Effect of Geogrid Inclusion on Ballast Resilient Modulus: The Concept of ‘Geogrid Gain Factor’

2018 ◽  
Author(s):  
S. M. Naziur Mahmud ◽  
Debakanta Mishra ◽  
David O. Potyondy
Keyword(s):  
Shear Strength ◽  
Research Study ◽  
Resilient Modulus ◽  
Structural Response ◽  
Gain Factor ◽  
Discrete Element Modeling ◽  
State University ◽  
Ongoing Research ◽  
Parametric Studies ◽  
Improved Performance

Geogrid reinforcement of railroad ballast improves its structural response under loading, limits lateral movement of ballast particles, and reduces vertical settlement through effective geogrid-ballast interlocking. This improved performance can be linked to improved shear strength and resilient modulus properties. An ongoing research study at Boise State University is focusing on investigating the effects of different specimen and test parameters on the mechanism of geogrid-ballast interaction. A commercially available Discrete Element Modeling (DEM) program (PFC3D®) is being used for this purpose, and the effect of geogrid inclusion is being quantified through calculation of the “Geogrid Gain Factor”, defined as the ratio between resilient-modulus of a geogrid-reinforced ballast specimen and that of an unreinforced specimen. Typical load-unload cycles in triaxial shear strength tests are being simulated, and parametric studies are being conducted to determine the effects of particle-size distribution, geogrid aperture size, and geogrid location on railroad-ballast modulus. This paper presents findings from the research study, and presents inferences concerning implications of the study findings on design and construction of better-performing ballast layers.

scholarly journals 132 Performance response of the grow-finish pig (38 to 142 kg) fed different levels of tryptophan:lysine in diets containing 40% dry distiller grains with solubles

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 110-111
Author(s):  
David A Clizer ◽  
Paul Cline ◽  
Brent Frederick ◽  
Ryan S Samuel
Keyword(s):  
South Dakota ◽  
Soybean Meal ◽  
Carcass Weight ◽  
State University ◽  
Research Facility ◽  
Performance Response ◽  
Improved Performance ◽  
Dietary Treatments ◽  
Swine Diets ◽  
Different Levels

Abstract Dried distiller grains with solubles (DDGS) is a popular protein source in grow-finish swine diets to replace soybean meal. An experiment was conducted at the South Dakota State University commercial swine research facility to determine the effect of standardized ileal digestible (SID) Trp:Lys ratio in grow-finish swine diets containing 40% DDGS compared to a standard corn-soybean meal diet. A total of 1,170 pigs (38.6 ± 0.2 kg initial BW) were utilized in a 98-d trial (9 pens per treatment). Pens of pigs were randomly allotted to 1 of 4 DDGS dietary treatments providing SID Trp at 15, 18, 21, and 24% of Lys or a corn-soybean meal diet (18%). Diets were isocaloric, with lysine at 100% of the requirement. From d 0 to 82, increasing Trp:Lys ratio in DDGS diets improved (P < 0.01) BW, ADG, and ADFI with no effect on F:G. Pigs fed the corn-soybean meal diet had greater (P < 0.01) BW, ADG, ADFI, and F:G compared to the DDGS diets with the exception of the ADFI of the 24% Trp:Lys treatment. From d 82 to 98, increasing SID Trp:Lys in DDGS diets had no effect on performance. Overall (d 0 to 98), increasing SID Trp:Lys in DDGS diets increased (P < 0.02) final BW and ADG, but pigs failed to perform to the same degree as the corn-soybean meal diet. Increasing SID Trp:Lys in DDGS diets resulted in an increase in hot carcass weight (P < 0.01); however, diets containing DDGS had decreased (P < 0.02) hot carcass weight, dressing percentage, percent lean, and loin depth compared to pigs fed the corn-soybean meal diet. These results indicate that increasing the SID Trp:Lys in diets containing 40% DDGS improved performance in early grow-finish phases with no effect in late finishing, but performance was inferior to standard corn-soybean meal diets.

Technological advances in high-efficiency particulate collection

1997 ◽  
Vol 211 (1) ◽  
pp. 53-65 ◽  
Author(s):  
K R Parker
Keyword(s):  
High Efficiency ◽  
Electrostatic Precipitator ◽  
Cost Effective ◽  
Vapour Phase ◽  
Air Toxics ◽  
Bag Filter ◽  
Element Analysis ◽  
Ongoing Research ◽  
Technological Advances ◽  
Improved Performance

Particulate control equipment for the larger industrial processes, which can effectively collect particles in the submicrometre range, is limited to the electrostatic precipitator and bag filter as cost effective methods. To meet ever decreasing emission levels, demanded by the Regulatory Agencies, the equipment suppliers and academics are involved in ongoing research and development activities in order to obtain a better understanding of the collection process itself, such as to achieve improved performance and, equally importantly, plant reliability and availability. This paper reviews some of the activities in the electrical, microelectronics, material sciences, fluid flow and finite element analysis fields and indicates how the findings are leading to new designs that are more reliable and also how the improvements are making the equipment more cost effective while operating at a higher performance level. Finally, with the concern over the emission of ‘air toxics’, while both the electrostatic precipitator and bag filter are established technology for effectively removing solid and liquid particulates with sizings well below 1 micrometre there is now an additional requirement for collecting vapour phase materials to meet the latest regulatory emission levels. Some ideas and approaches are examined which can prove effective in collecting the majority of materials classified as ‘air toxics’, such that the equipment will meet the existing and possible future emission standards.

scholarly journals Developing A Comprehensive Tool to Support Requirements Analyst During Elicitation Interviews [Kennesaw State University]

2019 ◽  
Author(s):  
Norah Jean-Charles ◽  
Paola Spoletini
Keyword(s):  
Mobile Application ◽  
State University ◽  
Research Project ◽  
Ongoing Research ◽  
Need Support ◽  
Voice Data ◽  
User Friendly ◽  
The Voice ◽  
Data Requirements ◽  
Voice Recording

This research is being conducted to provide requirements analysts with a supportive tool to use during elicitation interviews. In these interviews that were conducted as part of the overall project, stakeholders were asked a series of questions while wearing the Empatica E4 wristband and being recorded through various voice recording platforms. As a part of an ongoing research project, stakeholders have been interviewed using voice recordings and the Empatica E4 wristband to gather biofeedback data. Requirements analyst need support during elicitation interviews because of the ambiguity that arises during communication making it harder to collect proper requirements. In order to provide features such as visualizing the biofeedback collected from the Empatica E4 wristband and the voice waves, questions such as how to create a user-friendly application and how to synchronize the biofeedback and voice data must be researched. In conclusion, creating this mobile application would to assist requirements analysts in carrying out assessments during elicitation interviews.

Speculations on the post-pandemic university campus – a global inquiry

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Jay Deshmukh
Keyword(s):  
Higher Education ◽  
Teaching And Learning ◽  
Design Research ◽  
Research Study ◽  
Physical Space ◽  
Well Being ◽  
Virtual Classroom ◽  
Human Interaction ◽  
Ongoing Research ◽  
Content Type

PurposeThe pandemic-induced global shift to remote learning calls for rethinking the foundations of design for higher education. This watershed moment in global health and human interaction has accelerated changes in higher education that were long emergent and amplified specific deficiencies and strengths in pedagogical models, causing institutions to reevaluate current structures and operations of learning and campus life as they question their vision and purpose. Since physical space has largely been taken out of the equation of university life, it is evident that fresh design research related to this new normal is required.Design/methodology/approachThis qualitative research study speculates on new possibilities for the future of campus, based upon insights and inferences gained from one-on-one interviews with faculty and students in multiple countries about their personal experiences with the sudden shift to the virtual classroom. The longer the mode of physical distancing stretched through Spring 2020, these phone and web-enabled dialogues – first with faculty (teachers) and then with students (learners) – lead to a deeper, more nuanced understanding of how the notion of the campus for higher education was itself morphing in ways expected and unexpected.FindingsAt the heart of this study lies the question – Has COVID-19 killed the campus? This study suggests that it has not. However, campuses are now on a path of uneven evolution, and risk shedding the good with the extraneous without eyes-wide-open rethinking and responsive planning. This two-part qualitative analysis details the experiments and strategies followed by educators and students as the pandemic changed their ways of teaching and learning. It then speculates out-of-the-norm possibilities which campuses could explore as they navigate the uncertainty of future terms and address paradigm shifts questioning what defines a post-secondary education.Research limitations/implicationsThis paper draws inferences from discussions limited to the first 100 days of the pandemic. This on-the-ground aspect as the pandemic continues is its strength and its limitation. As Fall 2020 progresses across global campuses, new ideas and perspectives are already reinforcing or upending some of this paper's speculations. This researcher is already engaged in new, currently-ongoing research, following up with interviewees from Spring 2020, as well as bringing in new voices to delve deeper into the possibilities discussed in this paper. This follow-up research is shaping new thinking which is not reflected in this paper.Originality/valueDesign practitioners have long-shaped campuses on the belief that the built “environment is the third teacher” and that architecture fosters learning and shapes collective experience. Educators recognize that a multiplicity of formal and informal interactions occur frequently and naturally across campus, supporting cognitive and social development, collegiality and well-being. Even today's digital-native-students perceive the inherent value of real interpersonal engagement for meaningful experiences. This research study offers new planning and design perspectives as institutional responses to the pandemic continue to evolve, to discover how design can support what lies at the core of the campus experience.

Resolving a Workforce Crisis in the U.S. Roofing Industry

2020 ◽  
pp. 191-207
Author(s):  
John G. Schehl
Keyword(s):  
Great Recession ◽  
Research Study ◽  
Trade Association ◽  
State University ◽  
Arizona State University ◽  
Workforce Shortage ◽  
The Great Recession ◽  
Labor Statistics ◽  
Bureau Of Labor Statistics ◽  
The U.S

The National Roofing Contractors Association (NRCA), a nonprofit construction trade association established in 1886, was challenged to find a solution to overcome a severe industry workforce shortage that emerged as the economy recovered from the great recession. The NRCA leadership, staff, and other industry stakeholders focused on developing strategies to address the workforce crisis head-on and committed resources to develop a series of performance-based programs to overcome the crisis. The new initiatives relied on limited U.S. Department of Labor's Bureau of Labor Statistics (BLS) data to support development decisions. Aware that the available BLS data was insufficient, NRCA commissioned the Arizona State University (ASU) to conduct the roofing industry's first ever comprehensive demographics research study. New data gleaned from the research changed not only NRCA's approach to resolving the workforce crisis, but it may potentially change how the entire roofing industry operates.

scholarly journals Computer Programming and Agricultural Economists—Bridging the Gap

1976 ◽  
Vol 8 (1) ◽  
pp. 193-197
Author(s):  
Marilyn G. Kletke ◽  
Darrel D. Kletke
Keyword(s):  
Computer Programming ◽  
Agricultural Economics ◽  
State University ◽  
Oklahoma State University ◽  
Paper Briefly ◽  
Ongoing Research ◽  
Advantages And Disadvantages ◽  
Economics Department ◽  
Computer Programmer

Most ongoing research in the agricultural economics department at Oklahoma State University uses the computer at some time during its development. This is also true nationwide. It has become apparent that efforts need to be made to improve communications between economist and computer. This paper briefly presents alternatives available to the economist and advantages and disadvantages associated with each. Based on experiences of the agricultural economics department at Oklahoma State University, a method for improving communication between economist and computer programmer will be developed.

scholarly journals Modeling and Simulating the Static Structural Response and Lift Off of a Preloaded Bolted Joint on a Flange

Proceedings ◽  
2020 ◽  
Vol 63 (1) ◽  
pp. 10
Author(s):  
Rami Alfattani
Keyword(s):  
Structural Response ◽  
Segment Length ◽  
Bolted Joint ◽  
Element Analysis ◽  
Linear Finite Element ◽  
Bolt Preload ◽  
Gap Opening ◽  
Parametric Studies ◽  
Contact Surfaces ◽  
Lift Off

The present paper describes the structural analysis performed on a preloaded bolted joint. The first joint modeled was comprised of a conventional cylindrical flange that was sliced to simplify the analysis for two bolts in lieu of four. This involved an L-shaped flat segment flange. Parametric studies were performed using elastic, large-deformation, non-linear finite element analysis to determine the influence of several factors on the bolted-joint response. The factors considered included bolt preload, contact surfaces, edge boundary conditions, and joint segment length in this first approach. The second model applied the previous preloaded torque on a complex flange to study the flange lift off. Joint response is reported in terms of displacements, gap opening, and surface strains. Most of the factors studied were determined to have minimal effect on the bolted joint response.

Triaxial Characterization of Minnesota Road Research Project Granular Materials

1997 ◽  
Vol 1577 (1) ◽  
pp. 27-36 ◽  
Author(s):  
Navneet Garg ◽  
Marshall R. Thompson
Keyword(s):  
Shear Strength ◽  
Granular Materials ◽  
Resilient Modulus ◽  
Axial Strain ◽  
Confining Pressure ◽  
Engineering Properties ◽  
Shear Tests ◽  
Road Project ◽  
Load Tests ◽  
Repeated Load

Six granular materials were used as base and subbase materials in the flexible pavement test sections for the Minnesota Road Research (Mn/ROAD) project. Crushed/fractured particles are not allowed in aggregate classes CL-1Fsp, CL-1Csp, CL-3sp, and CL-4sp. Ten to 15 percent crushed/fractured particles are required for CL-5sp. One hundred percent crushed/ fractured particles are required for CL-6sp. A comprehensive laboratory testing program was established to determine pertinent engineering properties of the granular materials. Rapid shear tests and repeated-load tests were conducted to determine the shear strength parameters (friction angle and cohesion), resilient modulus, rutting potential, stress history effects on shear strength, and moisture susceptibility. The results from the rapid shear tests and permanent deformation tests show that the rutting potential of a granular material can be characterized from rapid shear test at a confining pressure of 15 psi (103.35 kPa). The rutting parameter A was a function of the shear strength of the granular materials. The shear strength results obtained from rapid shear tests performed at a confining pressure of 15 psi reflect the rutting trends observed in the low-volume road test sections at the Mn/ROAD project. Results from repeated-load tests were used to develop the parameters for K-θ, UT-Austin, and Uzan’s models for evaluating the resilient modulus of granular materials. The axial strain values calculated from the resilient modulus models appear to be in good agreement with the measured axial strain values, except for the very low shear strength material CL-1Csp.

The Influence of Truck Hunting Severity on Freight Car Structures

1980 ◽  
Vol 102 (4) ◽  
pp. 322-326
Author(s):  
M. F. Hengel ◽  
C. Montgomery ◽  
R. H. Billingsley
Keyword(s):  
Linear Instability ◽  
State University ◽  
Arizona State University ◽  
Hunting Behavior ◽  
Lateral Instability ◽  
Railroad Industry ◽  
Field Investigations ◽  
Research Organizations ◽  
Parametric Studies ◽  
Freight Car

In recent years much effort has been expended within the industry on investigating the causes of truck lateral instability or hunting. To determine the cause of this phenomenon various research organizations, among them the Association of American Railroads and Arizona State University have performed comprehensive tests to validate mathematical models which can be used to conduct parametric studies. These models allow for investigating various means for alleviating the non-linear instability problem. In addition, much effort has been expended by a number of private companies to develop freight car trucks with superior hunting performance. It is now well understood by the railroad industry that, given the current state-of-the-art in freight car truck design, some truck hunting behavior is unavoidable. Less attention, however, has been directed toward determination of what amount of truck hunting, if any, is acceptable. This paper describes the results of two field investigations in which truck hunting instability led to either excessive wear or structural degradation. Various means readily available to the industry were then investigated as to their effectiveness in controlling hunting. Results are presented showing that the particular problems encountered were avoided by control of the hunting phenomenon rather than its complete elimination.

scholarly journals Using a Dynamic Substructuring Approach to Model the Effects of Acoustic Damping in Coupled Acoustic–Structure Systems

2019 ◽  
Vol 141 (2) ◽  
Author(s):  
R. Benjamin Davis ◽  
Ryan Schultz
Keyword(s):  
Structural Response ◽  
Frequency Separation ◽  
System Response ◽  
Acoustic Structure ◽  
Resonant Frequencies ◽  
Acoustic Damping ◽  
Initial Separation ◽  
Dynamic Substructuring ◽  
Parametric Studies ◽  
Low Levels

Acoustic–structure coupling can substantially alter the frequency response of air-filled structures. Coupling effects typically manifest as two resonance peaks at frequencies above and below the resonant frequency of the uncoupled structural system. Here, a dynamic substructuring approach is applied to a simple acoustic–structure system to expose how the system response depends on the damping in the acoustic subsystem. Parametric studies show that as acoustic damping is increased, the frequencies and amplitudes of the coupled resonances in the structural response undergo a sequence of changes. For low levels of acoustic damping, the two coupled resonances have amplitudes approximating the corresponding in vacuo resonance. As acoustic damping is increased, resonant amplitudes decrease dramatically while the frequency separation between the resonances tends to increase slightly. When acoustic damping is increased even further, the separation of the resonant frequencies decreases below their initial separation. Finally, at some critical value of acoustic damping, one of the resonances abruptly disappears, leaving just a single resonance. Counterintuitively, increasing acoustic damping beyond this point tends to increase the amplitude of the remaining resonance peak. These results have implications for analysts and experimentalists attempting to understand, mitigate, or otherwise compensate for the confounding effects of acoustic–structure coupling in fluid-filled test structures.

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