. Yuill, Andrew H. Coward Apr 2008

Measurement And Analysis Of Vitiation Of Secondary Air In Air Distribution Systems (Rp-1276), David P. Yuill, Grenville K. Yuill, Andrew H. Coward

David Yuill

Appendix A of ANSI/ASHRAE Standard 62.1-2007, Ventilation for Acceptable Indoor Air Quality, describes the recycling of unvitiated ventilation air in a recirculating air-handling system. Equation A-2 considers air delivered through the primary air path (central air distribution system) and secondary air paths, such as fan-powered boxes or transfer-air fans. It contains a variable, Er, that describes the extent to which the secondary air comes from the zone in question, as opposed to coming from “average system return air.” This paper describes the development of an equation that can be used to quantify Er, and shows the results of ...


7 - تأثير نوع پوشش محوطه اطراف ساختمان بر مصرف سالانه انرژي, Alireza Zolfaghari, Mehdi Maerefat Apr 2008

7 - تأثير نوع پوشش محوطه اطراف ساختمان بر مصرف سالانه انرژي, Alireza Zolfaghari, Mehdi Maerefat

Dr Alireza Zolfaghari

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.


Three-Dimensional Data Merging Using Holoimage, Song Zhang, Shing-Tung Yau Mar 2008

Three-Dimensional Data Merging Using Holoimage, Song Zhang, Shing-Tung Yau

Song Zhang

Three-dimensional data merging is vital for full-field three-dimensional (3D) shape measurement. All 3D range data patches, acquired from either different sensors or the same sensor in different viewing angles, have to be merged into a single piece to facilitate future data analysis. A novel method for 3D data merging using Holoimage is proposed. Similar to the 3D shape measurement system using a phase-shifting method, Holoimage is a phase-shifting–based computer synthesized fringe image. The 3D information is retrieved from Holoimage using a phase-shifting method. If two patches of 3D data with overlapping areas are rendered by OpenGL, the overlapping areas ...


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