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2,680 full-text articles. Page 76 of 82.

The Analysis Of Heat Transfer In A Gas-Gas Heat Exchanger Operated Under A Heat-Recirculating Mode, Mariusz Salaniec, Wojciech M. Budzianowski 2011 Wroclaw University of Technology

The Analysis Of Heat Transfer In A Gas-Gas Heat Exchanger Operated Under A Heat-Recirculating Mode, Mariusz Salaniec, Wojciech M. Budzianowski

Wojciech Budzianowski

The present paper presents the analysis of heat transfer in a gas-gas heat exchanger operated in a heat-recirculating mode.


An Overview Of Technologies For Upgrading Of Biogas To Biomethane, Wojciech M. Budzianowski 2011 Wroclaw University of Technology

An Overview Of Technologies For Upgrading Of Biogas To Biomethane, Wojciech M. Budzianowski

Wojciech Budzianowski

The present contribution presents an overview of technologies available for upgrading of biogas to biomethane. Technologies under study include pressure swing adsorption (PSA), high-pressure water wash (HPWW), reactive absorption (RA), physical absorption (PA), membrane separation (MS) and cryogenic separation (CS).


Influence Of Energy Policy On The Rate Of Implementation Of Biogas Power Plants In Germany During The 2001-2010 Decade, Izabela Chasiak, Wojciech M. Budzianowski 2011 Wroclaw University of Technology

Influence Of Energy Policy On The Rate Of Implementation Of Biogas Power Plants In Germany During The 2001-2010 Decade, Izabela Chasiak, Wojciech M. Budzianowski

Wojciech Budzianowski

The current article describes energy policy tools, which caused intensive development of biogas-based power generation in Germany during the 2001-2010 decade. The German system of financial support to biogas power plants is presented in details. It is shown that in Germany, i.e. in a country characterised by similar climate and potentials to renewable energy to Poland, biogas power plants cover 10,7% of electricity demands in 2010, while all renewable energy sources cover only 5,4% of electricity demands. It is emphasised that under favourable Polish energy policy, the development of biogas energy can be very rapid.


High Temperature, Low Cycle Fatigue Of A Hybrid Particulate/Fiber Aluminum Metal-Matrix Composite , Justin Clark 2011 Michigan Technological University

High Temperature, Low Cycle Fatigue Of A Hybrid Particulate/Fiber Aluminum Metal-Matrix Composite , Justin Clark

Dissertations, Master's Theses and Master's Reports - Open

The effect of shot particles on the high temperature, low cycle fatigue of a hybrid fiber/particulate metal-matrix composite (MMC) was studied. Two hybrid composites with the general composition A356/35%SiC particle/5%Fiber (one without shot) were tested. It was found that shot particles acting as stress concentrators had little effect on the fatigue performance. It appears that fibers with a high silica content were more likely to debond from the matrix. Final failure of the composite was found to occur preferentially in the matrix. SiC particles fracture progressively during fatigue testing, leading to higher stress in the ...


Processing And Mechanical Properties Of Cast Aluminum Containing Scandium, Zirconium, And Ytterbium , Nicholas D. Johnson 2011 Michigan Technological University

Processing And Mechanical Properties Of Cast Aluminum Containing Scandium, Zirconium, And Ytterbium , Nicholas D. Johnson

Dissertations, Master's Theses and Master's Reports - Open

A series of aluminum alloys containing additions of scandium, zirconium, and ytterbium were cast to evaluate the effect of partial ytterbium substitution for scandium on tensile behavior. Due to the high price of scandium, a crucible-melt interaction study was performed to ensure no scandium was lost in graphite, alumina, magnesia, or zirconia crucibles after holding a liquid Al-Sc master alloy for 8 hours at 900 °C in an argon atmosphere. The alloys were subjected to an isochronal aging treatment and tested for conductivity and Vickers microhardness after each increment. For scandium-containing alloys, peak hardnesses of 520-790 MPa, and peak tensile ...


Structure And Properties Of Graphene Nano Disks (Gnd) With And Without Edge-Dopants, Pubodee Ratana-arsanarom 2011 Michigan Technological University

Structure And Properties Of Graphene Nano Disks (Gnd) With And Without Edge-Dopants, Pubodee Ratana-Arsanarom

Dissertations, Master's Theses and Master's Reports - Open

Graphene is one of the most important materials. In this research, the structures and properties of graphene nano disks (GND) with a concentric shape were investigated by Density Functional Theory (DFT) calculations, in which the most effective DFT methods - B3lyp and Pw91pw91 were employed.

It was found that there are two types of edges - Zigzag and Armchair in concentric graphene nano disks (GND). The bond length between armchair-edge carbons is much shorter than that between zigzag-edge carbons. For C24 GND that consists of 24 carbon atoms, only armchair edge with 12 atoms is formed. For a GND larger than the ...


Technique To Measure Heats Of Reaction Of Ti-B, Al-Ti-B, And Al-Ti-B4c Powder Blends, Andrew H. Baker 2011 Michigan Technological University

Technique To Measure Heats Of Reaction Of Ti-B, Al-Ti-B, And Al-Ti-B4c Powder Blends, Andrew H. Baker

Dissertations, Master's Theses and Master's Reports - Open

In this research, a modification to initiation aid ignition in bomb calorimetry that involves systemically blending levels of boron and potassium nitrate initiation aids with a bulk structural energetic elemental power blend is developed. A regression is used to estimate the nominal heat of reaction for the primary reaction. The technique is first applied to the synthesis of TiB2 as a validation study to see if close proximity to literature values can be achieved. The technique is then applied to two systems of interest, Al-Ti-B, and Al-Ti-B4C. In all three investigations, x-ray diffraction is used to characterize the product phases ...


Graphene Based Anode Materials For Lithium-Ion Batteries, Sree Lakshmi Cheekati 2011 Wright State University

Graphene Based Anode Materials For Lithium-Ion Batteries, Sree Lakshmi Cheekati

Browse all Theses and Dissertations

Improvements of the anode performances in Li-ions batteries are in demand to satisfy applications in transportation. In comparison with graphitic carbons, transition metal oxides as well as graphene can store over twice amount of lithium per gram. Recently, graphene-based anodes for Li-ion batteries are under extensive development. In this research, lithium storage characteristics in graphene oxide (GO), GO/Manganese acetate (GO/MnAc), GO/manganese oxide (GO/MnOx) composites and Nano Graphene Platelets (NGP) were studied. The prepared GO delivered reversible capacities of 706mAh/g with an average columbic efficiency of 87%. Reversible capacities of 533 mAh/g were observed for ...


The Functionalization And Characterization Of Adherent Carbon Nanotubes With Silver Nanoparticles For Biological Applications, Adam A. Maleszewski 2011 Wright State University

The Functionalization And Characterization Of Adherent Carbon Nanotubes With Silver Nanoparticles For Biological Applications, Adam A. Maleszewski

Browse all Theses and Dissertations

The purpose of this project is to form silver nanoparticles (Ag-NP) attached to a hierarchical substrate for possible use in biological applications. The effectiveness of these Ag-NP-containing devices, including biofilters and biosensors, may be dramatically enhanced by the use of hierarchical structures such as carbon nanotubes (CNT), as they offer a high surface area surface suitable for cell-device interactions, while Ag-NP would be a suitable component in many such devices due to its plasmonic surface properties (e.g. in sensor and directed energy applications) and its anti-microbial properties (desirable for fluid filtration due to its low weight. Meaningful control over ...


Effect Of Fullerene Nano-Spheres On Evaporation Kinetics Of Fluids, Wenhu Wang 2011 Wright State University

Effect Of Fullerene Nano-Spheres On Evaporation Kinetics Of Fluids, Wenhu Wang

Browse all Theses and Dissertations

As the interest in fluid evaporation kinetics keeps increasing, it's inevitably noticed that fullerene nanospheres play an important role on it. In this study, we investigate the C60 nanospheres' effect on the evaporation kinetics and thermal transitions of different solvents (water, chlorobenzene) over the entire range of solubility. According to distinct polarity of different solvent, fullerene solution would behave differently, the trend of increasing in evaporation rate as the concentration increased was observed in aromatic solvents while the rate kept decreasing in water. The result of differential scanning calorimetry (DSC) and Raman spectroscopy provided an evidence about structuring in ...


Highly Active Porous Catalysts Fabricated By Attachment Of Palladium Nanoparticles On Hierarchical Carbon Structures, Hema Vijwani 2011 Wright State University

Highly Active Porous Catalysts Fabricated By Attachment Of Palladium Nanoparticles On Hierarchical Carbon Structures, Hema Vijwani

Browse all Theses and Dissertations

The effectiveness of metal-based catalysts can be significantly enhanced by increasing the available surface area relative to the volume through the creation of hierarchical nanostructures. The catalyst demonstrated here is palladium, which is a widely recognized heterogeneous catalyst suitable for a variety of industrial applications such as water purification, hydrogen storage, and electrochemical devices. In this study, a novel multi-scale supporting material developed in this group, has been used as support. It consists of micro-porous graphitic carbon with strongly attached carbon nanotubes. This can increase the surface area by orders of magnitude without increasing the size or weight while still ...


Nanostructured Arrays For Sensing And Energy Storage Applications, Raghu Mangu 2011 University of Kentucky

Nanostructured Arrays For Sensing And Energy Storage Applications, Raghu Mangu

University of Kentucky Doctoral Dissertations

Vertically aligned multi walled carbon nanotube (MWCNT) arrays fabricated by xylene pyrolysis in anodized aluminum oxide (AAO) templates without the use of a catalyst, were integrated into a resistive sensor design. The steady state sensitivities as high as 5% and 10% for 100 ppm of NH3 and NO2 respectively at a flow rate of 750 sccm were observed. A study was undertaken to elucidate (i) the dependence of sensitivity on the thickness of amorphous carbon layers, (ii) the effect of UV light on gas desorption characteristics and (iii) the dependence of room temperature sensitivity on different NH3 ...


Dispersive Wave Equations For Solids With Microstructure, A. Berezovski, Juri Engelbrecht, Mihhail Berezovski 2011 Tallinn University of Technology

Dispersive Wave Equations For Solids With Microstructure, A. Berezovski, Juri Engelbrecht, Mihhail Berezovski

Publications

The dispersive wave motion in solids with microstructure is considered in the one-dimensional setting in order to understand better the mechanism of dispersion. It is shown that the variety of dispersive wave propagation models derived by homogenization, continualisation, and generalization of continuum mechanics can be unified in the framework of dual internal variables theory.


Use Of Environmental Scanning Electron Microscopy For In Situ Observation Of Interaction Of Cells With Micro- And Nanoprobes, Alexander Goponenko, B. J. Boyle, K. I. Jahan, Maxim V. Gerashchenko, Dmitri E. Fomenko, Vadim N. Gladyshev, Yuris A. Dzenis 2011 University of Nebraska-Lincoln

Use Of Environmental Scanning Electron Microscopy For In Situ Observation Of Interaction Of Cells With Micro- And Nanoprobes, Alexander Goponenko, B. J. Boyle, K. I. Jahan, Maxim V. Gerashchenko, Dmitri E. Fomenko, Vadim N. Gladyshev, Yuris A. Dzenis

Mechanical & Materials Engineering Faculty Publications

Precision intracellular sensing, probing and manipulation offer unprecedented opportunities for advances in biological sciences. Next-generation ultra-fine probes will be capable of targeting individual cell organelles. Development of such probes as well as probes capable of penetrating through tough cell walls requires detailed knowledge of cell-probe interaction. This Letter evaluated the applicability of environmental scanning electron microscopy (ESEM) for cell and cell-probe interaction imaging. Several types of cells (plant and yeast cells as well as mouse spermatozoa) were successfully imaged in their natural state, with mouse spermatozoa observed by ESEM for the first time. Computerized stage applied to image was tough ...


Simulation Of Electrospun Nanofiber Deposition On Stationary And Moving Substrates, Linhua Liu, Yuris A. Dzenis 2011 GE (China) Research and Development Center, Shanghai

Simulation Of Electrospun Nanofiber Deposition On Stationary And Moving Substrates, Linhua Liu, Yuris A. Dzenis

Mechanical & Materials Engineering Faculty Publications

Electrospinning produces continuous fibers with diameters from single nanometers to microns by jetting polymer solutions in high electric fields. Electrospun non-woven filamentary materials attract rapidly growing interest for broad range of applications. Properties of these materials depend on their nano- and microstructure that is determined in turn by the electric field and nanofiber collector. Despite critical importance, deposition of electrospun fibers on substrates has not yet been extensively studied theoretically and new methods of nanofiber collection continue to be developed mostly empirically. The objective of this Letter was to develop and demonstrate numerical simulation of electrospun nanofiber deposition on moving ...


A Model Of Giant Vacuole Dynamics In Human Schlemm’S Canal Endothelial Cells, Ryan M. Pedrigi, David Simon, Ashley Reed, W. Daniel Stamer, Darryl R. Overby 2011 University of Nebraska-Lincoln

A Model Of Giant Vacuole Dynamics In Human Schlemm’S Canal Endothelial Cells, Ryan M. Pedrigi, David Simon, Ashley Reed, W. Daniel Stamer, Darryl R. Overby

Mechanical & Materials Engineering Faculty Publications

Aqueous humour transport across the inner wall endothelium of Schlemm’s canal likely involves flow through giant vacuoles and pores, but the mechanics of how these structures form and how they influence the regulation of intraocular pressure (IOP) are not well understood. In this study, we developed an in vitro model of giant vacuole formation in human Schlemm’s canal endothelial cells (HSCECs) perfused in the basal-to-apical direction (i.e., the direction that flow crosses the inner wall in vivo) under controlled pressure drops (2 or 6 mmHg). The system was mounted on a confocal microscope for time-lapse en face ...


Polymer Based Microfabrication And Its Applications In Optical Mems And Biomems, Guocheng Shao 2011 Louisiana State University and Agricultural and Mechanical College

Polymer Based Microfabrication And Its Applications In Optical Mems And Biomems, Guocheng Shao

LSU Doctoral Dissertations

Due to its ease of fabrication, low cost and great variety of functionalities, polymer has become an important material in microfabrication. MEMS devices with polymer as the structure material have found applications in various fields, especially in BioMEMS and optical MEMS. In this dissertation, three polymer based microfabricated devices/components have been developed and tested. Various polymer based fabrication techniques, such as high aspect ratio SU-8 photolithography, three dimensional polydimethylsiloxane (PDMS) soft lithography, multi-layer soft lithography and PDMS double casting technique have been developed/studied and employed in the device fabrication process. The main contribution of this dissertation includes: (1 ...


Characterization Of Novel Akermanite:Poly-E-Caprolactone Scaffolds For Bone Tissue Engineering Aapplications Combined With Human Adipose-Derived Stem Cells, Andre S. Zanetti 2011 Louisiana State University and Agricultural and Mechanical College

Characterization Of Novel Akermanite:Poly-E-Caprolactone Scaffolds For Bone Tissue Engineering Aapplications Combined With Human Adipose-Derived Stem Cells, Andre S. Zanetti

LSU Doctoral Dissertations

The development of porous materials useful as scaffolds for the sustained three-dimensional (3D) growth of human adipose-derived stem cells (hASC) is of particular interest to facilitate healing after musculoskeletal injuries. In this study, a composite porous material obtained by blending akermanite with poly-e-caprolactone (PCL) is proposed as novel alternative to bone tissue regeneration. The objectives of this study are (1) to characterize the akermanite:PCL scaffold properties; (2) to investigate the in vitro osteogenic potential of hASC loaded to optimal akermanite:PCL scaffolds; (3) to assess the metabolic activity and osteogenesis of hASC loaded to optimal akermanite:PCL scaffolds post-thawing ...


The Influence Of Pressure Relaxation On The Structure Of An Axial Vortex, Robert L. Ash, Irfan Zardadkhan, Allan J. Zuckerwar 2011 Old Dominion University

The Influence Of Pressure Relaxation On The Structure Of An Axial Vortex, Robert L. Ash, Irfan Zardadkhan, Allan J. Zuckerwar

Mechanical & Aerospace Engineering Faculty Publications

Governing equations including the effects of pressure relaxation have been utilized to study an incompressible, steady-state viscous axial vortex with specified far-field circulation. When sound generation is attributed to a velocity gradient tensor-pressure gradient product, the modified conservation of momentum equations that result yield an exact solution for a steady, incompressible axial vortex. The vortex velocity profile has been shown to closely approximate experimental vortex measurements in air and water over a wide range of circulation-based Reynolds numbers. The influence of temperature and humidity on the pressure relaxation coefficient in air has been examined using theoretical and empirical approaches, and ...


Effects Of Silicon Content And Cooling Rate On Mechanical Properties Of Heavy Section Ductile Cast Iron , Meghan Haycock 2011 Michigan Technological University

Effects Of Silicon Content And Cooling Rate On Mechanical Properties Of Heavy Section Ductile Cast Iron , Meghan Haycock

Dissertations, Master's Theses and Master's Reports - Open

The effects of Si and cooling rate are investigated for their effect on the mechanical properties and microstructure. Three alloys were chosen with varying C and Si contents and an attempt to keep the remainder of the elements present constant. Within each heat, three test blocks were poured. Two blocks had chills – one with a fluid flowing through it to cool it (active chill) and one without the fluid (passive) – and the third block did not have a chill. Cooling curves were gathered and analyzed. The mechanical properties of the castings were correlated to the microstructure, cooling rate and Si ...


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