Gathering for God : George Brown in Oceania

Combining 'the gathering of artefacts with the gathering of souls', George Brown was a key figure in the Christian, and especially the Wesleyan Methodist, history of nineteenth-century Oceania. Using his life as a case study, Helen Bethea Gardner examines the role of Christian missionaries in the Pacific Islands. Brown's career (1860-1908) spanned one of the most tumultuous political periods in the South Pacific, as one by one islands were colonised by imperial nations. He was one of the most politically engaged of all missionaries, encouraging colonial rule in the Pacific by America, Britain, Germany and, eventually, Australia and New Zealand. Originally from the north of England, he worked as a missionary in Samoa from 1860, moving to the Bismarck Archipelago (now Papua New Guinea) in 1875. From the 1880s until his retirement in 1907, he worked in Sydney as the general secretary of the Australasian Methodist Overseas Mission. Gathering for God examines Brown's missionary letters, journals and journalism, exploring how he attracted Pacific Islanders to Christian teachings, analysing his leadership during an armed attack on New Britain villages accused of cannibalism, and looking at his work in the new discipline of anthropology. He was a major collector of artefacts (his collection is now in the Osaka Museum) and photographer of Pacific peoples (his collection is in the Australian Museum).

Development of a building integrated photovoltaic/thermal solar collector based on steel roofing

The use of onsite renewable energy cogeneration from structural building elements is a relatively new concept, and one that is gaining considerable interest in the building industry. In this study the design, development, testing and production methods for a novel building integrated photovoltaic/thermal (BIPVT) solar energy cogeneration system are examined and discussed.

During the analysis of the design, adhesives (ADH), resistance seam welding (RSW) and autoclaving (ATC) were identified as the most appropriate for fabricating BIPVT panels for roofing and façade applications. Of these manufacturing methods ADH was found to be most suitable for low volume production systems due to its low capital cost.

Furthermore, a prototype panel was fabricated using ADH methods and exhibited good thermal performance. In addition it was shown, using experimental testing, that the performance of a BIPVT could be theoretically predicted using a one-dimensional heat transfer model. Furthermore, the model was used to suggest further improvements that could be made to the design. Finally, a transient simulation of the BIPVT was performed in TRNSYS and was used to illustrate the long term benefits of the system.

Application of the Hottel-Whillier equations to the analysis of a building integrated photovoltaic/thermal solar collector

The idea of combining photovoltaic and solar thermal collectors (PVT collectors) to provide electrical and heat energy is not new, however it is an area that has received only limited attention. With concern growing over energy sources and their usage, PVTs have become an area receiving more attention. Although PVTs are not as prevalent as solar thermal systems, the integration of photovoltaic and solar thermal collectors into the walls or roofing structure of a building could provide greater opportunity for the use of renewable solar energy technologies in domestic, commercial and industrial applications. As such, the design of a novel building integrated photovoltaic/thermal (BIPVT) solar collector is theoretically analysed through the use of a modified Hottel-Whillier model. The thermal and electrical efficiency under a range of conditions are subsequently determined and results showing how key design parameters influence the performance of the BIPVT system are presented.

Analysis of the current distribution in an aluminum electrolysis cell with copper collector-bar cathode assembly

Understanding the magneto-hydrodynamic forces generated due to the external magnetic field and current density distribution within the cell (current in cell linings) is important in the optimization of cell dynamics. It is well documented that these factors play a crucial role in establishing the metal-pad stability of the cell. Conventional cells use the cathode-collector-bar assembly to carry the current through molten aluminium, the cathode and the steel collector-bar to nearest external bus. The electrical conductivity of the steel is so poor relative to the molten aluminium that the outer third of the collector bar carries the maximum load, which in turn increases the horizontal components of the current within the cell. Previous studies have modelled improvement in the cell instability through external magnetic compensation by redistributing current in the cathode busbar. Very little to date has been published on work to improve the current distribution within the cell. In this work, the current distribution in an aluminium electrolysis cell with copper collector-bar was predicted using finite element modelling. A 2D cross-section of a commercial cell was used under steady conditions of electrical fields in anode, electrolyte, molten aluminium and copper cathode-assembly. Different shapes and sizes of the cathode assembly are also considered to optimise the distribution of current throughout the cathode lining. The findings indicated that the copper-bar of similar size to steel could save voltage up to 150 mV. There is a reduction of more than 70% in peak current density value due to the copper inserts. The predicted trends of current distribution show a good agreement with previously published data.

Electrospinning of nanofibre yarns using rotating ring collector

 In this project, a novel ring collector was used to convert newly electrospun nanofibres into yarn. This setup has been designed to separate electrospinning from yarn drafting/twisting in two distinct zones. Three different types of electrospinning systems, i.e. needle, needleless, and needle/needleless hybrid, were utilized to produce nanofibre yarns.

Direct electrospinning of nanofibre yarns using a rotating ring collector

Nanofibres prepared by electrospinning typically have randomly oriented fibrous structure. They have large surface-to-volume (or weight) ratio and excellent porous characteristic, which have shown enormous potential in diverse applications. However, electrospun nanofibres are often prepared in the form of randomly orientated fibrous web, which are fragile and difficult to be tailored in fibrous structures. Herein, we demonstrate a novel yarn electrospinning method which uses a rotating ring collector to convert newly electrospun nanofibres directly into a continuous yarn. The use of ring collector separates the yarn formation from the electrospinning zone. The deposition of later-spun nanofibres to the inner surface of fibrous cone eliminates hooked or curled nanofibres in the final yarn. The effects of polymer concentration and operating parameters on nanofibre and yarn morphology, diameter and the ring collector on yarn twist feature were examined. The nanofibre yarns had a surface twist angle up to 54.4°, and tensile strength as high as 93.6 MPa (elongation at break 242.6%). Increasing twist levels improves tensile strength and strain values.

A solar collector with the absorber divided by rectangular slots

A new solar absorber structure has been proposed and studied in this paper. The metal tubes running perpendicular to a set of parallel rectangular metal fins make the solar absorber with rectangular slots. Studies on the collector were theoretically carried out in the aspects of heat transfer, thermodynamics and . hydrodynamics. The calculating methods for calculating fin efficiency F and efficiency factors of the collector F' were obtained. The results showed that the new solar collector would have the higher efficiency and better performance at higher fluid temperature than that of the traditional flat-plate collectors. A collector prototype with the new structure was built and tested. The testing results agree with our theoretical results.

The rising prevalence of diabetes and impaired glucose tolerance : the Australian diabetes, obesity and lifestyle study

OBJECTIVE—To determine the population-based prevalence of diabetes and other categories of glucose intolerance (impaired glucose tolerance [IGT] and impaired fasting glucose [IFG]) in Australia and to compare the prevalence with previous Australian data.

RESEARCH DESIGN AND METHODS—A national sample involving 11,247 participants aged >=25 years living in 42 randomly selected areas from the six states and the Northern Territory were examined in a cross-sectional survey using the 75-g oral glucose tolerance test to assess fasting and 2-h plasma glucose concentrations. The World Health Organization diagnostic criteria were used to determine the prevalence of abnormal glucose tolerance.

RESULTS—The prevalence of diabetes in Australia was 8.0% in men and 6.8% in women, and an additional 17.4% of men and 15.4% of women had IGT or IFG. Even in the youngest age group (25–34 years), 5.7% of subjects had abnormal glucose tolerance. The overall diabetes prevalence in Australia was 7.4%, and an additional 16.4% had IGT or IFG. Diabetes prevalence has more than doubled since 1981, and this is only partially explained by changes in age profile and obesity.

CONCLUSIONS—Australia has a rapidly rising prevalence of diabetes and other categories of abnormal glucose tolerance. The prevalence of abnormal glucose tolerance in Australia is one of the highest yet reported from a developed nation with a predominantly Europid background.

Abbreviations: 2hPG, 2-h plasma glucose • AusDiab, Australian Diabetes, Obesity and Lifestyle Study • CD, Census Collector District • FPG, fasting plasma glucose • IFG, impaired fasting glucose • IGT, impaired glucose tolerance • KDM, known diabetes mellitus • NDM, newly diagnosed diabetes mellitus • OGTT, oral glucose tolerance test • WHO, World Health Organization

Weight and place: a multilevel cross-sectional survey of area-level social disadvantage and overweight/obesity in Australia

Objective: To estimate variation between small areas in adult body mass index (BMI), and assess the importance of area level socioeconomic disadvantage in predicting BMI.

Methods: We identified all census collector districts (CCDs) in the 20 innermost Local Government Areas in metropolitan Melbourne, Australia, and ranked them by the percentage of low income households (<$400/week). In all, 50 CCDs were randomly selected from the least, middle and most disadvantaged septiles of the ranked list and 4913 residents (61.4% participation rate) completed one of two surveys. Multilevel linear regression was used to estimate area level variance in BMI and the importance of area level socioeconomic disadvantage in predicting BMI.

Results: There were significant variations in BMI between CCDs for women, even after adjustment for individual and area SES (P=0.012); significant area variation was not found for men. Living in the most versus least disadvantaged areas was associated with an average difference in BMI of 1.08 kg/m² (95% CI: 0.48–1.68 kg/m²) for women, and of 0.93 kg/m² (95% CI: 0.32–1.55 kg/m²) for men. Living in the mid versus least disadvantaged areas were associated with an average difference in BMI of 0.67 kg/m² (95% CI: 0.09–1.26 kg/m²) for women, and 0.43 kg/m² for men (95% CI: -0.16–1.01).

Conclusion: These findings suggest that area disadvantage is an important predictor of adult BMI, and support the need to focus on improving local environments to reduce socioeconomic inequalities in overweight and obesity.

In search of a future strategy for market research services : clients' views on market research suppliers

The market research environment is transforming rapidly and research suppliers may not be keeping up with changing research client needs. This paper examines research client perceptions of current research supplier performance and future competencies. The key findings are that research suppliers need to move their staffing profiles beyond technical expertise in conducting research (generating outputs) to functional expertise in understanding research outcomes within internal and external organizational contexts. The transition from data collector to expert advisor may involve anew business model and new pricing strategies based on intellectual expertise rather than margins on data collection services.

Needleless-electrospinning of PVA nanofibres

In this paper, we demonstrated that a thin metal disk can be used as nozzle to electrospin PVA nanofibres on a large-scale. With the rotation of a disk covered with a thin layer of electrically charged PVA solution, a large number of fibres were electrospun simultaneously from two sides of the disk and deposited on the electrode collector. The fibre production rate can be as high as 6.0 glhr, which is about 270 times higher than that of a corresponding normal needle based electrospinning system (0.022 g/hr). The effects of applied voltage, the distance between the disk nozzle and collector, and PVA concentration on the fibre morphology were examined. The dependency of fibre diameter on the PV A concentration showed a similar trend to that for a conventional electrospinning system using a syringe needle nozzle, but the diameter distribution was slightly wider for the disk electrospun fibres. The profiles of electric field strength in disk electrospinning showed considerable dependence on the disk thickness, with a thin disk exhibiting similar electric field strength profile to that of a needle electrospinning system.

Disk-electrospinning of PVA nanofibres

In this study, we demonstrated that a thin aluminium disk can be used as nozzle to electrospin PVA nanofibres on a large-scale. A schematic of this electrospinning system and a SEM image of as-spun PVA nanofibers are shown in Figure 1. The lower part of the disk is inside a bath containing the polymer solution, which is connected to a high voltage powder supply. During electrospinning, the disk rotates and picks up a thin layer of electrically charged PVA solution. A large number of fibres are then electrospun simultaneously from two sides of tile disk and deposited on the electrode collector.
With the small prototype unit we used, the fibre production rate can be as high as 6.0 which is about 270 times higher than that of a corresponding normal needle electrospinning system (0.022g/hr). The effects of appliedb voltage, the distance between the disk nozzle and collector, and PVA concentration on the fibre morphology were examined. The dependency of fibre diameter on the PVA concentration showed a similar trend to that for a conventional electrospinning system using a syringe needle nozzle, but the diameter distribution was wider for the disk electrospun fibres in this study.
The profiles of electric field strength in disk electrospinning showed considerable dependence on the disk thickness, with a thin disk exhibiting similar electric field profile to
that of a needle electrospinning system, but a thick disk (cylinder) exhibiting levelled electric field between the disk and the collector. PVA nanofibres electrospun from disk electrospinning were compared to that electrospun from syringe needle and metal cylinder nozzles.

Morphological evolution of nanofibers during electrospinning

Electrospinning is a very useful technique to produce polymeric nanofibers. It involves fast-drawing a polymer fluid into nanofibers under a strong electric filed, and depositing randomly on an electrode collector to form non-woven nanofiber mat in most cases [1]. The fibre stretching during electrospinning is a fast and incessant process which can be divided into three consecutive stages: jet initiation, whipping instability and fibre deposition. From the initial jet to dry fibres, the fibre stretching takes place in milliseconds, so it has been hardly so far to observe fiber morphology changes by any normal methods, such as high speed photography [2-5]. In this study, we used a facile and practical approach to realize the observation of nanofiber morphology changes during electrospinning. Through a special collection device with coagulation bath, newly electrospun nanofibers can be solidified at different electro spinning distances, and by associating the fiber morphology with the electrospinning distance (d), the morphological evolution of nanofibers can be established. We used polyacrylonitrile (PAN) and polystyrene (PS) as two model polymers to demonstrate this method in present research. From experimental results, we found the massive jet-thinning happens at the initial stage of the process. The formation of uniform PAN nanofibers (7%) and the beads structure changes on beads-on-string PAN nanofibers (5%) have also been successful observed. Using the same method, we also observed PS nanofiber (10%) morphology changes to understand the beads formation 011 nanofibers during electrospinning process, and how the beads was eliminated when ionic surfactant is added into the PS solution for electrospinning.

Preparation of nanofibre yarns from electrospun nonwoven strips

From ancient to modern time, humans have been trying to use finer fibres to make fibrous products for various purposes and believing that finer fibres have better aesthetic qualities. So far, the commercial fibres have been reduced to microns in diameter, but it seems difficult to further reduce the fibre fineness to submicrons using conventional fibre-making techniques.
Electrospinning is a promising technique to produce continuous fibres with diameters on nanometre scales. This technique involves stretching a polymer fluid under a strong electric field into fine filaments, which are deposited randomly on the electrode collector forming a nonwoven nanofibre mat in most cases. Despite considerable efforts in exploring the applications of electrospun nanofibres in non-fibrous fields [1], very limited work has been conducted on using this material to process mechanically robust nanofibre yarns [2,3].

The effect of colour on the thermal performance of building integrated solar collectors

The use of solar collectors with coloured absorbers for water heating is an area of particular interest when considering their integration with buildings. By matching the absorber colour with that of the roof or façade of the building, it is possible to achieve an architecturally and visually pleasing result. Despite the potential for the use of coloured absorbers, very little work has been undertaken in the field.

In this study, the thermal performance of a series of coloured (ranging from white to black), building integrated solar collectors for water heating was examined both theoretically and experimentally. Subsequently, the annual solar fraction for typical water heating systems with coloured absorbers was calculated. The results showed that coloured solar collector absorbers can make noticeable contributions to heating loads. Furthermore, although their thermal efficiency is lower than highly developed selective coating absorbers, they offer the advantage of improved aesthetic integration with buildings.