Digital Commons Network^™

Impact Of Ambient Stable Stratification On Gravity Currents Propagating Over A Submerged Canopy, Jian Zhou, Subhas K. Venayagamoorthy

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

The structure and propagation of lock-release bottom gravity currents in a linearly stratified ambient with the presence of a submerged canopy are investigated for the first time using large-eddy simulations. The canopy density (i.e. The solid volume fraction), the strength of ambient stratification and the canopy height are varied to study their respective effects on the gravity current. Both denser canopies and stronger ambient stratification tend to switch the horizontal boundary along which the current propagates from the channel bed towards the canopy top (i.e. The through-To-over flow transition). It is found that the dilution of the current density is …

Applications Of Polynomial Chaos-Based Cokriging To Aerodynamic Design Optimization Benchmark Problems, Jethro Nagawkar, Leifur Leifsson, Xiaosong Du

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this work, the polynomial chaos-based Cokriging (PC-Cokriging) is applied to a benchmark aerodynamic design optimization problem. The aim is to perform fast design optimization using this multifidelity metamodel. Multifidelity metamodels use information at multiple levels of fidelity to make accurate and fast predictions. Higher amount of lower fidelity data can provide important information on the trends to a limited amount of high-fidelity (HF) data. The PC-Cokriging metamodel is a multivariate version of the polynomial chaos-based Kriging (PC-Kriging) metamodel and its construction is similar to Cokriging. It combines the advantages of the interpolation-based Kriging metamodel and the regression-based polynomial chaos …

A B-Spline-Based Generative Adversarial Network Model For Fast Interactive Airfoil Aerodynamic Optimization, Xiaosong Du, Ping He, Joaquim R.R.A. Martins

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Airfoil aerodynamic optimization is of great importance in aircraft design; however, it relies on high-fidelity physics-based models that are computationally expensive to evaluate. In this work, we provide a methodology to reduce the computational cost for airfoil aerodynamic optimization. Firstly, we develop a B-spline based generative adversarial networks (BSplineGAN) parameterization method to automatically infer design space with sufficient shape variability. Secondly, we construct multi-layer neural network (MNN) surrogates for fast predictions on aerodynamic drag, lift, and pitching moment coefficients. The BSplineGAN has a relative error lower than 1% when fitting to UIUC database. Verification of MNN surrogates shows the root …

Adherence To A Home Exercise Programme Following A Clinical Programme For Non-Acute Non-Specific Low Back Pain: An Exploratory Study, Judith L'Heureux, Marie-France Coutu, Djamal Berbiche, Christian Larivière

Études primaires

Purpose:Lack of adherence to home exercise programmes is hypothesised to partially explain the modest clinical effects seen in patients with low back pain. This study explored the association between the main biopsychosocial factors and adherence using a theory-driven approach including the fear-avoidance model, the common-sense model and the working alliance concept.

Methods: A repeated measures design was used. During and after an eight-week clinical exercise programme, 48 participants with non-acute and disabling low back pain followed a home exercise programme. Questionnaires assessed home exercise adherence and biopsychosocial factors at baseline, after the eight-week clinical programme and at the six-month follow-up. …

On Site Comparison Of The Osha 42, Asset Ez4-Nco, Iso-Chek, Dan And Cip10 Methods For Measuring Toluene Diisocyanate (Tdi) At A Polyurethane Foam Factory, Simon Aubin, El Mekki Hamdi, Audrey Joly, Philippe Sarazin, Jacques Lesage, Livain Breau, Mark Spence, Sébastien Gagné

Études primaires

Because of the semi-volatile nature of diisocyanates (being airborne in both physical vapor and particulate phases), their high reactivity and low occupational exposure limits, diisocyanate exposure evaluation has been challenging for industrial hygienists and laboratories. The objective of this study was to compare the toluene diisocyanate (2,4 and 2,6 isomers, TDI) concentration measured by five methods in a flexible polyurethane foam factory using different collection or derivatization approaches. The methods used were: OSHA 42 modified (filter, 1-(2-pyridyl)piperazine) (OSHA), Asset EZ4-NCO (denuder and filter, dibutylamine) (Asset), Iso-Chek (double-filter, 9-(N-methylaminomethyl) anthracene and 1,2-methoxyphenylpiperazine), DAN (filter, 1,8-diaminonaphthalene), and CIP10 (centrifugation, 1,2-methoxyphenylpiperazine). Particle real-time …

Three-Month Efficacy Of Three Knee Braces In The Treatment Of Medial Knee Osteoarthritis In A Randomized Crossover Trial, Xavier Robert-Lachaine, Yoann Dessery, Étienne L. Belzile, Sylvie Turmel, Philippe Corbeil

Études primaires

Immediate biomechanical and functional effects of knee braces are often reported, however, the duration and type of knee brace treatment for knee osteoarthritis (KOA) remain unclear. The objective was to evaluate usage, comfort, pain, and knee adduction moment (KAM) of three knee braces each worn 3 months by patients. Twenty-four patients with KOA were assigned in a randomized crossover trial a valgus three-point bending system brace (V3P-brace), an unloader brace with valgus and external rotation functions (VER-brace) and a stabilizing brace used after ligament injuries (ACL-brace). Functional questionnaires and gait assessment were carried out before and after each brace wear …

The Other Side Of The Door: The Art Of Compassion In Policing, Rachel Parish, Jack J. Cambria

DRI Press

The Other Side of the Door is an account of an extraordinary experiment by a remarkable group, jointly headed by contemporary artist Rachel Parish and Jack Cambria, the longtime commander of the New York Police Department's elite Hostage Negotiation Team. The group also included law enforcement professionals and students, performance poets, an emergency medicine physician, conflict management experts, a sociologist and two psychologists.

With the unprecedented combination of viewpoints and talents the group set out to create a new approach to police training form emotional competence. They learned as much from what did not work as from what did. Both …

Post-Military Service Coping Behaviors Of Student Veterans, Benjamin Wilson

Master's Theses and Doctoral Dissertations

The purpose of this paper was to examine the relationship between post-military service stress reactions and subsequent coping behaviors among military veterans at Eastern Michigan University (EMU). The analytical approach was based on Agnew’s general strain theory, which contends that individuals turn to unhealthy or illegitimate coping mechanisms to deal with pain, whether that be physical or psychological. Data was gathered in the form of a survey of student veterans using both dichotomous and Likert-scale questions designed to assess both their level of post-service stress and coping mechanisms with emphasis on identifying post-traumatic stress disorder (PTSD) type conditions. PTSD assessment …

Direct Numerical Simulation Of Turbulent Pressure Fluctuations Over A Cone At Mach 8, Junji Huang, Lian Duan, Katya M. Casper, Ross M. Wagnild, Neal P. Bitter

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Direct numerical simulations (DNS) were conducted to characterize the pressure fluctuations under the turbulent portion of the boundary layer over a sharp 7◦ half-angle cone at a nominal freestream Mach number of 8 and a unit Reynolds number of Reunit = 13.4 x 106/m. The axisymmetric cone geometry and the flow conditions of the DNS matched those measured in the Sandia Hypersonic Wind Tunnel at Mach 8 (Sandia HWT-8). The DNS-predicted wall pressure statistics, including the root-mean-square (r.m.s.) fluctuations and the power spectral density (PSD), were compared with those measured in the Sandia HWT-8. A good comparison between the DNS …

Robustness Metric For Robust Design Optimization Under Time-And Space-Dependent Uncertainty Through Metamodeling, Xinpeng Wei, Xiaoping Du

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Product performance varies with respect to time and space in many engineering applications. This paper discusses how to measure and evaluate the robustness of a product or component when its quality characteristics (QCs) are functions of random variables, random fields, temporal variables, and spatial variables. At first, the existing time-dependent robustness metric is extended to the present time-and space-dependent problem. The robustness metric is derived using the extreme value of the quality characteristics with respect to temporal and spatial variables for the nominal-the-better type quality characteristics. Then, a metamodel-based numerical procedure is developed to evaluate the new robustness metric. The …