Roughness effects in turbulent forced convection

We conducted direct numerical simulations (DNSs) of turbulent flow over three-dimensional sinusoidal roughness in a channel. A passive scalar is present in the flow with Prandtl number $Pr=0.7$, to study heat transfer by forced convection over this rough surface. The minimal channel is used to circumvent the high cost of simulating high Reynolds number flows, which enables a range of rough surfaces to be efficiently simulated. The near-wall temperature profile in the minimal channel agrees well with that of the conventional full-span channel, indicating it can be readily used for heat-transfer studies at a much reduced cost compared to conventional DNS. As the roughness Reynolds number, $k^+$, is increased, the Hama roughness function, $\Delta U^+$, increases in the transitionally rough regime before tending towards the fully rough asymptote of $\kappa_m^{-1}\log(k^+)+C$, where $C$ is a constant that depends on the particular roughness geometry and $\kappa_m\approx0.4$ is the von K\'arm\'an constant. In this fully rough regime, the skin-friction coefficient is constant with bulk Reynolds number, $Re_b$. Meanwhile, the temperature difference between smooth- and rough-wall flows, $\Delta\Theta^+$, appears to tend towards a constant value, $\Delta\Theta^+_{FR}$. This corresponds to the Stanton number (the temperature analogue of the skin-friction coefficient) monotonically decreasing with $Re_b$ in the fully rough regime. Using shifted logarithmic velocity and temperature profiles, the heat transfer law as described by the Stanton number in the fully rough regime can be derived once both the equivalent sand-grain roughness $k_s/k$ and the temperature difference $\Delta \Theta^+_{FR}$ are known. In meteorology, this corresponds to the ratio of momentum and heat transfer roughness lengths, $z_{0m}/z_{0h}$, being linearly proportional to $z_{0m}^+$, the momentum roughness length [continued]...Comment: Accepted (In press) in the Journal of Fluid Mechanic

Fish culture in British East Africa

Volume: I

The impacts of urbanisation and climate change on urban flooding and urban water quality: a review of the evidence concerning the United Kingdom

Study region: United Kingdom (UK). Study focus: Climate change and urbanization pose significant threats for flooding and water quality in urban areas. This paper reviews the evidence concerning the combined impacts of urbanisation and climate on the urban water environment of inland catchments of the United Kingdom and assesses the degree of confidence in reported directions of change and response. It also assesses the utility of the evidence for setting environmental legislation and managing the urban water environment in the future and identifies knowledge gaps that limit effective and management interventions. New hydrological insights: There is a lack of nationally research focused on the dual impacts of climate change and urbanisation on flooding and water quality in UK urban areas. This is despite there being a clear acceptance that flood risk is increasing, water quality is generally not meeting desirable levels, and that combined population and climate change projections pose a pressing challenge. The available evidence has been found to be of medium-high confidence that both pressures will result in (i) an increase in pluvial and fluvial flood risk, and (ii) further reduction in water quality caused by point source pollution and altered flow regimes. Evidence concerning urban groundwater flooding, diffuse pollution and water temperature was found to be more sparse and was ascribed a low-medium confidence that both pressures will further exacerbate existing issues. The confidence ascribed to evidence was also found to reflect the utility of current science for setting policy and urban planning. Recurring factors that limit the utility of evidence for managing the urban environment includes: (i) climate change projection uncertainty and suitability, (ii) lack of sub-daily projections for storm rainfall, (iii) the complexity of managing and modelling the urban environment, and (iv) lack of probable national-scale future urban landuse projections. Suitable climate products are increasingly being developed and their application in applied urban research is critical in the wake of a series of extreme flooding events across the UK and timely for providing state-of-the-art evidence on which to base possible future water quality legislation in a post Brexit-WFD era

Turbulent flow over a long flat plate with uniform roughness

For turbulent boundary-layer flow under a uniform freestream speed U∞ over a plate of length L, covered with uniform roughness of nominal sand-grain scale k_s, the physical behaviors underlying two distinguished limits at large Re_L≡U∞L/ν are explored: the fully rough wall flow where k_s/L is fixed and the long-plate limit where Re_k≡U∞k_s/ν is fixed. For the fully rough limit it is shown that not only is the drag coefficient C_D independent of Re_L but that a universal skin-friction coefficient C_f and normalized boundary-layer thickness δ/k_s can be found that depends only on ks_/x, where x is the downstream distance. In the long-plate limit, it is shown that the flow becomes asymptotically smooth at huge Re_L at a rate that depends on Re_k. Comparisons with wind-tunnel and field data are made

Indiana Consortium for Innovation in Biomedical Imaging

poster abstractThe Indiana Consortium for Innovation in Biomedical Imaging (Indiana-CIBI) has been established to leverage the biomedical imaging strengths of several major academic institutions throughout Indiana. This initiative provides the environment, infrastructure, and resources necessary for establishing one of the premier translational, research and educational imaging networks in the United States. The Indiana-CIBI will facilitate the identification of crucial clinical problems and unmet research needs; stimulate the development of innovative solutions; and help translate optimized patient care services into practice at partner health-care delivery facilities. The objectives of the Indiana-CIBI include: Providing national leadership in translation from concept to practice. Encouraging targeted problem-driven technology development. Nurturing innovation and progress through facile access to advanced resources. Focusing Indiana state-wide interdisciplinary partnerships in the development of new, innovative imaging technologies and the utilization of imaging resources. Cultivating investigator engagement and channeling intrinsic motivation. The stated objectives of the Indiana-CIBI define the operational model for the consortium. Key steps in the innovation-focused process include: 1) Identification of critical clinical or biomedical research needs by physician or biomedical investigator(s); 2) Creation of innovative solutions through innovation incubator teams, imaging innovation marathons, and crowdsourcing solicitations; 3) Translation to practice through a large medical physics/radiology network; and 4) Translation to advanced core services through the Indiana-CTSI core resource network. Critical success factors for the Indiana-CIBI include tight integration within academic health care facilities, consolidation of fragmented resources, and expansion of critical support resources, eliminating the need to duplicate some types of services across multiple sites in Indiana. For further information regarding the Indiana Consortium for Innovation in Biomedical Imaging and its programs please contact Mark Holland or Gary Hutchins at [email protected]. The Indiana-CIBI is supported, in part, by contributions from the IUPUI Office of the Vice Chancellor for Research

Risk Sharing, Crew Quality, Labor Shares and Wages in the Nineteenth Century American Whaling Industry

This paper examines 36.640 labor contracts signed between whalemen and the agents who organized 1,258 whaling voyages that departed from New Bedford, Massachusetts between January I. 1840 and December 31, 1858 and between January I and December 31, 1866. The contracts contain information on the whaleman's station (occupation) and on his lay (the fraction of output of the voyage that he was entitled to receive upon completion). The paper investigates the benefits associated with this unique contract. examines the occupational and spatial distribution of lays. and compares wages in whaling with those available in the merchant marine and those earned in shore based pursuits. It also attempts to assess the efficiency of this early labor market and to explore the relationship between the labor contract, crew quality. technical change. and productivity.

Design of a Multi-Color Plenoptic Camera for Snapshot Hyperspectral Imaging

The design of a custom camera lens including: a two-lens optical system, filter array, and iris has been developed enabling a greyscale plenoptic camera to acquire full field-of-view, 2D, instantaneous hyperspectral measurements. This work focuses on the use of 7 discrete color filters and their effect on the image quality. It was determined that the placement of the filters inside the aperture plane of the camera was paramount to mitigating image artifacts. In addition, design rules were developed such that the optimal optical parameters (image distance, working distance, and focal length) can be easily determined from a few charts

Combination GLP-1 and Insulin Treatment Fails to Alter Myocardial Fuel Selection Versus Insulin Alone in Type 2 Diabetes

Context Glucagon-like peptide-1 (GLP-1) and the clinically available GLP-1 agonists have been shown to exert effects on the heart. It is unclear whether these effects occur at clinically used doses in vivo in humans, possibly contributing to CVD risk reduction. Objective To determine whether liraglutide at clinical dosing augments myocardial glucose uptake alone or in combination with insulin compared to insulin alone in metformin-treated Type 2 diabetes mellitus. Design Comparison of myocardial fuel utilization after 3 months of treatment with insulin detemir, liraglutide, or combination detemir+liraglutide. Setting Academic hospital Participants Type 2 diabetes treated with metformin plus oral agents or basal insulin. Interventions Insulin detemir, liraglutide, or combination added to background metformin Main Outcome Measures Myocardial blood flow, fuel selection and rates of fuel utilization evaluated using positron emission tomography, powered to demonstrate large effects. Results We observed greater myocardial blood flow in the insulin-treated groups (median[25th, 75th percentile]: detemir 0.64[0.50, 0.69], liraglutide 0.52[0.46, 0.58] and detemir+liraglutide 0.75[0.55, 0.77] mL/g/min, p=0.035 comparing 3 groups and p=0.01 comparing detemir groups to liraglutide alone). There were no evident differences between groups in myocardial glucose uptake (detemir 0.040[0.013, 0.049], liraglutide 0.055[0.019, 0.105], detemir+liraglutide 0.037[0.009, 0.046] µmol/g/min, p=0.68 comparing 3 groups). Similarly there were no treatment group differences in measures of myocardial fatty acid uptake or handling, and no differences in total oxidation rate. Conclusions These observations argue against large effects of GLP-1 agonists on myocardial fuel metabolism as mediators of beneficial treatment effects on myocardial function and ischemia protection

Research Center for Quantitative Renal Imaging

poster abstractMission: The mission of the Research Center for Quantitative Renal Imaging is to provide a focused research environment and resource for the development, implementation, and dissemination of innovative, quantitative imaging methods designed to assess the status of and mechanisms associated with acute and chronic kidney disease and evaluate efficacy of therapeutic interventions. Nature of the Center: This Research Center provides a formal mechanism to link research programs focused on understanding the fundamental mechanisms associated with kidney diseases with those associated with the development of advanced imaging methods and quantitative analyses into a focused effort dedicated toward the development and implementation of quantitative renal imaging methods. Goals of the IUPUI Research Center for Quantitative Renal Imaging: Identify, develop, and implement innovative imaging methods that provide quantitative imaging biomarkers for assessing and inter-relating renal structure, function, hemodynamics and underlying tissue micro-environmental factors contributing to kidney disease. Establish an environment that facilitates and encourages interdisciplinary collaborations among investigators and offers research support to investigators focused on developing and utilizing innovative quantitative imaging methods in support of kidney disease research. Provide a resource to inform the greater research and healthcare communities of advances in quantitative renal imaging and its potential for enhanced patient management and care. Offer an imaging research resource to companies engaged in product development associated with the diagnosis and treatment of kidney diseases. Further Information: For further information regarding the IUPUI Research Center for Quantitative RenalImaging and its funding programs please visit http://www.renalimaging.iupui.edu/ or contact the Center at [email protected]. Acknowledgments: The IUPUI Research Center for Quantitative Renal Imaging is supported by contributions from the IUPUI Signature Center Initiative, the Department of Radiology & Imaging Sciences; the Division of Nephrology, the IUPUI School of Science, the IUPUI School of Engineering & Technology, and the Indiana Clinical and Translational Sciences Institute (CTSI)

Design and development of a novel upper-limb cycling prosthesis

The rise in popularity of the Paralympics in recent years has created a need for effective, low-cost sports-prosthetic devices for upper-limb amputees. There are various opportunities for lower-limb amputees to participate in cycling; however, there are only few options for those with upper-limb amputations. If the individual previously participated in cycling, a cycling-specific prosthesis could allow these activities to be integrated into rehabilitation methods. This article describes the processes involved with designing, developing and manufacturing such a prosthesis. The fundamental needs of people with upper-limb amputation were assessed and realised in the prototype of a transradial terminal device with two release mechanisms, including a sliding mechanism (for falls and minor collisions) and clamping mechanism (for head-on collisions). The sliding mechanism requires the rider to exert approximately 200 N, while the clamping mechanism requires about 700 N. The force ranges can be customised to match rider requirements. Experiments were conducted in a controlled environment to demonstrate stability of the device during normal cycling. Moreover, a volunteer test-rider was able to successfully activate the release mechanism during a simulated emergency scenario. The development of this prosthesis has the potential to enable traumatic upper-limb amputees to participate in cycling for rehabilitation or recreation