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Full-Text Articles in Mechanical Engineering

Investigation Of The Convective Heat Transfer Coefficient Of The Hand And Fingers In Firefighter Gloves Using A Thermal Hand, Jie Yang, Li Wang, Weiwei Chen, Rui Li, Liwen Wang, Huanjiao Dong, Chunhui Xiang, Akm Mashud Alam, Guowen Song Jan 2018

Investigation Of The Convective Heat Transfer Coefficient Of The Hand And Fingers In Firefighter Gloves Using A Thermal Hand, Jie Yang, Li Wang, Weiwei Chen, Rui Li, Liwen Wang, Huanjiao Dong, Chunhui Xiang, Akm Mashud Alam, Guowen Song

International Textile and Apparel Association (ITAA) Annual Conference Proceedings

The heat transfer coefficients of the hands are critical inputs of the thermoregulation model that can simulate thermal responses of the hand and fingers. Besides, the hand has a greater surface area to mass ratio and complex anthropometric parameters, thus is extremely important in heat transfer and thermoregulation.

However, the convective heat transfer coefficients of the fingers, palm, and dorsal of the hand are not fully investigated and understood. Accordingly, there is an urgent need for full understanding of the convective heat transfer coefficients in both the whole-hand and regional segments. The results of this study will provide guidance for ...


Phased Array Ultrasonic Inspection Method For Homogeneous Tube Inspection Over Wide Oblique Angle Range, Benoit Lepage, Guillaume Painchaud-April Jan 2016

Phased Array Ultrasonic Inspection Method For Homogeneous Tube Inspection Over Wide Oblique Angle Range, Benoit Lepage, Guillaume Painchaud-April

Review of Progress in Quantitative Nondestructive Evaluation

As seamless tube manufacturers push quality requirements for their products, automated phased array Rotating Tube Inspection Systems (RTIS) are now required to provide continuous NDE detection performances over a wide angular range of oblique flaws. One major impact of this new reality is a paradigm shift for the calibration method driven by the requirement to meet homogeneous detection over broad oblique flaw angle intervals, whereas standard practice only requires calibration at specific discrete angles. An innovative method specifically designed to obtain high productivity and homogeneous inspection measurements over an oblique flaw range extending from -45 to 45 degrees is presented ...


Cellulose–Hemicellulose And Cellulose–Lignin Interactions During Fast Pyrolysis, Jing Zhang, Yong S. Choi, Chang G. Yoo, Tae H. Kim, Robert C. Brown, Brent H. Shanks Jan 2015

Cellulose–Hemicellulose And Cellulose–Lignin Interactions During Fast Pyrolysis, Jing Zhang, Yong S. Choi, Chang G. Yoo, Tae H. Kim, Robert C. Brown, Brent H. Shanks

Chemical and Biological Engineering Publications

Previously, the primary product distribution resulting from fast pyrolysis of cellulose, hemicellulose, and lignin was quantified. This study extends the analysis to the examinations of interactions between cellulose–hemicellulose and cellulose–lignin, which were determined by comparing the pyrolysis products from their native mixture, physical mixture, and superposition of individual components. Negligible interactions were found for both binary physical mixtures. For the native cellulose–hemicellulose mixture, no significant interaction was identified either. In the case of the native cellulose–lignin mixture, herbaceous biomass exhibited an apparent interaction, represented by diminished yield of levoglucosan and enhanced yield of low molecular weight ...


Ultrasound-Assisted Synthesis Of Mesoporous Β-Ni(Oh)2 And Nio Nano-Sheets Using Ionic Liquids, Tarek Alammar, Osama Shekhah, Jonas Wohlgemuth, Anja V. Mudring Jan 2012

Ultrasound-Assisted Synthesis Of Mesoporous Β-Ni(Oh)2 And Nio Nano-Sheets Using Ionic Liquids, Tarek Alammar, Osama Shekhah, Jonas Wohlgemuth, Anja V. Mudring

Anja V. Mudring

Via a facile ultrasound synthesis from nickel acetate and sodium hydroxide with ionic liquids as the solvent and template it is possible to obtain nano-β-Ni(OH)2 of various dimensionalities depending on the reaction conditions with the ionic liquid (IL) being the most important factor. Scanning electron microscopy (SEM) imaging showed β-Ni(OH)2 to form as nanosheets, nanorods and nanospheres depending on the IL. ILs with strong to moderate hydrogen bonding capability like [C3mimOH][Tf2N] (1-(3-hydroxypropyl)-3-methylimidazolium bis(trifluoromethanesulfonylamide)), [C4mim][Tf2N] (1-butyl-3-methylimidazolium bis(trifluoromethanesulfonylamide)) and [Edimim][Tf2N] (1-ethyl-2,3-diemethylimidazolium bis(trifluoromethanesulfonylamide)) lead to the formation of nanosheets whilst ...


Melting Point Suppression In New Lanthanoid(Iii) Ionic Liquids By Trapping Of Kinetic Polymorphs: An In Situsynchrotron Powder Diffraction Study, Anthony S.R. Chesman, Mei Yang, Bert Mallick, Tamsyn M. Ross, Ian A. Gass, Glen B. Deacon, Stuart R. Batten, Anja V. Mudring Jan 2012

Melting Point Suppression In New Lanthanoid(Iii) Ionic Liquids By Trapping Of Kinetic Polymorphs: An In Situsynchrotron Powder Diffraction Study, Anthony S.R. Chesman, Mei Yang, Bert Mallick, Tamsyn M. Ross, Ian A. Gass, Glen B. Deacon, Stuart R. Batten, Anja V. Mudring

Anja V. Mudring

he inclusion of lanthanoids in ionic liquids (ILs) offers an ideal route to incorporate their unique luminescent and magnetic properties into a bulk solution.1,2 However, lanthanoid compounds often exhibit a poor solubility in commonly used ILs because the IL anions are typically very weakly coordinating, prohibiting the simple dissolution of a lanthanoid salt by complexation to any beneficial extent.2 One strategy used to achieve high lanthanoid concentrations is to incorporate the lanthanoid cation directly into an anion that will form ILs.3 This is best accomplished by employing a ligand which readily coordinates to a lanthanoid atom ...


Broadband Measurement Of Rate-Dependent Viscoelasticity At Nanoscale Using Scanning Probe Microscope: Poly(Dimethylsiloxane) Example, Zhonghua Xu, Kyongsoo Kim, Qingze Zou, Pranav Shrotriya Sep 2008

Broadband Measurement Of Rate-Dependent Viscoelasticity At Nanoscale Using Scanning Probe Microscope: Poly(Dimethylsiloxane) Example, Zhonghua Xu, Kyongsoo Kim, Qingze Zou, Pranav Shrotriya

Mechanical Engineering Publications

A control approach to achieve nanoscale broadband viscoelasticmeasurement using scanning probe microscope(SPM) is reported. Current SPM-based force measurement is too slow to measure rate-dependent phenomena, and large (temporal) measurement errors can be generated when the sample itself changes rapidly. The recently developed model-less inversion-based iterative control technique is used to eliminate the dynamics and hysteresis effects of the SPM hardware on the measurements, enabling rapid excitation and measurement of rate-dependent material properties. The approach is illustrated by the mechanical characterization of poly(dimethylsiloxane) over a broad frequency range of three orders of magnitude (∼1 Hz to 4.5 KHz).


Effect Of Sample Aging On The Accuracy Of The International Energy Agency's Tar Measurement Protocol, Ming Xu, Robert C. Brown, Glenn Norton Jan 2006

Effect Of Sample Aging On The Accuracy Of The International Energy Agency's Tar Measurement Protocol, Ming Xu, Robert C. Brown, Glenn Norton

Mechanical Engineering Publications

The Working Group of the Biomass Gasification Task of the International Energy Agency (IEA) Bioenergy Agreement has developed a protocol for sampling and analysis of tar and particulates from biomass gasifiers, which is commonly accepted as a standard for reliable measurement of tar in producer gas. The methodology is dependent upon dissolving tar in a solvent for subsequent recovery by evaporation or distillation. This paper investigates whether storage of the tar/solvent sample prior to analysis affects the accuracy of the tar measurement. On the basis of the results of this study, we recommend that samples be analyzed within a ...


Line-Focus Acoustic Mcroscopy Measurements Of Thin-Film Elastic Constants, Jin O. Kim, Jan D. Achenbach Jan 1993

Line-Focus Acoustic Mcroscopy Measurements Of Thin-Film Elastic Constants, Jin O. Kim, Jan D. Achenbach

Review of Progress in Quantitative Nondestructive Evaluation

Thin film materials are widely used as hard, protective coatings for softer surfaces. It is known that fracture strength and hardness are related to the elastic and plastic properties [1]. The elastic constants of the film deposited on a substrate are, however, difficult to measure. By a technique which was recently discussed [2] the elastic constants of amorphous (isotropic) films and single-crystal (anisotropic) films can be obtained by measuring the velocities of surface acoustic waves (SAWs) propagating over a thin-film/ substrate specimen by the use of a line-focus acoustic microscope.


A Reflection Ultrasonic Interference Method For Measurement Of The Acoustic Velocity Of Thin Layers, D. K. Mak, G. Langlois Jan 1993

A Reflection Ultrasonic Interference Method For Measurement Of The Acoustic Velocity Of Thin Layers, D. K. Mak, G. Langlois

Review of Progress in Quantitative Nondestructive Evaluation

Ultrasonic waves can be used to measure the velocities and other properties of a material layer by determining the difference in the time-of-flight of the successive echoes from the backwall of the layer. The top and bottom surfaces must be sufficiently far apart for the successive echoes to be distinct. This method can be used to measure the velocity of a protective epoxy layer on a pipeline wall to determine the deviation of an ultrasonic wave scattered from a defect. It has been used to determine the strength of adhesive bonds [1].


Ultrasonic Attenuation Of Water-Infiltrated Thermal Barrier Coatings, Joachim Bamberg, Heinz Schmitt Jan 1993

Ultrasonic Attenuation Of Water-Infiltrated Thermal Barrier Coatings, Joachim Bamberg, Heinz Schmitt

Review of Progress in Quantitative Nondestructive Evaluation

For advanced aircraft gas-turbine engines greater efficiencies and higher thrust are demanded. One possibility to achieve this is to increase the gas temperature at the turbine-section. Then thermal barrier coatings are necessary to protect the metallic structures.


Thermal Coating Characterization Using Thermoelasticity, Christopher S. Welch, Michael J. Zickel Jan 1993

Thermal Coating Characterization Using Thermoelasticity, Christopher S. Welch, Michael J. Zickel

Review of Progress in Quantitative Nondestructive Evaluation

Synchronous demodulation techniques have been used for some time to measure thermal radiation produced by the small temperature changes associated with elastic stress in materials, the thermoelastic effect[l]. As reviewed in [2], these measurements have been employed primarily for inferring stress distributions in materials from the associated temperature distributions. Images of stress distribution have been made most often by assembling a large number of individual synchronous component measurements using specialized equipment [3]. Other investigators [4,5] have used subtraction of stroboscopic samples to build up similar images. Recently, techniques using full-field synchronous demodulation [6,7] have been reported using ...


Fast Photothermal Inspection Of Plasma-Sprayed Coatings Of Primary Circulation Seal Rings Of A Nuclear Reactor. Part Two: After The Trial Run, R. Lehtiniemi, J. Hartikainen, J. Rantala, J. Varis, M. Luukkala Jan 1993

Fast Photothermal Inspection Of Plasma-Sprayed Coatings Of Primary Circulation Seal Rings Of A Nuclear Reactor. Part Two: After The Trial Run, R. Lehtiniemi, J. Hartikainen, J. Rantala, J. Varis, M. Luukkala

Review of Progress in Quantitative Nondestructive Evaluation

In the 1991 QNDE conference [1] we described a photothermal inspection of the plasma-sprayed coatings of two seal rings used in the main pump of the primary circulation in the PWR-type nuclear reactor. The measurements concentrated on detecting the most critical flaw type, adhesion defects at the interface between the coating and the substrate. The samples were tested immediately after they were coated and lapped, and already then two thermal anomalies could be found.