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The purpose of this paper is to determine technological potential of using multi‐frequency electromagnetic fields for the optimization of induction heating process.

The aim of the research is achieved by using phase‐modulated current feeding the solenoid that excites the magnetic field. In this case, the magnetic field, side by side with the carrier frequency, contains frequency spectrum arising due to modulation. At that, spectral components possess different penetration depths, which ensures a more uniform current density distribution over the cross‐section of the heated object. The results are obtained using theoretical analysis of electrodynamic and thermal processes in the heated body.

In the course of the work, a basic possibility of the objective realization is established, and its high enough efficiency is achieved using a sufficiently large range of modulation parameters.

The described method can significantly improve the technology of thermal treatment of metals and alloys liable to the formation of surface defects due to extreme temperature stresses.

The novelty of the paper consists in the use of phase‐modulated currents in induction heating.

Smallholder families in Papua New Guinea (PNG) feed the nation and produce income-generating cash crops such as coffee and cocoa. However, agricultural extension has not yet effectively reached many farming families in the country, and many families still work with semi-subsistence practices. As a result, the majority of farming families have insecure livelihoods, with many living below the poverty line. This chapter explores a collaborative research for development project that sought to address this issue.

Using data from two highlands sites in the Western Highlands and Jiwaka provinces, we outline the empowerment processes we developed in both our research and our learning activities. We illustrate how the experiential learning processes enabled women, especially those with low education, to confidently engage in this form of agricultural extension. Our work surfaced the knowledge of both women and men and supported families to determine how to work together in effective and equitable planned farming.

The Papua New Guinea (PNG) LNG project had a direct impact on many rural villagers in the project area. A Livelihood Restoration (LR) program, and later a Community Livelihood Improvement Program (CLIP), was established to assist displaced villagers with food supply and entry into the cash economy. Here we use a case study of the food processing component to focus on gender and social issues addressed through the action research process.

Over the period from 2015 to 2017, over 9000 women and men had received some training during the CLIP program, of whom 77 per cent were women. In the food processing component, women and men were trained to produce a variety of dishes. Training was also conducted in preparation of tasty and nutritious meals for the households, basic human nutrition and hygiene.

Using the action research process, we modified the program as the situation changed and as we learnt from the successes and failures in the program. Overall, the LR and CLIP programs were very successful. Several positive social outcomes occurred, including improved financial independence of many women, raised status of women in their community and a reduction in domestic violence.

Contributions to the program’s success include a gender-balanced team of agricultural, food processing and community engagement specialists; the team learnt from mistakes and modified the program using the action research process; the program was well funded by the PNG LNG Project; and success in the early stages of the program led to ongoing funding once the construction phase ended.

Effective rural agribusiness development requires dedicated training programmes therefore, this paper is an attempt to investigate smallholder farmers’ TNs in the dairy agribusiness sector. The purpose of this paper is to study a bigger research project of the dairy value chain in agribusiness framework in the Rwenzori region.

A sample size of 100 dairy farmers were randomly selected from two Districts in the Rwenzori region. The descriptive statistics (mean and standard deviation) provided a basis for discussion. Furthermore, parametric Pearson coefficient test was conducted to examine the smallholder farmers’ TNs and assess its association with selected socio-demographic characteristics of the dairy farmers.

The analysis indicated that dairy farmers expressed the need for a training program. Most frequently requested topics include: fodder cultivation, quality and safe milk handling, milk marketing, calf feeding and rearing, animal nutrition and financial literacy out of 12 topics. The least desired TNs was record keeping.

The findings contribute to the understanding of dairy farmers’ TNs.

The identified 12 key training intervention areas for the dairy farmers inform policymakers Dairy Development Authority and other development bodies in the Rwenzori region to address the challenges and improve smallholder dairy farming practices.

The study applies a synthesis review to identify theoretically acceptable variables that measure smallholder farmers’ TNs in the dairy agribusiness. The paper also shares the empirical evidence of a pioneering attempt to identify smallholder dairy farmers’ TNs in Uganda.

Agricultural extension has played a central role in building the capacity of smallholders for decades. In efforts to improve extension outcomes, demand-driven approaches have emerged to better align extension content with smallholder context. The aim of this paper is to explore the challenges facing demand-driven extension in Papua New Guinea.

Exploratory case study methodology was used to explore the challenges facing demand-driven extension from the perspectives of 11 practitioners experienced in community engagement in Papua New Guinea.

Although there is great potential for demand-driven extension, this research found extension services in Papua New Guinea are ill-equipped to introduce and sustain a resource-intensive approach like demand-driven extension. It further found that rural farmers who extension organisations have long neglected lack the necessary skills and trust to gain from these services.

A limitation of this research is that it only reflects the opinions of practitioners working in Papua New Guinea. Further research featuring a broader sample of value chain actors connected to extension would provide a more complete understanding of the potential challenges to demand-driven engagement in this context.

With a growing interest among development projects to utilise demand-driven engagement with farmers, this research is the first study to explore the challenge facing this promising approach in Papua New Guinea.

The purpose of this paper is to investigate the effect of pulsed magnetic field (PMF) with different duty cycles on the melt flow and heat transfer behaviors during direct-chill (DC) casting of large-size magnesium alloy billet and find the appropriate range of duty cycle.

A transient two-dimensional mathematical model coupled electromagnetic field, flow field and thermal field, is conducted to study the melt flow and temperature field under PMF and compared with that under the harmonic magnetic field.

The results reveal that melt vibration and fluctuation are generated due to the instantaneous impact of repeated thrust and pull effects of Lorentz force under PMF. The peak of Lorentz force decreases greatly with the increasing duty cycle, but the melt fluctuation region is expanded with higher duty cycle, which accelerates the interior melt velocity and reduces the temperature gradient at the liquid-solid interface. However, PMF with overly high duty cycle has adverse effect on the melt convection and limited influence on the interior melt. A duty cycle of 20% to 50% is a reasonable range.

This paper can provide guiding significance for the setting of duty cycle parameters on DC casting under PMF.

There are few reports on the effect of PMF parameters during DC casting with applying PMF, especially for duty cycle, a parameter unique to PMF. The findings will be helpful for applying the external field of PMF on DC casting.

Induction heating applications aided by power electronic control have become very attractive in the recent past. For cooking applications, power electronics circuits are very suitable to feed power to multi loads with an appropriate control technique. The purpose of this paper is to develop a three leg inverter to feed power to three loads simultaneously and independently.

Pulse density modulation control technique is used to control the output power independently with constant switching frequency.

Multi-load handling converter with independent power control is achieved with reduced number of switching devices (two switches/per load) with simple control strategy.

The proposed system is simulated in MATLAB/Simulink, and the thermal analysis is carried out in COMSOL multi-physics software. The hardware realisation is performed for a 1 kW prototype with 20 kHz switching frequency and 10 kHz pulse density modulation frequency. PIC16F877A microcontroller is used to validate the experimental results for various values of control signals (D_PDM). The simulation and experimental results are in good agreement and validates the developed system.

The purpose of this paper is to investigate the effect of the rotating magnetic field of permanent magnets on the aluminium melt bath.

This model was developed in the ANSYS software package and is based on the application of the finite element method and finite volume.

The distribution of the velocity of the melt in a cylindrical vertical bath and the dependence of the maximum value of the melt displacement on the angular rotation velocity of the system of permanent magnets is obtained.

This work focusses on the interaction of the magnetic field of the moving magnets with the molten metal.

The UN forecast of a 3-degree Celsius global temperature increase by 2,100 will exacerbate excessive heat. Population growth, urban densification, climate change and global warming contribute to heat waves, which are more intense in high-density environments. With urbanisation, vegetation is replaced by impervious materials which contribute to the urban heat island effect. Concurrently, adverse health outcomes and heat- related deaths are increasing, and heat stress affects labour productivity. More green infrastructure, such as green walls, is needed to mitigate these effects; however maintenance costs, OH&S issues and perceptions of fire risk inhibit take up. What if these barriers could be overcome by a green Wallbot? This research examines the feasibility of integrating smart technology in the form of a Wallbot.

The research design comprised two workshops with key stakeholders; comprising green wall designers and installers, green wall maintenance teams, project managers and building owners with green wall installations, horticulture scientists, designers and mechatronics engineers. The aim was to gain a deeper understanding of the issues affecting maintenance of green walls on different building types in New South Wales Australia to inform the design of a prototype robot to maintain green walls.

The Wallbot has great potential to overcome the perceived barriers associated with maintaining green walls and also fire risk and detection. If these barriers are addressed, other locations, such as the sides of motorways or rail corridors, could be used for more green wall installations thereby increasing mitigation of UHI. This innovation would be a welcome addition to smart building technology and property maintenance.

This is a pilot study, and the sample of stakeholders attending the workshops was small, though experienced. The range of green walls is varied, and it was decided to focus initially on a specific type of green wall design for the prototype Wallbot. Therefore other types and sizes of green walls may suit other specifications of Wallbot design.

To date, no robot exists that maintains green walls, and this innovative research developed a prototype for trialling maintenance and inspection.

To date, no robot exists that maintains green walls. No study to date has assessed stakeholder perceptions and developed prototype Wallbot technology.

This paper aimed to examine the impact of the removal of bottled water on the campus community. This paper presents the findings of a survey conducted at the first Australian university to remove single-use bottled water from sale on a small regional university campus. The removal of bottled water from sale at the university formed part of the university’s commitment to environmental sustainability.

The study was conducted substantially by undergraduate students who participated in an action learning project in which they assisted in the design, implementation and analysis of an online snapshot survey made available to all staff and students of the university.

The results indicated some evidence of changes to pro-environmental behaviors such as increased use of re-fillable bottles, but there were less desirable outcomes such as drinking less water. Community perceptions were dramatically polarized. Restrictions on freedom of choice, concerns about health as a result of increased use of high-sugar drinks and the continued availability of other plastic drink bottles were provided as strong objections to the removal of bottled water from sale on campus.

The study provides useful insights for university sustainability planners and administrators about the complex range of issues associated with the implementation of sustainability initiatives on a university campus.

While extensive literature exists about the environmental impacts of bottled water, few studies have explored the impacts or community responses to the removal of bottled water in the university context.