Mechanical Engineering Commons^™

Numerical-Analytical Assessment On Solar Chimney Power Plant, Nima Fathi, Seyed Sobhan Aleyasin, Peter Vorobieff

Nima Fathi

Muscle Synergies Improve Estimation Of Knee Contact Forces During Walking, Benjamin Fregly, Jonathan Walter, Allison Kinney, Scott Banks, Darryl D'Lima, Thor Besier, David Lloyd

Allison Kinney

This study investigates whether use of subject-specific muscle synergies can improve optimization predictions of muscle excitation patterns and knee contact forces during walking. Muscle synergies describe how a small number of neural commands generated by the nervous system can be linearly combined to produce the broad range of muscle electromyographic (EMG) signals measured experimentally. By quantifying the interdependence of individual EMG signals, muscle synergies provide dimensionality reduction for the neural control redundancy problem. Our hypothesis was that use of subjectspecific muscle synergies to limit muscle excitation patterns would improve prediction of muscle EMG patterns at the hip, knee, and ankle …

Muscle Synergy Constraints Improve Prediction Of Knee Contact Force During Gait, Benjamin Fregly, Jonathan Walter, Allison Kinney, Scott Banks, Darryl D'Lima, Thor Besier, David Lloyd

Allison Kinney

Knowledge of patient-specific muscle and joint contact forces during activities of daily living could improve the treatment of movement-related disorders (e.g., osteoarthritis, stroke, cerebral palsy, Parkinson’s disease). Unfortunately, it is currently impossible to measure these quantities directly under common clinical conditions, and calculation of these quantities using computer models is limited by the redundant nature of human neural control (i.e., more muscles than theoretically necessary to actuate the available degrees of freedom in the skeleton). Walking is a particularly important task to understand, since loss of mobility is associated with increased morbidity and decreased quality of life. Though numerous musculoskeletal …

Evaluation Of Different Optimal Control Problem Formulations For Solving The Muscle Redundancy Problem, Friedl De Groote, Allison Kinney, Anil Rao, Benjamin Fregly

Allison Kinney

This study evaluates several possible optimal control problem formulations for solving the muscle redundancy problem with the goal of identifying the most efficient and robust formulation. One novel formulation involves the introduction of additional controls that equal the time derivative of the states, resulting in very simple dynamic equations. The nonlinear equations describing muscle dynamics are then imposed as algebraic constraints in their implicit form, simplifying their evaluation. By comparing different problem formulations for computing muscle controls that can reproduce inverse dynamic joint torques during gait, we demonstrate the efficiency and robustness of the proposed novel formulation.

Material Properties And Microstructural Characterization Of Specimens, T.J. Silverman, Allison Kinney, B. South, W. Yong, J.H. Koo

Allison Kinney

The HiQ upgrade to the 3D Systems Vanguard selective laser sintering (SLS) machine incorporates a revised thermal calibration system and new software. This paper quantifies differences in mechanical and morphological properties of specimens built first using a Vanguard HS (high-speed) system and again using the same system with the HiQ upgrade applied. Standard specimens are built from DuraForm PA material and tested for tensile modulus, tensile strength, elongation at break, flexural modulus and Izod impact strength. The design of the specimen battery, the conduction of the tests and the significance of the results are discussed. The upgrade is found to …

Synergies Controls Improve Prediction Of Knee Contact Forces And Muscle Excitations During Gait, Benjamin Fregly, Jonathan Walter, Allison Kinney, Scott Banks, Darryl D'Lima, Thor Besier, David Lloyd

Allison Kinney

This study investigates whether use of muscle excitation controls constructed from subjectspecific muscle synergy information can improve optimization prediction of knee contact forces and muscle excitations during walking. Muscle synergies quantify how a large number of experimental muscle electromyographic (EMG) signals can be reconstructed by linearly mixing a much smaller number of neural commands generated by the nervous system. Our hypothesis was that controlling all muscle excitations with a small set of experimentally calculated neural commands would improve prediction of knee contact forces and leg muscle excitations compared to using independently controlled muscle excitations.

Comparison Of Material Properties And Microstructure Of Specimens Built Using The 3d Systems Vanguard Hs And Vanguard Hiq+Hs Sls Systems, T.J. Silverman, Allison Kinney, W. Yong, J.H. Koo

Allison Kinney

The HiQ upgrade to the 3D Systems Vanguard selective laser sintering (SLS) machine incorporates a revised thermal calibration system and new control software. The paper compares the tensile modulus, tensile strength, elongation at break, flexural modulus, Izod impact resistance and microstructure of two batteries of standard specimens built from recycled Duraform PA (Nylon 12). The first set is built on a Vanguard HS system and the second on the same system with the HiQ upgrade installed. The upgrade reduces user intervention, decreases total build time and improves surface finish. However, using the default processing parameters, tensile, flexure and impact properties …

U.S. Billion-Ton Update: Biomass Supply For A Bioenergy And Bioproducts Industry, Robert D. Perlack, Laurence M. Eaton, Anthony F. Turhollow Jr., Matt H. Langholtz, Craig C. Brandt, Mark E. Downing, Robin L. Graham, Lynn L. Wright, Jacob M. Kavkewitz, Anna M. Shamey, Richard G. Nelson, Bryce J. Stokes, William L. Rooney, David J. Muth Jr., J. Richard Hess, Jared M. Abodeely, Chad Hellwinckel, Danial De La Torre Ugarte, Daniel C. Yoder, James P. Lyon, Timothy G. Rials, Timothy A. Volk, Thomas S. Buchholz, Lawrence P. Abrahamson, Robert P. Anex, Thomas B. Voigt, William Berguson, Don E. Riemenschneider, Douglas Karlen, Jane M. F. Johnson, Robert B. Mitchell, Kenneth P. Vogel, Edward P. Richard Jr., John Tatarko, Larry E. Wagner, Kenneth E. Skog, Patricia K. Lebow, Dennis P. Dykstra, Marilyn A. Buford, Patrick D. Miles, D. Andrew Scott, James H. Perdue, Robert B. Rummer, Jamie Barbour, John A. Stanturf, David B. Mckeever, Ronald S. Zalesny Jr., Edmund A. Gee, P. Daniel Cassidy, David Lightle

Douglas L Karlen

The Report, Biomass as Feedstock for a Bioenergy and Bioproducts Industry: The Technical Feasibility of a Billion-Ton Annual Supply (generally referred to as the Billion-Ton Study or 2005 BTS), was an estimate of “potential” biomass within the contiguous United States based on numerous assumptions about current and future inventory and production capacity, availability, and technology. In the 2005 BTS, a strategic analysis was undertaken to determine if U.S. agriculture and forest resources have the capability to potentially produce at least one billion dry tons of biomass annually, in a sustainable manner—enough to displace approximately 30% of the country’s present petroleum …

A Platinum Nanowire Network As A Highly Effective Current Collector For Intermediate Temperature Solid Oxide Fuel Cells, Hanping Ding, Xingjian Xue

Xingjian "Chris" Xue

We report the fabrication and evaluation of a platinum nanowire network as a highly efficient current collector for solid oxide fuel cells (SOFCs). The ink of carbon-black supported platinum nanoparticles was sprayed onto the cathode. After firing, the carbon black was oxidized and disappeared as carbon dioxide gas while the platinum nanoparticles connect with one another, forming a tree-branch-like nanowire network. The diameters of the nanowires range from 100 nm to 400 nm. Compared to a conventional platinum paste current collector, the polarization resistance of the PrBaCo₂O_5+δ (PBCO) cathode with a nanowire current collector was reduced …

A Platinum Nanowire Network As A Highly Effective Current Collector For Intermediate Temperature Solid Oxide Fuel Cells, Hanping Ding, Xingjian Xue

Xingjian "Chris" Xue

We report the fabrication and evaluation of a platinum nanowire network as a highly efficient current collector for solid oxide fuel cells (SOFCs). The ink of carbon-black supported platinum nanoparticles was sprayed onto the cathode. After firing, the carbon black was oxidized and disappeared as carbon dioxide gas while the platinum nanoparticles connect with one another, forming a tree-branch-like nanowire network. The diameters of the nanowires range from 100 nm to 400 nm. Compared to a conventional platinum paste current collector, the polarization resistance of the PrBaCo2O5+δ (PBCO) cathode with a nanowire current collector was reduced by 44% at 650 …

الگو و دستورالعمل تهيه و تدوين پايان نامه کارشناسي ارشد, Dr Alireza Zolfaghari

Dr Alireza Zolfaghari

No abstract provided.

Umass Amherst Green Building Guidelines 2013, Ludmilla Pavlova-Gillham, Ted Mendoza, Ezra Small, Patricia O'Flaherty, Nariman Mostafavi, Mohamed Farzinmoghadam, Somayeh Tabatabaee Pozveh

Ludmilla D Pavlova

Facilities & Campus Services, Sustainable UMass and Campus Planning support sustainability and energy conservation initiatives by providing in-house resources to campus staff as well as designers and contractors working with the University. The UMass Amherst Green Building Guidelines provide a framework for approaching new construction and major renovation projects at UMass Amherst that are undergoing LEED certification by focusing the conversation on green building aspects that are most important to the campus. They are intended to be the beginning of a dynamic conversation between designers, environmental consultants and constructors, university stakeholders, and users of new high performance buildings.

Umass Amherst Energy Modeling Guidelines, Nariman Mostafavi, Ted Mendoza, Jeffrey G. Quackenbush, Sandy J. Beauregard, Jason J. Burbank, Mohamad Farzinmoghadam, Ludmilla Pavlova-Gillham, Kylie A. Landrey

Ludmilla D Pavlova

Facilities & Campus Services, Sustainable UMass and Campus Planning support sustainability and energy conservation initiatives by providing in-house resources to campus staff as well as designers and contractors working with the University. The Campus energy Modeling Guidelines were developed in 2015 as a resource on how to: i) generate energy models for campus buildings; ii) provide quality assurance review of current energy models; and iii) share UMass Amherst energy modeling input parameters with project design teams for them to establish a baseline building energy profile.

University Of Massachusetts Amherst 2012-2021 Capital Improvement Projects, Douglas Vigneau, Juanita Holler, John Mathews, Ludmilla Pavlova-Gillham, Ezra Small

Ludmilla D Pavlova

In 2013 the University of Massachusetts, on behalf of the University of Massachusetts Building Authority and Massachusetts Division of Capital Asset Management and Maintenance (DCAMM), submitted an Expanded Environmental Notification Form for the University's 2012 - 2021 Capital Improvement Plan to the Executive Office of Energy and Environmental Affairs (EOEEA) Massachusetts Environmental Policy Act Office (MEPA). Taken individually, the majority of the Projects, comprising of 13 building/space, 7 site/landscape, and 5 facility/ utility scale improvement projects, do not require MEPA review as most of the Project sites are confined to infill areas on campus that are currently or have been …

Entrochemical Thermal Battery Design For Atmospheric Heat Collectors

Sanza Kazadi

Low Cost Solar Chimney Performance-Improving Enhancement, Sanza Kazadi, Meishan Liang, Aaron Togelang, Daniel Chan

Sanza Kazadi

Effects Of Heat-Treatments On Tensile Strength And Electrical Conductivity Of Locally Formulated Al-Ni Alloys, R. A. Muriana, O. K. Abubakre, S. B. Tajiri

Innovative Research Publications IRP India

This Paper investigated effects of annealing and age hardening on the ultimate tensile strength (UTS) and electrical conductivity of aluminium-nickel cast using sand mould. Pure aluminium melt was alloyed with nickel, which was added in 2% to 10% step 2. Annealing and age hardenings were carried out and obtained results showed that Al-2%Ni alloy has the highest UTS of 604.44MPa. On the other hand, Al-6%Ni Annealed alloy has the highest electrical conductivity, with a value of 6.15 × 107 S/m. The Al-4%Ni alloy combined both high strength and conductivity, having UTS of 603.28MPa and electrical conductivity of 5.69 × 107 …

Rational Design Of Mixed Ionic And Electronic Conducting Perovskite Oxides For Solid Oxide Fuel Cell Anode Materials: A Case Study For Doped Srtio3, Suwit Suthirakun, Guoliang Xiao, Salai Ammal, Fanglin Chen, Hans-Conrad Zur Loye, Andreas Heyden

Salai C. Ammal

No abstract provided.

Mechanism Of Sulfur Poisoning Of Sr2Fe1.5Mo0.5O6-Δ Perovskite Anode Under Solid Oxide Fuel Cell Conditions, Eric Walker, Salai Ammal, Suwit Suthirakun, Fanglin Chen, Gabriel Terejanu, Andreas Heyden

Salai C. Ammal

No abstract provided.

Modeling And Experiment Of Solar Crop Dryer For Rural Application, Dawit Abay Tesfamariam, Mulu Bayray Kahsay, Meseret Tesfay Kahsay, Ftwi Yohaness Hagos

Ftwi Yohaness Hagos

An indirect passive convectional solar dryer consisting of a solar air heater and dryer chamber is designed, manufactured and tested for its performance. It plays a major role in reducing crop wastage and opens a way to food preservation. The area of the solar collector required to dry a batch of 10 kg of tomato within two days is calculated. The performance of the collector is improved through the use corrugated absorber to create turbulence for air flow and a highly insulating material to minimize heat losses. The thermal performance of the solar dryer is tested under the local weather …

Effects Of Nano Additives On Hydrogen Storage Behavior Of The Multinary Complex Hydride Libh4/Linh2/Mgh2., Sesha Srinivasan, Michael Niemann, Jason Hattrick-Simpers, Kimberly Mcgrath, Prakash Sharma, D. Goswami, Elias Stefanakos

Jason R. Hattrick-Simpers

No abstract provided.

Development Of Combined Optical Cell And Sieverts-Type Apparats For In-Situ Measurement Of Hydrogen Storage Materials, Chun Chiu, Jason Hattrick-Simpers, Edwin Heilweil, Leonid Bendersky

Jason R. Hattrick-Simpers

No abstract provided.

Raman Spectroscopic Observation Of Dehydration In Ball-Milled Linh2-Libh4-Mgh2 Nanoparticles, Jason Hattrick-Simpers, James Maslar, Michael Niemann, Chun Chiu, Sesha Srinivasan, Elias Stefanakos, Leonid Bendersky

Jason R. Hattrick-Simpers

No abstract provided.

Observation Of Phase Transitions In Hydrogenated Yttrium Films Via Normalized Infrared Emissivity, Jason Hattrick-Simpers, Ke Wang, Lei Cao, Chun Chiu, Edwin Heilweil, Robert Downing, Leonid Bendersky

Jason R. Hattrick-Simpers

No abstract provided.

Optical Cell For Combinatorial In Situ Raman Spectroscopic Measurements Of Hydrogen Storage Materials At High Pressures And Temperatures, Jason Hattrick-Simpers, Wilbur Hurst, Sesha Srinivasan, James Maslar

Jason R. Hattrick-Simpers

An optical cell is described for high-throughput backscattering Raman spectroscopic measurements of hydrogen storagematerials at pressures up to 10 MPa and temperatures up to 823 K. High throughput is obtained by employing a 60 mm diameter × 9 mm thick sapphire window, with a corresponding 50 mm diameter unobstructed optical aperture. To reproducibly seal this relatively large window to the cell body at elevated temperatures and pressures, a gold o-ring is employed. The sample holder-to-window distance is adjustable, making this cell design compatible with optical measurement systems incorporating lenses of significantly different focal lengths, e.g., microscope objectives and single element …

A Combinatorial Characterization Scheme For High-Throughput Investigations Of Hydrogen Storage Materials, Jason Hattrick-Simpers, Zhuopeng Tan, Hiroyuki Oguchi, Chun Chiu, Edwin Heilweil, James Maslar, Leonid Bendersky

Jason R. Hattrick-Simpers

No abstract provided.

Modeling Of Chemical-Mechanical Couplings In Anode-Supported Solid Oxide Fuel Cells And Reliability Analysis, Xinfang Jin, Xingjian Xue

Xingjian "Chris" Xue

Oxygen ionic transport in conducting ceramics is an important mechanism enabling solid oxide fuel cell (SOFC) technology. The multi-physicochemical processes lead to the fact that the distribution of oxygen vacancy site fraction is not uniform in a positive-electrode electrolyte negative-electrode (PEN) assembly. Different oxygen vacancy concentrations induce different volumetric expansion of ceramics, resulting in complicated chemical–mechanical coupling phenomena and chemical stress in SOFCs. In this research, a mathematical model is developed to study oxygen ionic transport induced chemical stress in an SOFC. The model is validated using experimental polarization curves. Comprehensive simulations are performed to investigate chemical stress distribution in …

Redox Stable Anodes For Solid Oxide Fuel Cells, Guoliang Xiao, Fanglin Chen

Fanglin Chen

Solid oxide fuel cells (SOFCs) can convert chemical energy from the fuel directly to electrical energy with high efficiency and fuel flexibility. Ni-based cermets have been the most widely adopted anode for SOFCs. However, the conventional Ni-based anode has low tolerance to sulfur-contamination, is vulnerable to deactivation by carbon build-up (coking) from direct oxidation of hydrocarbon fuels, and suffers volume instability upon redox cycling. Among these limitations, the redox instability of the anode is particularly important and has been intensively studied since the SOFC anode may experience redox cycling during fuel cell operations even with the ideal pure hydrogen as …

La0.7Sr0.3Fe0.7Ga0.3O3-Δ As Electrode Material For A Symmetrical Solid Oxide Fuel Cell, Zhibin Yang, Yu Chen, Chao Jin, Guoliang Xiao, Minfang Han, Fanglin Chen

Fanglin Chen

In this research, La_0.7Sr_0.3Fe_0.7Ga_0.3O_3−δ (LSFG) perovskite oxide was successfully prepared using a microwave-assisted combustion method, and employed as both anode and cathode in symmetrical solid oxide fuel cells. A maximum power density of 489 mW cm⁻² was achieved at 800 °C with wet H₂ as the fuel and ambient air as the oxidant in a single cell with the configuration LSFG|La_0.8Sr_0.2Ga_0.83Mg_0.17O_3−δ|LSFG. Furthermore, the cells demonstrated good stability in H₂ and acceptable sulfur tolerance.

Direct Synthesis Of Methane From Co2-H2O Co-Electrolysis In Tubular Solid Oxide Electrolysis Cells, Long Chen, Fanglin Chen, Changrong Xia

Fanglin Chen

Directly converting CO₂ to hydrocarbons offers a potential route for carbon-neutral energy technologies. Here we report a novel design, integrating the high-temperature CO₂–H₂O co-electrolysis and low-temperature Fischer–Tropsch synthesis in a single tubular unit, for the direct synthesis of methane from CO₂ with a substantial yield of 11.84%.