Search results

The average residence time of liquid flowing over the surface of a rotating cone was determined numerically. The development and propagation of the free surface flow was simulated using the volume of fluid (VOF) method. The numerical simulations were validated using laboratory experiments using soy‐oil as a model liquid, and approximate analytical solutions of the simplified governing equations. The numerical simulations revealed the importance of the cone rotation frequencies and the minor influence of the cone angles on the residence times. Higher liquid throughputs produced smaller residence times. As expected, an increasing cone size results in proportionally higher residence times. Furthermore, it was established that even for small cones with a characteristic diameter of, e.g. less than 1m, relatively high (∼1 kg/s) throughputs of liquid are possible. It appears that the combination of the decreasing layer thickness and the increasing size of the numerical grid cells with increasing radial cone coordinate hampers the numerical simulation of this system.

The volume of fluid (VOF) method is a numerical technique to track the developing free surfaces of liquids in motion. This method can, for example, be applied to compute the liquid flow patterns in a rotating cone reactor. For this application a spherical coordinate system is most suited. The novel derivation of the extended VOF algorithms for this class of applications is presented here. Some practical limitations of this method, that are inherent in the geometry of the described system, are discussed.

The purpose of this paper is to study the steady mixed convection flow over a vertical cone in the presence of surface mass transfer when the axis of the cone is inline with the flow.

In this case, the numerical difficulties to obtain the non‐similar solution are overcome by applying an implicit finite difference scheme in combination with the quasilinearization technique.

Numerical results are reported here to display the effects of Prandtl number, buoyancy and mass transfer (injection and suction) parameters at different stream‐wise locations on velocity and temperature profiles, and on skin friction and heat transfer coefficients.

Thermo‐physical properties of the fluid in the flow model are assumed to be constant except the density variations causing a body force term in the momentum equation. The Boussinesq approximation is invoked for the fluid properties to relate the density changes to temperature changes and to couple in this way the temperature field to the flow field.

Convective heat transfer over a stationary cone is important for the thermal design of various types of industrial equipments such as heat exchangers, conisters for nuclear waste disposal, nuclear reactor cooling systems and geothermal reservoirs, etc.

The combined effects of thermal diffusion and surface mass transfer on a vertical cone has been studied.

In the previous chapter, the reader will have become familiar with the idea of screening for traumatic experiences within organisations as a way to identify those who may benefit most from interventions and support. In this chapter, I present an overview of the trauma therapy literature in the first instance and then explore some of the debates regarding specific trauma-informed treatments versus general therapeutic approaches. The multicultural competency literature is discussed, and the multicultural orientation approach of cultural humility, cultural opportunity and cultural comfort is highlighted in a practice context. This chapter concludes with a case study vignette that brings it all together with a clinical example of what trauma-informed therapy through a multicultural lens might look like. As such I operationalise choice, collaboration , trust and transparency, and cultural principles from the trauma-informed care literature. Although applied here to specific trauma-informed organisations, some of the methods and processes that I unpack can be used in non-specific organisations where social/case managers are employed and wish to operationalise choice and collaboration in a structured way.

Haiti was struck by a heavy earthquake in 2010 and international aid poured into the country. News reports in 2011 were not very positive about the results of post-disaster reconstruction: “The relief efforts are only putting Haiti on life-support instead of evolving into the next stage of development”. One of the non-governmental organisations (NGOs) involved in Haiti was Cordaid, implementing a ‘transitional shelter strategy’ to support the transformation of neigh-bourhoods from a state of life-support into a state of self-sustaining development. The strategy was implemented in both a rural and an urban area. The main feature of the strategy was the provision of structures that could be adapted from simple shelters to permanent houses. Since the results of the strategy were mixed and ambiguous, a comparative case study was conducted to evaluate the shelter strategy in both areas. The objective was to draw lessons about what has to be taken into account when formulating future urban shelter strategies. The case study is discussed in this article. The main finding from the case study is that producing the intended number of shelters within the financial and time budgets that were set (efficiency), was more difficult in the urban area than in the rural area. But the conditions for linking relief and development (effectiveness) are more favourable in the urban context. NGOs may achieve long-term (effective) results in the urban context when a lower efficiency can be justified. That is why NGOs need to engage in a debate about the extent to which they are able to focus on long-term shelter or housing strategies. The important element in the debate is communication with the donors who are often focused on short-term relief measures. However urban areas cannot be rebuilt with only short-term interventions. The link between relief and development has to be made by a process-orientated approach focusing on capacities of local participants.

Global mobility remains one of the most pressing challenges of our times. Countries in the north are turning to major ‘sending’ countries in the south to secure their cooperation in controlling their borders and in repatriation processes. By explicitly linking migration to global security threats and weak governance, these migration control initiatives are justified by development goals and sometimes financed by official development assistance (ODA). By connecting criminology with international development scholarship, this chapter seeks to advance our understanding of the novel intersections between criminal justice, security and development to govern mass migration. Focusing on UK policies and the analysis of specific programmes, it interrogates what does the sustainable development goal (10.7) of facilitating ‘orderly, safe, regular and responsible migration’ concretely entail? And to what extent does the language of ‘managed migration’ legitimise restrictive border controls policies and even conflict with other global development goals?

The purpose of this paper is to present an intervention strategy for promoting career awareness among IT students in a South African context, followed by a reflection thereof based on qualitative data collected from students. Career awareness during study has shown to be a factor in the work-readiness of IT graduates.

The paper suggests an intervention strategy aimed at promoting IT students' career awareness. It provides context of the exit-level higher education (HE) module used to implement the intervention. Career awareness is achieved by industry talks, projects and events. Interpretive data collection and content analysis are used to understand the impact of the intervention from the students' perspective.

Recommendations are made towards productive interventions for raising career awareness among IT students using industry participation in higher education. The proposed intervention comprises of a combination of industry talks, capstone projects and specific events. Students had largely positive reactions and made suggestions for additional interventions they would find beneficial. A hackathon attended proved the most influential where seven out of eight involved students received job offers from one company. Other students became aware of their own employability, limitations and preferred career paths.

Findings provide confirmation on existing feasible approaches and also introduces new interventions that may be generalised to other fields of study. The paper not only provides an instructional design for a module to raise career awareness but also reflects on the feedback of the students. The reflection provided by students acts as a point of reference to ensure that the process followed for the intervention is practical within a South African context. The paper highlights the perceived benefits of involving industry in higher education to raise career awareness, factors that may prevent career awareness among IT students and valuable suggestions made by students to further enhance the intervention strategy. An implication of the research is a set of guidelines identified towards bridging the IT theory–practice gap. These guidelines can be used by many educators in similar environments to justify their interventions.