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

Engineering Commons™

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

Discipline
Institution
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 81031 - 81060 of 196627

Full-Text Articles in Engineering

Computational Modeling Of Transcatheter Aortic Valves, Mostafa Abbasi Jan 2018

Computational Modeling Of Transcatheter Aortic Valves, Mostafa Abbasi

Electronic Theses and Dissertations

Transcatheter aortic valve replacement (TAVR) is an established therapy alternative to surgical valve replacement in high-risk and intermediate-risk patients with severe aortic stenosis. Currently, although TAVR is an alternative and less-invasive treatment for high-risk and intermediate-risk patients, surgical aortic valves replacement (SAVR) was still considered as the gold standard for low-risk patients. TAVR could potentially be applied to lower-risk younger patients if the indications can be safely expanded to the patients and transcatheter aortic valve (TAV) long-term durability can match with that of surgical bioprostheses. In contrast to surgical aortic valves (SAVs), there have been limited clinical data on the …


Muscle Activity-Driven Green-Oriented Random Number Generation Mechanism To Secure Wbsn Wearable Device Communications, Yuanlong Cao, Guanghe Zhang, Fanghua Liu, Ilsun You, Guanglou Zheng, Oluwarotimi W. Samuel, Shixiong Chen Jan 2018

Muscle Activity-Driven Green-Oriented Random Number Generation Mechanism To Secure Wbsn Wearable Device Communications, Yuanlong Cao, Guanghe Zhang, Fanghua Liu, Ilsun You, Guanglou Zheng, Oluwarotimi W. Samuel, Shixiong Chen

Research outputs 2014 to 2021

Wireless body sensor networks (WBSNs) mostly consist of low-cost sensor nodes and implanted devices which generally have extremely limited capability of computations and energy capabilities. Hence, traditional security protocols and privacy enhancing technologies are not applicable to the WBSNs since their computations and cryptographic primitives are normally exceedingly complicated. Nowadays, mobile wearable and wireless muscle-computer interfaces have been integrated with the WBSN sensors for various applications such as rehabilitation, sports, entertainment, and healthcare. In this paper, we propose MGRNG, a novel muscle activity-driven green-oriented random number generation mechanism which uses the human muscle activity as green energy resource to generate …


A Security Review Of Local Government Using Nist Csf: A Case Study, Ahmed Ibrahim, Craig Valli, Ian Mcateer, Junaid Chaudhry Jan 2018

A Security Review Of Local Government Using Nist Csf: A Case Study, Ahmed Ibrahim, Craig Valli, Ian Mcateer, Junaid Chaudhry

Research outputs 2014 to 2021

Evaluating cyber security risk is a challenging task regardless of an organisation’s nature of business or size, however, an essential activity. This paper uses the National Institute of Standards and Technology (NIST) cyber security framework (CSF) to assess the cyber security posture of a local government organisation in Western Australia. Our approach enabled the quantification of risks for specific NIST CSF core functions and respective categories and allowed making recommendations to address the gaps discovered to attain the desired level of compliance. This has led the organisation to strategically target areas related to their people, processes, and technologies, thus mitigating …


Evaluating An Analytical Model To Predict Subsurface Lnapl Distributions And Transmissivity From Current And Historic Fluid Levels In Groundwater Wells: Comparing Results To Numerical Simulations, Robert J. Lenhard, Kaveh Sookhak Lari, John L. Rayner, Greg B. Davis Jan 2018

Evaluating An Analytical Model To Predict Subsurface Lnapl Distributions And Transmissivity From Current And Historic Fluid Levels In Groundwater Wells: Comparing Results To Numerical Simulations, Robert J. Lenhard, Kaveh Sookhak Lari, John L. Rayner, Greg B. Davis

Research outputs 2014 to 2021

A recent analytical model predicts free, entrapped, and residual LNAPL saturations and the LNAPL transmissivity in the subsurface from current and historic fluid levels in groundwater wells. As such, the model accounts for effects of fluid level fluctuations in a well. The model was developed to predict LNAPL specific volumes and transmissivities from current fluid level measurements in wells and either recorded historic fluid level fluctuations in wells or estimates. An assumption is made in the model that the predictions are not dependent on whether the historic highest or lowest fluid level elevations in a well occur first. To test …


A Comprehensive Review Of Fruit And Vegetable Classification Techniques, Khurram Hameed, Douglas Chai, Alexander Rassau Jan 2018

A Comprehensive Review Of Fruit And Vegetable Classification Techniques, Khurram Hameed, Douglas Chai, Alexander Rassau

Research outputs 2014 to 2021

Recent advancements in computer vision have enabled wide-ranging applications in every field of life. One such application area is fresh produce classification, but the classification of fruit and vegetable has proven to be a complex problem and needs to be further developed. Fruit and vegetable classification presents significant challenges due to interclass similarities and irregular intraclass characteristics. Selection of appropriate data acquisition sensors and feature representation approach is also crucial due to the huge diversity of the field. Fruit and vegetable classification methods have been developed for quality assessment and robotic harvesting but the current state-of-the-art has been developed for …


Bowel Sounds Identification And Migrating Motor Complex Detection With Low-Cost Piezoelectric Acoustic Sensing Device, Xuhao Du, Gary Allwood, Katherine Mary Webberley, Adam Osseiran, Barry J. Marshall Jan 2018

Bowel Sounds Identification And Migrating Motor Complex Detection With Low-Cost Piezoelectric Acoustic Sensing Device, Xuhao Du, Gary Allwood, Katherine Mary Webberley, Adam Osseiran, Barry J. Marshall

Research outputs 2014 to 2021

Interpretation of bowel sounds (BS) provides a convenient and non-invasive technique to aid in the diagnosis of gastrointestinal (GI) conditions. However, the approach’s potential is limited by variation between BS and their irregular occurrence. A short, manual auscultation is sufficient to aid in diagnosis of only a few conditions. A longer recording has the potential to unlock additional understanding of GI physiology and clinical utility. In this paper, a low-cost and straightforward piezoelectric acoustic sensing device was designed and used for long BS recordings. The migrating motor complex (MMC) cycle was detected using this device and the sound index as …


Evaluation Of Bio-Asphalt Binders Modified With Biochar: A Pyrolysis By-Product Of Mesua Ferrea Seed Cover Waste, Abhinay Kumar, Rajan Choudhary, Rumi Narzari, Rupam Kataki, Sanjay K. Shukla Jan 2018

Evaluation Of Bio-Asphalt Binders Modified With Biochar: A Pyrolysis By-Product Of Mesua Ferrea Seed Cover Waste, Abhinay Kumar, Rajan Choudhary, Rumi Narzari, Rupam Kataki, Sanjay K. Shukla

Research outputs 2014 to 2021

With growing global concerns related to energy security and sustainability, interest in bio-fuels has increased significantly. Production of biofuel mostly begins with pyrolysis, a process that converts the biomass to liquid biooil, solid biochar and gases. A large amount of carbonaceous biochar is generated as a by-product during the pyrolysis. However, no major effort has been made in the past decade to utilize the biochar in pavement applications, especially as a bio-modifier to asphalt binders. In this study, an attempt was made to evaluate the carbonaceous biochar, obtained during bio-fuel production through pyrolysis of Mesua ferrea seed cover waste, as …


Stability Analysis And Design Charts For A Sandy Soil Slope Supporting An Embedded Strip Footing, Emmanuel Baah-Frempong, Sanjay Kumar Shukla Jan 2018

Stability Analysis And Design Charts For A Sandy Soil Slope Supporting An Embedded Strip Footing, Emmanuel Baah-Frempong, Sanjay Kumar Shukla

Research outputs 2014 to 2021

In several field situations, especially in the hilly terrains, the construction of footings on slopes becomes essential. The factor of safety of a slope supporting a loaded footing on the crest is dependent on the position of the footing from the crest edge. Most studies in the past have focused on analysing the bearing capacity and settlement behaviour of a footing resting on a slope crest, but foundations in most infrastructure projects are usually built at some depth below the ground surface. Therefore, the availability of some form of design charts for determining the factor of safety of a slope …


Influence Of Substrate Stage Temperature And Rotation Rate On The Magneto-Optical Quality Of Rf-Sputtered Bi2.1dy0.9fe3.9ga1.1o12 Garnet Thin Films, Mohammad E. Alam, Mikhail Vasiliev, Kamal Alameh Jan 2018

Influence Of Substrate Stage Temperature And Rotation Rate On The Magneto-Optical Quality Of Rf-Sputtered Bi2.1dy0.9fe3.9ga1.1o12 Garnet Thin Films, Mohammad E. Alam, Mikhail Vasiliev, Kamal Alameh

Research outputs 2014 to 2021

Highly bismuth-substituted iron garnet thin films are prepared on quartz substrates by using a radio frequency (RF) magnetron sputtering technique. We study the factors (process parameters associated with the RF magnetron sputter deposition technique) affecting the magneto-optical (MO) properties of ferrite garnet films of composition Bi2.1Dy0.9Fe3.9Ga1.1O12. All films show high MO response across the visible range of wavelengths after being annealed. In particular, the effects of substrate stage temperature and rotation rate on the various properties of films are studied. Experimental results reveal that the characteristics of garnet films of this type can be tuned and optimized for use in …


Copper Removal From Acid Mine Drainage-Polluted Water Using Glutaraldehyde-Polyethyleneimine Modified Diatomaceous Earth Particles, Mikael Larsson, Ataollah Nosratia, Simarpreet Kaur, Jochen Wagner, Ulf Baus, Magnus Nydén Jan 2018

Copper Removal From Acid Mine Drainage-Polluted Water Using Glutaraldehyde-Polyethyleneimine Modified Diatomaceous Earth Particles, Mikael Larsson, Ataollah Nosratia, Simarpreet Kaur, Jochen Wagner, Ulf Baus, Magnus Nydén

Research outputs 2014 to 2021

Mine waters and tailings generated from mining and mineral processing activities often have detrimental impact on the local environment. One example is acid mine drainage, in which sulphides in the mining waste react with water and oxygen to produce an acidic environment that subsequently dissolves host rock minerals from the waste containing toxic metals and trace elements. Copper is one such metal of significance, as it is mined at large volumes in sulphide containing ores. It has strong biocidal activity that greatly affects ecosystems. We have previously reported that glutaraldehyde (GA)-crosslinked polyethyleneimine (PEI) has strong affinity and selectivity for copper …


Grey Wolf Optimization-Based Optimum Energy-Management And Battery-Sizing Method For Grid-Connected Microgrids, Kutaiba Sabah Nimma, Monaaf D. A. Al-Falahi, Hung Duc Nguyen, S. D. G. Jayasinghe, Thair Mahmoud, Michael Negnevitsky Jan 2018

Grey Wolf Optimization-Based Optimum Energy-Management And Battery-Sizing Method For Grid-Connected Microgrids, Kutaiba Sabah Nimma, Monaaf D. A. Al-Falahi, Hung Duc Nguyen, S. D. G. Jayasinghe, Thair Mahmoud, Michael Negnevitsky

Research outputs 2014 to 2021

In the revolution of green energy development, microgrids with renewable energy sources such as solar, wind and fuel cells are becoming a popular and effective way of controlling and managing these sources. On the other hand, owing to the intermittency and wide range of dynamic responses of renewable energy sources, battery energy-storage systems have become an integral feature of microgrids. Intelligent energy management and battery sizing are essential requirements in the microgrids to ensure the optimal use of the renewable sources and reduce conventional fuel utilization in such complex systems. This paper presents a novel approach to meet these requirements …


Application Of 3d Delaunay Triangulation In Fingerprint Authentication System, Wencheng Yang, Ahmed Ibrahim, Junaid Chaudhry, Song Wang, Jiankun Hu, Craig Valli Jan 2018

Application Of 3d Delaunay Triangulation In Fingerprint Authentication System, Wencheng Yang, Ahmed Ibrahim, Junaid Chaudhry, Song Wang, Jiankun Hu, Craig Valli

Research outputs 2014 to 2021

Biometric security has found many applications in Internet of Things (IoT) security. Many mobile devices including smart phones have supplied fingerprint authentication function. However, the authentication performance in such restricted environment has been downgraded significantly. A number of methods based on Delaunay triangulation have been proposed for minutiae-based fingerprint matching, due to some favorable properties of the Delaunay triangulation under image distortion. However, all existing methods are based on 2D pattern, of which each unit, a Delaunay triangle, can only provide limited discrimination ability and could cause low matching performance. In this paper, we propose a 3D Delaunay triangulation based …


Photonic Crystal-Supported Long-Range Surface Plasmon-Polaritons Propagating Along High-Quality Silver Nanofilms, Sergey K. Sekatskii, Anton Smirnov, Giovanni Dietler, Mohammad Nur E. Alam, Mikhail Vasiliev, Kamal Alameh Jan 2018

Photonic Crystal-Supported Long-Range Surface Plasmon-Polaritons Propagating Along High-Quality Silver Nanofilms, Sergey K. Sekatskii, Anton Smirnov, Giovanni Dietler, Mohammad Nur E. Alam, Mikhail Vasiliev, Kamal Alameh

Research outputs 2014 to 2021

Long-range surface plasmon-polaritons (LRSPP) with a propagation length equal to 180 microns at the wavelength of 633 nm have been observed at the interface of 12.5 nm-thick silver nanofilm, coated by a 20 nm-thick protective ZnS layer, with air. Their propagation has been supported by a specially prepared 40-layer 1D Photonic Crystal designed in such a manner that silver layer has been deposited directly onto thin ZnS layer, earlier shown to be a non-oxide material most suitable for the preparation of high-quality thin silver nanofilms.


Ultrafast Consolidation Of Bulk Nanocrystalline Titanium Alloy Through Ultrasonic Vibration, Peng Chen, W. B. Liao, Lehua Liu, F Luo, Xiaoyu Wu, Peijie Li, C Yang, M Yan, Y. J. Liu, Laichang Zhang, Zhiyuan Liu Jan 2018

Ultrafast Consolidation Of Bulk Nanocrystalline Titanium Alloy Through Ultrasonic Vibration, Peng Chen, W. B. Liao, Lehua Liu, F Luo, Xiaoyu Wu, Peijie Li, C Yang, M Yan, Y. J. Liu, Laichang Zhang, Zhiyuan Liu

Research outputs 2014 to 2021

Nanocrystalline (NC) materials have fascinating physical and chemical properties, thereby they exhibit great prospects in academic and industrial fields. Highly efficient approaches for fabricating bulk NC materials have been pursued extensively over past decades. However, the instability of nanograin, which is sensitive to processing parameters (such as temperature and time), is always a challenging issue to be solved and remains to date. Herein, we report an ultrafast nanostructuring strategy, namely ultrasonic vibration consolidation (UVC). The strategy utilizes internal friction heat, generated from mutually rubbing between Ti-based metallic glass powders, to heat the glassy alloy rapidly through its supercooled liquid regime, …


Field-Scale Multi-Phase Lnapl Remediation: Validating A New Computational Framework Against Sequential Field Pilot Trials, Kaveh Sookhak Lari, Colin Johnson, John Rayner, Greg Davis Jan 2018

Field-Scale Multi-Phase Lnapl Remediation: Validating A New Computational Framework Against Sequential Field Pilot Trials, Kaveh Sookhak Lari, Colin Johnson, John Rayner, Greg Davis

Research outputs 2014 to 2021

Remediation of subsurface systems, including groundwater, soil and soil gas, contaminated with light non-aqueous phase liquids (LNAPLs) is challenging. Field-scale pilot trials of multi-phase remediation were undertaken at a site to determine the effectiveness of recovery options. Sequential LNAPL skimming and vacuum-enhanced skimming, with and without water table drawdown were trialled over 78 days; in total extracting over 5 m3 of LNAPL. For the first time, a multi-component simulation framework (including the multi-phase multi-component code TMVOC-MP and processing codes) was developed and applied to simulate the broad range of multi-phase remediation and recovery methods used in the field trials. …


A Review Of Latest Developments, Progress, And Applications Of Heat Pipe Solar Collectors, Abdellah Sharifian, Mehdi Khiadani, Ataollah Nosrati Jan 2018

A Review Of Latest Developments, Progress, And Applications Of Heat Pipe Solar Collectors, Abdellah Sharifian, Mehdi Khiadani, Ataollah Nosrati

Research outputs 2014 to 2021

Among all the available solutions to the current high energy demand and consequent economic and environmental problems, solar energy, without any doubt, is one of the most promising and widespread solutions. However, conventional solar systems face some intractable challenges affecting their technical performance and economic feasibility. To overcome these challenges, increasing attention has been drawn towards the utilization of heat pipes, as an efficient heat transfer technology, in conventional solar systems. To the authors’ knowledge, despite many valuable studies on heat pipe solar collectors (mainly during the last decade), a comprehensive review which surveys and summarizes those studies and identifies …


A Simplified Simulation Model To Estimate The Storage Length Of The Right-Turn Lane In Left-Hand Traffic At Signalised Intersections For Different Signal Phases And Cycle Timings, Noura Ishak-Thomas, Steven J. Richardson, Sanjay K. Shukla Jan 2018

A Simplified Simulation Model To Estimate The Storage Length Of The Right-Turn Lane In Left-Hand Traffic At Signalised Intersections For Different Signal Phases And Cycle Timings, Noura Ishak-Thomas, Steven J. Richardson, Sanjay K. Shukla

Research outputs 2014 to 2021

Introduction:

A large number of the current guidelines and models are used to estimate the right-turn lane (RTL) length in left-hand traffic at signalised intersections under split phase, in which the movement of traffic in the right-turn lane and through lane happen concurrently. There is a need to examine other phase types and timings as a part of the RTL design. This is particularly significant in the case of established intersections that cannot be modified due to physical constraints.

Methods:

A MATLAB based simulation programme was developed to provide an estimate of the right-turn lane storage length for different traffic …


An Entropy-Histogram Approach For Image Similarity And Face Recognition, Mohammed Aljanabi, Zahir Hussain, Song F. Lu Jan 2018

An Entropy-Histogram Approach For Image Similarity And Face Recognition, Mohammed Aljanabi, Zahir Hussain, Song F. Lu

Research outputs 2014 to 2021

Image similarity and image recognition are modern and rapidly growing technologies because of their wide use in the field of digital image processing. It is possible to recognize the face image of a specific person by finding the similarity between the images of the same person face and this is what we will address in detail in this paper. In this paper, we designed two new measures for image similarity and image recognition simultaneously. The proposed measures are based mainly on a combination of information theory and joint histogram. Information theory has a high capability to predict the relationship between …


Semi-Transparent Energy-Harvesting Solar Concentrator Windows Employing Infrared Transmission-Enhanced Glass And Large-Area Microstructured Diffractive Elements, Mikhail Vasiliev, Kamal Alameh, Mohsin Badshah, Seok-Min Kim, Mohammad Alam Jan 2018

Semi-Transparent Energy-Harvesting Solar Concentrator Windows Employing Infrared Transmission-Enhanced Glass And Large-Area Microstructured Diffractive Elements, Mikhail Vasiliev, Kamal Alameh, Mohsin Badshah, Seok-Min Kim, Mohammad Alam

Research outputs 2014 to 2021

We report on the study of energy-harvesting performance in medium-size (400 cm2) glass-based semitransparent solar concentrators employing edge-mounted photovoltaic modules. Systems using several different types of glazing system architecture and containing embedded diffractive structures are prepared and characterized. The technological approaches to the rapid manufacture of large-area diffractive elements suitable for use in solar window-type concentrators are described. These elements enable the internal deflection and partial trapping of light inside glass-based concentrator windows. We focus on uncovering the potential of pattern-transfer polymer-based soft lithography for enabling both the improved photon collection probability at solar cell surfaces, and the …


Towards Characterizing Lnapl Remediation Endpoints, Kaveh Sookhak Lari, John L. Rayner, Greg B. Davis Jan 2018

Towards Characterizing Lnapl Remediation Endpoints, Kaveh Sookhak Lari, John L. Rayner, Greg B. Davis

Research outputs 2014 to 2021

Remediating sites contaminated with light non-aqueous phase liquids (LNAPLs) is a demanding and often prolonged task. It is vital to determine when it is appropriate to cease engineered remedial efforts based on the long-term effectiveness of remediation technology options. For the first time, the long term effectiveness of a range of LNAPL remediation approaches including skimming and vacuum-enhanced skimming each with and without water table drawdown was simulated through a multi-phase and multi-component approach. LNAPL components of gasoline were simulated to show how component changes affect the LNAPL's multi-phase behaviour and to inform the risk profile of the LNAPL. The …


Real Time Spectroscopic Ellipsometry Analysis Of First Stage Cuin1-Xgaxse2 Growth: Indium-Gallium Selenide Co-Evaporation, Puja Pradhan, Puruswottam Aryal, Dinesh Attygalle, Abdel-Rahman Ibdah, Prakash Koirala, Jian Li, Khagendra P. Bhandari, Geethika K. Liyanage, Randy J. Ellingson, Michael J. Heben, Sylvain Marsillac, Robert W. Collins, Nikolas J. Podraza Jan 2018

Real Time Spectroscopic Ellipsometry Analysis Of First Stage Cuin1-Xgaxse2 Growth: Indium-Gallium Selenide Co-Evaporation, Puja Pradhan, Puruswottam Aryal, Dinesh Attygalle, Abdel-Rahman Ibdah, Prakash Koirala, Jian Li, Khagendra P. Bhandari, Geethika K. Liyanage, Randy J. Ellingson, Michael J. Heben, Sylvain Marsillac, Robert W. Collins, Nikolas J. Podraza

Electrical & Computer Engineering Faculty Publications

Real time spectroscopic ellipsometry (RTSE) has been applied for in-situ monitoring of the first stage of copper indium-gallium diselenide (CIGS) thin film deposition by the three-stage co-evaporation process used for fabrication of high efficiency thin film photovoltaic (PV) devices. The first stage entails the growth of indium-gallium selenide (In1-xGax)₂Se₃ (IGS) on a substrate of Mo-coated soda lime glass maintained at a temperature of 400 °C. This is a critical stage of CIGS deposition because a large fraction of the final film thickness is deposited, and as a result precise compositional control is desired in order to …


Assessment Of Spatiotemporal Fusion Algorithms For Planet And Worldview Images, Chiman Kwan, Xiaolin Zhu, Feng Gao, Bryan Chou, Daniel Perez, Jinag Li, Yuzhong Shen, Krzysztof Koperski, Giovanni Marchisio Jan 2018

Assessment Of Spatiotemporal Fusion Algorithms For Planet And Worldview Images, Chiman Kwan, Xiaolin Zhu, Feng Gao, Bryan Chou, Daniel Perez, Jinag Li, Yuzhong Shen, Krzysztof Koperski, Giovanni Marchisio

Electrical & Computer Engineering Faculty Publications

Although Worldview-2 (WV) images (non-pansharpened) have 2-m resolution, the re-visit times for the same areas may be seven days or more. In contrast, Planet images are collected using small satellites that can cover the whole Earth almost daily. However, the resolution of Planet images is 3.125 m. It would be ideal to fuse these two satellites images to generate high spatial resolution (2 m) and high temporal resolution (1 or 2 days) images for applications such as damage assessment, border monitoring, etc. that require quick decisions. In this paper, we evaluate three approaches to fusing Worldview (WV) and Planet images. …


Fast Identification Of High Utility Itemsets From Candidates, Jun-Feng Qu, Mengchi Liu, Chunsheng Xin, Zhongbo Wu Jan 2018

Fast Identification Of High Utility Itemsets From Candidates, Jun-Feng Qu, Mengchi Liu, Chunsheng Xin, Zhongbo Wu

Electrical & Computer Engineering Faculty Publications

High utility itemsets (HUIs) are sets of items with high utility, like profit, in a database. Efficient mining of high utility itemsets is an important problem in the data mining area. Many mining algorithms adopt a two-phase framework. They first generate a set of candidate itemsets by roughly overestimating the utilities of all itemsets in a database, and subsequently compute the exact utility of each candidate to identify HUIs. Therefore, the major costs in these algorithms come from candidate generation and utility computation. Previous works mainly focus on how to reduce the number of candidates, without dedicating much attention to …


Transient Lattice Deformations Of Crystals Studied By Means Of Ultrafast Time-Resolved X-Ray And Electron Diffraction, Runze Li, Kyle Sundqvist, Jie Chen, H. E. Elsayed-Ali, Jie Zhang, Peter M. Rentzepis Jan 2018

Transient Lattice Deformations Of Crystals Studied By Means Of Ultrafast Time-Resolved X-Ray And Electron Diffraction, Runze Li, Kyle Sundqvist, Jie Chen, H. E. Elsayed-Ali, Jie Zhang, Peter M. Rentzepis

Electrical & Computer Engineering Faculty Publications

Ultrafast lattice deformation of tens to hundreds of nanometer thick metallic crystals, after femtosecond laser excitation, was measured directly using 8.04 keV subpicosecond x-ray and 59 keV femtosecond electron pulses. Coherent phonons were generated in both single crystal and polycrystalline films. Lattice compression was observed within the first few picoseconds after laser irradiation in single crystal aluminum, which was attributed to the generation of a blast force and the propagation of elastic waves. The different time scales of lattice heating for tens and hundreds nanometer thick films are clearly distinguished by electron and x-ray pulse diffraction. The electron and lattice …


Plasma Medicine: A Brief Introduction, Mounir Laroussi Jan 2018

Plasma Medicine: A Brief Introduction, Mounir Laroussi

Electrical & Computer Engineering Faculty Publications

This mini review is to introduce the readers of Plasma to the field of plasma medicine. This is a multidisciplinary field of research at the intersection of physics, engineering, biology and medicine. Plasma medicine is only about two decades old, but the research community active in this emerging field has grown tremendously in the last few years. Today, research is being conducted on a number of applications including wound healing and cancer treatment. Although a lot of knowledge has been created and our understanding of the fundamental mechanisms that play important roles in the interaction between low temperature plasma and …


Evaluation Of Procurement Scenarios In One-Dimensional Cutting Stock Problem With A Random Demand Mix, Hüseyin Sarper, Nebojsa I. Jaksic Jan 2018

Evaluation Of Procurement Scenarios In One-Dimensional Cutting Stock Problem With A Random Demand Mix, Hüseyin Sarper, Nebojsa I. Jaksic

Electrical & Computer Engineering Faculty Publications

The one-dimensional cutting stock problem describes the problem of cutting standard length stock material into various specified sizes while minimizing the material wasted (the remnant or drop as manufacturing terms). This computationally complex optimization problem has many manufacturing applications. One-dimensional cutting stock problems arise in many domains such as metal, paper, textile, and wood. To solve it, the problem is formulated as an integer linear model first, and then solved using a common optimizer software. This paper revisits the stochastic version of the problem and proposes a priority-based goal programming approach. Monte Carlo simulation is used to simulate several likely …


Study Of Biomimetic Micro And Macro Structures For Drag Reduction, Justin S. Schrout Jan 2018

Study Of Biomimetic Micro And Macro Structures For Drag Reduction, Justin S. Schrout

Graduate Theses, Dissertations, and Problem Reports (ETD)

The ever increasing demand for global travel coupled with increasing costs of fuels have prompted many researchers to study new methods to save fuel to make travel more efficient. One of the proverbial low-hanging fruits for fuel efficiency is aerodynamic drag reduction. Simple changes in the shape or placement of structures on the surface of different types of vehicles have been shown to increase fuel efficiency by reducing drag (e.g., add-on lower and aft wake fairings on tractor trailers which have seen a tremendous rise in popularity on US highways in recent years). Areas of interest in drag reduction have …


An Origami-Based Thickness-Accommodating Bistable Mechanism In Monolithic Thick-Sheet Materials, Larry L. Howell, Spencer P. Magleby, Nathan A. Pehrson Jan 2018

An Origami-Based Thickness-Accommodating Bistable Mechanism In Monolithic Thick-Sheet Materials, Larry L. Howell, Spencer P. Magleby, Nathan A. Pehrson

Faculty Publications

Origami-based mechanisms can provide useful capabilities in folding large structures to stow in small volumes. However, when using monolithic thick-sheet materials for these types of mechanisms, accommodating the thickness proves challenging. One approach to solve this is to create compliant mechanisms along the fold lines that inherently store energy when actuated and causes the mechanism to tend toward its low energy state. This tendency can be used to create bistable states. We outline a method to use this stored energy to achieve bistable states and name the resulting mechanism an origami-based “Thickness-accommodating bistable interior vertex” (TABIV) in monolithic thick-sheet materials. …


Co2 Saturated Brine Injected Into Fractured Shale: An X-Ray Micro-Tomography In-Situ Analysis At Reservoir Conditions, Hongyan Yu, Yihuai Zhang, Maxim Lebedev, Zhenliang Wang, Jinfeng Ma, Zhihao Cui, Michael Verrall, Andrew Squelch, Stefan Iglauer Jan 2018

Co2 Saturated Brine Injected Into Fractured Shale: An X-Ray Micro-Tomography In-Situ Analysis At Reservoir Conditions, Hongyan Yu, Yihuai Zhang, Maxim Lebedev, Zhenliang Wang, Jinfeng Ma, Zhihao Cui, Michael Verrall, Andrew Squelch, Stefan Iglauer

Research outputs 2014 to 2021

Fracture morphology and permeability are key factors in enhanced gas recovery (EOR) and Carbon Geo-storage (CCS) in shale gas reservoirs as they determine production and injection rates. However, the exact effect of CO2-saturated (live) brine on shale fracture morphology, and how the permeability changes during live brine injection and exposure is only poorly understood. We thus imaged fractured shale samples before and after live brine injection in-situ at high resolution in 3D via X-ray micro-computed tomography. Clearly, the fractures’ aperture and connectivity increased after live brine injection.


Distributed Electric Propulsion Effects On Traditional Aircraft Through Multidisciplinary Optimization, Kevin Moore, Andrew Ning Jan 2018

Distributed Electric Propulsion Effects On Traditional Aircraft Through Multidisciplinary Optimization, Kevin Moore, Andrew Ning

Faculty Publications

Electric aircraft face a steep tradeoff between the demand for runway performance and range. While fuel based propulsion technologies typically increase in specific power with increasing size, electric propulsion is typically much more scalable. This system scalability enables alternative designs including distributed propulsion, optionally powered propulsion units, and vectored thrust, which can all contribute to better runway performance and range. In this paper, we explore how continuously powered distributed propulsion can reduce takeoff distance while still satisfying range constraints. We use a combination of a blade element momentum method, a vortex lattice method, experimental data, and nonlinear optimization techniques to …