Prediction of the thermal performance of horizontal-coupled ground source heat exchangers

The thermal performance of a horizontal-coupled ground-source heat pump system has been assessed both experimentally and numerically in a UK climate. A numerical simulation of thermal behaviour of the horizontal-coupled heat exchanger for combinations of different ambient air temperatures, wind speeds, refrigerant temperature and soil thermal properties was studied using a validated 2D transient model. The specific heat extraction by the heat exchanger increased with ambient temperature and soil thermal conductivity, however it decreased with increasing refrigerant temperature. The effect of wind speed was negligible.

Life histories of academics who become heads of department: socialisation, identity and career trajectory

Although the role of the academic head of department (HoD) has always been important to university management and performance, an increasing significance given to bureaucracy, academic performance and productivity, and government accountability has greatly elevated the importance of this position. Previous research and anecdotal evidence suggests that as academics move into HoD roles, usually with little or no training, they experience a problem of struggling to adequately manage key aspects of their role. It is this problem – and its manifestations – that forms the research focus of this study. Based on the research question, “What are the career trajectories of academics who become HoDs in a selected post-1992 university?” the study aimed to achieve greater understanding of why academics become HoDs, what it is like being a HoD, and how the experience influences their future career plans. The study adopts an interpretive approach, in line with social constructivism. Edited topical life history interviews were undertaken with 17 male and female HoDs, from a range of disciplines, in a post-1992 UK university. These data were analysed using coding, categorisation and theme formation techniques and developing profiles of each of the respondents. The findings from this study suggest that academics who become HoDs not only need the capacity to assume a range of personal and professional identities, but need to regularly adopt and switch between them. Whether individuals can successfully balance and manage these multiple identities, or whether they experience major conflicts and difficulties within or between them, greatly affects their experiences of being a HoD and may influence their subsequent career decisions. It is claimed that the focus, approach and analytical framework - based on the interrelationships between the concepts of socialisation, identity and career trajectory - provide a distinct and original contribution to knowledge in this area. Although the results of this study cannot be generalised, the findings may help other individuals and institutions move towards a firmer understanding of the academic who becomes HoD - in relation to theory, practice and future research.

Incorporating languages into histories of war: a research journey

This article discusses the ways in which languages can be integrated into histories of war and conflict, by exploring ongoing research in two case studies: the liberation and occupation of Western Europe (1944–47), and peacekeeping/peace building in Bosnia-Herzegovina (1995–2000). The article suggests that three methodological approaches have been of particular value in this research: adopting an historical framework; following the “translation” of languages into war situations; and contextualizing the figure of the interpreter/translator. The process of incorporating languages into histories of conflict, the article argues, has helped to uncover a broader languages landscape within the theatres of war.

Rheological and thermal behaviour of poly(N-isopropylacrylamide)/alginate smart polymeric networks

Interpenetrating polymeric networks based on sodium alginate and poly(N-isopropylacrylamide) (PNIPAAm) covalently crosslinked with N,N′-methylenebisacrylamide have been investigated using rheology, thermogravimetry, differential scanning calorimetry, X-ray diffraction measurements and scanning electron microscopy (SEM). An improved elastic response of the samples with a higher PNIPAAm content and increased amount of crosslinking agent was found. The temperature-responsive behaviour of the hydrogel samples was evidenced by viscoelastic measurements performed at various temperatures. It is shown that the properties of these gels can be tuned according to composition, amount of crosslinking agent and temperature changes. X-ray scattering analysis revealed that the hydrophobic groups are locally segregated even in the swollen state whilst cryo-SEM showed the highly heterogeneous nature of the gels.

Thermal and high hydrostatic pressure inactivation of myrosinase from green cabbage: a kinetic study

Myrosinase, a family of enzymes which coexist with glucosinolates in all Brassica vegetables, catalyses the hydrolysis of glucosinolates to yield compounds that can have beneficial effects on human health. In this study, the thermal and pressure inactivation of myrosinase from green cabbage was kinetically investigated. Thermal inactivation started at 35 C and inactivation kinetics was studied in the temperature range 35–55 C. Thermal inactivation of green cabbage myrosinase followed the well known consecutive step model. Pressure inactivation started at 300 MPa, even at 10 C, and the consecutive step model effectively described pressure inactivation in the range 300–450 MPa at 10 C. The combined effects of applying various pressures and temperatures on myrosinase inactivation kinetics were studied in the ranges 35–50 C and, 100–400 MPa. The inactivation followed first-order kinetics at all of the applied combinations. This study demonstrates that myrosinase from green cabbage is highly susceptible to both thermal and high pressure processing. Furthermore, it is also noted that myrosinase stability during processing appears to vary widely between different Brassica species.

A method to weight three categories of adaptive thermal comfort

The adaptive thermal comfort theory considers people as active rather than passive recipients in response to ambient physical thermal stimuli, in contrast with conventional, heat-balance-based, thermal comfort theory. Occupants actively interact with the environments they occupy by means of utilizing adaptations in terms of physiological, behavioural and psychological dimensions to achieve ‘real world’ thermal comfort. This paper introduces a method of quantifying the physiological, behavioural and psychological portions of the adaptation process by using the analytic hierarchy process (AHP) based on the case studies conducted in the UK and China. Apart from three categories of adaptations which are viewed as criteria, six possible alternatives are considered: physiological indices/health status, the indoor environment, the outdoor environment, personal physical factors, environmental control and thermal expectation. With the AHP technique, all the above-mentioned criteria, factors and corresponding elements are arranged in a hierarchy tree and quantified by using a series of pair-wise judgements. A sensitivity analysis is carried out to improve the quality of these results. The proposed quantitative weighting method provides researchers with opportunities to better understand the adaptive mechanisms and reveal the significance of each category for the achievement of adaptive thermal comfort.

Field study on thermal comfort and adaptive strategies in residential buildings in China

This paper fully describes a nation-wide field study on building thermal environment and thermal comfort of occupant, which was carried out in summer 2005 and in winter 2006 respectively in China, illustrating the adaptive strategies adopted by occupants in domestic buildings in China. According to the climate division in China, the buildings in Beijing (BJ), Shanghai (SH), Wuhan (WH) and Chongqing (CQ), Guangzhou (GZ), Kunming (KM), were selected as targets which are corresponding to cold zone, hot summer and cold winter zone (SWC-SH, WH, CQ), hot summer and warm winter zone and temperate zone, respectively. The methodology used in the field study is the combination of subjective questionnaire regarding thermal sensation and adaptive approaches and physical environmental monitoring including indoor air temperature and relative humidity. A total of 1671 subjects participate in this investigation with more than 80% response rate in all surveyed cities. Both physiological and non-physiological factors (behavioural and psychological adaptations) have been analysed.