Gay-Straight Alliances as Settings to Discuss Health Topics: Individual and Group Factors Associated with Substance Use, Mental Health, and Sexual Health Discussions

Sexual minority (e.g. lesbian, gay, bisexual, questioning; LGBQ) and gender minority (e.g. transgender) youth experience myriad health risks. Gay-Straight Alliances (GSAs) are school-based settings where they may have opportunities to discuss substance use, mental health, and sexual health issues in ways that are safe and tailored to their experiences. Attention to these topics in GSAs could aid in developing programming for these settings. Among 295 youth from 33 Massachusetts high-school GSAs (69% LGBQ, 68% cisgender female, 68% White, Mage = 16.06), we examined how often youth discussed these topics within their GSA and identified factors associated with having more of these discussions. Youth and GSAs as a whole varied in their frequency of discussing these topics. Youth who accessed more information/resources in the GSA and did more advocacy more frequently engaged in discussions around substance use, mental health and sexual health. Youth who reported greater victimization more often discussed substance use and mental health, but not sexual health. Finally, GSAs whose members collectively reported greater victimization more frequently discussed these topics. These findings can assist the development of health programming to be delivered within GSAs

A distributed model predictive control strategy for back-to-back converters

In recent years Model Predictive Control (MPC) has been successfully used for the control of power electronics converters with different topologies and for different applications. MPC offers many advantages over more traditional control techniques such as the ability to avoid cascaded control loops, easy inclusion of constraint and fast transient response. On the other hand, the controller computational burden increases exponentially with the system complexity and may result in an unfeasible realization on modern digital control boards. This paper proposes a novel Distributed Model Predictive Control, which is able to achieve the same performance of the classical Model Predictive Control whilst reducing the computational requirements of its implementation. The proposed control approach is tested on a AC/AC converter in a back-to-back configuration used for power flow management. Simulation results are provided and validated through experimental testing in several operating conditions

IGBT-SiC dual fed ground power unit

This paper presents the design and control of a three-phase ground power supply unit for aircraft servicing. A new mixed technology converter composed by a three-phase Silicon Carbide (SiC) full bridge unit and a three-phase full bridge IGBT unit connected across the same dc link is used instead of the conventional full bridge configuration. In order to satisfy the stringent requirements of the output voltage quality particular attention is given to the controller. The common dc link topology of the converter allows circulation of Zero Sequence Current (ZSC), therefore also a 0 axis regulator is necessary. The state space model of the system considering the LC output filter is presented and used in order to synthetize the controller parameters using the Optimal Control theory

uCube: control platform for power electronics

This paper presents a versatile tool for development, control and testing of power electronics converters. In the last decade, many different expensive off-the-shelf tools for rapid prototyping and testing have been developed and commercialised by few market players. Recently, the increasing diffusion of low cost, Do It Yourself targeted development tools gained market shares previously controlled by conventional players. This trend has been driven by the fact that, despite their lower performances, many of these low cost systems are powerful enough to develop simple power electronics systems for learning and teaching purposes. This paper describes a control platform developed within the University of Nottingham, targeting at the market and application segment in between the expensive off-the-shelf control boards and the low cost emerging systems. The platform is based on the Microzed evaluation board, equipped with the Xilinx Zynq System-on-Chip. Its flexibility, features and performances will be addressed and examples of how they are being experimentally validated on different rigs will be provided

High speed drives review: machines, converters and applications

The development of new power electronic device and high performance magnetic materials are the main technological factors that have led both industries and research community to focus their attention on high speed electrical drives. Several papers have already outlined the electrical machine and/or converter topology choice for certain high speed application. This choice depends on the applications under study. This paper aims to identify the most important high speed applications. For each of them, the main design challenges are highlighted and an overview of available market product is presented

Design optimization of a high-speed synchronous reluctance machine

Synchronous reluctance machines, including the per¬manent magnet assisted variants are competitive motor topologies if the application requires high efficiency and a cost effective solution with a high flux weakening capability. However, increas¬ing operating speeds incur challenging design and development decisions, mainly in order to find design solutions that ensure the machines structural integrity without compromising the overall performance. In this paper, a comprehensive design procedure for high speed synchronous reluctance machines is presented. In order to validate the procedure, a 5 kW, 80000 rpm machine is considered. The proposed strategy consists of a two-step procedure in which the electromagnetic and structural designs have been properly decoupled dividing the design space in two subsets. Each subset mainly affects the electromagnetic or the structural performances. Several structural design optimizations have been then performed with the aim of finding the optimal trade-off between the rotor geometrical complexity (that defines the required computational resources) and the electromagnetic performance. The reported experimental tests of the prototyped machine validate the proposed design strategy which can be used as general guidelines on the structural design of synchronous reluctance machines

IGBT-SiC dual fed open end winding PMSM drive

This paper proposes a dual fed common dc link inverter Open End Winding-Permanent Magnet Synchronous Motor (OEW-PMSM) Drive. In order to increase the system efficiency a dual technology converter is used, with one inverter composed of standard IGBT devices and the other composed of fast switching Silicon Carbide (SiC) devices. The common dc link OEW configuration allows the zero-sequence current (ZSC) to flow freely, and the low time constants of the zero-circuit can lead to high zero sequence current flow, with associated losses and stress on the power devices. To avoid this, the zero-sequence voltage produced by the switching combinations adopted to synthetize the control signals needs to be instantaneously eliminated. A novel modulation for dual converter configurations is proposed to eliminate the zero-sequence voltage(ZSV)

Body Satisfaction, Weight Gain, and Binge Eating Among Overweight Adolescent Girls

Objective: To examine if body satisfaction is associated with body mass index (BMI) change and whether it protects against the development of frequent binge eating among overweight and obese adolescent girls. Methods: We used prospective data from 9 waves of an ongoing cohort study of adolescents, the Growing Up Today Study. At enrollment in 1996, participants were 9 to 14 years old. Questionnaires were mailed to participants annually until 2001, then biennially through 2007. Girls who were overweight or obese in 1996 were included in the analysis (n=1 559). Our outcomes were annual change in BMI and incident frequent binge eating, defined as binge eating at least weekly and no use of compensatory behaviors. Results: At baseline, 57.2% of the overweight and obese girls were at least somewhat satisfied with their bodies. During 11 years of follow-up, 9.5% (95% confidence interval (CI) [7.8, 10.8]) of the girls started to binge eat frequently. Controlling for BMI and other confounders, overweight and obese girls who reported being at least somewhat satisfied with their bodies made smaller BMI gains (β=−0.10 kg/m$^2$, 95% CI [−0.19, −0.02]) and had 61% lower odds of starting to binge eat frequently (odds ratio (OR)=0.39, 95% CI [0.24, 0.64]) than their less satisfied peers. Compared to girls who were the least satisfied with their bodies, girls who were the most satisfied had 85% lower odds of starting to binge eat frequently (OR=0.15, 95% CI [0.06, 0.37]). The association between body satisfaction and starting to binge eat frequently was stronger for younger adolescents than older adolescents. Conclusions: While body dissatisfaction is common among overweight and obese girls, body satisfaction may protect against excessive weight gain and binge eating. Prevention of body dissatisfaction must begin early and should be considered as a component of both obesity and eating disorder prevention programs

An advanced modulation scheme emphasising neutral point ripple suppression using predictive control for three-level NPC converters in aircraft electric starter generator applications

Electrical starter/generator (ESG) system is one of the key innovations of more-electric aircraft initiative. The ESG cranks the engine and accelerates it up to self-sustained speed using electric energy (starter mode) and then runs as a generator to supply onboard loads. Three-level neutral point clamped (NPC) converter have been identified as a preferable choice for ESG applications due to high power quality as well as efficiency. However, the application of three-level NPC converter in the ESG systems has certain challenges. One of which is the low frequency neutral point voltage ripple, especially in generation mode when running at high speeds such that the flux weakening control is required. The paper proposes an advanced modulation scheme which can balance the neutral point voltage for the full range of speeds and loading conditions. Using the proposed technique, zero neutral point voltage deviation within each switching period is achieved by introducing a sharing factor computed in a deadbeat predictive approach. The proposed technique is validated with simulation results

Trade-off analysis and design of a high power density PM machine for flooded industrial pump

This paper presents the trade-off analysis and design of a high power-density machine for industrial pump applications. The developed permanent magnet synchronous machine drives an electric, oil flooded pump. Different slot/pole combination and winding configuration have been investigated in order to identify the optimal combination that satisfies the electromagnetic and thermal constraint while keeping the losses as small as possible. Several strategies such as the use of the Cobalt iron material for the stator core lamination and the adoption of Halbach array have been investigated in this work to improve the performance capabilities of the designed machine. The electromagnetic performances have been evaluated by using a finite element method. Thermal behaviour has been determined using a lumped parameter network. The outcome of the thermal analysis helped to identify the optimal cooling configurations. The final results are presented highlighting the achieved design targets