Engineering Commons^™

Study On Determination Of Iodine Ion At Chitosan Modified Glassy Carbon Electrode, Bin Liu, Xiang-Ying Sun, Jin-Rui Xu

Journal of Electrochemistry

In this paper, a chitosan modified glassy carbon electrode was prepared by the method of covalent-bond reaction, and the anodic stripping voltammetric characteristics of iodine on the modified electrode was studied. The results showed that the modified electrode has higher adsorption and selectivity for I^- , and the sensitivity for I^-  has been much improved in 0.1 mol·L^-1 KH₂PO₄ solution (pH=4.0). The anodic stripping peak current of I^- on the modified electrode varied linearly with I^-  concentration in the range of 2.0×10^-6～2.0×10^-3 mol·L^-1, and the detection limit …

Formation And Characterization Of Water-Repellent Nano Tio2 Coating And Studying Its Anticorrosion Property, Guang-Xia Shen, Yi-Cong Chen, Chang-Jian Lin

Journal of Electrochemistry

Using ethyl acetoacetate (EAcAc) as a chelating agent, ultra fine TiO₂ sol is prepared. Nano-TiO₂ coatings are deposited on the 316L stainless steel by the dip-coating. Hydrothermal post-treatment leads to crack-free coatings. Meanwhile, the surface struture and properties was optimized. Self-assembly of Hetadecafluorodecyltrimethoxysilane (FSA-13) fabricates hydrophobic layers on the surface of the nano-TiO₂ coatings. Particle sizes of TiO₂ sol was analysed by zeta pals potential analysis, and surface morphology, structure and properties was characterized by contract angle instrument, XRD, and SEM technologies. The results have shown that the surface of coatings is porous, with approx. 375 …

Study Of Electrochemical Properties Of The Hydride Alloy Electrode Zrcr0.4Mn0.2V0.1Co0.1Ni1.2 At High Temperature, Song Li, Shi-Jun Ji, Jun-Cai Sun

Journal of Electrochemistry

Electrochemical properties of the hydride alloy electrode ZrCr_0.4Mn_0.2V_0.1Co_0.1Ni_1.2 at the different temperature have been investigated. The results showed that the alloy electrodes possessed the maximum discharge capacities 336 mAh/g and 298 mAh/g at 25 ℃ and 70 ℃ respectively. The activation process of the alloy at 70 ℃ became faster, and the alloy reached its maximum capacity in less than 4 cycles, while in 13 cycles at 25 ℃. The high rate capability increased from 55 % at 25 ℃ to 71% at 70 ℃ at 300 mA/g. It was worth …

Electrochemical Synthesis Of Ferrate(Vi) By Anodic Oxidation, Jia-Ju Xu, Jian-Ming Wang, Wei-Hua Yang, Cheng Chen, Jian-Qing Zhang

Journal of Electrochemistry

The ferrate(Ⅵ) was synthesized by electrochemical anodic oxidation. The effects of preparation conditions on the current yield of ferrate(VI) synthesis have been studied in this work. The experimental results showed that grey cast iron as an anodic material is suitable for electrochemical synthesis and NaOH solution as an electrolyte results in a higher current yield than KOH solution. The highest current yield was obtained at a current density (4.54) mA·cm^-2, temperature 20 ℃ and 14 mol·dm^-3 NaOH. In this case, a current yield of 68.5% was obtained by electrolysis for 1 h.

Electrodeposition Nanolaminated Growth Of Zinc, Ying Cao, Tian-Hui Shen, Jing-Yuan Yao, Gui-Fu Ding

Journal of Electrochemistry

Nanolaminated growth of the electrodeposition of zinc was studied. The structure and size of crystalline in zinc coatings were investigated by using FEG-TEM and XRD. The corrosion tests of the zinc deposition and the Coatings-Neutral salt spray test were performed, the capability in corrosion resistance of the nanolaminated growth was better than that of others.

Growth Dynamics Of Isotactic Polypropylene Single Crystals During Isothermal Crystallization From A Miscible Polymeric Solvent, Rujul Mehta, Wirunya Keawwattana, Thein Kyu

College of Polymer Science and Polymer Engineering

The present article presents a spatiotemporal growth of isotactic polypropylene (iPP) single crystals, melt crystallized from a polymeric solvent, i.e., poly (ethylene octene) copolymer that is known to be miscible with iPP. Optical and atomic force microscopic investigations reveal that the melt grown single crystals of iPP develop in the form of two parallel rows of crystal lamellae, but these crystals merge at the tips. To elucidate the mechanism of these emerging parallel rows of iPP crystals, a phase field model pertaining to solidification phenomena has been employed that involves a nonconserved crystal order parameter and a chain-tilting angle. This …

Analyzing And Modeling Of Photobioreactors By Combining First Principles Of Physiology And Hydrodynamics, Hu Ping Luo, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Mixing in Photobioreactors is Known to Enhance Biomass Productivity Considerably, and Flow Dynamics Play a Significant Role in the Reactor's Performance, as They Determine the Mixing and the Cells' Movement. in This Work We Focus on Analyzing the Effects of Mixing and Flow Dynamics on the Photobioreactor Performance. based on Hydrodynamic Findings from the CARPT(Computer Automated Radioactive Particle Tracking) Technique, a Possible Mechanism for the Interaction between the Mixing and the Physiology of Photosynthesis is Presented, and the Effects of Flow Dynamics on Light Availability and Light Intensity Fluctuation Are Discussed and Quantitatively Characterized. Furthermore, a Dynamic Modeling Approach is …

Yucca Mountain Climate Technical Support Representative, Saxon E. Sharpe, Dick Reinhardt, Eric Smistad, Don Baepler, Amy J. Smiecinski

Publications (YM)

The principal investigator (PI), Saxon Sharpe, for Task ORD-FY04-012, DOE Cooperative Agreement DE-FC28-04RW12232, will serve as Yucca Mountain Climate Technical Support Representative for the Department of Energy (DOE) in a series of activities related to past, present, and future climate for the Yucca Mountain Project (YMP) climate program.

As stated in the Viability Assessment of a Repository at Yucca Mountain: “Climate and its changes over time directly affect system performance at Yucca Mountain.” Currently, information from climate studies is used in models that support the Total System Performance Assessment and Licensing Application. It is a model component of all key …

Modeling Of The Interactions Between Forest Vegetation, Disturbances, And Sediment Yields, Erkan Istanbulluoglu, David G. Tarboton, Robert T. Pack, Charles H. Luce

Civil and Environmental Engineering Faculty Publications

The controls of forest vegetation, wildfires, and harvest vegetation disturbances on the frequency and magnitude of sediment delivery from a small watershed (∼3.9 km2) in the Idaho batholith are investigated through numerical modeling. The model simulates soil development based on continuous bedrock weathering and the divergence of diffusive sediment transport on hillslopes. Soil removal is due to episodic gully erosion, shallow landsliding, and debris flow generation. In the model, forest vegetation provides root cohesion and surface resistance to channel initiation. Forest fires and harvests reduce the vegetation. Vegetation loss leaves the land susceptible to erosion and landsliding until the vegetation …

Male Breast Cancer During Finasteride Therapy [4], Shen C. Lee, Robert J. Ellis

Mechanical and Aerospace Engineering Faculty Research & Creative Works

No abstract provided.

Effects Of Earthquake Excitation On The Strength Properties Of Newly Poured Concrete, Jen-Hui Su, Tsong Yen

Journal of Marine Science and Technology–Taiwan

This study examines the 28-day strength properties of concrete under shaking, such as from an earthquake, during its strength development period. With a concrete strength of 20.59 MPa (3,000 psi), groups of concrete cylinders were made and tested on a shaking table. The peak value of ground acceleration (PGA) level of the simulated earthquake and the cylinder age are the two variables considered. The test results are as follows. If the concrete is older than three days, the earthquake excitation will not significantly reduce its 28-day strength. At younger than two days, earthquake excitation will reduce the strength of the …

Investigation Of Seakeeping Characteristics Of High-Speed Catamarans In Waves, Chih-Chung Fang, Hoi-Sang Chan

Journal of Marine Science and Technology–Taiwan

This paper presents the motion characteristics for high-speed catamarans travelling in waves. Two mathematical models, threedimensional translating-pulsating source distribution technique and three-dimensional pulsating source distribution technique, are used for predicting the motions of the wave-piercing catamaran in oblique waves. The comparison between numerical predictions and experimental data carried out in SSPA shows a good agreement except the one around the resonance regions of pitch motion. It may be due to the nonlinear effects of centre bow with large pitch motions in waves. The phase angles show some scatters in the high frequencies region at stern waves. The dynamic motions of …

Laterial Performance Of Drilled Shaft Considering Nonlinear Soil And Structure Material Behavior, Chao-Kuang Hsueh, San-Shyan Lin, Shuh-Gi Chern

Journal of Marine Science and Technology–Taiwan

In addition to nonlinear soil behavior has been assumed in conventional analytical method, performance of the laterally loaded drilled-shaft is also strongly influenced by possible concrete cracking, steel yielding, and shaft/soil separation and interaction. However, these factors are often neglected in the most of available methods and studied results. The main purpose of this paper is to investigate the importance of the above-mentioned effects on lateral performance of drilled reinforced-concrete shaft. The finite element code, ABAQUS, which is available in the three-dimensional analysis is adopted for taking into account the nonlinearity in shaft and soil materials, pilesoil interaction and nonlinear …

Unveiling The Crucial Role Of Impact Nergy Loss For So-Called Incompressible Fluid Flow, Jiunn-Shean Chiang, Shu-Hao Chuang, Hsing-Juin Lee

Journal of Marine Science and Technology–Taiwan

Experiments show that pipe flows with large expansion angle and area ratio always accompany with significant amount of energy loss, actually energy loss ratios over 70% of incoming flow kinetic energy are commonplace. It is generally believed that all the energy loss is entirely due to viscous dissipation effect. In this paper, several interesting demonstrations have been given to prove the existence and importance of impact energy loss. Literally, impact energy loss is usually more important than viscous energy loss in many cases. In fact, the pipe expansion flow can be configured as high-speed flow ramming into low-speed flow and …

Selection Of Area Suitable For Performing Partial-Depth Repair Of Corner Damage Of Concrete Paving Slab Under Wheel Load, Chau Lee, Xin-Hua Huang, Jhao-Bin Lin

Journal of Marine Science and Technology–Taiwan

This study reveals the characteristics of using different repair materials and different repair outline designs for the partial-depth repair of the damage to corners of concrete paving slabs under wheel load. 3D finite element models were used to study how the changes to the outlines of the repaired area affect the maximum-stress and lowstress proportions in concrete elements that are attached to repaired interface when different repairing materials are used. The results indicate that the maximum stress increased but the proportion of lowstress shrank as the repaired area became larger. When cementitious repair materials were used, the depth of a …

Surface States In Template Synthesized Tin Oxide Nanoparticles, A. Cabot, J. Arbiol, R. Ferre, J. R. Morante, Fanglin Chen, Meilin Liu

Faculty Publications

Tin–oxide nanoparticles with controlled narrow size distributions are synthesized while physically encapsulated inside silica mesoporous templates. By means of ultraviolet-visible spectroscopy, a redshift of the optical absorbance edge is observed. Photoluminescence measurements corroborate the existence of an optical transition at 3.2 eV. The associated band of states in the semiconductor gap is present even on template-synthesized nanopowders calcined at 800 °C, which contrasts with the evolution of the gap states measured on materials obtained by other methods. The gap states are thus considered to be surface localized, disappearing with surface faceting or being hidden by the surface-to-bulk ratio decrease.

Post-Acquisition Small-Animal Respiratory Gated Imaging Using Micro Cone-Beam Ct, Jicun Hu, Steven Thomas Haworth, Robert C. Molthen, Christopher A. Dawson

Biomedical Engineering Faculty Research and Publications

On many occasions, it is desirable to image lungs in vivo to perform a pulmonary physiology study. Since the lungs are moving, gating with respect to the ventilatory phase has to be performed in order to minimize motion artifacts. Gating can be done in real time, similar to cardiac imaging in clinical applications, however, there are technical problems that have lead us to investigate different approaches. The problems include breath-to-breath inconsistencies in tidal volume, which makes the precise detection of ventilatory phase difficult, and the relatively high ventilation rates seen in small animals (rats and mice have ventilation rates in …

Quantification Of Bronchial Circulation Perfusion In Rats, Christian Wieholt, Robert C. Molthen, Steven Thomas Haworth, David L. Roerig, Christopher A. Dawson, Anne V. Clough

Biomedical Engineering Faculty Research and Publications

The bronchial circulation is thought to be the primary blood supply for pulmonary carcinomas. Thus, we have developed a method for imaging and quantifying changes in perfusion in the rat lung due to development of the bronchial circulation. A dual-modality micro-CT/SPECT system was used to detect change in perfusion in two groups of rats: controls and those with a surgically occluded left pulmonary artery. Both groups were imaged following injections on separate days i) 2mCi of Tc99m labeled macroaggregated albumin (MAA) into the left carotid artery (IA) and ii) a similar injection into the femoral vein (IV). The IA injection …

Changes In Pulmonary Arterial Wall Mechanical Properties And Lumenal Architecture With Induced Vascular Remodeling, Robert C. Molthen, Amy Heinrich, Steven Thomas Haworth, Christopher A. Dawson

Biomedical Engineering Faculty Research and Publications

To explore and quantify pulmonary arterial remodeling we used various methods including micro-CT, high-resolution 3-dimensional x-ray imaging, to examine the structure and function of intact pulmonary vessels in isolated rat lungs. The rat is commonly used as an animal model for studies of pulmonary hypertension (PH) and the accompanying vascular remodeling, where vascular remodeling has been defined primarily by changes in the vessel wall composition in response to hypertension inducing stimuli such as chronic hypoxic exposure (CHE) or monocrotaline (MCT) injection. Little information has been provided as to how such changes affect the vessel wall mechanical properties or the lumenal …

Effects Of Friction Stir Welding On Polymer Microstructure, Seth R. Strand

Theses and Dissertations

This work establishes the relationships between several key Friction Stir Welding process parameters and the resulting microstructural and flexural properties of the welded joint. A series of four single parameter experiments were run. The parameters investigated were pin diameter, feedrate, shoe temperature, and pressure time. Butt welds were made in 6 mm thick stress-relieved extruded polypropylene sheet. Three-point bend tests were used to determine the ultimate flexural strength and coincident strain. The maximum bend angle before failure was used to label the welds as "good or bad." An optical microscope capable of cross polarization was used to examine and photograph …

Comments On Hilbert Transform Based Signal Analysis, David G. Long

Faculty Publications

The use of the Hilbert transform for time/frequency analysis of signals is briefly considered. While the Hilbert transform is based on arbitrary continuous signals, most practical signals are digitially sampled and time-limited. To avoid aliasing in the sampling process the signals must also be bandlimited. It is argued that it is reasonable to consider such sampled signals as periodic (this is the basis of the Discrete Fourier Transform [DFT]) since any other interpretation is inconsistent. A simple derivation of the Hilbert transform for a sampled, periodic is then given. It is shown that the instantaneous frequency can be easily computed …

Semi-Automatic Road Extraction From Aerial Images, Somkait Udomhunsakul, Samuel Peter Kozaitis, Uthai Thai Sritheeravirojana

Electrical Engineering and Computer Science Faculty Publications

In this work, we proposed a method to detect roads in aerial imagery. In our approach, we applied the wavelet transform in a multiresolution sense by forming the products of wavelet coefficients at the different scales to locate and identify roads. After detecting possible road pixels, we used a graph searching algorithm to identify roads. We found that our approach leads to an effective method to form the basis of a road extraction approach.

Alleviating Moisture Problems Hot, Humid Climate Housing, Florida Solar Energy Center, Subrato Chandra

FSEC Energy Research Center®

The Southeastern U.S. experiences hot, humid conditions throughout the summer months and in Florida, one of the high growth states with large number of homes, these conditions can prevail throughout most of the year. As a result it is not uncommon to find extensive mold, soft drywall, buckled floors, damaged ceilings and other moisture problems in new and existing site built and manufactured homes. Since 1999, as a result of participation in the U.S. DOE funded Building America program, the authors have developed first hand experience and conducted research in these areas. This paper provides a brief summary of the …

Evaluating The Effect Of Rain On Seawinds Scatterometer Measurements, David G. Long, David Draper

Faculty Publications

A simple wind/rain backscatter model is used with co-located precipitation radar (PR) data from the Tropical Rainfall Measuring Mission (TRMM) satellite to evaluate the effect of rain on SeaWinds on QuikSCAT σ° observations. The model incorporates wind-induced surface scattering, the surface rain perturbation, and atmospheric rain attenuation and scattering. The co-located PR measurements afford direct computation of SeaWinds-scale averaged rain rate and atmospheric rain attenuation and scattering. An estimate of the wind-induced surface backscatter is computed via numerical weather prediction (NWP) winds. By synergistically combining the SeaWinds, NWP, and PR data, estimates of surface rain perturbation and combined surface/atmospheric scattering …

Integrated Microbattery Charger For Autonomous Systems, Brian W. Lefevre

Theses and Dissertations

This thesis presents a microbattery recharging circuit suitable for autonomous microsystems. The battery charger chosen for this design is a constant current battery charger. Two methods of regulating the constant-current are discussed. A published shunt regulator design is analyzed and is presented with enhancements to the design. A series regulator that controls the current to the battery with a switch is designed and fabricated in a 1.5µm CMOS process. The fabricated prototype occupies less than 2.20x2.20mm and is expected to dissipate less than 25µW of power. A discrete model of the integrated circuit is constructed and tested to demonstrate that …

On The Implementation Of Swarmlinda? A Linda System Based On Swarm Intelligence (Extended Version), Ahmed Charles, Ronaldo Menezes, Robert Tolksdorf

Electrical Engineering and Computer Science Faculty Publications

Natural-forming multi-agent systems (aka Swarms) can grow to enormous sizes and perform seemingly complex tasks without the existence of any centralized control. Their success comes from the fact that agents are simple and the interaction with the environment and neighboring agents is local in nature. In this paper we discuss the implementation of SwarmLinda, a Linda-based system that abstracts Linda concepts in terms of swarm intelligence constructs such as scents and stigmergy. The goal of this implementation is to achieve many characteristics such as scalability, adaptiveness and some level of fault tolerance. This paper describes our initial version of SwarmLinda …

Statistical Image Differences, Degradation Features, And Character Distance Metrics, Elisa Barney Smith, Xiaohui Qiu

Electrical and Computer Engineering Faculty Publications and Presentations

Document image quality is degraded through processes such as scanning, printing, and photocopying. The resulting bilevel image degradations can be categorized based either on observable degradation features or on degradation model parameters. The image degradation features can be related mathematically to model parameters. In this paper we statistically compare pairs of populations of degraded character images created with different model parameters. The probability that the character populations were degraded by the same model parameters correlates with the relationship between observable degradation features and the model parameters. Two metrics of character difference are used: Hamming distance and moment feature distance. Knowledge …

Proposal For No-Cost Extension And Re-Scope For Unlv Trp Project: Neutron Multiplicity Measurements For The Afci Program (Advanced Fuel Cycle Initiative), Denis Beller

Transmutation Sciences Physics (TRP)

The U.S. Advanced Fuel Cycle Initiative (AFCI) is a program to develop economic and environmental methods to reduce the impact of waste from commercial nuclear fuel cycles. One concept for near-complete destruction of waste isotopes from used nuclear fuel is accelerator-driven transmutation. High-power accelerators would be used to produce high-energy charged particles, which then collide with heavy metal targets to create a cascade of neutrons. These neutrons then cause a nuclear chain reaction in subcritical systems. Fission neutrons then transmute fissile waste isotopes as well as other problematic isotopes such as technetium-99 and iodine-129. To design these systems, complex reactor …

Evaluation Of Interlayer Bonding In Hot Mix Asphalt Pavements, Stephen M. Gomba

Theses and Dissertations

This study investigates the potential of falling weight deflectometer (FWD) data for use in quantifying the level of interlayer bonding achieved in pavements. Data was obtained and used from the Federal Aviation Administration's (FAA) National Airport Pavement Test Facility located in Atlantic City, New Jersey. In this test facility, a section of the pavement had encountered a loss of bond between lifts of the surface hot mix asphalt (HMA) layer. FWD tests had been performed at locations throughout the pavement, on a monthly basis for the duration of the loading period. The FWD data, along with detailed material property data, …

Ccfss Technical Bulletin Spring 2004, Wei-Wen Yu Center For Cold-Formed Steel Structures

CCFSS Technical Bulletins (1993 - 2020)

No abstract provided.