Boiling instabilities in microtubes

This paper was presented at the 3rd Micro and Nano Flows Conference (MNF2011), which was held at the Makedonia Palace Hotel, Thessaloniki in Greece. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, Aristotle University of Thessaloniki, University of Thessaly, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute.Microprocessor and microchip speeds are continuously increasing with their shrinking sizes. For this reason, the size of subject related heat sinks are continuously decreasing from mini size to micro size. Among many microscale heat transfer cooling applications, the most practical and extensively used micro heat sinks are plain microchannels. This study addresses the lack of information about microchannel boiling instability phenomena and includes a parametric investigation in microtubes. Experimental data were obtained from a microtube having a 250~μm inner diameter, which was tested at low mass fluxes (78.9-276.3 kg/m2s) to reveal potential boiling instabilities. De-ionized water was used as a coolant, while the microtube was heated by Joule heating. Configurations prone to boiling instabilities (low system pressures, low mass velocities) were imposed to observe boiling instabilities in microtubes. After the experiments without any inlet restriction, experiments were conducted with the configuration with inlet restriction where pressure drop over inlet restriction element was 4 times as much as pressure drop over the microtube. Temperature and pressure drop fluctuation signals were recorded and processed once boiling instabilities were observed

A Critical Appraisal of Guidelines for Antenatal Care: Components of Care and Priorities in Prenatal Education

There are a variety of published prenatal care (PNC) guidelines that claim a scientific basis for the information included. Four sets of PNC guidelines published between 2005 and 2009 were examined and critiqued. The recommendations for assessment procedures, laboratory testing, and education/counseling topics were analyzed within and between these guidelines. The PNC components were synthesized to provide an organized, comprehensive appendix that can guide providers of antepartum care. The appendix may be used to locate which guidelines addressed which topics to assist practitioners to identify evidence sources. The suggested timing for introducing and reinforcing specific topics is also presented in the appendix. Although education is often assumed to be a vital component of PNC, it was inconsistently included in the guidelines that were reviewed. Even when education was included, important detail was lacking. Addressing each woman\u27s needs as the first priority was suggested historically and remains relevant in current practice to systematically provide care while maintaining the woman as the central player. More attention to gaps in current research is important for the development of comprehensive prenatal guidelines that contribute effectively to the long‐term health and well‐being of women, families, and their communities

General analysis of signals with two leptons and missing energy at the Large Hadron Collider

A signal of two leptons and missing energy is challenging to analyze at the Large Hadron Collider (LHC) since it offers only few kinematical handles. This signature generally arises from pair production of heavy charged particles which each decay into a lepton and a weakly interacting stable particle. Here this class of processes is analyzed with minimal model assumptions by considering all possible combinations of spin 0, 1/2 or 1, and of weak iso-singlets, -doublets or -triplets for the new particles. Adding to existing work on mass and spin measurements, two new variables for spin determination and an asymmetry for the determination of the couplings of the new particles are introduced. It is shown that these observables allow one to independently determine the spin and the couplings of the new particles, except for a few cases that turn out to be indistinguishable at the LHC. These findings are corroborated by results of an alternative analysis strategy based on an automated likelihood test.Comment: 18 pages, 3 figures, LaTe

Analysis of uncertainty in health care cost-effectiveness studies: an introduction to statistical issues and methods

Cost-effectiveness analysis is now an integral part of health technology assessment and addresses the question of whether a new treatment or other health care program offers good value for money. In this paper we introduce the basic framework for decision making with cost-effectiveness data and then review recent developments in statistical methods for analysis of uncertainty when cost-effectiveness estimates are based on observed data from a clinical trial. Although much research has focused on methods for calculating confidence intervals for cost-effectiveness ratios using bootstrapping or Fieller’s method, these calculations can be problematic with a ratio-based statistic where numerator and=or denominator can be zero. We advocate plotting the joint density of cost and effect differences, together with cumulative density plots known as cost-effectiveness acceptability curves (CEACs) to summarize the overall value-for-money of interventions. We also outline the net-benefit formulation of the cost-effectiveness problem and show that it has particular advantages over the standard incremental cost-effectiveness ratio formulation

3D modelling of angiogenesis and vascular tumour growth

This paper was presented at the 3rd Micro and Nano Flows Conference (MNF2011), which was held at the Makedonia Palace Hotel, Thessaloniki in Greece. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, Aristotle University of Thessaloniki, University of Thessaly, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute

Carboxyhaemoglobin levels and their determinants in older British men

Background: Although there has been concern about the levels of carbon monoxide exposure, particularly among older people, little is known about COHb levels and their determinants in the general population. We examined these issues in a study of older British men.Methods: Cross-sectional study of 4252 men aged 60-79 years selected from one socially representative general practice in each of 24 British towns and who attended for examination between 1998 and 2000. Blood samples were measured for COHb and information on social, household and individual factors assessed by questionnaire. Analyses were based on 3603 men measured in or close to (< 10 miles) their place of residence.Results: The COHb distribution was positively skewed. Geometric mean COHb level was 0.46% and the median 0.50%; 9.2% of men had a COHb level of 2.5% or more and 0.1% of subjects had a level of 7.5% or more. Factors which were independently related to mean COHb level included season (highest in autumn and winter), region (highest in Northern England), gas cooking (slight increase) and central heating (slight decrease) and active smoking, the strongest determinant. Mean COHb levels were more than ten times greater in men smoking more than 20 cigarettes a day (3.29%) compared with non-smokers (0.32%); almost all subjects with COHb levels of 2.5% and above were smokers (93%). Pipe and cigar smoking was associated with more modest increases in COHb level. Passive cigarette smoking exposure had no independent association with COHb after adjustment for other factors. Active smoking accounted for 41% of variance in COHb level and all factors together for 47%.Conclusion: An appreciable proportion of men have COHb levels of 2.5% or more at which symptomatic effects may occur, though very high levels are uncommon. The results confirm that smoking (particularly cigarette smoking) is the dominant influence on COHb levels

Implementation of Triple P-Positive Parenting Program in Hong Kong: Predictors of programme completion and clinical outcomes

This study examined the effectiveness of the Triple P-Positive Parenting Program in a government child health service delivery context with Chinese parents in Hong Kong. Specifically, the study sought to identify pre-intervention variables that might predict programme outcomes such as, level of clinical improvement and programme completion. Participants were 661 parents of pre-school and primary aged children participating in a group version of the Triple P-Positive Parenting Program. There were significant decreases in disruptive child behaviours, levels of parenting stress, general stress and anxiety and an increase in parenting sense of competence. Greater change in reports of child behaviour problems was related to lower levels of family income, new immigrant family status, and higher pre-intervention levels of parenting stress. The present study provides a profile of parents who are most likely to benefit from parent training programmes

The discursive construction of childhood and youth in AIDS interventions in Lesotho's education sector: Beyond global-local dichotomies

This is the post-print version of this article. The definitive, peer-reviewed and edited version of this article is published in Environment and Planning D,Society and Space 28(5) 791 – 810, 2010, available from the link below. Copyright @ 2010 Pion.In southern Africa interventions to halt the spread of AIDS and address its social impacts are commonly targeted at young people, in many cases through the education sector. In Lesotho, education-sector responses to AIDS are the product of negotiation between a range of ‘local’ and ‘global’ actors. Although many interventions are put forward as government policy and implemented by teachers in schools, funding is often provided by bilateral and multilateral donors, and the international ‘AIDS industry’—in the form of UN agencies and international NGOs—sets agendas and makes prescriptions. This paper analyses interviews conducted with policy makers and practitioners in Lesotho and a variety of documents, critically examining the discourses of childhood and youth that are mobilised in producing changes in education policy and practice to address AIDS. Focusing on bursary schemes, life-skills education, and rights-based approaches, the paper concludes that, although dominant ‘global’ discourses are readily identified, they are not simply imported wholesale from the West, but rather are transformed through the organisations and personnel involved in designing and implementing interventions. Nonetheless, the connections through which these discourses are made, and children are subjectified, are central to the power dynamics of neoliberal globalisation. Although the representations of childhood and youth produced through the interventions are hybrid products of local and global discourses, the power relations underlying them are such that they, often unintentionally, serve a neoliberal agenda by depicting young people as individuals in need of saving, of developing personal autonomy, or of exercising individual rights.RGS-IB

Insulin resistance in type 1 diabetes: what is ‘double diabetes’ and what are the risks?

In this review, we explore the concept of ‘double diabetes’, a combination of type 1 diabetes with features of insulin resistance and type 2 diabetes. After considering whether double diabetes is a useful concept, we discuss potential mechanisms of increased insulin resistance in type 1 diabetes before examining the extent to which double diabetes might increase the risk of cardiovascular disease (CVD). We then go on to consider the proposal that weight gain from intensive insulin regimens may be associated with increased CV risk factors in some patients with type 1 diabetes, and explore the complex relationships between weight gain, insulin resistance, glycaemic control and CV outcome. Important comparisons and contrasts between type 1 diabetes and type 2 diabetes are highlighted in terms of hepatic fat, fat partitioning and lipid profile, and how these may differ between type 1 diabetic patients with and without double diabetes. In so doing, we hope this work will stimulate much-needed research in this area and an improvement in clinical practice