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Articles 91741 - 91770 of 197988

Full-Text Articles in Engineering

The Role Of Surface Active Compounds In Crude Oil On Reservoir Wettability., Paulina Metili Mwangi Jan 2017

The Role Of Surface Active Compounds In Crude Oil On Reservoir Wettability., Paulina Metili Mwangi

LSU Doctoral Dissertations

This study examines the role of crude oil’s surface active compounds (SAC) in determining the reservoir wettability. Wettability describes the relative preference of a reservoir rock for oil or water. Wettability influences the distribution of fluids in a reservoir and the efficiency of oil recovery methods. Unfortunately, the chemical mechanisms controlling wettability in individual reservoirs remain hazy. Wettability is conditional and is influenced by rock mineralogy, fluid chemistry, and temperature. An extensive experimental study was executed to understand the impact of naturally-occurring SACs typically found in crude oil, on the wettability of sandstone and carbonate rocks over a range of …


Channel Estimation And Symbol Detection In Massive Mimo Systems Using Expectation Propagation, Kamran Ghavami Jan 2017

Channel Estimation And Symbol Detection In Massive Mimo Systems Using Expectation Propagation, Kamran Ghavami

LSU Doctoral Dissertations

The advantages envisioned from using large antenna arrays have made massive multiple- input multiple-output systems (also known as massive MIMO) a promising technology for future wireless standards. Despite the advantages that massive MIMO systems provide, increasing the number of antennas introduces new technical challenges that need to be resolved. In particular, symbol detection is one of the key challenges in massive MIMO. Obtaining accurate channel state information (CSI) for the extremely large number of chan- nels involved is a difficult task and consumes significant resources. Therefore for Massive MIMO systems coherent detectors must be able to cope with highly imperfect …


Analysis And Optimization Of Scientific Applications Through Set And Relation Abstractions, M. Tohid (Rastegar Tohid, Mohammed) Jan 2017

Analysis And Optimization Of Scientific Applications Through Set And Relation Abstractions, M. Tohid (Rastegar Tohid, Mohammed)

LSU Doctoral Dissertations

Writing high performance code has steadily become more challenging since the design of computing systems has moved toward parallel processors in forms of multi and many-core architectures. This trend has resulted in exceedingly more heterogeneous architectures and programming models. Moreover, the prevalence of distributed systems, especially in fields relying on supercomputers, has caused the programming of such diverse environment more difficulties. To mitigate such challenges, an assortment of tools and programming models have been introduced in the past decade or so. Some efforts focused on the characteristics of the code, such as polyhedral compilers (e.g. Pluto, PPCG, etc.) while others …


Distributed Kalman Filters Over Wireless Sensor Networks: Data Fusion, Consensus, And Time-Varying Topologies, Jianming Zhou Jan 2017

Distributed Kalman Filters Over Wireless Sensor Networks: Data Fusion, Consensus, And Time-Varying Topologies, Jianming Zhou

LSU Doctoral Dissertations

Kalman filtering is a widely used recursive algorithm for optimal state estimation of linear stochastic dynamic systems. The recent advances of wireless sensor networks (WSNs) provide the technology to monitor and control physical processes with a high degree of temporal and spatial granularity. Several important problems concerning Kalman filtering over WSNs are addressed in this dissertation. First we study data fusion Kalman filtering for discrete-time linear time-invariant (LTI) systems over WSNs, assuming the existence of a data fusion center that receives observations from distributed sensor nodes and estimates the state of the target system in the presence of data packet …


Osteogenic Potential Of Poly (L-Lactic Acid) Scaffolds Prepared By Thermally Controlled Methods On Human Adipose Derived Stem Cells, Harish Chinnasami Shanmugam Jan 2017

Osteogenic Potential Of Poly (L-Lactic Acid) Scaffolds Prepared By Thermally Controlled Methods On Human Adipose Derived Stem Cells, Harish Chinnasami Shanmugam

LSU Doctoral Dissertations

Thermally Induced Phase Separation (TIPS) method was used to make porous three-dimensional PLLA scaffolds. The effect of imposed thermal profile during freezing of the PLLA in dioxane solution on the scaffold was characterized by their micro-structure, porosity (%), pore-sizes distribution and mechanical strength. The porosity (%) decreased considerably with increasing concentrations of PLLA in the solution, while a decreasing trend was observed with increasing cooling rates. The mechanical strength increases with increase in PLLA concentration and also with increase in the cooling rate for both types of solvents. Therefore, mechanical strength was increased by higher cooling rates while the porosity …


Microcavity Enhanced Beaming And Magneto-Optical Switching Of Light, Ali Haddadpour Jan 2017

Microcavity Enhanced Beaming And Magneto-Optical Switching Of Light, Ali Haddadpour

LSU Doctoral Dissertations

In this dissertation, we show numerically that a compact structure, consisting of multiple optical microcavities at both the entrance and exit sides of a subwavelength plasmonic slit, can lead to greatly enhanced directional transmission through the slit. The microcavities increase the resonant enhancement of the emission in the normal direction and/or the coupling between free space waves and the slit mode. An optimized structure with two microcavities on both the entrance and exit sides of the slit leads to ~ 16 times larger transmission cross section per unit angle in the normal direction compared to the optimized reference slit without …


The Formation Of Polycyclic Aromatic Hydrocarbons From The Pyrolysis Of Model 1-Alkene Fuels, Eva Christine Caspary Jan 2017

The Formation Of Polycyclic Aromatic Hydrocarbons From The Pyrolysis Of Model 1-Alkene Fuels, Eva Christine Caspary

LSU Doctoral Dissertations

To understand the role of 1-alkenes and allylic radicals in the reaction pathways leading to the formation and growth of polycyclic aromatic hydrocarbons (PAH), pyrolysis experiments have been performed with three 1-alkene fuels—propylene (CH₂=CH–CH₃), 1-butene (CH₂=CH–CH₂–CH₃), and 1-pentene (CH₂=CH–CH₂–CH₂–CH₃)—at temperatures of 600 – 1000 °C and a fixed residence time of 0.31 s. The experiments are carried out in an isothermal laminar-flow quartz-tube reactor. Analyses of the pyrolysis products by gas-chromatographic and high-pressure liquid-chromatographic techniques reveal that the three fuels differ in: 1) their conversion behavior, 2) the relative amounts of the major C₂ – C₄ species produced, and 3) …


Atmospheric Boundary Layer Processes To Mimic Peak Pressures On Low-Rise Buildings: Cfd Versus Full-Scale And Wind Tunnel Measurements, Hamzeh Gol Zaroudi Jan 2017

Atmospheric Boundary Layer Processes To Mimic Peak Pressures On Low-Rise Buildings: Cfd Versus Full-Scale And Wind Tunnel Measurements, Hamzeh Gol Zaroudi

LSU Doctoral Dissertations

Realistic prediction of peak wind pressures is indispensable in a safe design of low-rise buildings. For several decades wind tunnel testing was employed to obtain wind loads on buildings and other structures. However, there is still doubt in the wind engineering community regarding the adequacy of wind tunnels to predict accurately full-scale pressures on low-rise buildings and small-size structures. The recommendations of the American Society of Civil Engineers (ASCE) 7-10 standard for external pressure coefficients, for roof components and cladding (C&C) design are also based on published wind tunnel data. Recent field measurements show significant deviation of full-scale pressures from …


Modeling Of Size Effects In Metallic Samples Of Confined Volumes, Mohammadreza Yaghoobi Jan 2017

Modeling Of Size Effects In Metallic Samples Of Confined Volumes, Mohammadreza Yaghoobi

LSU Doctoral Dissertations

In material science, size effects is described as the variation of material properties as the sample size changes. In this dissertation, the size dependency of the material strength is addressed as size effects. The size effects underlying mechanisms depend on the nature of the considered material. In the case of crystalline metals, size effects in crystalline metals are governed by the dislocations, as the primary deformation mechanism, and their interactions with one another and other defects such as grain boundaries. In this dissertation, the size and strain rate effects of fcc metallic samples of confined volumes are investigated during the …


Modeling Of Two Dimensional Graphene And Non-Graphene Material Based Tunnel Field Effect Transistors For Integrated Circuit Design, Md Shamiul Fahad Jan 2017

Modeling Of Two Dimensional Graphene And Non-Graphene Material Based Tunnel Field Effect Transistors For Integrated Circuit Design, Md Shamiul Fahad

LSU Doctoral Dissertations

The Moore’s law of scaling of metal oxide semiconductor field effect transistor (MOSFET) had been a driving force toward the unprecedented advancement in development of integrated circuit over the last five decades. As the technology scales down to 7 nm node and below following the Moore’s law, conventional MOSFETs are becoming more vulnerable to extremely high off-state leakage current exhibiting a tremendous amount of standby power dissipation. Moreover, the fundamental physical limit of MOSFET of 60 mV/decade subthreshold slope exacerbates the situation further requiring current transport mechanism other than drift and diffusion for the operation of transistors. One way to …


Advances On Software Defined Wireless Networking, D. B. Rawat, M. Song, C. Xin Jan 2017

Advances On Software Defined Wireless Networking, D. B. Rawat, M. Song, C. Xin

Electrical & Computer Engineering Faculty Publications

Software defined wireless networking is regarded as an emerging technology to enhance spectrum efficiency and improve the overall network performance. In this paper, we summarise the special issue on recent advances in software defined wireless networking. Specifically, this special issue publishes following findings: i) a novel context aware medium access control scheme for multichannel buffer-aided cognitive networks to reduce the delay by exploiting the packets’ contexts; ii) a utility-based uplink scheduling algorithm that accommodates different performance metrics and adapts its decisions based on user-specified profiles by incorporating an intermediary layer between the MAC and network layer; iii) an opportunistic spectrum …


Design Of Electrical Layout Of Offshore Wind Farms, Shirshak K. Dhali, Mahidhar Nandigam Jan 2017

Design Of Electrical Layout Of Offshore Wind Farms, Shirshak K. Dhali, Mahidhar Nandigam

Electrical & Computer Engineering Faculty Publications

The cost and efficiency of offshore wind farms are determined by a variety of factors which include the type of electrical system (AC or DC), transmission length, transmission voltage, rated power, wind turbine type, farm topology, and wind speed. Since the design variable space is large for such problems, computational optimization is necessary to find an optimal solution. This paper discusses a design methodology to determine the optimal values of components to minimize the cost of an offshore wind farm. The cost, loss, reliability models, and the application of geometric programing for optimization of the layout and configuration of an …


Selective Fusion Of Structural And Functional Data For Improved Glaucoma Detection, Paul Y. Kim, Khan M. Iftekharuddin, Pinakin G. Davey, Gabor Holló, Martha Tóth, Anita Garas, Edward A. Essock Jan 2017

Selective Fusion Of Structural And Functional Data For Improved Glaucoma Detection, Paul Y. Kim, Khan M. Iftekharuddin, Pinakin G. Davey, Gabor Holló, Martha Tóth, Anita Garas, Edward A. Essock

Electrical & Computer Engineering Faculty Publications

This work proposes novel selective feature fusion of structural and functional data for improved glaucoma detection. The structural data such as retinal nerve fiber layer (RNFL) thickness measurement acquired by scanning laser polarimetry (SLP) is fused with the functional visual field (VF) measurement recorded from the standard automated perimetry (SAP) test. The proposed selective feature fusion exploits correspondence between structural and functional data obtained over multiple sectors. The correlation coefficients for corresponding structural-function sector pairs are used as weights in subsequent feature selection. The sectors are ranked according to the correlation coefficients and the first four highly ranked sectors are …


Siso Output Affine Feedback Transformation Group And Its Faá Di Bruno Hopf Algebra, W. Steven Gray, Kurusch Ebrahimi-Fard Jan 2017

Siso Output Affine Feedback Transformation Group And Its Faá Di Bruno Hopf Algebra, W. Steven Gray, Kurusch Ebrahimi-Fard

Electrical & Computer Engineering Faculty Publications

The general goal of this paper is to identify a transformation group that can be used to describe a class of feedback interconnections involving subsystems which are modeled solely in terms of Chen-Fliess functional expansions or Fliess operators and are independent of the existence of any state space models. This interconnection, called an output affine feedback connection, is distinguished from conventional output feedback by the presence of a multiplier in an outer loop. Once this transformation group is established, three basic questions are addressed. How can this transformation group be used to provide an explicit Fliess operator representation of …


Seebeck Coefficient Measurements Of Polycrystalline And Highly Ordered Metal-Organic Framework Thin Films, Xin Chen, Zhenbang Wang, Zeinab M. Hassan, Pengtao Lin, Kai Zhang, Helmut Baumgart, Engelbert Redel Jan 2017

Seebeck Coefficient Measurements Of Polycrystalline And Highly Ordered Metal-Organic Framework Thin Films, Xin Chen, Zhenbang Wang, Zeinab M. Hassan, Pengtao Lin, Kai Zhang, Helmut Baumgart, Engelbert Redel

Electrical & Computer Engineering Faculty Publications

In this work highly oriented Surface Anchored Metal-Organic Framework (SURMOF) films were fabricated quasi-epitaxial and were electrically characterized by Seebeck analysis and benchmarked against random polycrystalline MOF films loaded with tetracyano-quinodimethane (TCNQ) infiltration. The horizontal Seebeck coefficient of the oriented SURMOF films and the random polycrystalline MOF films parallel to the sample surface was measured and has been discussed. The isotropic random polycrystalline MOF films exhibit a high positive Seebeck coefficient of 422.32 μV/K at 350 K. However, the horizontal Seebeck coefficient of highly oriented SURMOF films fluctuates around 0 μV/K instead. Because the quasi-epitaxial oriented SURMOF films are highly …


Light Soaking Phenomena In Organic-Inorganic Mixed Halide Perovskite Single Crystals, Hye Ryung Byun, Dae Young Park, Hye Min Oh, Gon Namkoong, Mun Seok Jeong Jan 2017

Light Soaking Phenomena In Organic-Inorganic Mixed Halide Perovskite Single Crystals, Hye Ryung Byun, Dae Young Park, Hye Min Oh, Gon Namkoong, Mun Seok Jeong

Electrical & Computer Engineering Faculty Publications

Recently, organic inorganic mixed halide perovskite (MAPbX3; MA = CH3NH3+, X = Cl-, Br-, or I-) single crystals with low defect densities have been highlighted as candidate materials for high-efficiency photovoltaics and optoelectronics. Here we report the optical and structural investigations of mixed halide perovskite (MAPbBr3-xIx) single crystals. Mixed halide perovskite single crystals showed strong light soaking phenomena with light illumination conditions that were correlated to the trapping and detrapping events from defect sites. By systematic investigation with optical analysis, we found that the …


Impact Of Trucking Network Flow On Preferred Biorefinery Locations In The Southern United States, Timothy M. Young, Lee D. Han, James H. Perdue, Stephanie R. Hargrove, Frank M. Guess, Xia Huang, Chung-Hao Chen Jan 2017

Impact Of Trucking Network Flow On Preferred Biorefinery Locations In The Southern United States, Timothy M. Young, Lee D. Han, James H. Perdue, Stephanie R. Hargrove, Frank M. Guess, Xia Huang, Chung-Hao Chen

Electrical & Computer Engineering Faculty Publications

The impact of the trucking transportation network flow was modeled for the southern United States. The study addresses a gap in existing research by applying a Bayesian logistic regression and Geographic Information System (GIS) geospatial analysis to predict biorefinery site locations. A one-way trucking cost assuming a 128.8 km (80-mile) haul distance was estimated by the Biomass Site Assessment model. The "median family income," "timberland annual growth-to-removal ratio," and "transportation delays" were significant in determining mill location. Transportation delays that directly impacted the costs of trucking are presented. A logistic model with Bayesian inference was used to identify preferred site …


Deep Models For Engagement Assessment With Scarce Label Information, Feng Li, Guangfan Zhang, Wei Wang, Roger Xu, Tom Schnell, Jonathan Wen, Frederic Mckenzie, Jiang Li Jan 2017

Deep Models For Engagement Assessment With Scarce Label Information, Feng Li, Guangfan Zhang, Wei Wang, Roger Xu, Tom Schnell, Jonathan Wen, Frederic Mckenzie, Jiang Li

Electrical & Computer Engineering Faculty Publications

Task engagement is defined as loadings on energetic arousal (affect), task motivation, and concentration (cognition) [1]. It is usually challenging and expensive to label cognitive state data, and traditional computational models trained with limited label information for engagement assessment do not perform well because of overfitting. In this paper, we proposed two deep models (i.e., a deep classifier and a deep autoencoder) for engagement assessment with scarce label information. We recruited 15 pilots to conduct a 4-h flight simulation from Seattle to Chicago and recorded their electroencephalograph (EEG) signals during the simulation. Experts carefully examined the EEG signals and labeled …


Teaching Hands-On Cyber Defense Labs To Middle School And High School Students: Our Experience From Gencyber Camps, Peng Jiang, Xin Tian, Chunsheng Xin, Wu He Jan 2017

Teaching Hands-On Cyber Defense Labs To Middle School And High School Students: Our Experience From Gencyber Camps, Peng Jiang, Xin Tian, Chunsheng Xin, Wu He

Electrical & Computer Engineering Faculty Publications

With the high demand of the nation for next generation cybersecurity experts, it is important to design and provide hands-on labs for students at the K-12 level in order to increase their interest in cybersecurity and enhance their confidence in learning cybersecurity skills at the young age. This poster reports some preliminary analysis results from the 2016 GenCyber summer camp held at Old Dominion University (ODU), which is part of a nationwide grant program funded by the National Security Agency (NSA) and the National Science Foundation (NSF). This poster also demonstrates the design of three hands-on labs which have been …


Metal Cutting And Manufacturing Economics Project For Freshmen, Hüseyin Sarper, Nebojsa I. Jaksic, Linda Vahala Jan 2017

Metal Cutting And Manufacturing Economics Project For Freshmen, Hüseyin Sarper, Nebojsa I. Jaksic, Linda Vahala

Electrical & Computer Engineering Faculty Publications

This paper describes a laboratory experiment and a team project to teach manufacturing concepts to new students. This project is one of two team projects of 1.5 credit portion of a two-credit course in exploration of engineering and technology. This course teaches students skills they need late and teamwork is a major skill that they acquire. They organize into a group with specialized responsibilities for the purpose of calculating the total production time and cost of a manufactured part using turning, drilling, and milling operations. Students also learn or improve spreadsheet skills while performing data entry and necessary machining calculations. …


New Efficient And Robust Multimedia Archiving Technique Using Quick-Response Codes, Sayani Sarkar Jan 2017

New Efficient And Robust Multimedia Archiving Technique Using Quick-Response Codes, Sayani Sarkar

LSU Master's Theses

A Quick Response (QR) code is a two-dimensional bar-code, which is quite popular due to its excellent storage capacity and error resilience. Generally, QR codes are widely used to store text information such as URL links, geographical coordinates, name cards, inventory information, authorship, etc. To reach the current limit of QR codes, in this thesis, we would like to propose an innovative multimedia archiving technique, which is built upon the advanced signal processing scheme to tackle the multiple QR codes all at once. The multimedia data often include texts, images, audio data, special-purpose codes, music files etc. The recently proposed …


Accumulation And Dynamics Of Petrogenic Pahs On Leaves Of Black Mangrove (Avicennia Germinans), Matthew Decell Jan 2017

Accumulation And Dynamics Of Petrogenic Pahs On Leaves Of Black Mangrove (Avicennia Germinans), Matthew Decell

LSU Master's Theses

Crude oil from Deepwater Horizon Macondo oil spill is currently present in Louisiana coastal surface sediments and its effects on the coastal ecosystem are still being realized. Deposition of 2- and 3-ring PAHs (alkylated naphthalenes and phenanthrenes) on the exterior of Spartina alterniflora and Avicennia germinans leaves have been demonstrated in marshes impacted by Macondo spill. Whether these deposition events result from contaminated tidal water or volatilization followed by deposition onto the leaf surface has not been conclusively established. Measurements of PAH deposition on the leaf surface of black mangrove (Avicennia germinans) can provide important evidence of the mechanism of …


Novel Design Of Nanostructured Material For Advanced Energy Conversion And Storage Devices, Wangwang Xu Jan 2017

Novel Design Of Nanostructured Material For Advanced Energy Conversion And Storage Devices, Wangwang Xu

LSU Master's Theses

Nowadays, the fast-increasing energy demand for efficient, sustainable and environmentally-friendly energy storage devices remains a significant and challenging issue. Lithium ion batteries (LIBs) have been widely used as commercial energy devices in portable electronics and also shown great promise in upcoming large scale applications due to their advantages of environmental safety, efficiency in energy delivering and light weight. However, due to their limited capacity, energy densities and cycle ability, LIBs still need further improvement to expand their applications to a larger field, especially electric vehicle (EVs) and hybrid electric vehicles (HEVs), in which energy storage devices with large capacity and …


Heat And Mass Transfer In A Cylindrical Heat Pipe With Idealized Porous Lining, Pramesh Regmi Jan 2017

Heat And Mass Transfer In A Cylindrical Heat Pipe With Idealized Porous Lining, Pramesh Regmi

LSU Master's Theses

Many devices use heat pipes for cooling. They can be of different cross-sectional shapes and can range from 15 m long to 10 mm. In this work, the heat and mass transfer in a cylindrical heat pipe is modelled. The heat pipe is lined with a wick next to the wall. The wick consists of straight capillaries that run the whole length of the pipe and radially aligned capillaries that span the width of the wick. The capillaries are filled with a partially wetting liquid, and the center of the pipe is filled with its vapor. The radial capillaries are …


Impact Of Connected Vehicle Safety Applications On Driving Behavior At Varying Market Penetrations: A Driving Simulator Study, Matthew Alexander Theriot Jan 2017

Impact Of Connected Vehicle Safety Applications On Driving Behavior At Varying Market Penetrations: A Driving Simulator Study, Matthew Alexander Theriot

LSU Master's Theses

The studies conducted in this thesis evaluate the safety benefits of a blind spot warning (BSW) application and a do not pass warning (DNPW) application at low, medium, and high market penetrations (MP) of connected vehicles (CV) using a high-fidelity driving simulator. Using vehicle-to-vehicle (V2V) communication, CVs can exchange information to alert drivers of potential safety hazards and reduce potential crashes during lane change and overtaking maneuvers. A CV testbed was developed to relay visual and auditory warnings when dangerous thresholds were met for each application. For the BSW a proximity-based threshold was used to trigger a warning as a …


A Sound Idea: An Investigation Into Accessible Video Game Design For The Deaf And Hard Of Hearing, Luke James Brook Jan 2017

A Sound Idea: An Investigation Into Accessible Video Game Design For The Deaf And Hard Of Hearing, Luke James Brook

Theses: Doctorates and Masters

A widely accepted, and incorrect, assumption towards hearing accessibility in video games is that deaf and hard of hearing (DHH) users are those who encounter the least barriers and are generally well catered for. Rapid advancement in video game technology has seen video game sound evolve from simple blips generated by internal circuitry to fully realised digital audio used to convey critical information. To accommodate the DHH, this information needs to be conveyed in an alternative manner. However, evidence suggests existing accessible design solutions for the DHH lack specificity and are insufficient. Thus, the inability to hear, or hear well, …


From Gd2o3suspension To Nanocomposite: Synthesis, Properties And Radiation Protection, Ly B. T. La Jan 2017

From Gd2o3suspension To Nanocomposite: Synthesis, Properties And Radiation Protection, Ly B. T. La

Theses: Doctorates and Masters

This study provides details for the design, preparation of an environmentally friendly, clinically safe and lightweight radiation protective shield made ofGd2O3/epoxy nanocomposite (Gd-nanocomposite) which is proposed as an alternative to traditional toxic lead (Pb)-based aprons for diagnostic X-ray protection. In theory, this particulate nanocomposite can possess significant features of both inorganic particles and organic polymeric matrices. However, in practice, its performance does not simply depend on the sum of the individual contributions of characteristics of the constituent phases but on the interaction of their inner interfaces and the homogeneous dispersion of inorganic particles in the polymer matrix.

The miniaturization of …


Microstructure, Texture Evolution And Mechanical Properties Of Vt3-1 Titanium Alloy Processed By Multi-Pass Drawing And Subsequent Isothermal Annealing, Xiaofei Lei, Limin Dong, Zhiaqiang Zhang, Yujing Liu, Yulin Hao, Rui Yang, Laichang Zhang Jan 2017

Microstructure, Texture Evolution And Mechanical Properties Of Vt3-1 Titanium Alloy Processed By Multi-Pass Drawing And Subsequent Isothermal Annealing, Xiaofei Lei, Limin Dong, Zhiaqiang Zhang, Yujing Liu, Yulin Hao, Rui Yang, Laichang Zhang

Research outputs 2014 to 2021

Microstructure, texture evolution, and mechanical properties of Ti–6Al–1.5Cr–2.5Mo–0.5Fe–0.3Si (VT3-1) titanium alloy processed by multi-pass drawing and subsequent isothermal annealing were systematically investigated. A fiber-like microstructure is formed after warm drawing at 760 °C with 60% area reduction. After isothermal annealing, the samples deformed to different amounts of area reduction show a similar volume fraction (80%) of α phase, while the sample deformed to 60% exhibits a homogeneous microstructure with a larger grain size (5.8 μm). The major texture component of α phase developed during warm drawing is centered at a position of {φ1 = 10°, φ = 65°, φ …


Nanoscale In Photocatalysis, Zhaohui Wang, Hongqi Sun Jan 2017

Nanoscale In Photocatalysis, Zhaohui Wang, Hongqi Sun

Research outputs 2014 to 2021

Rationally harvesting sunlight to carry out chemical reactions, for example, photochemistry and photocatalysis, has appeared as a beautiful episode within the long history of solar-energy utilization by human beings. Before solar-driven chemical processes approach the scale of solar panel or solar thermal application, considerate efforts are still required from effective collaborations among academia, industries, and governments. Over past few decades, the photocatalysis frontier has been continuously explored by means of interdisciplinary research. Emerging understanding in the nanoscale is most likely to lead photocatalysis into the future.


Determination Of Forming Ability Of High Pressure Die Casting For Zr-Based Metallic Glass, Lehua Liu, Jiang Ma, Chunyan Yu, Xiusong Huang, Liangju He, Laichang Zhang, Peijie Li, Zhiyuan Liu Jan 2017

Determination Of Forming Ability Of High Pressure Die Casting For Zr-Based Metallic Glass, Lehua Liu, Jiang Ma, Chunyan Yu, Xiusong Huang, Liangju He, Laichang Zhang, Peijie Li, Zhiyuan Liu

Research outputs 2014 to 2021

Large-sized industrial grade Zr55Cu30Ni5Al10 bulk metallic glass (BMG) was fabricated by a two-step arc-melting process and adding a trace of rare earth yttrium elements. A model to calculate critical cooling rate for forming BMG was established by considering the effect of pressure. Based on the model, the most important indicator, namely the critical size of forming BMG, for design and fabrication of BMG components by high pressure die casting (HPDC) is determined in consideration of different processing parameters, including the pressure and casting temperature. Theoretical calculation and numerical simulation indicated that increasing applied …