Engineering Commons^™

Alterations In Cortical Sensorimotor Connectivity Following Complete Cervical Spinal Cord Injury: A Prospective Resting-State Fmri Study, Akinwunmi Oni-Orisan, Mayank Kaushal, Wenjun Li, Jack Leschke, B. Douglas Ward, Aditya Vedantam, Benjamin Kalinosky, Matthew D. Budde, Brian D. Schmit, Shi-Jiang Li, Viashnavi Muqeet, Shekar N. Kurpad

Biomedical Engineering Faculty Research and Publications

Functional magnetic resonance imaging (fMRI) studies have demonstrated alterations during task-induced brain activation in spinal cord injury (SCI) patients. The interruption to structural integrity of the spinal cord and the resultant disrupted flow of bidirectional communication between the brain and the spinal cord might contribute to the observed dynamic reorganization (neural plasticity). However, the effect of SCI on brain resting-state connectivity patterns remains unclear. We undertook a prospective resting-state fMRI (rs-fMRI) study to explore changes to cortical activation patterns following SCI. With institutional review board approval, rs-fMRI data was obtained in eleven patients with complete cervical SCI (>2 years …

Effect Of Electric Field/Current On Liquid Phase Sintering, Jesus Gonzalez-Julian, Olivier Guillon

Electric Field Assisted Sintering and Related Phenomena Far From Equilibrium

Sintering behavior of ionic and electric conductor ceramics is enhanced when an external electric field is applied during the sintering process by Joule heating, generation of Frenkel defects, mobility of point defects, electrochemical reactions and electromigration mechanisms. The applied electric field modifies the sintering behavior in two ways, depending mainly on the strength of the field (V/cm) and the electrical properties of the sample. Intermediate fields enhance the sintering kinetics apparently due to the retardation of grain growth, which is called field assisted sintering. In contrast, high fields generate massive densification just in few seconds, which is recently referenced as …

First Stage In Flash Sintering Of Zirconia Based Ceramics, Marlu Cesar Steil, Emmanuelle Bichaud, Claude Carry, Jean Marc Chaix

Electric Field Assisted Sintering and Related Phenomena Far From Equilibrium

Flash sintering ability to densify ceramic material in less than 5 seconds, at much lower furnace temperatures than conventional sintering has been reported and studied for a large set of conductive ceramics and recently of composite ceramic materials. Since no die is used, the current mandatorily flows through the sample and the flash process is characterized by an abrupt increase in the sample conductivity accompanied by shrinkage and densification. In the literature two types of experiments are reported, referring to the furnace temperature: Constant heating rate (CHR) and isothermal experiments. The flash sintering elementary mechanisms are not yet fully understood. …

Effect Of (External) Electric Fields On Heterogeneous Solid State Reactions – Special Role Of Grain Boundary Diffusion, Carsten Korte

Electric Field Assisted Sintering and Related Phenomena Far From Equilibrium

During ope­ra­tion ceramic materials are of­ten ex­posed to high elec­tri­cal fields, which create a se­cond dri­ving force for mobile com­po­nents in ad­di­tion to the chemical po­ten­tial gra­dient. Due to the ongoing miniaturisation in modern appli­ca­tions, interfaces gain in importance for the materials pro­per­ties. So­lid state reac­tions, neg­li­gi­ble on ma­cro­scopic length sca­les, be­come more im­portant on the nanoscale and thus be­come a frequent source of materials degra­da­tion

In this contribution the influence of an electric field on the kinetics and the morphological evo­lution of (hetero­ge­ne­ous) solid state model reactions will be highlighted [1-4]. Experiments on the reac­tion couples MgO + In …

Electric Field–Induced Electronic Conduction In Bulk Oxide Ceramics, Anthony West

Electric Field Assisted Sintering and Related Phenomena Far From Equilibrium

Field-induced electronic conduction is widely recognised in (a) materials whose resistance is dominated by interfacial Schottky barriers and (b) thin films that exhibit high field-induced filamentary conduction. A third category of (low) field-sensitive conduction occurs in bulk oxide ceramics that show enhanced hole conduction if they are acceptor-doped, but reduced n-type conduction if they are donor-doped. Examples in these two categories are acceptor-doped titanate perovskites [1] and rutile that is slightly oxygen-deficient [2]. More recently, reversible, field-induced electronic conduction has been demonstrated in yttria-doped zirconia ceramics [3] and a reversible, insulator-metal transition in Ca-doped BiFeO3 ceramics [4].

A survey of …

Oxygen Vacancy Formation Due To Dc Electric Fields During Flash Sintering In Batio3, Takashida Yamamoto

Electric Field Assisted Sintering and Related Phenomena Far From Equilibrium

A unique sintering technique called FLASH sintering has been developed by Raj’s research group¹⁾. When green compacts are heated under DC electric fields beyond threshold strength, specimen current abruptly increases at a critical temperature, and then densification is immediately completed at very short time. The sintering temperature and time largely decrease with the increasing DC electric fields. Cologna et al. successfully obtained fully densified YSZ at 850°C for 5s at 120V/cm without any outer pressure. After their reports, flash sintering has been applied for various kinds of ceramic materials such as Y₂O₃, Al …

The Modification Of The Temperature Gradient In A Large Sample Sintered By Sps, Mirva Eriksson

Electric Field Assisted Sintering and Related Phenomena Far From Equilibrium

The SPS is a sintering unit where heating and the uniaxial pressure is applied to a powder placed in a die. The best pressure and temperature distribution in the sample is achieved when the sample has the shape of a round pellet. In some cases it would be beneficial to be able to sinter square or rectangular plates. The processing of a large square/rectangular plate is a challenging task because the shape will increase the temperature gradient in the horizontal direction in the plate resulting to uneven properties in corners compared to the middle. In this study we present results …

Spark And Plasma Aided Densification Mechanisms During Spark Plasma Sintering Of Ceramic Powders, Rachman Chaim

Electric Field Assisted Sintering and Related Phenomena Far From Equilibrium

Spark plasma sintering (SPS) currently used for rapid and full densification of ceramic particles assisted by a pulsed dc current passed through the powder compact. Our investigations with different ceramic powders (LiF, NiO, and YAG) as model systems discovered local melting of the particle and nano-particle surfaces, confirming the formation of spark and plasma during the SPS. However, spark and plasma form at certain material and process conditions. The ceramic yield stress and its electrical conductivity, and their temperature dependence mainly determine the conditions at which spark and plasma will take place in a given non-conducting granular compact. We introduce …

Electrical Conduction Mechanism At High Voltages And Dielectric Breakdown Strength In Bulk Ceramic Insulators, Gerold Schneider, Claudia Neusel

Electric Field Assisted Sintering and Related Phenomena Far From Equilibrium

Electrical conductivity at high electric fields and dielectric breakdown of bulk ceramic insulators is not well understood. In order to gain more insight we performed current-voltage measurements on different ceramics to identify whether ohmic, space charge limited, Schottky, or Poole-Frenkel conduction, is the dominating conduction mechanism. Voltages up to 70 kV were applied and revealed that space charge limited conduction (SCLC) prevails at high electric fields in all investigated ceramics. As SCLC is a size dependent phenomenon the transition from ohmic to SCLC was determined as a function of the thickness of the disc-shaped samples. As a consequence electric field …

Effect Of Plug In Hybrid Electric Vehicle Adoption On Gas Tax Revenue, Local Pollution, And Greenhouse Gas Emissions, Neil Mccall

Theses and Dissertations

Plug-in hybrid electric vehicles (PHEV) are likely to increase in popularity in the near future. However, the environmental benefits of PHEVs involve tradeoffs between the benefits of reduced tailpipe emissions against the drawbacks of increased emissions at marginal electric generation plants and reduced gasoline tax income. In this report, a model is developed that will enable these tradeoffs to be studied. The model accounts for local commuting patterns and marginal electric generation in New Jersey. The result allows the effect of PHEV adoption on gasoline tax, CO2, NOx and SOx to be predicted on a county level. Sample calculations are …

Large-Area Graphene-Based Nanofiltration Membranes By Shear Alignment Of Discotic Nematic Liquid Crystals Of Graphene Oxide, Abozar Akbari, Phillip Sheath, Samuel T. Martin, Dhanraj B. Shinde, Mahdokht Shaibani, Parama Chakraborty Banerjee, Rachel Tkacz, Dibakar Bhattacharyya, Mainak Majumder

Chemical and Materials Engineering Faculty Publications

Graphene-based membranes demonstrating ultrafast water transport, precise molecular sieving of gas and solvated molecules shows great promise as novel separation platforms; however, scale-up of these membranes to large-areas remains an unresolved problem. Here we demonstrate that the discotic nematic phase of graphene oxide (GO) can be shear aligned to form highly ordered, continuous, thin films of multi-layered GO on a support membrane by an industrially adaptable method to produce large-area membranes (13 × 14 cm²) in < 5 s. Pressure driven transport data demonstrate high retention (> 90%) for charged and uncharged organic probe molecules with a hydrated radius above 5 Å as well as modest (30–40%) retention of …

A R-Som Analysis Of The Link Between Financial Market Conditions And A Systemic Risk Index Based On Ica-Factors Of Systemic Risk Measures, Patrick Kouontchou, Amaury Lendasse, Yoan Miche, Alejandro Modesto, Peter Sarlin, Bertrand Maillet

Engineering Management and Systems Engineering Faculty Research & Creative Works

Due to the Recent Financial Crisis, Several Systemic Risk Measures Have Been Proposed in the Literature for Quantifying Financial System Wide Distress. in This Note We Propose an Aggregated Index for Financial Systemic Risk Measurement based on EOF and Ica Analyses on the Several Systemic Risk Measures Released in the Recent Literature. We Use This Index to Further Identify the States of the Market as Suggested in Kouontchou Et Al. [18]. We Show, by Characterizing Markets Conditions with a Robust Kohonen Self-Organizing Maps Algorithm that This Measure is Directly Linked to Crises Markets States and There is a Strong Link …

Peer Reviewed Safety Management System (Sms): Collaboration For Continuous Improvement (Literature Review), Michael F. Canders Ph.D. Cfii

International Journal of Aviation, Aeronautics, and Aerospace

Safe operations are essential for organizational success, perhaps no more so than in aviation. A culture of safety can be a leading contributor to an aviation organization’s success but developing such a culture and maintaining it can be very challenging. Collegiate aviation programs provide an exceptional opportunity to teach essential safety culture components to new aviators. A Safety Management System (SMS) is an effective framework to present and reinforce key safety principles and can be effectively tailored for the collegiate aviation flight training environment. Some aviation colleges may have developed a safety program or SMS but sharing and benchmarking the …

Towards Developing Product Applications Of Thick Origami Using The Offset Panel Technique, Michael R. Morgan, Robert J. Lang, Spencer P. Magleby, Larry L. Howell

Faculty Publications

Several methods have been developed to accommodate for the use of thick materials in origami models which preserve either the model’s full range of motion or its kinematics. The offset panel technique (OPT) preserves both the range of motion and the kinematics while allowing for a great deal of flexibility in design. This work explores new possibilities for origami-based product applications presented by the OPT. Examples are included to illustrate fundamental capabilities that can be realized with thick materials such as accommodation of various materials in a design and manipulation of panel geometry resulting in an increased stiffness and strength. …

Flash Sintering Of Covalent Non–Oxide Ceramics At Low Temperatures With Low Dc Electric Fields: An In Situ Edxrd Study By Synchrotron Probe, Thomas Tsakalajos

Electric Field Assisted Sintering and Related Phenomena Far From Equilibrium

The fundamental purpose in Functional Ceramics Technology is to obtain 100% dense polycrystalline covalent nonoxide ceramics with grain size / micro B₄C powder at low temperature <1000 >^oC so as to obtain a properly sintered ceramics. Also as to obtain a fully with small grain size. The applied electric field helps to reduce the sintering temperature by at least a factor 0.33. The time frames involved are measured in minutes/seconds and not in tens of hours/days. We will focus on the B4C system. However, other nonoxide ceramics nanocomposites such as ZrB₂, TiB₂, Si_{3 …}

Highly Transparent Spinel Windows By Microwave Sintering, Jasbinder Sanghera

Electric Field Assisted Sintering and Related Phenomena Far From Equilibrium

Transparent magnesium aluminate spinel (MgAl₂O₄) ceramic possesses excellent mechanical and optical properties enabling its potential use in many applications, especially those in harsh environments. We have previously demonstrated fabrication of transparent spinel ceramic with very low absorption loss (6ppm/cm) at 1 mm using the hot pressing method. However, microwave sintering offers several potential advantages over conventional densification methods such as uniform heating, shorter sintering time, finer microstructure of the ceramics, and scalability to large sizes. Previous attempts to microwave sinter spinel powder resulted in only opaque or translucent ceramics. In this talk, we report the fabrication …

Spark Plasma Sintering Of A Functionally Graded Material Consisting Of A High– Alloyed Crmnni–Steel And Varying Mg–Psz Content, Sabine Decker, Lutz Kruger

Electric Field Assisted Sintering and Related Phenomena Far From Equilibrium

A functionally graded material (FGM) consisting of a TRIP steel matrix (TRansformation Induced Plasticity) and a varying Mg-PSZ particle reinforcement (MgO Partially Stabilized Zirconia) was sintered by Spark Plasma Sintering (SPS). The used steel is high-alloyed (16 wt.% Cr, 7 wt.% Mn, 3 wt.% Ni) and the Mg-PSZ content decreases along the sample height from 100 vol.% to 0 vol.%. Hence, the bottom of the sample consists of a pure ceramic layer. Due to the different melting temperatures and therefore different optimal sintering temperatures of steel and Mg-PSZ, it is challenging …

Influence Of An Electric Field On Grain Growth And Sintering In Strontium Titanate, Wolfgang Rheinheimer, Fabian Lemke, Michael Hoffman

Electric Field Assisted Sintering and Related Phenomena Far From Equilibrium

Within the last five years considerable efforts were done in investigating electric field assisted sintering (flash sintering). However the experiments are hard to control: shrinkage occurs within seconds and the local temperature is undefined due to joule heating. Therefore the present study removes these two parameters by investigating grain growth under electric field in the no-current-case for strontium titanate.

The impact of an electric field on grain growth in strontium titanate is investigated between 1350°C and 1550°C for fields of up to 50V/mm. To prevent joule heating by a current flowing through the material insulating Al2O3 plates separate the electrodes …

The Influence Of Fields And Dopants On Grain Boundary Mobility, Wayne Kaplan, Amir Gabay

Electric Field Assisted Sintering and Related Phenomena Far From Equilibrium

During field assisted sintering, exposure to an electric field often results in faster sintering rates compared to conventional sintering methods. This research focuses on the influence of electromagnetic fields on grain growth. As a model system, SiC was sintered using conventional pressureless sintering at 2100°C. Samples then underwent conventional annealing, and annealing using spark plasma sintering (SPS) without pressure, at identical and at lower temperatures, and the grain size as a function of annealing time was characterized.

From these experiments, the grain boundary mobility of SiC at 2100°C under conventional heating versus SPS was determined. SPS annealing resulted in a …

Field–Assisted And Flash Sintering Of Nanocrystalline Yttria: Densification And Microstructural Evolution, Hidehiro Yoshida

Electric Field Assisted Sintering and Related Phenomena Far From Equilibrium

Y₂O₃ ceramics have special chemical and physical properties such as high resistance to halogen-plasma corrosion and thermal stability. At the same time they are difficult to sinter. Conventional sintering requires very high temperatures typically >1400°C, and a vacuum or hydrogen atmosphere. We show that high-purity, undoped Y₂O₃ can be sintered nearly instantaneously to almost full density by flash-sintering, where densification occurs in a few seconds under a threshold condition of temperature and applied field [1]. The Y₂O₃ shows flash-sintering at the fields above 300 V/cm. For instance, full densification is achieved …

Flash Sintering Of Zno, Tio2 And Other Oxides: The Origin Of Onset Flash And Effects Of Atmosphere, Doping And Particle Size, Jian Luo

Electric Field Assisted Sintering and Related Phenomena Far From Equilibrium

Flash sintering of ZnO, TiO₂ and a few other oxide systems has been investigated. A quantitative model has been developed to forecast the thermal runaway conditions (Fig. 1) [1]. The predicted thermal runaway temperatures from the measured conductivities are in excellent agreements with the observed onset flash temperatures for at least 15 cases with different base materials, doping and surface treatments, particle sizes, and sintering atmospheres, attesting that the “flash” starts as a thermal runaway.

Furthermore, a range of new phenomena of electric field/current effects on sintering and microstructural evolution have been observed and explained, which include: …

Flash Microwave Sintering Of Oxide Ceramics, Kirill Rybakov

Electric Field Assisted Sintering and Related Phenomena Far From Equilibrium

We report the results of flash microwave sintering of various oxide ceramics to full density in a time less than several minutes. Ultra-rapid microwave sintering has been observed on Al₂O₃, Y₂O₃, MgAl₂O₄, and (Yb_0.05La_0.1Y_0.85)₂O₃ samples compacted from nanosized and submicron powders.

The samples were heated in the applicator of a gyrotron system for microwave processing of materials with a maximum microwave power of up to 6 kW at a frequency of 24 GHz with a feedback computer control over …

Mechanistic And Economical Characteristics Of Asphalt Rubber Mixtures, Mena I. Souliman, Annie Eifert

Civil Engineering Faculty Publications and Presentations

Load associated fatigue cracking is one of the major distress types occurring in flexible pavement systems. Flexural bending beam fatigue laboratory test has been used for several decades and is considered to be an integral part of the new superpave advanced characterization procedure. One of the most significant solutions to prolong the fatigue life for an asphaltic mixture is to utilize flexible materials as rubber. A laboratory testing program was performed on a conventional and Asphalt Rubber- (AR-) gap-graded mixtures to investigate the impact of added rubber on the mechanical, mechanistic, and economical attributes of asphaltic mixtures. Strain controlled fatigue …

Session E-3: Addressing Ngss Engineering Standards With An Alternative Energy Module, Peter Clancy, Mark Carlson

Professional Learning Day

In our Engineering class at IMSA, we have taught an Alternative Energy unit over the last four semesters. We will discuss how the 4 engineering NGSS standards are addressed through the various activities involved with this unit. We will also discuss how the unit has evolved over the last 2 years.

Session B-4: Stem Integration: Statistics Is The Connection, Karen Togliatti, Lindsey Herlehy

Professional Learning Day

In this activity, participants will complete a STEM-integrated lesson incorporating problems in aerodynamics. Using the mathematical, science and engineering practice standards, they will design and model parachutes to determine a life-size chute to support their body weight. Participants will also consider design criteria for rate of descent, and graphically represent data and mathematical information as a scatter plot.

Session C-3: Engineering With Reinforced Concrete, Patrick Young

Professional Learning Day

Does your school need a shelter? Whether your students are concerned about tornadoes, sharknadoes, or a zombie apocalypse, reinforced concrete is the answer! Learn about the history and chemistry of concrete. Make your own. Design a test to evaluate the strength of your concrete, based on anticipated threat (the natural or unnatural disaster of your choice). Conduct that test using small, preformed slabs. Making and breaking concrete is easy and fun, but wear your play-clothes. You will get dirty.

Dimensionality Reduction Based Optimization Algorithm For Sparse 3-D Image Reconstruction In Diffuse Optical Tomography, Tanmoy Bhowmik, Hanli Liu, Zhou Ye, Soontorn Oraintara

Bioengineering Faculty Publications - Archive

No abstract provided.

Advance Transit Real Time Bus Arrival Smartphone App, Donald Stayner, Paul Donnelly, Roxana Gheorghe, Adam Grounds, Nicolas Gutierrez

ENGS 89 Reports (BE Students)

Advance Transit (AT) is a non-profit transit company annually serving around 600,000

free rides across the Upper Valley. Though real time estimates for bus arrivals are available

through AT’s website and automated call line, there is currently no simple way for AT riders to

visualize their bus route and bus arrival times from a smartphone. Over 44% of riders surveyed in

October 2015 indicated they would ride the bus more often if they had easier access to real-time

bus arrival information. The goal of the project is to develop a system that gives AT riders easy

access to their bus …

Predicted Molecular Signaling Guiding Photoreceptor Cell Migration Following Transplantation Into Damaged Retina, Uchenna John Unachukwu, Alice Warren, Ze Li, Shawn Mishra, Jing Zhou, Moira Sauane, Hyungsik Lim, Maribel Vazquez, Stephen Redenti

Publications and Research

To replace photoreceptors lost to disease or trauma and restore vision, laboratories around the world are investigating photoreceptor replacement strategies using subretinal transplantation of photoreceptor precursor cells (PPCs) and retinal progenitor cells (RPCs). Significant obstacles to advancement of photoreceptor cell-replacement include low migration rates of transplanted cells into host retina and an absence of data describing chemotactic signaling guiding migration of transplanted cells in the damaged retinal microenvironment. To elucidate chemotactic signaling guiding transplanted cell migration, bioinformatics modeling of PPC transplantation into light-damaged retina was performed. The bioinformatics modeling analyzed whole-genome expression data and matched PPC chemotactic cell-surface receptors to …

Winning The Water War Starts With Winning The Battle On Data | College Of Engineering, Usu College Of Engineering

College of Engineering News

March 3, 2016 – The water meter buried in your front yard isn’t exactly the most cutting-edge piece of technology. While they are accurate, most residential water meters are read only once per month, resulting in rough usage data – often rounded to the nearest 1,000 gallons. With the limited data, water utility managers can’t distinguish individual uses, such as sprinklers versus toilets, or determine usage by time of day. This limits their ability to spot costly leaks or see opportunities for water conservation. And it gives water users no useful information about how and when they use water.