A comprehensive comparison of computational methods on propeller modelling of an AUV

The propeller of a self-propelled marine vehicle isthe key to understanding the hull-propeller interactions. Thepresence of a propeller not only provides the necessary propulsionforce, but also significantly modifies the flow field around themarine vehicle. This modification made to flow field influences thehydrodynamic loading experienced by the marine vehicle and thushas an impact on its maneuvering characteristics. There arevarious methods to represent the actions of a propeller for a rangeof marine applications within CFD. Actuator disc or virtual disc isone of the earliest and most commonly used approach. Thisapproach solves the body force generated as an equally distributedforce over a cylindrical disc while ignoring the geometry of thepropeller. Another method to evaluate the force of a propeller isdirect simulations, which replicate a propeller based on its truegeometry within CFD. This method utilizes the overset meshtechnology within CFD that enables the propeller to rotateindependently with respect to the background mesh. The presentpaper primarily used commercially available CFD softwarepackage, Star-CCM+ to investigate the accuracy and feasibility ofrepresenting the propeller of an Explorer Class AUV using theearlier mentioned methods. The solved advance ratio, and forwardvelocity from the two methods was benchmarked against openwatertrial data

Search for rare quark-annihilation decays, B --> Ds(*) Phi

We report on searches for B- --> Ds- Phi and B- --> Ds*- Phi. In the context of the Standard Model, these decays are expected to be highly suppressed since they proceed through annihilation of the b and u-bar quarks in the B- meson. Our results are based on 234 million Upsilon(4S) --> B Bbar decays collected with the BABAR detector at SLAC. We find no evidence for these decays, and we set Bayesian 90% confidence level upper limits on the branching fractions BF(B- --> Ds- Phi) Ds*- Phi)<1.2x10^(-5). These results are consistent with Standard Model expectations.Comment: 8 pages, 3 postscript figues, submitted to Phys. Rev. D (Rapid Communications

T-cell Subsets and Antifungal Host Defenses

It has been long appreciated that protective immunity against fungal pathogens is dependent on activation of cellular adaptive immune responses represented by T lymphocytes. The T-helper (Th)1/Th2 paradigm has proven to be essential for the understanding of protective adaptive host responses. Studies that have examined the significance of regulatory T cells in fungal infection, and the recent discovery of a new T-helper subset called Th17 have provided crucial information for understanding the complementary roles played by the various T-helper lymphocytes in systemic versus mucosal antifungal host defense. This review provides an overview of the role of the various T-cell subsets during fungal infections and the reciprocal regulation between the T-cell subsets contributing to the tailored host response against fungal pathogens

A novel TOPSIS–CBR goal programming approach to sustainable healthcare treatment

Cancer is one of the most common diseases worldwide and its treatment is a complex and time-consuming process. Specifically, prostate cancer as the most common cancer among male population has received the attentions of many researchers. Oncologists and medical physicists usually rely on their past experience and expertise to prescribe the dose plan for cancer treatment. The main objective of dose planning process is to deliver high dose to the cancerous cells and simultaneously minimize the side effects of the treatment. In this article, a novel TOPSIS case based reasoning goal-programming approach has been proposed to optimize the dose plan for prostate cancer treatment. Firstly, a hybrid retrieval process TOPSIS–CBR [technique for order preference by similarity to ideal solution (TOPSIS) and case based reasoning (CBR)] is used to capture the expertise and experience of oncologists. Thereafter, the dose plans of retrieved cases are adjusted using goal-programming mathematical model. This approach will not only help oncologists to make a better trade-off between different conflicting decision making criteria but will also deliver a high dose to the cancerous cells with minimal and necessary effect on surrounding organs at risk. The efficacy of proposed method is tested on a real data set collected from Nottingham City Hospital using leave-one-out strategy. In most of the cases treatment plans generated by the proposed method is coherent with the dose plan prescribed by an experienced oncologist or even better. Developed decision support system can assist both new and experienced oncologists in the treatment planning process

Energy expenditure during flight in relation to body mass: effects of natural increases in mass and artificial load in Rose Coloured Starlings

Rose Coloured Starlings (Sturnus roseus) flew repeatedly for several hours in a wind tunnel while undergoing spontaneous variation in body mass. The treatments were as follows: flying unrestrained (U), with a control harness of 1.2% of their body mass (C), or with a harness of 7.4% of their body mass, which was either applied immediately before the flight (LS) or at least 9 days in advance (LL). Energy expenditure during flight (ef in W) was measured with the Doubly Labelled Water method. Flight costs in LS and LL were not significantly different and therefore were pooled (L). The harness itself did not affect ef, i.e. U and C flights were not different. ef was allometrically related with body mass m (in g). The slopes were not significantly different between the treatments, but ef was increased by 5.4% in L compared to C flights (log10(ef) = 0.050 + 0.47 × log10(m) for C, and log10(ef) = 0.073 + 0.47 × log10(m) for L). The difference in ef between C, LS and LL was best explained by taking the transported mass mtransp (in g) instead of m into account (log10(ef) = −0.08 + 0.54 × log10(mtransp)). Flight costs increased to a lesser extent than expected from interspecific allometric comparison or aerodynamic theory, regardless of whether the increase in mass occurred naturally or artificially. We did not observe an effect of treatment on breast muscle size and wingbeat frequency. We propose that the relatively low costs at a high mass are rather a consequence of immediate adjustments in physiology and/or flight behaviour than of long-term adaptations

The survey of serum retinol of the children aged 0~4 years in Zhejiang Province, China

<p>Abstract</p> <p>Background</p> <p>Vitamin A can have a positive impact on growth and development of children, but vitamin A deficiency (VAD) was found to be a public health problem in Zhejiang Province, China in 1998. There have been no studies on this topic in Zhejiang Province recently. This study was designed to evaluate the serum retinol levels of children aged 0~4 years in Zhejiang Province, southeast China. This epidemiological data will help design supplementation strategies for vitamin A in high-risk groups and improve their vitamin A status.</p> <p>Methods</p> <p>Children were randomly recruited for this study using a stratified sampling method. A blood sample was collected from each child. Assessment included C-reactive protein (CRP), serum retinol measured with HPLC and a questionnaire completed providing for family information and nutritional status. Logistic regression analysis was used to evaluate the risk factors for VAD in children.</p> <p>Results</p> <p>A group of 357 subjects aged 1 day to 4 years were recruited. The mean plasma retinol concentration was 1.653 (sd 0.47) μmol/L. There were 3.08% (11/357) of children affected with VAD, and 7.28% (26/357) of children had low vitamin A status, but none of the children showed any clinical symptoms of VAD. There was no significant difference in the levels of plasma retinol and the incidence rate of VAD between male and female children. Multivariate logistic regression analysis showed that living in urban region, having parents with good education and taking vitamin A capsule regularly prevented children from VAD, whereas being young (less than 2 years old) was a risk factor.</p> <p>Conclusion</p> <p>Low vitamin A status remains a nutritional problem in Zhejiang Province. The high-risk group in this study were young, dwelled in rural regions, had parents with poor education and did not take a regular vitamin A containing supplement.</p

Emergency logistics for wildfire suppression based on forecasted disaster evolution

This paper aims to develop a two-layer emergency logistics system with a single depot and multiple demand sites for wildfire suppression and disaster relief. For the first layer, a fire propagation model is first built using both the flame-igniting attributes of wildfires and the factors affecting wildfire propagation and patterns. Second, based on the forecasted propagation behavior, the emergency levels of fire sites in terms of demand on suppression resources are evaluated and prioritized. For the second layer, considering the prioritized fire sites, the corresponding resource allocation problem and vehicle routing problem (VRP) are investigated and addressed. The former is approached using a model that can minimize the total forest loss (from multiple sites) and suppression costs incurred accordingly. This model is constructed and solved using principles of calculus. To address the latter, a multi-objective VRP model is developed to minimize both the travel time and cost of the resource delivery vehicles. A heuristic algorithm is designed to provide the associated solutions of the VRP model. As a result, this paper provides useful insights into effective wildfire suppression by rationalizing resources regarding different fire propagation rates. The supporting models can also be generalized and tailored to tackle logistics resource optimization issues in dynamic operational environments, particularly those sharing the same feature of single supply and multiple demands in logistics planning and operations (e.g., allocation of ambulances and police forces). © 2017 The Author(s