Computational simulation of gas flow and heat transfer near an immersed object in fluidized beds

To improve the understanding of the heat transfer mechanism and to find a reliable and simple heat-transfer model, the gas flow and heat transfer between fluidized beds and the surfaces of an immersed object is numerically simulated based on a double particle-layer and porous medium model. The velocity field and temperature distribution of the gas and particles are analysed during the heat transfer process. The simulation shows that the change of gas velocity with the distance from immersed surface is consistent with the variation of bed voidage, and is used to validate approximately dimensional analysing result that the gas velocity between immersed surface and particles is 4.6Umf/εmf. The effects of particle size and particle residence time on the thermal penetration depth and the heat-transfer coefficients are also discussed.

Computational simulation of gas flow and heat transfer near immersed object in fluidised bed

To improve the understanding of the heat transfer mechanism and find a reliable and simple heat-transfer model, the gas flow and heat transfer between fluidised beds and immersed object surfaces was numerically simulated based on a double particlelayer and porous medium model. The velocity field and temperature distribution of gas were discussed to analyse the heat transfer process.

Supporting knowledge transfer in web-based managed IT support

Purpose – The purpose of this paper is to highlight the importance and complexities of the knowledge transfer process in the provision of effective managed after-sales IT support, when the web is used for service delivery.

Design/methodology/approach – The paper features an interpretive case study of a multinational Managed Service Provider (MSP) and a focus group of representatives from five comparable MSPs.

Findings – The paper finds that MSPs that use web-based channels for the provision of after-sales IT support services need to address a range of important social and organisational issues in order to realise cost and efficiency-based benefits.

Research limitations/implications – The paper provides a four stage processual model of knowledge transfer in the provision of web-based managed after-sales IT support services. The barriers and enablers of knowledge transfer at each stage are identified. The paper adopts a MSP perspective and suggests that further research from the customer perspective is required.

Practical implications – The paper highlights some important social and organisational enablers and barriers, which will guide MSPs when providing managed after-sales IT support using webbased channels.

Originality/value – The paper provides the first staged model of inter-organisational knowledge transfer in a complex multi-organisational and multi-channel web-based context.

Improving transfer of mental health care for rural and remote consumers in South Australia

In Australia, it is commonplace for tertiary mental health care to be provided in large regional centres or metropolitan cities. Rural and remote consumers must be transferred long distances, and this inevitably results in difficulties with the integration of their care between primary and tertiary settings. Because of the need to address these issues, and improve the transfer process, a research project was commissioned by a national government department to be conducted in South Australia. The aim of the project was to document the experiences of mental health consumers travelling from the country to the city for acute care and to make policy recommendations to improve transitions of care. Six purposively sampled case studies were conducted collecting data through semistructured interviews with consumers, country professional and occupational groups and tertiary providers. Data were analysed to produce themes for consumers, and country and tertiary mental healthcare providers. The study found that consumers saw transfer to the city for mental health care as beneficial in spite of the challenges of being transferred over long distances, while being very unwell, and of being separated from family and friends. Country care providers noted that the disjointed nature of the mental health system caused problems with key aspects of transfer of care including transport and information flow, and achieving integration between the primary and tertiary settings. Improving transfer of care involves overcoming the systemic barriers to integration and moving to a primary care-led model of care. The distance consultation and liaison model provided by the Rural and Remote Mental Health Services, the major tertiary provider of services for country consumers, uses a primary care-led approach and was highly regarded by research participants. Extending the use of this model to other primary mental healthcare providers and tertiary facilities will improve transfer of care.

A question of continuing control -balancing building quality of housing and building codes

The Building Code of Australia seeks to establish “nationally consistent, minimum necessary standards of relevant, health, safety (including structural safety and safety from fire), amenity and sustainability objectives efficiently”. These goals are laudable – but where are the goals of quality and maintenance, which are also an essential part of achieving adequate and continuing health and safety for the built environment?

Defects such as dampness, settlement and cracking, staining, wood rot, termite damage, rusting, and roof leakage are common enough to suggest that there are still issues with building quality in housing. They are caused by a combination of initial poor workmanship and poor quality materials and latterly by poorly executed or inadequate maintenance.

Local architecture, developed over many years of trial and error, produce buildings linked to their climate and local materials (think of the typical “Queenslander” house). Today’s architecture imports technologies and materials from many differing countries and climates – that are not necessarily suitable for the location, nor is there necessarily the same quality control over the material quality and production. Inappropriate use and inadequate understanding of new materials and techniques can lead to the generation of further defects.

Whilst the building code contains provisions for initial-build material quality and workmanship, there is no continuing control over a house over its life span. Reliance is placed on advertising the need, for example, to employ qualified tradespeople; replace batteries in smoke detectors; and other good advice to help maintain housing to a minimum standard. Is this sufficient?

Mechanisms to make the transfer of knowledge to those who need to use it – be it the workforce or the houseowner – need to be improved. Should the building code be more visual and accessible in it’s content? Should the building code include provisions for maintenance? Should the building code require every house to have a “users manual” – much like a car? An extensive review of literature identifies the scale of the problem of poor quality housing and highlights some suggested causes – inadequate knowledge of the BCA by general housebuilders being one. However little work has been done to investigate what could be done to improve the situation. This work suggests that improvements to knowledge transfer would improve the quality of housing and a model of the knowledge transfer process is proposed, identifying those areas where the knowledge flows need to occur that would impact both the builders and users of housing.

Inter-family transfers and altruism

Examines various models of altruistically motivated transfers between family members. The issues investigated are, keeping up with the Joneses type behaviour, the transfer of intermediate commodities, the transfer process as an informal way of insurance, and the efficiency of market exchange as opposed to private transactions.

Residential auction clearance rates – what do they really mean?

The residential market in Melbourne is often referred to as the ‘auction capital of the world’ with approximately 30-35% of housing transfers undertaken via the auction process, most of which are conducted on the weekend and then reported in the media the following day. The most quoted measurement of auction success is via the clearance rate which simply indicates the proportion of signed contracts of sale within the auction process. At the same time the clearance rate can have a relatively large variance where the residential market can traditionally range from very good (i.e. a high clearance rate) to very poor (i.e. a low clearance rate). The subsequent effect on the market can directly increase or decrease demand, predominantly based only on this single measure of the perceived level of auction clearance rates only.

This paper examines the concept of the auction clearance rates and the heavy reliance on the only one measure of success (i.e. the clearance rates), regardless of other variables. The emphasis is placed on the auction clearance rate as one measure of demand in the housing market but within the context of the definition of market value i.e. willing buyer-willing seller. This is supported by a discussion about other variables including the asking price, the auction process itself, marketing considerations and seasonal adjustments. The findings provide an insight into how to correctly interpret the auction clearance rate in the context of the overall supply-demand interactions. Whilst the auction process is clearly an integral part of the residential transfer process it is essential that the auction clearance rate is used with caution and also in conjunction with other variables.

Reconstructing the south : how commercial myths compete for identity value through the ideological shaping of popular memories and countermemories

This study explicates the coconstitutive relationships between commercial myth- making and popular memory that arise through myth market competitions for identity value. We develop a genealogical analysis of the representational strategies and ideological rationales that two prominent New South mythmakers use to shape popular memories in relation to their competitive goals and to efface counter- memories that contradict their mythologized representations. We then derive a conceptual model that highlights competitive, historical, and ideological influences on commercial mythmaking and their transformative effects on popular memory, which have not been addressed by prior theorizations of the meaning transfer process.

Cocoon of the silkworm Antheraea pernyi as an example of a thermally insulating biological interface.

Biological materials are hierarchically organized complex composites, which embrace multiple practical functionalities. As an example, the wild silkworm cocoon provides multiple protective functions against environmental and physical hazards, promoting the survival chance of moth pupae that resides inside. In the present investigation, the microstructure and thermal property of the Chinese tussah silkworm (Antheraea pernyi) cocoon in both warm and cold environments under windy conditions have been studied by experimental and numerical methods. A new computational fluid dynamics model has been developed according to the original fibrous structure of the Antheraea pernyi cocoon to simulate the unique heat transfer process through the cocoon wall. The structure of the Antheraea pernyi cocoon wall can promote the disorderness of the interior air, which increases the wind resistance by stopping most of the air flowing into the cocoon. The Antheraea pernyi cocoon is wind-proof due to the mineral crystals deposited on the outer layer surface and its hierarchical structure with low porosity and high tortuosity. The research findings have important implications to enhancing the thermal function of biomimetic protective textiles and clothing.

The effect of fibrous structural difference on thermal insulation properties of biological composites: silkworm cocoons

As a biological fibrous structure, silkworm cocoon provides multiple protective functionalities to safeguard the silk moth pupa’s metabolic activity. The mechanism of this protection could be adopted in clothing manufacture to provide more comfortable apparel. In this study, the thermal insulation properties of both domestic Bombyx mori (B. mori) and wild Antheraea pernyi (A. pernyi) cocoons were investigated under both warm and cold environmental conditions. Computational fluid dynamics models have been developed to simulate the heat transfer process through both types of cocoon wall structures. The simulation results show that the wild A. pernyi cocoon reduces the intensity of convection and heat flux between the environment and the cocoon interior and has higher wind resistance than its domestic counterpart. Compared with A. pernyi cocoon, the B. mori cocoon facilitates easy air transfer and decreases the temperature lag when the surrounding conditions are changed. The new knowledge has significant implications for developing biomimetic thermal functional materials.

Improvement of coating durability, interfacial adhesion and compressive strength of UHMWPE fiber/epoxy composites through plasma pre-treatment and polypyrrole coating

Ultra-high-molecular-weight polyethylene (UHMWPE) fibers have exceptionally higher specific strength and stiffness compared with other high-performance fibers. However, the interfacial adhesion and compressive performance of UHMWPE fiber-reinforced polymer composites (FPCs) are extremely low. The challenges are to achieve load transfer at the interface between the fiber and matrix at a molecular level. Here, we show that plasma pre-treatment of UHMWPE fibers followed by coating with polypyrrole (PPy) results in an 848% improvement in the interfacial adhesion and 54% enhancement in compressive performance. This method takes advantage of a toughening mechanism observed in spider silk and collagen, which the hydrogen bond power the load transfer. The results showed that these improvements of interfacial adhesion and compressive strength were attributed to hydrogen-bonding interactions between the plasma pre-treated UHMWPE and PPy, which improves the fiber-matrix-fiber load transfer process. In addition, the hydrogen-bonded PPy coatings also endowed durability electrical conductivity properties of the UHMWPE fiber.

Numerical simulation of heat and mass transfer in fluidised bed heat treatment furnaces

In this paper, a novel combined theoretical and computational model is developed to simulate the heat and mass transfer between a fluidised bed and a workpiece surface, and within the workpiece by considering the fluidised bed as a medium consisting of a double-particle layer and an even porous layer. The heat and mass-transfer flux from the fluidised bed to the workpiece surface is contributed by dense and bubble phases, respectively. The convective heat and mass transfer is simulated by analysing the gas dynamics in the fluidised bed, while radiative heat transfer is modelled by simulating photon emission in a three-dimensional particle array. The simulation shows that convection is approximately constant, while radiation contributes significantly to the heat transfer. The heat-transfer coefficient on an immersed surface near particles is about 6–10 times that on other areas. The transient heat and mass-transfer coefficient, heat and mass-transfer flux on any surface of the workpiece, transient temperature and carbon distributions at any position of the workpiece during the metal carburising process are studied with the simulation.

Simultaneous volatility transmissions and spillover effects: U.S. and Hong Kong stock and futures markets

Contemporaneous transmission effects across volatilities of the Hong Kong Stock and Index futures markets and futures volume of trade are tested by employing a structural systems approach. Competing measures of volatility spillover, constructed from the overnight U.S. S&P500 index futures, are tested and found to impact on the Hong Kong asset return volatility and volume of trade patterns. The examples utilize intra-day 15-min sampled data from this medium-sized Asia Pacific equity and derivative exchange. Both the intra- and inter-day patterns in the Hong Kong market are allowed for in the estimation process.

How do critical care nurses define the discharge planning process?

Background: Professional, political and organisational factors have focused attention on the discharge planning process in the Victorian health care sector. Discharge planning for patients, as part of continuity of care, is seen as a key concept in the delivery of nursing care. However, there is no question that discharge planning has emerged as a complex area of practice, and is, perhaps, most complex in the critical care area.

Aim: The study reported here is part of a larger thesis exploring critical care nurses’ perceptions and understanding of the discharge planning process in the health care system in the state of Victoria, Australia. As part of the survey participants were asked to define discharge planning as it related to the critical care environment in which they worked.

Methods: Utilising an exploratory descriptive approach, 502 Victorian critical care nurses were approached to take part in the study. The resultant net total of 218 participants completed the survey, which represented a net response rate of 43.4%. The data were analysed using quantitative and qualitative methodologies.

Findings: Three common themes emerged. A significant number of participants did not believe that discharge planning occurred in critical care, and therefore, thought that they could not provide a definition. There was uncertainty as to what the discharge planning process actually referred to in terms of discharge from critical care to the general ward or discharge from the hospital. There was an emphasis on movement of the patient to the general ward, which was considered in three main ways by first, getting the patient ready for transfer; second, ensuring a smooth transition to the ward and third, transfer of the patient to the ward often occurred because the critical care bed was needed for another patient.

Conclusion: The findings presented here suggest at a nursing level, the discharge planning process is not well understood and some degree of mutual exclusivity still remains. There is a need for further education of critical care nurses with regard to the underlying principles of the discharge planning process.

Fault detection in a cold forging process through feature extraction with a neural network

This paper investigates the application of neural networks to the recognition of lubrication defects typical to an industrial cold forging process employed by fastener manufacturers. The accurate recognition of lubrication errors, such as coating not being applied properly or damaged during material handling, is very important to the quality of the final product in fastener manufacture. Lubrication errors lead to increased forging loads and premature tool failure, as well as to increased defect sorting and the re-processing of the coated rod. The lubrication coating provides a barrier between the work material and the die during the drawing operation; moreover it needs be sufficiently robust to remain on the wire during the transfer to the cold forging operation. In the cold forging operation the wire undergoes multi-stage deformation without the application of any additional lubrication. Four types of lubrication errors, typical to production of fasteners, were introduced to a set of sample rods, which were subsequently drawn under laboratory conditions. The drawing force was measured, from which a limited set of features was extracted. The neural network based model learned from these features is able to recognize all types of lubrication errors to a high accuracy. The overall accuracy of the neural network model is around 98% with almost uniform distribution of errors between all four errors and the normal condition.