The Influence of Geometry on the Thermal Performance of Microchannels in Laminar Flow with Viscous Dissipation

This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.Micro heat exchangers (MHXs) may achieve very high heat transfer coefficients thanks to their small dimensions and high Area-to-Volume ratio even in laminar flow. The main drawback of these devices is the high frictional losses – especially for liquid flows – that make viscous dissipation no longer negligible. In order to enhance heat transfer, modification of the channels’ cross-section is a viable strategy. In the present work the fully developed steady laminar flow of a Newtonian liquid through a microchannel subject to H1 boundary conditions in the presence of viscous dissipation is investigated. Entropy generation numbers and FG1a performance evaluation criterion are employed to assess the influence of smoothing the corners of an initially rectangular cross-section, with an aspect ratio ranging from 1 to 0.03 under four different types of geometrical constraints. The governing equations and the results are expressed in non-dimensional form, the intensity of viscous dissipation being exemplified by the Brinkman number, which is demonstrated to increase its maximum allowable value when corners are smoothed. The results are reported as a function of the non-dimensional radius of curvature Rc and aspect ratio and show that smoothing the corners almost invariably brings about a benefit for a fixed heated perimeter

Modelling of Natural Convective Heating of a Standard Wet Brick for Oven Energy Consumption Tests

The environmental impact of buildings is directly influenced by low-efficiency appliances like electric ovens. Their energy class is estimated through a test prescribed by the EN 60350 European standard, where a wet clay brick is heated under set conditions and the energy consumption is measured; throughout the test, particular attention is devoted to the control of air temperature. In this work, a transient model of the oven suitable for control design was realized including the heat and mass transfer within the brick. A lumped-parameter approach was used to ensure good predictive properties and low computational cost. The dynamics of the cavity air and the Pt500, which is used in normal operation to maintain the desired set point, was also included in the model. Model parameters were determined through an optimization procedure based on the experimental data collected during energy consumption tests with the oven in natural convective heating mode. The model was then validated. Good results were obtained in the prediction of both temperature and heating time

The relevance and usefulness of the Implicit Associations Test (IAT) in adolescent development, attachment and depression

This thesis focuses on the Implicit Associations Test (IAT), as a measure of implicit cognition aiming to tap distortions of cognitive processing by unconsciously held personal and interpersonal attitudes and beliefs. Classically, IAT had revealed delays in processing of information when dissonant attitudes were activated, even when the participant denied these attitudes. It is a popular measure, but there is little scientific consensus about its value and reliably to detect individual differences across a number of domains. This thesis examined the validity if the IAT in a number of clinical contexts attempting to test its clinical relevance and practical usefulness as a psychometric instrument. The thesis contains 5 empirical studies: 1) Attachment transmission: The test is administered to a sample of mothers with infants of 1 year of age. IAT was used to measure the mother’s implicit attitudes towards attachment relationships and parenting in general and its capacity accurately to predict other measures of attachment, parenting, and psychopathology. In this context, the IAT resulted to be of little value. 2) A newly developed version of the IAT with the potential to measure implicit self-esteem was administered to a large sample of adolescents (14-24 y-o) to test the prediction that implicit self-esteem measured with the IAT is robust to age and gender of the sample. 3, and 5) Depression: Three studies aimed to validate the SE-IAT in the context of depression. The first assessed the ability of the SE-IAT to discriminate between depressed and non-depressed patients. The second study, cross-validated the SE-IAT against several other psychometric instruments in this depressed sample. The third study aimed to assess the value of the SE-IAT to predict and monitor individual gains in the psychotherapy for depression. The SE-IAT is useful at calculating discrepancies between explicit and implicit self-esteem to predict internalizing disorders

Analytical modeling of MHD flow over a permeable rotating disk in the presence of soret and dufour effects: Entropy analysis.

The main concern of the present article is to study steady magnetohydrodynamics (MHD) flow, heat transfer and entropy generation past a permeable rotating disk using a semi numerical/analytical method named Homotopy Analysis Method (HAM). The results of the present study are compared with numerical quadrature solutions employing a shooting technique with excellent correlation in special cases. The entropy generation equation is derived as a function of velocity, temperature and concentration gradients. Effects of flow physical parameters including magnetic interaction parameter, suction parameter, Prandtl number, Schmidt number, Soret and Dufour number on the fluid velocity, temperature and concentration distributions as well as entropy generation number are analysed and discussed in detail. Results show that increasing the Soret number or decreasing the Dufour number tends to decrease the temperature distribution while the concentration distribution is enhanced. The averaged entropy generation number increases with increasing magnetic interaction parameter, suction parameter, Prandtl number, and Schmidt number

Extending Elliptic Curve Chabauty to higher genus curves

We give a generalization of the method of "Elliptic Curve Chabauty" to higher genus curves and their Jacobians. This method can sometimes be used in conjunction with covering techniques and a modified version of the Mordell-Weil sieve to provide a complete solution to the problem of determining the set of rational points of an algebraic curve $Y$.Comment: 24 page

A randomised controlled trial of mentalization-based treatment versus structured clinical management for patients with comorbid borderline personality disorder and antisocial personality disorder.

BACKGROUND: Antisocial personality disorder (ASPD) is an under-researched mental disorder. Systematic reviews and policy documents identify ASPD as a priority area for further treatment research because of the scarcity of available evidence to guide clinicians and policymakers; no intervention has been established as the treatment of choice for this disorder. Mentalization-based treatment (MBT) is a psychotherapeutic treatment which specifically targets the ability to recognise and understand the mental states of oneself and others, an ability shown to be compromised in people with ASPD. The aim of the study discussed in this paper is to investigate whether MBT can be an effective treatment for alleviating symptoms of ASPD. METHODS: This paper reports on a sub-sample of patients from a randomised controlled trial of individuals recruited for treatment of suicidality, self-harm, and borderline personality disorder. The study investigates whether outpatients with comorbid borderline personality disorder and ASPD receiving MBT were more likely to show improvements in symptoms related to aggression than those offered a structured protocol of similar intensity but excluding MBT components. RESULTS: The study found benefits from MBT for ASPD-associated behaviours in patients with comorbid BPD and ASPD, including the reduction of anger, hostility, paranoia, and frequency of self-harm and suicide attempts, as well as the improvement of negative mood, general psychiatric symptoms, interpersonal problems, and social adjustment. CONCLUSIONS: MBT appears to be a potential treatment of consideration for ASPD in terms of relatively high level of acceptability and promising treatment effects. TRIAL REGISTRATION: ISRCTN ISRCTN27660668 , Retrospectively registered 21 October 2008

Attachment and Personality Disorders: A Short Review

Attachment theory is a biopsychosocial model referring to a person’s characteristic ways of relating in close relationships, such as with parents, children, and romantic partners. These ways of relating are learned during early infancy and mold subsequent intimate relationships. An adult who is securely attached has internalized a reliable relationship to his/her caregivers in infancy, and thus is capable of adapting to different social contexts and, more importantly, of maintaining an adequate equilibrium between self-regulation and interpersonal regulation of stress. Insecure adult attachment styles are divided into 1) anxious/preoccupied (individuals are hypersensitive to rejection and show compulsive care- and attention-seeking behavior); 2) avoidant/dismissing (individuals are hyposensitive to social interactions, and are socially isolated); and 3) unresolved/disorganized (individuals are unable to cope under stress, thus suffering pervasive affective dysregulation). This review discusses the theoretical, psychological, neuroscientific, and developmental aspects of attachment from an evidence-based perspective. It provides an updated account of the science regarding attachment and its relevance to the etiology, diagnosis, and treatment of mental illness. It examines the privileged relation between attachment and personality disorders (PDs) from multiple angles in order to introduce the most recent psychotherapeutic advances, based on attachment research, for the treatment of PDs, particularly borderline PD. Three effective, evidence-based psychotherapeutic interventions are described: Mentalization-Based Treatment, Transference-Focused Psychotherapy and Schema-Focused Therapy

Preliminary Real-World Evaluation of an Intervention for Parents of Adolescents: The Open Door Approach to Parenting Teenagers (APT)

Most parenting interventions report high dropout rates for parents who exhibit clinically high levels of stress and/or are parents of adolescents with severe emotional and/or behavioral difficulties. The objective of this preliminary study was to evaluate the feasibility and real-world effectiveness of the Open Door Approach to Parenting Teenagers (APT), a six-session individually delivered face-to-face intervention for typically hard to engage parents of 11 to 21-year-olds. A one-group, pre-post evaluation design was adopted due to the naturalistic clinic-based setting of the study. Participants were 279 parents reporting clinical levels of stress relating to parenting an adolescent. Parents receiving the APT intervention demonstrated lower dropout rates than other parenting programs and reported high scores across several items relating to service satisfaction. The APT intervention was associated with significant reductions in parental stress and improvements in parent-adolescent relationships immediately post-intervention. Findings suggest that parents found the APT intervention acceptable and beneficial, and further suggest that the intervention is feasible and effective in retaining hard to engage parents. Moreover, preliminary findings suggest that the APT intervention is a promising intervention that may support parents who fail to engage in group programs. However, further research is required to establish the efficacy of the intervention

Factors influencing the first thousand days of life

The first 1,000 days is a vulnerable phase in which parents, institutions and health professionals should create early interventions for the proper development and promotion of good health