Open Access. Powered by Scholars. Published by Universities.®
- Institution
-
- University of Nebraska - Lincoln (3877)
- California Polytechnic State University, San Luis Obispo (267)
- Ministry of Higher and Secondary Specialized Education of the Republic of Uzbekistan (99)
- SelectedWorks (55)
- The University of Akron (48)
-
- Western University (42)
- University of Tennessee, Knoxville (37)
- Brigham Young University (33)
- University of Massachusetts Amherst (32)
- Purdue University (31)
- Wayne State University (30)
- Michigan Technological University (29)
- University of South Carolina (25)
- Central Washington University (22)
- Clemson University (19)
- Selected Works (19)
- Virginia Commonwealth University (19)
- West Virginia University (19)
- University of Kentucky (18)
- Florida International University (14)
- Georgia Southern University (13)
- Embry-Riddle Aeronautical University (12)
- City University of New York (CUNY) (11)
- University of Alabama in Huntsville (11)
- University of Arkansas, Fayetteville (11)
- University of Louisville (11)
- Louisiana State University (10)
- The University of Maine (10)
- University of South Florida (10)
- Iowa State University (9)
- Keyword
-
- 1957 (29)
- Additive manufacturing (23)
- Design (23)
- CFD (21)
- 3D printing (18)
-
- Informacje dla studentów (in Polish) (18)
- Engineering (16)
- Manufacturing (16)
- Mechanical Engineering (15)
- International Harvester Company (13)
- Mechanical (13)
- Mechanical properties (13)
- Solar (13)
- Bicycle (12)
- Composites (12)
- Energy (10)
- Mechanical engineering (10)
- Sustainability (10)
- Turbulence (10)
- Additive Manufacturing (9)
- Composite (9)
- Engine (9)
- Hydraulics (9)
- Microstructure (9)
- Molecular dynamics (9)
- Robotics (9)
- Simulation (9)
- Vehicle (9)
- Vibration (9)
- Combustion (8)
- Publication Year
- Publication
-
- Nebraska Tractor Tests (3320)
- Department of Mechanical and Materials Engineering: Faculty Publications (523)
- Mechanical Engineering (206)
- Irrigation and Melioration (99)
- Faculty Publications (55)
-
- Williams Honors College, Honors Research Projects (48)
- Electronic Thesis and Dissertation Repository (42)
- Master's Theses (40)
- Electronic Theses and Dissertations (35)
- Masters Theses (34)
- Dissertations, Master's Theses and Master's Reports (29)
- Wojciech Budzianowski (29)
- Theses and Dissertations (28)
- All Undergraduate Projects (22)
- Doctoral Dissertations (22)
- Haseeb ASMA (21)
- Wayne State University Dissertations (21)
- Graduate Theses, Dissertations, and Problem Reports (19)
- Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research (17)
- The Summer Undergraduate Research Fellowship (SURF) Symposium (17)
- Theses and Dissertations--Mechanical Engineering (15)
- FIU Electronic Theses and Dissertations (14)
- All Theses (11)
- Honors Theses (11)
- Masters Theses 1911 - February 2014 (10)
- USF Tampa Graduate Theses and Dissertations (10)
- Dissertations and Theses (9)
- Mechanical Engineering Undergraduate Honors Theses (9)
- University of New Orleans Theses and Dissertations (9)
- Wayne State University Theses (9)
- Publication Type
Articles 1021 - 1050 of 5003
Full-Text Articles in Engineering
The Effect Of Biocomposite Material In A Composite Structure Under Compression Loading, Benjamin Andrew Sweeney
The Effect Of Biocomposite Material In A Composite Structure Under Compression Loading, Benjamin Andrew Sweeney
Master's Theses
While composite structures exhibit exceptional strength and weight saving possibilities for engineering applications, sometimes their overall cost and/or material performance can limit their usage when compared to conventional structural materials. Meanwhile ‘biocomposites’, composite structures consisting of natural fibers (i.e. bamboo fibers), display higher cost efficiency and unique structural benefits such as ‘sustainability’. This analysis will determine if the integration of these two different types of composites are beneficial to the overall structure. Specifically, the structure will consist of a one internal bamboo veneer biocomposite ply; and two external carbon fiber weave composite plies surrounding the bamboo biocomposite. To acquire results …
Dirichlet Process Gaussian Mixture Models For Real-Time Monitoring And Their Application To Chemical Mechanical Planarization, Jia (Peter) Liu, Omer F. Beyca, Prahalad K. Rao, Zhenyu (James) Kong, Satish T. S. Bukkapatnam
Dirichlet Process Gaussian Mixture Models For Real-Time Monitoring And Their Application To Chemical Mechanical Planarization, Jia (Peter) Liu, Omer F. Beyca, Prahalad K. Rao, Zhenyu (James) Kong, Satish T. S. Bukkapatnam
Department of Mechanical and Materials Engineering: Faculty Publications
The goal of this work is to use sensor data for online detection and identification of process anomalies (faults). In pursuit of this goal, we propose Dirichlet process Gaussian mixture (DPGM) models. The proposed DPGM models have two novel outcomes: 1) DP-based statistical process control (SPC) chart for anomaly detection and 2) unsupervised recurrent hierarchical DP clustering model for identification of specific process anomalies. The presented DPGM models are validated using numerical simulation studies as well as wireless vibration signals acquired from an experimental semiconductor chemical mechanical planarization (CMP) test bed. Through these numerically simulated and experimental sensor data, we …
Combustion Phasing Through Combustion Ionization In A Caterpillar C7 Compression Ignition Engine, Kamal Ashraf Assaad
Combustion Phasing Through Combustion Ionization In A Caterpillar C7 Compression Ignition Engine, Kamal Ashraf Assaad
Wayne State University Theses
To achieve the goals of best fuel economy, peak power and low soot emissions in military engines it is necessary to control the combustion process. An in-cylinder combustion sensor is required to achieve the goals of controlling the combustion process. Over the last four decades, in-cylinder pressure transducers and ion current sensors have been available for research and development. Most of the effort has focused on the pressure transducer, however up till now a pressure transducer suitable for use in production engines has not been developed yet, because of cost and durability concerns.This work presents the analysis of experimental data …
Turbulent Spray Combustion Modeling Using Direct Integration Of Chemistry And Flamelet Generated Manifolds, Ashraya Goyal
Turbulent Spray Combustion Modeling Using Direct Integration Of Chemistry And Flamelet Generated Manifolds, Ashraya Goyal
Wayne State University Theses
Turbulent spray combustion of n-dodecane was modeled at engine relevant conditions using various combustion models (Direct Integration of Chemistry and Flamelet Generated Manifolds) and turbulence models (Dynamic Structure Large Eddy Simulation and RNG Reynolds-Averaged Naiver-Stokes). A recently developed n-dodecane mechanism was utilized and the turbulent spray was simulated at various combustion chamber initial gas temperature and pressure conditions. Mesh with size of 31 microns was utilized to resolve small eddies around the spray. The pressure-based ignition delay, flame lift-off length, and spray and jet penetrations were studied and compared with experimental measurements. The Direct Integration of Chemistry and Flamelet Generated …
Built-In Bicycle Rack For Cars, Scott A. Hansberry
Built-In Bicycle Rack For Cars, Scott A. Hansberry
All Undergraduate Projects
Transporting a bicycle after riding somewhere and then needing to be pickup can be problematic. Bicycles will not fit in most vehicles without removing components. There is also the risk of damaging the inside of the vehicle. Expecting everyone to have a bike rack for their vehicle is unrealistic because the bike rack could be considered unappealing visually, take up to much space in the trunk, or limit the vehicle owner’s access to the trunk. The solution to this problem is a bike rack that mounts onto your car and then mounts your bike onto the rack. Most people don’t …
Pin Router Duplicator Base, Matthew Tebo
Pin Router Duplicator Base, Matthew Tebo
All Undergraduate Projects
The idea for the following project came from the Lean Manufacturing class that is offered at Central Washington University. In this class the manufacturing processes is demonstrated through the production of guitar kits. A problem with the class is that the CNC machine gets backed up causing a bottleneck in the production line. The solution to this problem was to make a pin router duplicator. A pin router duplicator is a device that allows the operator to trace a finished part with a pin while a router mimics its movements, cutting a new part. The component that is looked into …
Vorticella: A Protozoan For Bio-Inspired Engineering, Sangjin Ryu, Rachel E. Pepper, Moeto Nagai, Danielle C. France
Vorticella: A Protozoan For Bio-Inspired Engineering, Sangjin Ryu, Rachel E. Pepper, Moeto Nagai, Danielle C. France
Department of Mechanical and Materials Engineering: Faculty Publications
In this review, we introduce Vorticella as a model biological micromachine for microscale engineering systems. Vorticella has two motile organelles: the oral cilia of the zooid and the contractile spasmoneme in the stalk. The oral cilia beat periodically, generating a water flow that translates food particles toward the animal at speeds in the order of 0.1–1 mm/s. The ciliary flow of Vorticella has been characterized by experimental measurement and theoretical modeling, and tested for flow control and mixing in microfluidic systems. The spasmoneme contracts in a few milliseconds, coiling the stalk and moving the zooid at 15–90 mm/s. Because the …
Benchmark Burnishing With Almen Strip For Surface Integrity, Z. Y. Liu, C. H. Fu, M. P. Sealy, Y. Zhao, Y. B. Guo
Benchmark Burnishing With Almen Strip For Surface Integrity, Z. Y. Liu, C. H. Fu, M. P. Sealy, Y. Zhao, Y. B. Guo
Department of Mechanical and Materials Engineering: Faculty Publications
Burnishing is a surface treatment process widely used in aerospace, navy and other industries to improve fatigue and corrosion resistance by introducing a compressive residual stress layer. The measurement of residual stress by XRD is expensive, time consuming, and tedious. This work presented a quick method to determine the residual stress by using Almen strips. Inspired by the application of Almen strips in shot peening, deflections of burnished Almen strips under different burnishing conditions were measured. It was found that the deflection of Almen strip reflects the magnitude and penetration depth into subsurface of induced stress. Higher burnishing force, smaller …
Methods , Systems , And Devices Relating To Surgical End Effectors, Shane M. Farritor, Tom Fredrick, Joe Bartels
Methods , Systems , And Devices Relating To Surgical End Effectors, Shane M. Farritor, Tom Fredrick, Joe Bartels
Department of Mechanical and Materials Engineering: Faculty Publications
The embodiments disclosed herein relate to various medical device components, including components that can be incorporated into robotic and/or in vivo medical devices, and more specifically including end effectors that can be incorporated into such devices. Certain end effector embodiments include various vessel cautery devices that have rotational movement as well as cautery and cutting functions while maintaining a relatively compact structure. Other end effector embodiments include various end effector devices that have more than one end effector.
An Effective Methodology For Suppressing Structure-Borne Sound Radiation, Lingguang Chen
An Effective Methodology For Suppressing Structure-Borne Sound Radiation, Lingguang Chen
Wayne State University Dissertations
ABSTRACT
AN EFFECTIVE METHODOLOGY FOR SUPPRESSING
STRUCTURE-BORNE SOUND RADIATION
by
LINGGUANG CHEN
December 2017
Advisor: Dr. Sean F. Wu
Major: Mechanical Engineering
Degree: Doctor of Philosophy
This dissertation is primarily concerned with the development of an effective methodology for reducing structure-borne sound radiation from an arbitrarily shaped vibrating structure. There are three major aspects that separate the present methodology from all the previous ones. Firstly, it is a non-contact and non-invasive approach, which is applicable to a class of vibrating structures encountered in engineering applications. Secondly, the input data consists of a combined normal surface velocity distribution on a portion …
Biomechanics Of Concussion: The Importance Of Neck Tension, Ron Jadischke
Biomechanics Of Concussion: The Importance Of Neck Tension, Ron Jadischke
Wayne State University Dissertations
Linear and angular velocity and acceleration of the head are typically correlated to concussion. Despite improvements in helmet performance to reduce accelerations, a corresponding reduction in the incidence of concussion has not occurred (National Football League [NFL] 1996 – present).
There is compelling research that forces on and deformation to the brain stem are related to concussion. The brain stem is the center of control for respiration, blood pressure and heart rate and is the root of most cranial nerves. Injury to the brain stem is consistent with most symptoms of concussion reported in the National Football League and the …
Development Of A Finite Element Pelvis And Lower Extremity Model With Growth Plates For Pediatric Pedestrian Protection, Ming Shen
Wayne State University Dissertations
Finite element (FE) model is a useful tool frequently used for investigating the injury mechanisms and designing protection countermeasures. At present, no 10 years old (YO) pedestrian FE model has been developed from appropriate anthropometries and validated against limitedly available impact response data. A 10 YO child FE pelvis and lower extremities (PLEX) model was established to fill the gap of lacking such models in this age group. The baseline model was validated against available pediatric postmortem human subjects (PMHS) test data and additional scaled adult data, then the PLEX model was integrated to build a whole-body FE model representing …
Model Advancement And Hil Setup For Testing A P2 Phev Supervisory Controller, Sajjan Balakrishnan
Model Advancement And Hil Setup For Testing A P2 Phev Supervisory Controller, Sajjan Balakrishnan
Wayne State University Theses
Teams participating in Advanced Vehicle Technology Competitions such as EcoCAR3 are often bound by limited time and resources. Moreover, vehicle and component downtime due to mechanical and electrical issues reduce the time available for testing activities demanded by the Controls/Systems Modeling and Simulation teams. Therefore, the teams would benefit from identifying new approaches and being more pragmatic and productive in order to achieve satisfactory progress in the competition. This thesis summarizes the approach taken to improve the simulation accuracy of the Wayne State University EcoCAR3 team’s Pre-transmission Parallel Hybrid Electric Vehicle plant model and HIL setup. Focus is on testing …
C.V. - Wojciech Budzianowski, Wojciech M. Budzianowski
Renewable Energy And Sustainable Development (Resd) Group, Wojciech M. Budzianowski
Renewable Energy And Sustainable Development (Resd) Group, Wojciech M. Budzianowski
Wojciech Budzianowski
No abstract provided.
Mentoring Initial Research, Abigail Lisjak, Tim Leonard, Adam Foster, Patrick Gray
Mentoring Initial Research, Abigail Lisjak, Tim Leonard, Adam Foster, Patrick Gray
Sustainability and Connectivity
This document details the initial research the group gathered as the problem statement was being refined. Some of this research will be used to inform future elements of the project.
Strained Hybrid Perovskite Thin Films And Their Impact On The Intrinsic Stability Of Perovskite Solar Cells, Jingjing Zhao, Yehao Deng, Haotong Wei, Xiaopeng Zheng, Zhenhua Yu, Yuchuan Shao, Jeffrey E. Shield, Jinsong Huang
Strained Hybrid Perovskite Thin Films And Their Impact On The Intrinsic Stability Of Perovskite Solar Cells, Jingjing Zhao, Yehao Deng, Haotong Wei, Xiaopeng Zheng, Zhenhua Yu, Yuchuan Shao, Jeffrey E. Shield, Jinsong Huang
Department of Mechanical and Materials Engineering: Faculty Publications
Organic-inorganic hybrid perovskite (OIHP) solar cells have achieved comparable efficiencies to those of commercial solar cells, although their instability hinders their commercialization. Although encapsulation techniques have been developed to protect OIHP solar cells from external stimuli such as moisture, oxygen, and ultraviolet light, understanding of the origin of the intrinsic instability of perovskite films is needed to improve their stability. We show that the OIHP films fabricated by existing methods are strained and that strain is caused by mismatched thermal expansion of perovskite films and substrates during the thermal annealing process. The polycrystalline films have compressive strain in the out-of-plane …
An Integrated Curriculum For Technical Writing In Higher Education In China, Feifei Zhong, Gene Hou
An Integrated Curriculum For Technical Writing In Higher Education In China, Feifei Zhong, Gene Hou
Mechanical & Aerospace Engineering Faculty Publications
This study aims to develop an effective curriculum plan to improve technical writing in higher education in China. The paper first investigated the deficiency in the curriculum design in China for English technical writing by comparing the required courses offered in Southwest Jiaotong University (SWJTU) in China with those in Old Dominion University (ODU) in US. Questionnaires and interviews were then conducted among studying abroad Chinese students, visiting scholars, English as Second Language (ESL) instructors as well as engineering professors. The collected data revealed that the oversea Chinese students were struggled more with higher order concerns in writing than lower …
Computational Studies On Biomechanics Of Concussion And On Efficacy Of Football Helmets, David Labyak
Computational Studies On Biomechanics Of Concussion And On Efficacy Of Football Helmets, David Labyak
Dissertations, Master's Theses and Master's Reports
Football helmets have been used for many years to prevent head injuries to players. Over the years, the helmet design has evolved from a crude leather head covering to the more recent form fitting helmets that are seen today. The one design feature that has been common in the majority of all helmets is a hard polycarbonate shell with a foam cushion padding. The main goal of the padding layer was to reduce the amount of linear acceleration during an impact event. The one feature that has been overlooked is how stiff the padding is in rotation.
The purpose of …
Multiscale Modeling: Thermal Conductivity Of Graphene/Cycloaliphatic Epoxy Composites, Sorayot Chinkanjanarot
Multiscale Modeling: Thermal Conductivity Of Graphene/Cycloaliphatic Epoxy Composites, Sorayot Chinkanjanarot
Dissertations, Master's Theses and Master's Reports
The thermal property of epoxy as the binder in the Carbon Fiber (CF) composites, especially thermal conductivity is important to achieve the advance technology and to improve the performance of materials. Multiscale modeling including molecular dynamic (MD) modeling and micromechanical modeling is used to study the properties of neat Cycloaliphatic Epoxies (CE) and Graphene nanoplatelet (GNP)/CE with and without covalent functionalization.
The thermal properties (glass-transition temperature, thermal expansion coefficient, and thermal conductivity) and mechanical properties of CE system are investigated by MD modeling using OPLS-All Atom force field. A unique crosslinking technique is developed to achieve the cured CE models …
The Impact Of Water Injection On Spark Ignition Engine Performance Under High Load Operation, Jeremy Worm
The Impact Of Water Injection On Spark Ignition Engine Performance Under High Load Operation, Jeremy Worm
Dissertations, Master's Theses and Master's Reports
An experimental effort has been completed in which water injection was investigated as a means of enabling increases in engine output and high load efficiency. Water was injected into the intake port of a direct fuel injected, 4-cylinder, boosted engine with dual independent variable valve timing. The water was shown to increase volumetric efficiency and decrease the onset of knock which in turn enable more optimal combustion phasing. Both of these affects resulted increases in load of up to 5.5% at the same manifold pressure as the baseline case. The advancement of combustion phasing, combined with elimination of fuel enrichment …
Influence Of Magnetic Nanoparticles And Magnetic Stress On An Ionic Liquid Electrospray Source, Kurt Joseph Terhune
Influence Of Magnetic Nanoparticles And Magnetic Stress On An Ionic Liquid Electrospray Source, Kurt Joseph Terhune
Dissertations, Master's Theses and Master's Reports
Two electrospray sources were developed to operate on an ionic liquid ferrofluid; one source was a pressure‑fed capillary electrospray source and the other was a novel electrospray source which used a magnetically‑induced instability to produce a peak from which an electric field could extract electrospray. Multiple characteristics of electrospray operation were examined for both sources using faraday plates/cups, a quartz crystal microbalance, a retarding potential analyzer, and a time-of-flight mass spectrometer. The ILFF electrosprays for a capillary source were shown to operate in a mixed ion/droplet regime. The mass flow of the electrospray beam was primarily transported by larger particles …
Nondestructive Testing System Design For Biological Product Based On Vibration Signal Analysis Of Acceleration Sensor, Xiaohao Li, Tao Shen
Nondestructive Testing System Design For Biological Product Based On Vibration Signal Analysis Of Acceleration Sensor, Xiaohao Li, Tao Shen
Department of Mechanical and Materials Engineering: Faculty Publications
In order to reduce the disadvantages of current biological product quality testing methods, taking the quality testing in cocoon trade markets as an example, this paper has proposed a quality nondestructive testing method for biological products based on the analysis of vibration signal from acceleration sensors. According to the wavelet transformation analysis on the random vibration signal acquired from the acceleration sensor, the random vibration signal related to the silkworm chrysalis quality has been analyzed and reconstructed; then the characteristic values such as: mean value, variance, mean square root, waveform index, pulse factor, and so on of the quality signal …
Dissipative Elastic Metamaterial With A Lowfrequency Passband, Yongquan Liu, Jianlin Yi, Zheng Li, Xianyue Su, Wenlong Li, Mehrdad Negahban
Dissipative Elastic Metamaterial With A Lowfrequency Passband, Yongquan Liu, Jianlin Yi, Zheng Li, Xianyue Su, Wenlong Li, Mehrdad Negahban
Department of Mechanical and Materials Engineering: Faculty Publications
We design and experimentally demonstrate a dissipative elastic metamaterial structure that functions as a bandpass filter with a low-frequency passband. The mechanism of dissipation in this structure is well described by a mass-spring-damper model that reveals that the imaginary part of the wavenumber is non-zero, even in the passband of dissipative metamaterials. This indicates that transmittance in this range can be low. A prototype for this viscoelastic metamaterial model is fabricated by 3D printing techniques using soft and hard acrylics as constituent materials. The transmittance of the printed metamaterial is measured and shows good agreement with theoretical predictions, demonstrating its …
Solution Nuclear Magnetic Resonance Spectroscopy On A Nanostructured Diamond Chip, P. Kehayias, A. Jarmola, N. Mosavian, I. Fescenko, F.M. Benito, A. Laraoui, J. Smits, L. Bougas, D. Budker, A. Neumann, S.R.J. Brueck, V.M. Acosta
Solution Nuclear Magnetic Resonance Spectroscopy On A Nanostructured Diamond Chip, P. Kehayias, A. Jarmola, N. Mosavian, I. Fescenko, F.M. Benito, A. Laraoui, J. Smits, L. Bougas, D. Budker, A. Neumann, S.R.J. Brueck, V.M. Acosta
Department of Mechanical and Materials Engineering: Faculty Publications
Sensors using nitrogen-vacancy centers in diamond are a promising tool for small-volume nuclear magnetic resonance (NMR) spectroscopy, but the limited sensitivity remains a challenge. Here we show nearly two orders of magnitude improvement in concentration sensitivity over previous nitrogen-vacancy and picoliter NMR studies. We demonstrate NMR spectroscopy of picoliter-volume solutions using a nanostructured diamond chip with dense, high-aspect-ratio nanogratings, enhancing the surface area by 15 times. The nanograting sidewalls are doped with nitrogen-vacancies located a few nanometers from the diamond surface to detect the NMR spectrum of roughly 1 pl of fluid lying within adjacent nanograting grooves. We perform 1H …
Narrowband Nanocomposite Photodetector, Jinsong Huang, Fawen Guo, Liang Shen
Narrowband Nanocomposite Photodetector, Jinsong Huang, Fawen Guo, Liang Shen
Department of Mechanical and Materials Engineering: Faculty Publications
A photodetector includes an anode that is transparent or partially transparent to light, a cathode and an active layer disposed between the anode and the cathode. The active layer includes a nanocomposite material that has a polymer blended with nanoparticles or organic electron trapping particles. The photodetector has a low dark current when not illuminated by light and has a high conductivity when illuminated by light, in which the light passes the anode and is absorbed by the active layer. The active layer has a thickness selected such that the photodetector has a narrowband spectral response.
Role Of Copper Oxide Layer On Pool Boiling Performance With Femtosecond Laser Processed Surfaces, Corey Kruse, Edwin Peng, Craig Zuhlke, Jeff Shield, Dennis Alexander, Sidy Ndao, George Gogos
Role Of Copper Oxide Layer On Pool Boiling Performance With Femtosecond Laser Processed Surfaces, Corey Kruse, Edwin Peng, Craig Zuhlke, Jeff Shield, Dennis Alexander, Sidy Ndao, George Gogos
Department of Mechanical and Materials Engineering: Faculty Publications
Copper pool boiling surfaces are tested for pool boiling enhancement due to femtosecond laser surface processing (FLSP). FLSP creates self-organized micro/nanostructures on metallic surfaces and creates highly wetting and wicking surfaces with permanent surface features. In this study two series of samples were created. The first series consists of three flat FLSP copper surfaces with varying microstructures and the second series is an open microchannel configuration with laser processing over the horizontal surfaces of the microchannels. These microchannels range in height from 125 microns to 380 microns. Each of these surfaces were tested for pool boiling performance. It was found …
Quantification Of Re-Absorption And Re-Emission Processes To Determine Photon Recycling Efficiency In Perovskite Single Crystals, Yanjun Fang, Haotong Wei, Qingfeng Dong, Jinsong Huang
Quantification Of Re-Absorption And Re-Emission Processes To Determine Photon Recycling Efficiency In Perovskite Single Crystals, Yanjun Fang, Haotong Wei, Qingfeng Dong, Jinsong Huang
Department of Mechanical and Materials Engineering: Faculty Publications
Photon recycling, that is, iterative self-absorption and re-emission by the photoactive layer itself, has been speculated to contribute to the high open-circuit voltage in several types of high efficiency solar cells. For organic–inorganic halide perovskites that have yielded highly efficient photovoltaic devices, however, it remains unclear whether the photon recycling effect is significant enough to improve solar cell efficiency. Here we quantitatively evaluate the re-absorption and re-emission processes to determine photon recycling efficiency in hybrid perovskite with its single crystals by measuring the ratio of the re-emitted photons to the initially excited photons, which is realized by modulating their polarization …
Low-Drag Events In Transitional Wall-Bounded Turbulence, Richard D. Whalley, Jae Sung Park, Anubhav Kushwaha, David J.C. Dennis, Michael D. Graham, Robert J. Poole
Low-Drag Events In Transitional Wall-Bounded Turbulence, Richard D. Whalley, Jae Sung Park, Anubhav Kushwaha, David J.C. Dennis, Michael D. Graham, Robert J. Poole
Department of Mechanical and Materials Engineering: Faculty Publications
Intermittency of low-drag pointwise wall shear stress measurements within Newtonian turbulent channel flow at transitional Reynolds numbers (friction Reynolds numbers 70 – 130) is characterized using experiments and simulations. Conditional mean velocity profiles during low-drag events closely approach that of a recently discovered nonlinear traveling wave solution; both profiles are near the so-called maximum drag reduction profile, a general feature of turbulent flow of liquids containing polymer additives (despite the fact that all results presented are for Newtonian fluids only). Similarities between temporal intermittency in small domains and spatiotemporal intermittency in large domains is thereby found.
Atomically Informed Nonlocal Semidiscrete Variational Peierls-Nabarro Model For Planar Core Dislocations, Guisen Liu, Xi Cheng, Jian Wang, Kaiguo Chen, Yao Shen
Atomically Informed Nonlocal Semidiscrete Variational Peierls-Nabarro Model For Planar Core Dislocations, Guisen Liu, Xi Cheng, Jian Wang, Kaiguo Chen, Yao Shen
Department of Mechanical and Materials Engineering: Faculty Publications
Prediction of Peierls stress associated with dislocation glide is of fundamental concern in understanding and designing the plasticity and mechanical properties of crystalline materials. Here, we develop a nonlocal semi-discrete variational Peierls-Nabarro (SVPN) model by incorporating the nonlocal atomic interactions into the semi-discrete variational Peierls framework. The nonlocal kernel is simplified by limiting the nonlocal atomic interaction in the nearest neighbor region, and the nonlocal coefficient is directly computed from the dislocation core structure. Our model is capable of accurately predicting the displacement profile, and the Peierls stress, of planar-extended core dislocations in face-centered cubic structures. Our model could be …