Scheduling of Multiple Chillers in Trigeneration Plants

The scheduling of both absorption cycle and vapour compression cycle chillers in trigeneration plants is investigated in this work. Many trigeneration plants use absorption cycle chillers only but there are potential performance advantages to be gained by using a combination of absorption and compression chillers especially in situations where the building electrical demand to be met by the combined heat and power (CHP) plant is variable. Simulation models of both types of chillers are developed together with a simple model of a variable-capacity CHP engine developed by curve-fitting to supplier’s data. The models are linked to form an optimisation problem in which the contribution of both chiller types is determined at a maximum value of operating cost (or carbon emission) saving. Results show that an optimum operating condition arises at moderately high air conditioning demands and moderately low power demand when the air conditioning demand is shared between both chillers, all recovered heat is utilised, and the contribution arising from the compression chiller results in an increase in CHP power generation and, hence, engine efficiency

Identifying High Potential Police Officers and Role Characteristics.

Project commissioned in 2000 by the Metropolitan Police Service to carry out a psychometric assessment validation study as part of a career Pathways Project

Psychological health and attitude toward Christianity: a study among pupils attending Catholic schools in the Netherlands

This study examines the wider relevance of recent research conducted in England, Northern Ireland and Hong Kong concerning the association between religion and psychological health among young people, by administering translations of the same measures to a sample of 980 pupils attending Catholic secondary schools in the Netherlands. These pupils completed the short-form Revised Eysenck Personality Questionnaire together with the Francis Scale of Attitude toward Christianity. The data confirmed the key finding from previous research that a more positive attitude toward Christianity is associated with lower scores recorded on the psychoticism scale. The implications of these findings are discussed for religious educators

The use of computer modelling to evaluate the agronomic, economic and environmental impacts of N management in contrasting organic rotations

A new computer model (EU-ROTATE_N) has been developed with the aim of improving nitrogen management on all farms across Europe which include fi eld vegetables in their rotations. It brings together aspects of many existing models and contains a number of features to make it applicable to organic producers (e.g. taking account of nitrogen fixation by legume containing leys, nitrogen conservation by winter cover crops and nitrogen supply by manures and composts). A key feature is the model’s ability to simulate economic output and this enables it to be of value to policy makers when considering the impact of new measures to reduce environmental pollution. This paper describes the model and some initial work that has been conducted to evaluate it under UK organic field vegetable systems with contrasting fertility building strategies

A Longitudinal Study of Identifying and Paying Down Architectural Debt

Architectural debt is a form of technical debt that derives from the gap between the architectural design of the system as it "should be" compared to "as it is". We measured architecture debt in two ways: 1) in terms of system-wide coupling measures, and 2) in terms of the number and severity of architectural flaws. In recent work it was shown that the amount of architectural debt has a huge impact on software maintainability and evolution. Consequently, detecting and reducing the debt is expected to make software more amenable to change. This paper reports on a longitudinal study of a healthcare communications product created by Brightsquid Secure Communications Corp. This start-up company is facing the typical trade-off problem of desiring responsiveness to change requests, but wanting to avoid the ever-increasing effort that the accumulation of quick-and-dirty changes eventually incurs. In the first stage of the study, we analyzed the status of the "before" system, which indicated the impacts of change requests. This initial study motivated a more in-depth analysis of architectural debt. The results of this analysis were used to motivate a comprehensive refactoring of the software system. The third phase of the study was a follow-on architectural debt analysis which quantified the improvements made. Using this quantitative evidence, augmented by qualitative evidence gathered from in-depth interviews with Brightsquid's architects, we present lessons learned about the costs and benefits of paying down architecture debt in practice.Comment: Submitted to ICSE-SEIP 201

Victims, Crime and Society

Organized around the intersecting social divisions of class, race, age and gender, the book provides an engaging and authoritative overview of the nature of victimisation in society. In addition to a review of the major theoretical developments in relation to understanding aspects of victimization in society, individual chapters explore the political and social context of victimisation and the historical, comparative and contemporary research and scholarly work on it

Psychosocial predictors of health-related quality of life and health service utilisation in people with chronic low back pain

Psychological and social factors have been shown, separately, to predict outcome in individuals with chronic low back pain. Few previous studies, however, have integrated both psychological and social factors, using prospective study of clinic populations of low back pain patients, to identify which are the most important targets for treatment. One hundred and eight patients with chronic low back pain, newly referred to an orthopaedic outpatient clinic, completed assessments of demographic characteristics, details of back pain, measures of anxiety and depression (Hospital Anxiety and Depression Scale, HADS), fearful beliefs about pain (Fear Avoidance Beliefs Questionnaire), social stresses (Life Events and Difficulties Schedule) and physical aspects of health‐related quality of life [SF‐36 Physical Component summary Score scale (PCS)]. Six months later subjects completed the SF‐36 PCS and the number of healthcare contacts during follow‐up was recorded. Independent predictors of SF‐36 PCS at 6‐month follow‐up were duration of pain [(standardised regression coefficient (β) = −0.18, p = 0.04), HADS score (β) = −0.27, p = 0.003] and back pain related social difficulties (β = −0.42, p < 0.0005). Number of healthcare contacts over the 6 months ranged from 1 to 29, and was independently predicted by perceived cause of pain [Incident Rate Ratio (IRR) = 1.46, p = 0.03], Fear Avoidance Beliefs about work (IRR = 1.02, p = 0.009) and back pain related social difficulties (IRR = 1.16, p = 0.03). To conclude, anxiety, depression, fear avoidance beliefs relating to work and back pain related stresses predict impairment in subsequent physical health‐related quality of life and number of healthcare contacts. Interventions targeting these psychosocial variables in clinic patients may lead to improved quality of life and healthcare costs