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2015

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Articles 2371 - 2400 of 7527

Full-Text Articles in Engineering

Assessing The Validity And Reliability Of Dichotomous Test Results Using Item Response Theory On A Group Of First Year Engineering Students, Edmund Nevin, Avril Behan, Gavin Duffy, Stephanie Farrell, Rachel Harding, Robert Howard, Aaron Mac Raighne, Brian Bowe Jul 2015

Assessing The Validity And Reliability Of Dichotomous Test Results Using Item Response Theory On A Group Of First Year Engineering Students, Edmund Nevin, Avril Behan, Gavin Duffy, Stephanie Farrell, Rachel Harding, Robert Howard, Aaron Mac Raighne, Brian Bowe

Conference papers

Traditional measurement instruments employed to assess the performance of student’s studying on STEM (Science, Technology, Engineering and Mathematics) related programmes typically involve classification based on final scores. The validity and reliability of these instruments and test forms are important considerations when assessing whether a student understands content and if not, where and in what way they are struggling. The aim of this study is to examine, validate and analyse the test results of first-year engineering student’s at an Institute of Higher Learning in Ireland who took the Purdue Spatial Visualisation Test of Rotation (PSVT:R). Results obtained were analysed using the …


Optimum 3d Matrix Stiffness For Maintenance Of Cancer Stem Cells Is Dependent On Tissue Origin Of Cancer Cells, Esmaiel Jabbari, Samaneh K. Sarvestani, Leily Daneshian, Seyedsina Moeinzadeh Jul 2015

Optimum 3d Matrix Stiffness For Maintenance Of Cancer Stem Cells Is Dependent On Tissue Origin Of Cancer Cells, Esmaiel Jabbari, Samaneh K. Sarvestani, Leily Daneshian, Seyedsina Moeinzadeh

Faculty Publications

Introduction

The growth and expression of cancer stem cells (CSCs) depend on many factors in the tumor microenvironment. The objective of this work was to investigate the effect of cancer cells’ tissue origin on the optimum matrix stiffness for CSC growth and marker expression in a model polyethylene glycol diacrylate (PEGDA) hydrogel without the interference of other factors in the microenvironment.

Methods

Human MCF7 and MDA-MB-231 breast carcinoma, HCT116 colorectal and AGS gastric carcinoma, and U2OS osteosarcoma cells were used. The cells were encapsulated in PEGDA gels with compressive moduli in the 2-70 kPa range and optimized cell seeding density …


Automatic Fault Injection For Driver Robustness Testing, Kai Cong, Li Lei, Zhenkun Yang, Fei Xie Jul 2015

Automatic Fault Injection For Driver Robustness Testing, Kai Cong, Li Lei, Zhenkun Yang, Fei Xie

Computer Science Faculty Publications and Presentations

Robustness testing is a crucial stage in the device driver development cycle. To accelerate driver robustness testing, effective fault scenarios need to be generated and injected without requiring much time and human effort. In this pa- per, we present a practical approach to automatic runtime generation and injection of fault scenarios for driver robust- ness testing. We identify target functions that can fail from runtime execution traces, generate effective fault scenarios on these target functions using a bounded trace-based it- erative strategy, and inject the generated fault scenarios at runtime to test driver robustness using a permutation-based injection mechanism. We …


Shooting For The Sky: Martin Tengler Is Part Of A Team That Wants To Use Drones To Plant A Billion Trees A Year, Gerry Boyle Jul 2015

Shooting For The Sky: Martin Tengler Is Part Of A Team That Wants To Use Drones To Plant A Billion Trees A Year, Gerry Boyle

Colby Magazine

Martin Tengler '12 can picture a time when aerial drones fan out to map vast reaches of deforested land and then plant thousands of seed pods that will turn wasteland into new forest.


Rating Rectangular Farm Delivery Meter Gates For Flow Measurement, Daniel J. Howes, Charles M. Burt Jul 2015

Rating Rectangular Farm Delivery Meter Gates For Flow Measurement, Daniel J. Howes, Charles M. Burt

BioResource and Agricultural Engineering

Traditional meter gates for farm delivery flow measurement from an open channel conveyance have traditionally incorporated round canal gates (Armco type) for control. In recent years, some irrigation water agencies (i.e., irrigation districts) have replaced deteriorating round gates with lower-cost rectangular gates that cover round holes. Similar to the situation described in a companion paper, where round gates were examined, there have been no investigations into flow measurement uncertainty using the existing rating tables for these gates. In this study, two commonly used rectangular gate sizes, 0.46 m (18-in.) and 0.61 m (24-in.), were tested under scenarios of various gate …


Accuracy Of Round Meter Gates For On-Farm Deliveries, Daniel J. Howes, Charles M. Burt Jul 2015

Accuracy Of Round Meter Gates For On-Farm Deliveries, Daniel J. Howes, Charles M. Burt

BioResource and Agricultural Engineering

Recent California legislation requires irrigation water agencies larger than 25,000 acres to measure volumetric water deliveries within specified levels of relative uncertainty. Although the meter gate is one of the most widely used flow measurement devices in California, little investigation has been conducted into the accuracy, limitations, and uncertainties of the rating tables developed over 60 years ago. A meter gate testing facility was constructed at the Cal Poly Irrigation Training and Research Center’s Water Resources Facility capable of testing gates up to 0.76 m (30 in.). The facility was constructed with gates oriented perpendicular to the supply channel flow …


Secondary Organic Aerosol Formation From The Β-Pinene+No3 System: Effect Of Humidity And Peroxy Radical Fate, C. M. Boyd, J. Sanchez, L. Xu, Alexis J. Eugene, T. Nah, W. Y. Tuet, Marcelo I. Guzman, N. L. Ng Jul 2015

Secondary Organic Aerosol Formation From The Β-Pinene+No3 System: Effect Of Humidity And Peroxy Radical Fate, C. M. Boyd, J. Sanchez, L. Xu, Alexis J. Eugene, T. Nah, W. Y. Tuet, Marcelo I. Guzman, N. L. Ng

Chemistry Faculty Publications

The formation of secondary organic aerosol (SOA) from the oxidation of β-pinene via nitrate radicals is investigated in the Georgia Tech Environmental Chamber (GTEC) facility. Aerosol yields are determined for experiments performed under both dry (relative humidity (RH) < 2 %) and humid (RH = 50 % and RH = 70 %) conditions. To probe the effects of peroxy radical (RO2) fate on aerosol formation, "RO2 + NO3 dominant" and "RO2 + HO2 dominant" experiments are performed. Gas-phase organic nitrate species (with molecular weights of 215, 229, 231, and 245 amu, which likely correspond to molecular formulas of C10H17NO4, C10H15NO5, C10H17NO …


The Role Of Damage And Recrystallization In The Elastic Properties Of Columnar Ice, Scott A. Snyder, Erland M. Schulson, Carl E. Renshaw Jul 2015

The Role Of Damage And Recrystallization In The Elastic Properties Of Columnar Ice, Scott A. Snyder, Erland M. Schulson, Carl E. Renshaw

Dartmouth Scholarship

Effects of damage on elastic properties were studied in columnar-grained specimens of freshwater and saline ice, subjected, at −10°C, to varying levels of inelastic strain. The ice was compressed uniaxially at constant strain rates up to 0.20 strain, which caused localized recrystallization and imparted damage in the form of non-propagating cracks. Damage was quantified in terms of dimensionless crack density, which, along with recrystallized area fraction, was determined from thin sections. The change in porosity due to stress-induced cracks served as another indicator of damage. Elastic properties were derived using P-wave and S-wave ultrasonic transmission velocities measured in across-column directions …


Impurity Diffusion As A Possible Metal Chronometer For Pre-Detonation Nuclear Forensics, Edward T. Peskie, Howard L. Hall Jul 2015

Impurity Diffusion As A Possible Metal Chronometer For Pre-Detonation Nuclear Forensics, Edward T. Peskie, Howard L. Hall

International Journal of Nuclear Security

The ability to determine the age of seized nuclear material—that is, the time that has passed since it was formed— would provide crucial data to be used in its investigation. This paper reviews the methods and mathematical reasoning behind the use of diffusion theory, as previously applied to analysis of metals in ancient artifacts and other objects, to modern investigations in nuclear science. We here examine the time-dependent processes of diffusion, including grain boundary diffusion and discontinuous precipitation, and we assess the utility of examining the profiles of impurity and alloying element concentrations for use as a tool in pre-detonation …


A Course In Sustainable Manufacturing, Young Moon Jul 2015

A Course In Sustainable Manufacturing, Young Moon

Mechanical and Aerospace Engineering - All Scholarship

Sustainable manufacturing is a vision that the manufacturing community has for contributing to the global society's ability to address sustainability issues. While there is no standard definition of sustainable manufacturing, one universally accepted notion is that sustainable manufacturing must optimally address a comprehensive set of highly interdependent objectives from environmental, economic and social perspectives. This is impossible without systems' thinking that guides the sustainable manufacturing activities every step of the way from product idea generation, to adoption of sustainable design and manufacturing processes, to selection of sustainable materials, and ultimately to product disposal, reuse or recycling. New course on sustainable …


Student Writing Competition Jul 2015

Student Writing Competition

International Journal of Nuclear Security

No abstract provided.


Cover Jul 2015

Cover

International Journal of Nuclear Security

No abstract provided.


Masthead Jul 2015

Masthead

International Journal of Nuclear Security

No abstract provided.


From The Editor Jul 2015

From The Editor

International Journal of Nuclear Security

No abstract provided.


The Nuclear Security Science And Policy Institute At Texas A&M University, Claudio A. Gariazzo, Kelley H. Ragusa, David R. Boyle, William S. Charlton, Sunil S. Chirayath, Craig M. Marianno, Paul Nelson Jr. Jul 2015

The Nuclear Security Science And Policy Institute At Texas A&M University, Claudio A. Gariazzo, Kelley H. Ragusa, David R. Boyle, William S. Charlton, Sunil S. Chirayath, Craig M. Marianno, Paul Nelson Jr.

International Journal of Nuclear Security

The Nuclear Security Science and Policy Institute (NSSPI) is a multidisciplinary organization at Texas A&M University and was the first U.S. academic institution focused on technical graduate education, research, and service related to the safeguarding of nuclear materials and the reduction of nuclear threats. NSSPI employs science, engineering, and policy expertise to: (1) conduct research and development to help detect, prevent, and reverse nuclear and radiological proliferation and guard against nuclear terrorism; (2) educate the next generation of nuclear security and nuclear nonproliferation leaders; (3) analyze the interrelationships between policy and technology in the field of nuclear security; and (4) …


Addressing Imbalances In Us Nuclear Economic And Nonproliferation Policies, Matthew S. Duchene, Howard L. Hall Jul 2015

Addressing Imbalances In Us Nuclear Economic And Nonproliferation Policies, Matthew S. Duchene, Howard L. Hall

International Journal of Nuclear Security

Foreign civilian nuclear start-ups have an increasing number of international partners capable of supplying fuel cycle technologies. The desire to prevent the spread of dual-use enrichment and reprocessing technology by asking partner states to rely on international fuel markets is a major obstacle for US negotiating civilian nuclear trade agreements, leading to delays. US participation in emerging nuclear markets is being undercut by foreign competition, leading to decreasing economic competition and influence in international nonproliferation issues. It is therefore necessary for the US to reinvest and complete its domestic nuclear fuel cycle and modify its process for implementing civilian nuclear …


Radiation Damage As A Possible Metal Chronometer For Pre-Detonation Nuclear Forensics, Edward T. Peskie, Howard L. Hall Jul 2015

Radiation Damage As A Possible Metal Chronometer For Pre-Detonation Nuclear Forensics, Edward T. Peskie, Howard L. Hall

International Journal of Nuclear Security

The better we can determine how long ago nuclear material was made, the sharper our tools for investigating seized nuclear materials. This paper examines the effects of radiation damage caused by the decay of uranium isotopes, and assesses how experts in nuclear forensics could use the analyses of these damaged regions to determine how much time has passed since metal samples were formed. It also draws parallels from fission track dating studies of mineral samples under geologic time, and proposes modifications to past publications on α-recoil track dating in order to determine the time since a metal sample was cast …


20150709: Department Of Engineering, 2008, College Of Engineering And Computer Sciences Jul 2015

20150709: Department Of Engineering, 2008, College Of Engineering And Computer Sciences

Guides to University Archives

These items include materials from Engineering at Marshall University from 2008. Items were received in 2015 and include notable materials from or about the History of Engineering Department at Marshall University among other support and presentations about Engineering at Marshall and enrollment information. This is not an exhaustive list. Please download the finding aid for a full list of contents.


Exploring New Lagrangian Cyclers To Enhance Science: Communications With Cubesat Technology, Pedro P. Llanos, Abdiel Santos Galindo, John Ford Jul 2015

Exploring New Lagrangian Cyclers To Enhance Science: Communications With Cubesat Technology, Pedro P. Llanos, Abdiel Santos Galindo, John Ford

Publications

This paper discusses the opportunities that abound by using the CubeSat technology to travel to and communicate with the International Space Station, explore space, monitor space weather, monitor space debris and perhaps travel to Mars.


The Robert & Esther Goddard Papers, Robert H. Goddard Jul 2015

The Robert & Esther Goddard Papers, Robert H. Goddard

Finding Aids

Dr. Robert H. Goddard was a member of the Clark Physics Department for 29 years. Foremost American pioneer of rocket research, he laid the technical and theoretical foundations for many of the developments in long-range rockets, missiles, satellites and space flight, which collectively put us into the Space Age.

The collection includes correspondence, diaries, journals, patent applications and awards, reports, and photographs. The collection also includes original paintings by Dr. Goddard.


Bio-Fuel Alternatives In South African Airways (Saa) Operations - Is It An Effective Response To Vulnerability Over Carbon Taxes And Penalty?, Daniel Kwasi Adjekum Jul 2015

Bio-Fuel Alternatives In South African Airways (Saa) Operations - Is It An Effective Response To Vulnerability Over Carbon Taxes And Penalty?, Daniel Kwasi Adjekum

International Journal of Aviation, Aeronautics, and Aerospace

The paper did a comparative analysis of the carbon emission and European Union Emission Trading Surcharges (EU ETS) of South African Airways (SAA) current fleet that used aviation jet A1 fuel and the same fleet if it had used a 25% bio-fuel ‘drop in’ for the European routes within the first quarter of the 2014 flying year (FY 14). Operational data in terms of the flight scheduled, aircraft type, total time enroute, route stage length, passenger estimates were obtained through SAA’s flight operations website. An independent t–test was conducted to compare means of the emissions. The mean carbon dioxide …


College Of Engineering News, Georgia Southern University Jul 2015

College Of Engineering News, Georgia Southern University

College of Engineering & Computing: News & Publications (2010-2023)

  • Engineering Professor Delivers Invited Talk at CTS 2015


Platinum-Bismuth Bimetallic Catalysts: Synthesis, Characterization And Applications, Jose A. Saucedo Jr, Yang Xiao, Arvind Varma Jul 2015

Platinum-Bismuth Bimetallic Catalysts: Synthesis, Characterization And Applications, Jose A. Saucedo Jr, Yang Xiao, Arvind Varma

The Summer Undergraduate Research Fellowship (SURF) Symposium

Bimetallic catalysts have been explored and shown to exhibit unique characteristics which are not present in monometallic catalysts. Platinum is well known as an effective catalyst for oxidation and reduction reactions, and it can be made more effective when bismuth is introduced as a promotor. Thus, the effectiveness of the Pt-Bi catalyst was demonstrated in prior work. What is not clear, however, is the mechanism behind the catalyst function; why addition of bismuth to platinum decreases deactivation and increases selectivity, and how effective would the Pt-Bi catalyst be in deoxygenation reactions? In this work, the effectiveness of different variations of …


Using Problem Based Learning To Develop Graduate Attributes In First Year Engineering Students., Una Beagon, Dervilla Niall Jul 2015

Using Problem Based Learning To Develop Graduate Attributes In First Year Engineering Students., Una Beagon, Dervilla Niall

Conference papers

This paper investigates the use of a PBL project in a developing country community setting to assess how effectively this teaching pedagogy can develop graduate attributes in first year students. The project requires engineering students to design sustainable infrastructural projects for developing countries. The basis of this project was to design a pedestrian bridge to span 6m across a river. Nairobi was chosen as the locality for the project and the research and design needed to take cognisance of the local conditions, materials and labour available in that area.

Eighty first year engineering students were given six weeks to research, …


Advancing Seismic Simulation Of Cold-Formed Steel Framed Buildings, American Iron And Steel Institute Jul 2015

Advancing Seismic Simulation Of Cold-Formed Steel Framed Buildings, American Iron And Steel Institute

American Iron and Steel Institute (AISI) Specifications, Standards, Manuals and Research Reports (1946 - present)

The objective of this research is to create a computationally efficient seismic analysis framework for cold-formed steel (CFS) framed-buildings supported by hysteretic nonlinear models for CFS members and screw-fastened connections. Design of CFS structures subjected to lateral seismic forces traditionally relies on the strength of subassemblies subjected to lateral loading of systems, such as strapped/sheathed shear walls and diaphragms, to provide adequate protection against collapse. Enabling performance-based seismic design of CFS buildings requires computationally efficient and accurate modeling tools that predict the nonlinear cyclic behavior of CFS buildings, the individual CFS components and connections. Such models should capture the energy …


Iron Range Engineering Pbl Experience, Ron Ulseth, Bart Johnson Jul 2015

Iron Range Engineering Pbl Experience, Ron Ulseth, Bart Johnson

Integrated Engineering Department Publications

A new PBL model started in 2010 in Minnesota, United States. The PBL model is upper-division (the last two years of four-year bachelor’s of engineering degree). Entering students are graduates of Minnesota’s community colleges. The Aalborg PBL model served as an inspiration for the program’s development. Unique attributes of the program include industry clients, semester-long projects, emphasis on development of self-regulated learning abilities, dedicated project rooms, technical competence learned in one-credit, small (3-4 student) groups with one academic staff called learning competencies, and an emphasis on continuous improvement. The program has earned ABET accreditation. Seventy-five students have graduated and are …


How To Save The World: One Life (And Uav) At A Time!, Natalie A. Wright Jul 2015

How To Save The World: One Life (And Uav) At A Time!, Natalie A. Wright

STAR Program Research Presentations

The proliferation of Uninhabited Aerial Vehicles (UAV’s) in commercial and public service aviation arenas has begun to gain the attention of many citizens. Popularized vehicles such as quadcopters have applications in aerial photography, small package delivery and hobbyist/consumer interests. Use of small-scale, fixed- and rotary-wing, remotely operated systems has been popularized as a result of such vehicles’ size and operational simplicity, which widens the range of application of this technology. Public service applications have the potential to advance emergency services management, which can substantially contribute to the public wellbeing. This research will examine the utility of multi-rotor systems in the …


Improving Flow Measurement Accuracy At Farm Delivery Gates In California, Charles M. Burt, Daniel J. Howes Jul 2015

Improving Flow Measurement Accuracy At Farm Delivery Gates In California, Charles M. Burt, Daniel J. Howes

BioResource and Agricultural Engineering

ITRC, through a CSU ARI grant, constructed a meter gate testing facility and tested five gates of various sizes and designs. The gate testing was conducted by varying the multiple parameters including upstream and downstream head, supply channel velocity, gate opening, and head above the gate. Data was also collected at various locations on the downstream side of the gate. In total, ITRC staff collected over 10,000 points of data during this evaluation. Using the new rating tables for the three gates examined, the relative uncertainty is less than ±5 to ±7% at the 95% confidence level with the new …


Contours For Planar Cracks Growing In Three Dimensions: Illustration For Transversely Isotropic Solid, Louis Milton Brock Jul 2015

Contours For Planar Cracks Growing In Three Dimensions: Illustration For Transversely Isotropic Solid, Louis Milton Brock

Mechanical Engineering Faculty Publications

Three-dimensional dynamic steady state growth of a semi-infinite plane crack in a transversely isotropic solid is considered. Growth takes place on a principal plane with the material symmetry axis as one tangent. Fracture is brittle, and driven by compressive loads that translate on the crack surfaces. Translation speed is constant and subcritical, but direction with respect to the principal axes is arbitrary. An analytical solution is obtained, and examined in light of the dynamic energy release rate criterion for the case of a translating compressive point force. Introduction of quasipolar coordinates leads to a nonlinear first-order differential equation for the …


Connecting Self-Efficacy And Nature Of Science Shifts In Undergraduate Research Experiences, Gina Quan Jul 2015

Connecting Self-Efficacy And Nature Of Science Shifts In Undergraduate Research Experiences, Gina Quan

Faculty Publications

Undergraduate research can support students’ more central participation in physics. We present analysis of one way this participation may shift: changes in their beliefs about the Nature of Science coupled to changes in a sense of ability to contribute to authentic research. Students in the study worked with faculty and graduate student research mentors on research projects and also participated in a seminar where they learned about research and reflected on their experiences. In videotaped interviews, we asked students to describe their experiences in research. Students developed nuanced views about how the research process works coupled to shifts in their …