Multiphase porous media model for heat and mass transfer during drying of agricultural products

Modelling of food processing is complex because it involves sophisticated material and transport phenomena. Most of the agricultural products such fruits and vegetables are hygroscopic porous media containing free water, bound water, gas and solid matrix. Considering all phase in modelling is still not developed. In this article, a comprehensive porous media model for drying has been developed considering bound water, free water separately, as well as water vapour and air. Free water transport was considered as diffusion, pressure driven and evaporation. Bound water assumed to be converted to free water due to concentration difference and also can diffuse. Binary diffusion between water vapour and air was considered. Since, the model is fundamental physics based it can be applied to any drying applications and other food processing where heat and mass transfer takes place in porous media with significant evaporation and other phase change.

The influence of social media on international students' choice of university and course

This thesis is a qualitative study of the influence of social media on the university and course decision making process of international students. It examines the role of social media in influencing international students' decisions on course and university selection and the role of social media in meeting their information needs. It also gathered inputs on how universities could engage, collaborate and communicate using social media communities and channels for more effective recruitment strategies.

Setting limits to laughter : university teaching and the boundaries of humour

This paper forms one part of a broadly-based study into the use of humour within tertiary teaching. One theme to emerge from semi-structured, in-depth interviews with university academics concerns the setting of boundaries to the appropriate use of humour within lectures and tutorials. Following the ‘benign violations’ theory of humour—wherein, to be funny, a situation/statement must be some kind of a social violation, that violation must be regarded as relatively benign, and the two ideas must be held simultaneously—this paper suggests that the willingness of academics to use particular types of humour in their teaching revolves around the complexities of determining the margins of the benign. These margins are shaped in part by pedagogic limitations, but also by professional delimitations. In terms of limitations, the boundaries of humour are set by the academic environment of the university, by the characteristics of different cohorts of students, and by what those students are prepare to laugh at. In terms of delimitations—where humour choice is moderated, not by the possibility of immediate laughter, but rather by the consequences of that choice—academic seniority and security play a large role in determining what kinds of humour will be used, and where boundaries are to be set. The central conclusion here is that formal maxims of humour use—‘Never tease students’, ‘Don’t joke about potentially sensitive issues’—fail to account for the complexity of teaching relationships, for the differences between student cohorts, and for the talents and standing of particular teachers.

Porous fuel injection with oxygen enrichment in a viable scramjet engine

Oxygen enriched, porous fuel injection has been numerically investigated in this study with the aim of understanding mixing and combustion enhancements achievable in a viable scramjet engine. Four injection configurations were studied: a fuel only case, a pre-mixed case and two staged injection cases where fuel and oxidiser were injected independently. All simulations were performed on a flight scale vehicle at Mach 8 flow conditions. Results show that the addition of oxygen with the fuel increases the mixing efficiency of the engine, however, is less sensitive to the method of oxygen addition: premixed versus staged. When the fuel-oxidiser-air mixture was allowed to combust, the method of additional oxygen delivery had a more significant impact. For pre-mixed fuel and oxidiser, the engine was found to choke, whereas in contrast, in the staged enrichment cases the engine failed to ignite. This result indicates that there exists an optimised configuration between pre-mixed and staged oxygen enrichment which results in a started, and combusting engine.

Entrepreneurship Programs and the Modern University

Entrepreneurship Programs and the Modern University is an excellent resource for those who intend to set up an entrepreneurship program or centre, and arguably even more so for those who wish to coordinate or expand such activities into an effective "entrepreneurship eco-system" across the university and its external stakeholders. Morris, Kuratko, and Cornwall's intention in writing this book is to "advocate a more strategic and integrative framework for building the curricular, co-curricular, research, community engagement, and infrastructure components of a program" (p. xii).

Unsupervised online learning of condition-invariant images for place recognition

This paper presents an online, unsupervised training algorithm enabling vision-based place recognition across a wide range of changing environmental conditions such as those caused by weather, seasons, and day-night cycles. The technique applies principal component analysis to distinguish between aspects of a location’s appearance that are condition-dependent and those that are condition-invariant. Removing the dimensions associated with environmental conditions produces condition-invariant images that can be used by appearance-based place recognition methods. This approach has a unique benefit – it requires training images from only one type of environmental condition, unlike existing data-driven methods that require training images with labelled frame correspondences from two or more environmental conditions. The method is applied to two benchmark variable condition datasets. Performance is equivalent or superior to the current state of the art despite the lesser training requirements, and is demonstrated to generalise to previously unseen locations.

Natural convection heat transfer in a baffled triangular enclosure

To reduce the natural convection heat loss from enclosures many researchers used convection suppression devices in the past. In this study a single baffle is used under the top tip to investigate numerically the natural convection heat loss in an attic shaped enclosure which is a cost effective approach. The case considered here is one inclined wall of the enclosure is uniformly heated while the other inclined wall is uniformly cooled with adiabatic bottom wall. The finite volume method has been used to discretize the governing equations, with the QUICK scheme approximating the advection term. The diffusion terms are discretized using central-differencing with second order accuracy. A wide range of governing parameters are studied (Rayleigh number, aspect ratio, baffle length etc.). It is observed that the heat transfer due to natural convection in the enclosure reduces when the baffle length is increased. Effects of other parameters on heat transfer and flow field are described in this study.

Onset of transition in mixed convection of a lid-driven trapezoidal enclosure filled with water-Al2O3 nanofluid

A numerical study is carried out to investigate the transition from laminar to chaos in mixed convection heat transfer inside a lid-driven trapezoidal enclosure. In this study, the top wall is considered as isothermal cold surface, which is moving in its own plane at a constant speed, and a constant high temperature is provided at the bottom surface. The enclosure is assumed to be filled with water-Al2O3 nanofluid. The governing Navier–Stokes and thermal energy equations are expressed in non-dimensional forms and are solved using Galerkin finite element method. Attention is paid in the present study on the pure mixed convection regime at Richandson number, Ri = 1. The numerical simulations are carried out over a wide range of Reynolds (0.1 ≤ Re ≤ 103) and Grashof (0.01 ≤ Gr ≤ 106) numbers. Effects of the presence of nanofluid on the characteristics of mixed convection heat transfer are also explored. The average Nusselt numbers of the heated wall are computed to demonstrate the influence of flow parameter variations on heat transfer. The corresponding change of flow and thermal fields is visualized from the streamline and the isotherm contour plots.

University life and Australian homes : three case studies of international Muslim students in Brisbane

Despite a significant increase in enrolments of postgraduate international Muslim students within Australian universities, little is known about their perceptions of life within Australian homes while undertaking their studies. The aim of this study is to investigate the ways in which students’ cultural and religious traditions affect their use of domestic spaces within the homes in which they reside. The research found that participants faced some minor difficulties in achieving privacy, maintaining modesty and extending hospitality while able to perform their daily activities in Australian designed homes. The findings suggest that greater research attention needs to be given to the development of Australian home designs that are adaptable to the needs of a multicultural society. Australian society encompasses diverse cultural customs and requirements with respect to home design, and these are yet to be explored.

Fouling of waste heat recovery : numerical and experimental results

Numerical results are presented to investigate the performance of a partly-filled porous heat exchanger for waste heat recovery units. A parametric study was conducted to investigate the effects of inlet velocity and porous block height on the pressure drop of the heat exchanger. The focus of this work is on modelling the interface of a porous and non-porous region. As such, numerical simulation of the problem is conducted along with hot-wire measurements to better understand the physics of the problem. Results from the two sources are then compared to existing theoretical predictions available in the literature which are unable to predict the existence of two separation regions before and after the porous block. More interestingly, a non-uniform interface velocity was observed along the streamwise direction based on both numerical and experimental data.

Uncertainty quantification applied to the performance analysis of a conical diffuser

This paper offers an uncertainty quantification (UQ) study applied to the performance analysis of the ERCOFTAC conical diffuser. A deterministic CFD solver is coupled with a non-statistical generalised Polynomial Chaos(gPC)representation based on a pseudo-spectral projection method. Such approach has the advantage to not require any modification of the CFD code for the propagation of random disturbances in the aerodynamic field. The stochactic results highlihgt the importance of the inlet velocity uncertainties on the pressure recovery both alone and when coupled with a second uncertain variable. From a theoretical point of view, we investigate the possibility to build our gPC representation on arbitray grid, thus increasing the flexibility of the stochastic framework.

Conference report : ‘For the Socially Responsible University’. Reflections on Universidad 2014, the 9th International Higher Education congress in Havana, Cuba, February 2014

This article describes salient aspects of 'Universidad', the 9th International Higher Education conference held in Havana, Cuba, in February 2014. Addressing the conference theme, 'For the Socially Responsible University', participants debated the university's capacity to lead societies in matters of knowledge creation and diffusion, and discussed how it could help governments in the quest for solutions to inequality and exclusion. A particularly interesting panel was one that discussed the social commitment of Hugo Chavez, the late president of Venezuela, and his work to support the expansion of education.

Navigating uncertainty in Australia : fostering informed citizenship through teaching controversial issues with pre-service teachers

Australia is a multicultural immigrant society created by public policy and direct state action over a period of two hundred years. It is now one of the world’s most diverse societies. However, like many nations, Australia faces challenges to managing ‘unauthorized arrivals’ who claim to be refugees. The issue of how to deal with unauthorized arrivals is controversial and highly emotive as it challenges public policy and government capacity to manage the multicultural ‘mix’ of Australia’s population. It also raises questions about border security. Given that it is impossible to discern beforehand who is a ‘proper’ refugee and who is not, claims to refugee status by unauthorised arrivals in Australia need to be tested against international convention criteria devised by the United Nations High Commissioner for Refugees (UNHCR). There are no simple solutions to controversial questions such as how and where should unauthorised arrivals, and the children accompanying them, be housed whilst their claims are investigated? Moreover, as this issue continues to prompt division and heated debate in Australian society, teachers new to the profession are often reluctant to explore it in the classroom. However, there are opportunities in national and state curriculum documents for the values dimensions of curriculum inquiries into controversial issues such as this to be addressed. For example, the most recent national statement on the goals for schooling in Australia, the Melbourne Declaration (MCEETYA, 2008), makes clear that Australian students need to be prepared for the challenges of the 21st century and to develop the capacity for innovation and complex problem-solving. The Melbourne Declaration informs the first national curriculum to be implemented in the Australian states and territories, and all other national and state initiatives. Its focus on developing active and informed citizens who can contribute to a socially cohesive society implies a capacity to deal with a range of issues associated with cultural diversity, This chapter explores the ways in which pre-service and early career teachers in one Australian state reflect upon curriculum opportunities to address controversial issues in the social sciences and history classroom. As part of their pre-service education, all the participants in this study completed a final year social science curriculum method unit that embedded a range of controversial issues, including the placement of children in Australian Immigration Detention Centres (IDCs), for investigation. By drawing from interviews and focus groups conducted with different cohorts of pre-service teachers in their final year of university study and beginning years of teaching, this chapter analyses the range of perceptions about how controversial issues can be examined in the secondary classroom as part of fostering informed citizenship. The discussion and analysis of the qualitative data in this study makes no claims for the representativeness of its findings, rather, a range of beginner teacher insights into a complex and important facet of teaching in a period of change and uncertainty is offered.

Convolutional Neural Network-based place recognition

Recently Convolutional Neural Networks (CNNs) have been shown to achieve state-of-the-art performance on various classification tasks. In this paper, we present for the first time a place recognition technique based on CNN models, by combining the powerful features learnt by CNNs with a spatial and sequential filter. Applying the system to a 70 km benchmark place recognition dataset we achieve a 75% increase in recall at 100% precision, significantly outperforming all previous state of the art techniques. We also conduct a comprehensive performance comparison of the utility of features from all 21 layers for place recognition, both for the benchmark dataset and for a second dataset with more significant viewpoint changes.