Numerical modelling of free-surface flows

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Logic -\u3e Proof -\u3e REST

REST is a common architecture for networked applications. Applications that adhere to the REST constraints enjoy significant scaling advantages over other architectures. But REST is not a panacea for the task of building correct software. Algebraic models of computation, particularly CSP, prove useful to describe the composition of applications using REST. CSP enables us to describe and verify the behavior of RESTful systems. The descriptions of each component can be used independently to verify that a system behaves as expected. This thesis demonstrates and develops CSP methodology to verify the behavior of RESTful applications

Developing Theoretically Based and Culturally Appropriate Interventions to Promote Hepatitis B Testing in 4 Asian American Populations, 2006–2011

INTRODUCTION: Hepatitis B infection is 5 to 12 times more common among Asian Americans than in the general US population and is the leading cause of liver disease and liver cancer among Asians. The purpose of this article is to describe the step-by-step approach that we followed in community-based participatory research projects in 4 Asian American groups, conducted from 2006 through 2011 in California and Washington state to develop theoretically based and culturally appropriate interventions to promote hepatitis B testing. We provide examples to illustrate how intervention messages addressing identical theoretical constructs of the Health Behavior Framework were modified to be culturally appropriate for each community. METHODS: Intervention approaches included mass media in the Vietnamese community, small-group educational sessions at churches in the Korean community, and home visits by lay health workers in the Hmong and Cambodian communities. RESULTS: Use of the Health Behavior Framework allowed a systematic approach to intervention development across populations, resulting in 4 different culturally appropriate interventions that addressed the same set of theoretical constructs. CONCLUSIONS: The development of theory-based health promotion interventions for different populations will advance our understanding of which constructs are critical to modify specific health behaviors

Passive Gas-Liquid Separation Using Hydrophobic Porous Polymer Membranes: A Study on the Effect of Operating Pressure on Membrane Area Requirement

The use of hydrophobic porous polymer membranes to vent unwanted gas bubbles from liquid streams is becoming increasingly more common in portable applications such as direct methanol fuel cells (DMFCs) and micro-fluidic cooling of electronic circuits. In order for these portable systems to keep up with the ever increasing demand of the mobile user, it is essential that auxiliary components, like gas-liquid separators (GLS), continue to decrease in weight and size. While there has been significant progress made in the field of membrane-based gas-liquid separation, the ability to miniaturize such devices has not been thoroughly addressed in the available literature. Thus, it was the purpose of this work to shed light on the scope of GLS miniaturization by examining how the amount porous membrane required to completely separate gas bubbles from a liquid stream varies with operating pressure. Two membrane characterization experiments were also employed to determine the permeability, k, and liquid entry pressure (LEP) of the membrane, which provided satisfying results. These parameters were then implemented into a mathematical model for predicting the theoretical membrane area required for a specified two-phase flow, and the results were compared to experimental values. It was shown that the drastically different surface properties of the wetted materials within the GLS device, namely polytetrafluoroethylene (PTFE) and acrylic, caused the actual membrane area requirement to be higher than the theoretical predictions by a constant amount. By analyzing the individual effects of gas and liquid flow, it was also shown that the membrane area requirement increased significantly when the liquid velocity exceeded an amount necessary to cause the flow regime to transition from wedging/slug flow to wavy/semi-annular flow

A Critical Evaluation Of Empirical Non-Linear Control System And System Dynamics Modeling Theories For Mitigating Risks Arising From Bullwhip Effect

Bullwhip effect is a threat observed in multi-echelon supply chains, which is one of the prominent indicators of inefficiencies in a supply chain. Primarily, bullwhip effect occurs as a result of disruptions in information and materials flow, lead-time delays, lack of coordination, and panic stocking amidst visibility into local risk factors. When bullwhip effect occurs, the demand variations entering the supply chain from the customer end amplifies gradually as it flows upstream towards the supplier ends. This may cause unused inventory and may later lead to wastage and obsolescence. Bullwhip effect can be curbed through many approaches. This study has focused on control theory approach that promotes small-scale control behaviors throughout the supply chain to dampen the bullwhip tidal waves. The approach investigated in this research is a combination of control system modeling and systems dynamics modeling, which is not researched adequately by bullwhip academics. Based on the investigations, a six-step approach for reducing Bullwhip effect is proposed in this research and illustrated with examples. The six-step approach comprises of first-level multi-echelon survey to derive the initial system dynamics model, second-level survey to collect primary data for all the variables and relationships formed, principal component analysis and Cronbach Alpha / split-half testing for reliability, verification, and validity testing and exploring the best optimal construct using structural equation modeling, and finally, applying controllers to the optimal systems dynamics model through interpretive analysis of the model

Oxygen Cost of Recreational Horse-Riding in Females

Version: as accepted for publication.BACKGROUND: The purpose of this study was to characterize the physiological demands of a riding session comprising different types of recreational horse riding in females. METHODS: Sixteen female recreational riders (aged 17 to 54 years) completed an incremental cycle ergometer exercise test to determine peak oxygen consumption (VO₂peak) and a 45-minute riding session based upon a British Horse Society Stage 2 riding lesson (including walking, trotting, cantering and work without stirrups). Oxygen consumption (VO₂), from which metabolic equivalent (MET) and energy expenditure values were derived, was measured throughout. RESULTS: The mean VO₂ requirement for trotting/cantering (18.4 ± 5.1 ml·kg⁻¹·min⁻¹; 52 ± 12% VO₂peak; 5.3 ± 1.1 METs) was similar to walking/trotting (17.4 ± 5.1 ml·kg⁻¹·min⁻¹; 48 ± 13% VO₂peak; 5.0 ± 1.5 METs) and significantly higher than for work without stirrups (14.2 ± 2.9 ml·kg⁻¹·min⁻¹; 41 ± 12% VO₂peak; 4.2 ± 0.8 METs) (P = .001). CONCLUSIONS: The oxygen cost of different activities typically performed in a recreational horse riding session meets the criteria for moderate intensity exercise (3-6 METs) in females, and trotting combined with cantering imposes the highest metabolic demand. Regular riding could contribute to the achievement of the public health recommendations for physical activity in this population

Gender and cultural diversity in Australian sport

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