Digital Commons Network^™

Understanding Impurities In Copper Electrometallurgy, Paul Laforest

Masters Theses

"This work involves examining two industrial reports of methods to handle impurities in copper electrowinning and electrorefining. The first part evaluates the addition of Hydrostar, Cyquest N-900, DXG-F7, and Guartec EW to copper electrowinning electrolyte to affect MnO₂ deposition on coated titanium anodes (CTAs). The second part examines the effects of anode chemistry and thiourea addition on the ductility of electrorefined copper starter sheet.

In part one, a laboratory cell was used to simulate a short cycle electrowinning cell via chronopotentiometric operation with an IrO₂-Ta₂O₅ CTA at 40⁰C. A cyclic voltammetric sweep was applied …

Sensitivity Of Cellular Oxidative Damage To Biosynthetic Rate And Metabolic Rate, Palihawadana Walauwe Kamalika Kaushalya Amunugama

Masters Theses

"The relationship between energy expenditure and longevity is a long standing question in aging studies. The empirical results have contradictory effects on the existing theories. A theoretical model and an experimental test of it were presented, revealing the detailed tradeoffs between metabolic rate, biosynthetic rate and cellular damage level. The dissipative mechanisms of oxidative metabolism cause various forms of cellular damages. To counteract the accumulation of damage, organisms have evolved highly efficient maintenance mechanisms. If there is no other energy demand possess, then most of the cellular damage would be repaired, regardless of how metabolic rate varies. However, the repairing …

Developing A Novel Methodolgy And Testbed For Fatigue Analysis Of Metal Specimens, Sai Aravind Palepu

Masters Theses

"A prototype of fatigue testing machine was built to determine the fatigue strength of materials. Proposed testing prototype was displacement controlled magnetic type bend fatigue testing machine. Designed prototype was tuned to operate at or near resonance of the specimen in order to amplify excitation displacement. Low maintenance i.e. zero wear of the parts was achieved, there were no moving components in the prototype machine. Crucial components used to build were: DC power supply, solenoid, Arduino UNO, supports and laser displacement sensor. DC source used to pass current through solenoid producing magnetic field; mosfet and Arduino generated square waves of …

Development Of Two Color Imaging Pyrometer For Studying Thermal History Of Laser Metal Deposition, Niroop Matta

Masters Theses

"The laser aided manufacturing process is a process in which parts are built by adding material into the melt pool created by a laser. This process involves a complex thermal history which is important in determining the quality of the parts built. The objective of this study is to develop a high resolution two color imaging pyrometer which can measure the temperature of an object without the dependence of spectral emissivity of the material at an economical price. An 8.8 MP CMOS sensor is used as an imaging sensor. The visible spectrum of light is used for temperature measurement. The …

A Gaussian Mixture Model For Automated Vesicle Fusion Detection And Classification, Haohan Li

Masters Theses

"Accurately detecting and classifying vesicle-plasma membrane fusion events in fluorescence microscopy, is of primary interest for studying biological activities in a close proximity to the plasma membrane. In this paper, we present a novel Gaussian mixture model for automated identification of vesicle-plasma membrane fusion and partial fusion events in total internal reflection fluorescence microscopy image sequences. Image patches of fusion event candidates are detected in individual images and linked over consecutive frames. A Gaussian mixture model is fit on each image patch of the patch sequence with outliers rejected for robust Gaussian fitting. The estimated parameters of Gaussian functions over …

Hybrid Manufacturing Process Of SicF/Sic Composite Using Preceramic Polymer, Robert Raymond Meinders

Masters Theses

"Continuous fiber-reinforced silicon carbide (SiC_f/SiC) ceramic composites have been increasingly used due to their high temperature strength and graceful failure mechanisms. A disadvantage is the high cost and lengthy production processes that are required to develop these materials. Polymer infiltration and pyrolysis (PIP) is one of the most attractive fabrication processes for composites due to shape flexibility, mass production and relatively low cost; however, the quality of material obtained by this method has been considered insufficient due to the microstructure defects of the material obtained. This study investigated a hybrid of multiple polymer manufacturing processes to maximize quality …

Parameter Determination And Experimental Validation Of A Wire Feed Additive Manufacturing Model, Kannan Suresh Kumar

Masters Theses

“Laser metal deposition is an additive manufacturing method with great scope and robustness. The wire fed additive manufacturing method has great opportunities in space applications and other zero gravity manufacturing processes. Process parameters play an important role in controlling the complex phenomenon and obtaining an ideal manufactured part. These parameters can be efficiently determined using simulation tools which are highly essential in visualizing real world experiments, therefore saving time and experimental costs. The objective of this study is to develop a transient 3D model of laser aided wire feed metal deposition which realizes the heat transfer and fluid flow behavior …

On The Design Of A Nearly Constant-Force Modular Device Based On A Compliant Slider Mechanism, Krutika Karthik

Masters Theses

"Compliant mechanisms derive some or all of their mobility from the deflection of their flexible members. A pseudo-rigid-body model (PRBM) provides a simple and efficient way of modeling and analyzing large deflections in compliant mechanisms. In this work, a partially compliant slider mechanism, composed of rigid and compliant segments as well as rigid-body revolute and prismatic pairs, is considered. In recent works, such mechanisms have been dimensionally synthesized to produce substantially constant-force output over a finite range of input link displacement in an in-line PRBM of a compliant slider mechanism. In this thesis, the current practice of using partially compliant …

On The Dynamic Analysis Of Compliant Mechanisms Based On The Pseudo-Rigid-Body Model, Andrew Christian

Masters Theses

"Compliant mechanisms derive some or all of their mobility from the deflection of flexible members. A pseudo-rigid-body model (PRBM) provides an elegant and simple way of modeling and analyzing traditionally nonlinear large-deflection problems pertaining to compliant mechanisms. In this work, several aspects pertainting to the dynamics of compliant mechanisms are considered. First, dynamic models are derived to predict not only the natural frequency of the large-deflection systems, but also the transient response, using the PRBM approach. A unique multi-stage damping model is developed to determine the transient response in free vibration. Recent works have neglected to consider the transient response …

Stochastic Interdigitation As A Toughening Mechanism At The Interface Between Tendon And Bone, Y. Hu, Victor Birman, A. Demyier-Black, A. G. Schwartz, S. Thomopoulos, G. M. Genin

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.

Searching For Stochastic Gravitational Waves Using Data From The Two Colocated Ligo Hanford Detectors, J. Aasi, Marco Cavaglia, For Full List Of Authors, See Publisher's Website.

Physics Faculty Research & Creative Works

Searches for a stochastic gravitational-wave background (SGWB) using terrestrial detectors typically involve cross-correlating data from pairs of detectors. The sensitivity of such cross-correlation analyses depends, among other things, on the separation between the two detectors: the smaller the separation, the better the sensitivity. Hence, a colocated detector pair is more sensitive to a gravitational-wave background than a noncolocated detector pair. However, colocated detectors are also expected to suffer from correlated noise from instrumental and environmental effects that could contaminate the measurement of the background. Hence, methods to identify and mitigate the effects of correlated noise are necessary to achieve the …

Mode-Multiplexed Transmission Over Conventional Graded-Index Multimode Fibers, Roland Ryf, Nicolas K. Fontaine, H. Chen, B. Guan, B. Huang, Mina Esmaeelpour

Electrical and Computer Engineering Faculty Research & Creative Works

We present experimental results for combined mode-multiplexed and wavelength multiplexed transmission over conventional graded-index multimode fibers. We use mode-selective photonic lanterns as mode couplers to precisely excite a subset of the modes of the multimode fiber and additionally to compensate for the differential group delay between the excited modes. Spatial mode filters are added to suppress undesired higher order modes. We transmit 30-Gbaud QPSK signals over 60 WDM channels, 3 spatial modes, and 2 polarizations, reaching a distance of 310 km based on a 44.3 km long span. We also report about transmission experiments over 6 spatial modes for a …

A Rapid And High Content Assay That Measures Cyto-Id-Stained Autophagic Compartments And Estimates Autophagy Flux With Potential Clinical Applications, Sujuan Guo, Yanping Liang, Susan F. Murphy, Angela Huang, Haihong Shen, Deborah F. Kelly, Pablo Sobrado, Zhi Sheng

Chemistry Faculty Research & Creative Works

The lack of a rapid and quantitative autophagy assay has substantially hindered the development and implementation of autophagy-targeting therapies for a variety of human diseases. To address this critical issue, we developed a novel autophagy assay using the newly developed Cyto-ID fluorescence dye. We first verified that the Cyto-ID dye specifically labels autophagic compartments with minimal staining of lysosomes and endosomes. We then developed a new Cyto-ID fluorescence spectrophotometric assay that makes it possible to estimate autophagy flux based on measurements of the Cyto-ID-stained autophagic compartments. By comparing to traditional autophagy approaches, we found that this assay yielded a more …

In Planta Variation Of Volatile Biosynthesis: An Alternative Biosynthetic Route To The Formation Of The Pathogen-Induced Volatile Homoterpene Dmnt Via Triterpene Degradation In Arabidopsis Roots, Reza Sohrabi, Jung Hyun Huh, Somayesadat Badieyan, Liva Harinantenaina Rakotondraibe, Daniel J. Kliebenstein, Pablo Sobrado, Dorothea Tholl

Chemistry Faculty Research & Creative Works

Plant-derived volatile compounds such as terpenes exhibit substantial structural variation and serve multiple ecological functions. Despite their structural diversity, volatile terpenes are generally produced from a small number of core 5- to 20-carbon intermediates. Here, we present unexpected plasticity in volatile terpene biosynthesis by showing that irregular homo/norterpenes can arise from different biosynthetic routes in a tissue specific manner. While Arabidopsis thaliana and other angiosperms are known to produce the homoterpene (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) or its C16-analog (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene by the breakdown of sesquiterpene and diterpene tertiary alcohols in aboveground tissues, we demonstrate that Arabidopsis roots biosynthesize DMNT by the degradation of …

One-Dimensional Triple Periodic Dual-Beam Microstrip Leaky-Wave Antenna, Zi Long Ma, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

In this letter, a novel dual-beam microstrip leaky-wave antenna based on one-dimensional triple periodic (TP) structure is proposed. Through theoretical dispersion relation analysis, it is found that compared to the conventional periodic structure, TP structure has reduced the separation of space harmonics. Hence, more space harmonic modes are brought into the leaky-wave radiation region. Through proper design, m = - 1 and m = - 2 modes are excited simultaneously. Consequently, the forward and backward propagation waves of these two modes generate two radiation beams in the far-field region. At different frequencies, symmetrical and asymmetrical beam pairs are realized. It …

Dispersion Characteristics Analysis Of One Dimensional Multiple Periodic Structures And Their Applications To Antennas, Zi Long Ma, Li (Lijun) Jun Jiang, Shulabh Gupta, Wei E.I. Sha

Electrical and Computer Engineering Faculty Research & Creative Works

This paper proposes a general characterization of one dimensional multiple periodic (MP) structures for electromagnetic transmission and radiation. Studies are conducted from three aspects: Firstly, the dispersion relations of non-dispersive (conventional) and dispersive (composite right/left-handed (CRLH)) materials are analyzed. Regarding each category of materials, detailed analyses for distributed layered media and lumped circuits are presented. Through studies, we found that the periodicity increase opens up multiple stopbands. According to our physical explanations and numerical results, the relation between stopbands and periodicity is clarified. Additionally, the periodicity increase also reduces the separation distance of space harmonic modes along the phase constant …

Electrospray Of An Energetic Ionic Liquid Monopropellant For Multi-Mode Micropropulsion Applications, Steven P. Berg, Joshua L. Rovey, Benjamin D. Prince, Shawn W. Miller, Raymond J. Bemish

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The multi-mode chemical-electric propulsion capable energetic ionic liquid propellant [Emim][EtSO4]-HAN is electro sprayed in a 100 µm capillary emitter to test the electric-mode performance of the propellant. The ionic liquid exhibits stable electrospray emission in both cation and anion extraction modes at a nominal extraction voltage of 3400 V. Near field measurements of current and mass flow rate distribution are taken at flow rates from 0.19 nL/s to 3.06 nL/s. Total emission current, as measured by Faraday cup and integrated, increases from 754 nA to 3195 nA for cation emission and from 552 nA to 2012 nA for anion emission. …

Linear Precoding For The Mimo Multiple Access Channel With Finite Alphabet Inputs And Statistical Csi, Yongpeng Wu, Chao Kai Wen, Chengshan Xiao, Xiqi Gao, Robert Schober

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, we investigate the design of linear precoders for the multiple-input-multiple-output (MIMO) multiple access channel (MAC). We assume that statistical channel state information (CSI) is available at the transmitters and consider the problem under the practical finite alphabet input assumption. First, we derive an asymptotic (in the large system limit) expression for the weighted sum rate (WSR) of the MIMO MAC with finite alphabet inputs and Weichselberger's MIMO channel model. Subsequently, we obtain the optimal structures of the linear precoders of the users maximizing the asymptotic WSR and an iterative algorithm for determining the precoders. We show that …

Damage Characteristics In 3d Stitched Composites With Various Stitch Parameters Under In-Plane Tension, Arief Yudhanto, Gilles Lubineau, Isaac Aguilar Ventura, Naoyuki Watanabe, Yutaka Iwahori, Hikaru Hoshi

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Three-dimensional (3D) reinforcement by stitching is effective in improving the impact resistance of composites. Stitching, however, adversely affects the composite's in-plane mechanical responses, and alters its damage mechanisms due to stitch-induced irregularities. We experimentally investigate the effect of two important stitch parameters, stitch density and thread diameter, on the damage characteristics of 3D stitched multidirectional composites under in-plane tension using X-ray radiography, X-ray micro-computed tomography and digital image correlation (DIC). Our study shows that composites stitched with thicker thread exhibit improved tensile strength due to effective hindrance of edge-delamination. We also found that stitch thread affects damage behaviors. A higher …

Low Complexity Polynomial Expansion Detector For Massive Mimo Uplink With Multiple-Antenna Users, An An Lu, Xiqi Gao, Chengshan Xiao

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a low complexity polynomial expansion (PE) detector for massive multi-input multi-output (MIMO) uplink transmissions is proposed. In contrast to most massive MIMO systems in the literature, where single-antenna user equipment's (UEs) are assumed, multiple-antenna UEs are employed in this paper. Furthermore, each link between a user and the base station forms a jointly correlated Rician fading channel. The PE detector reduces the complexity of the minimum mean square error (MMSE) detector by replacing the matrix inversion with an approximate matrix polynomial. In the design of the low complexity PE detector, the approximations of the moments of the …

Time-Domain Partial Element Equivalent Circuit Solver Including Non-Linear Magnetic Materials, Daniele Romano, Giulio Antonini, Albert E. Ruehli

Electrical and Computer Engineering Faculty Research & Creative Works

The PEEC solution of problems which include magnetic materials has recently been considered. Most of these solvers include linear magnetic material only. In this paper, we present a new PEEC solver including non-linear magnetic materials. A benchmark problem is presented in the time domain where the magnetic material operates in the non-linear region.

Palladium-Catalyzed Reaction Of Haloarenes With Diarylethynes: Synthesis, Structural Analysis, And Properties Of Methylene-Bridged Arenes, Che-Wei Lee, En Chih Liu, Yao-Ting Wu

Chemistry Faculty Research & Creative Works

Fluorenes and methylene-bridged polyarenes were easily and efficiently synthesized from haloarenes (or aryl triflates) and diarylethynes by a one-pot, two-step procedure. This protocol involves the palladium-catalyzed cycloisomerization and a subsequent base-mediated retro-aldol condensation. A major advantage is that the starting materials need not have ortho functional groups to complete the annulation. The backbone of the designed products was enlarged using dihaloarenes, highly π-conjugated haloarenes, or diarylalkynes. The mechanism of the formation of benzo[a]fluorene was investigated. The bowl-shaped structure of methylene-bridged indenocorannulene was verified by X-ray crystallography. The photophysical and electrochemical properties of the products thus prepared were investigated.

Mitochondria- Targeted Antioxidant Skq1 Reverses Glaucomatous Lesions In Rabbits, Elena N. Iomdina, Inna P. Khoroshilova-Maslova, Olga V. Robustova, Olga A. Averina, Nadezhda A. Kovaleva, Gjumrakch Aliev, V. Prakash Reddy, Andrey A. Zamyatnin, Maxim V. Skulachev, Ivan I. Senin, Vladimir P. Skulachev

Chemistry Faculty Research & Creative Works

Glaucoma is the main cause of irreversible blindness worldwide. This disease is characterized by apoptosis of retinal ganglion cells (RGC) and visual field loss that seems to be related to elevated intraocular pressure (IOP). Several lines of evidences have implicated the crucial role of mitochondrial dysfunction in the pathogenesis of glaucoma. Increased mitochondrial oxidative stress in RGC may underlie or contribute to susceptibility of RGC to apoptosis. In our work we (i) designed a rabbit model of chronic, moderately elevated IOP for studying glaucoma and (ii) demonstrated efficacy of mitochondria- Targeted antioxidant SkQ1 as a tool to reverse several traits …

Model For Consolidation Analysis Of Layered Soils Under Depth-Dependent Loading, Hefu Pu, Patrick J. Fox

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

A numerical model is presented for one-dimensional large strain consolidation of a layered soil stratum. The algorithm accounts for vertical strain, soil self-weight, conventional constitutive relationships, changing material properties during consolidation, unload/reload, time-dependent loading and boundary conditions, an externally applied hydraulic gradient, and multiple soil layers with different material properties. The model can also accommodate depth-dependent loading and variable preconsolidation stress profiles. Verification checks of the model show excellent agreement with available analytical and numerical solutions for consolidation of soils with multiple layers and depth-dependent loading. An overview of this model is presented, and a parametric study is performed to …

Effect Of Resin Thickness, And Curing Time On The Micro-Hardness Of Bulk-Fill Resin Composites, Shaymaa M. Nagi, Lamiaa M. Moharam, Mohamed H. Zaazou

Chemical and Biochemical Engineering Faculty Research & Creative Works

Background: Bulk-fill resin composite has been introduced, their manufacturers claimed that they can be applied in bulks of 4mm, without necessitating a prolonged curing time, or a light curing unit with increased irradiance. Thus, this study was conducted to evaluate the effect of resin thickness and curing time on the micro-hardness of two bulk -fill resin composites: Tetric Evo-Ceram [TE], and X-trafil [XF]. Material and Methods: 120 cylindrical specimens were prepared and divided into 24 groups (n=5/group), representing the two bulk-fill resin composites, three different material thicknesses (2, 3 and 4 mm) and the four curing times used in the …

A Systematic Review Of Social Networks Research In Information Systems: Building A Foundation For Exciting Future Research, Jinwei Cao, Kamile Asli Basoglu, Hong Sheng, Paul Benjamin Lowry

Business and Information Technology Faculty Research & Creative Works

Social networking applications such as blogs, instant messengers, podcasts, social networking websites (e.g., Renren in China, Vkontakte in Russia, Facebook), professional networking websites (e.g., LinkedIn), Twitter, and virtual worlds (e.g., Second Life) have become increasingly popular in the last few years. Because these applications have substantial implications for users, organizations, and society, social networks (SNs) have gained attention from information systems (IS) researchers and grown steadily as a research area since 2004 However, to organize the accumulated research and encourage researchers to examine new and pressing issues in SNs, available knowledge needs to be synthesized and research gaps need to …

Nonmarine Time-Stratigraphy In A Rift Setting: An Example From The Mid-Permian Lower Quanzijie Low-Order Cycle Bogda Mountains, Nw China, Jonathan Obrist-Farner, Wan Yang

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Sedimentological and stratigraphic studies of seven stratigraphic sections of Permian Hongyanchi (HYC) and Quanzijie (QZJ) low-order cycles (LCs) in the Tarlong-Taodonggou half graben and Dalongkou area in Bogda Mountains, NW China, demonstrate effective approaches and methodology in cyclo- and time-stratigraphic analyses of complex fluvial-lacustrine deposits in an intracontinental rift setting. A new synchronous stratigraphic unit, the lower QZJ LC is defined. The lower and upper boundaries of this cycle include a regionally correlative disconformity, erosional unconformity, and conformity, across which significant and abrupt changes in palaeoenvironments and tectonic and climatic conditions occurred. The lower boundary is an erosional unconformity and …

Origin Of The Term "Jazz", Gerald Leonard Cohen

Arts, Languages and Philosophy Faculty Research & Creative Works

The book (193 pages, soft-covered) is intended as a scholarly study and therefore contains more detail than would appear in a book intended for a broad readership.

Angiogenic Effect Of Bioactive Borate Glass Microfibers And Beads In The Hairless Mouse, Richard J. Watters, Roger F. Brown, D. E. Day

Biological Sciences Faculty Research & Creative Works

The purpose of this project was to investigate the angiogenic mechanism of bioactive borate glass for soft tissue repair in a 'hairless' SKH1 mouse model. Subcutaneous microvascular responses to bioactive glass microfibers (45S5, 13-93B3, and 13-93B3Cu) and bioactive glass beads (13-93, 13-93B3, and 13-93B3Cu) were assessed via: noninvasive imaging of skin microvasculature; histomorphometry of microvascular densities; and quantitative PCR measurements of mRNA expression of VEGF and FGF-2 cytokines. Live imaging via dorsal skin windows showed the formation at two weeks of a halo-like structure infused with microvessels surrounding implanted borate-based 13-93B3 and 13-93B3Cu glass beads, a response not observed with …

Real Time Mission Planning, Emad William Saad, Stefan Richard Bieniawski, Riley Pigg, Paul Edward, John Lyle Vian, Paul Michael Robinette, Donald C. Wunsch

Electrical and Computer Engineering Faculty Research & Creative Works

The different advantageous embodiments provide a system comprising a number of computers, a graphical user interface, first program code stored on the computer, and second program code stored on the computer. The graphical user interface is executed by a computer in the number of computers. The computer is configured to run the first program code to define a mission using a number of mission elements. The computer is configured to run the second program code to generate instructions for a number of assets to execute the mission and monitor the number of assets during execution of the mission.