52 resultados para concentrate


Relevância:

10.00% 10.00%

Publicador:

Resumo:

This paper describes a lightweight, modular and energy efficient robotic vehicle platform designed for broadacre agriculture - the Small Robotic Farm Vehicle (SRFV). The current trend in farming is towards increasingly large machines that optimise the individual farmer’s productivity. Instead, the SRFV is designed to promote the sustainable intensification of agriculture by allowing farmers to concentrate on more important farm management tasks. The robot has been designed with a user-centred approach which focuses the outcomes of the project on the needs of the key project stakeholders. In this way user and environmental considerations for broadacre farming have informed the vehicle platform configuration, locomotion, power requirements and chassis construction. The resultant design is a lightweight, modular four-wheeled differential steer vehicle incorporating custom twin in-hub electric drives with emergency brakes. The vehicle is designed for a balance between low soil impact, stability, energy efficiency and traction. The paper includes modelling of the robot’s dynamics during an emergency brake in order to determine the potential for tipping. The vehicle is powered by a selection of energy sources including rechargeable lithium batteries and petrol-electric generators.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In this article, we investigate the complex relationship between concerns about children and young people’s exposure to cinema in 1920s Australia and the use of film in education. In part, the Royal Commission into the Moving Picture Industry in Australia aimed to ‘ascertain the effect and the extent of the power of film upon juveniles’ and Commissioners spoke to educationalists, psychologists, medical professions, police officers and parents to gain insight into the impacts of movies on children. Numerous issues were canvassed in the Commission hearings such as exposure to sexual content, ‘excesses’ in film content, children’s inability to concentrate at school following cinema attendance and the influence of cinema on youth crime. While the Commission ultimately suggested it was parents’ role to police children’s engagements with cinema, it did make recommendations for restricting children’s access to films with inappropriate themes. Meanwhile, the Commission was very positive about film’s educational role stating that ‘the advantage to be gained by the use of the cinematograph as an adjunct to educational methods should be assisted in every possible way by the Commonwealth’. We draw on the Commission’s minutes of evidence, the Commission report and newspaper articles form the 1920s to the 1940s to argue that the Commission provides valuable insight into the beginnings of the use of screen content in formal schooling, both as a resource across the curriculum and as a specific focus of education through film appreciation and, later, broader forms of media education. The article argues debates about screen entertainment and education rehearsed in the Commission are reflected today as parents, concerned citizens and educators ponder the dangers and potential of new media technologies and media content used by children and young people such as video games, social media and interactive content.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Visible light can drive esteri fi cation from aldehydes and alcohols using supported gold nanoparticles (Au/Al 2 O 3 ) as photo- catalysts at ambient temperatures. The gold nanoparticles (AuNPs) absorb visible light due to the localized surface plasmon resonance (LSPR) e ff ect, and the conduction electrons of the AuNPs gain the energy of the incident light. The energetic electrons, which concentrate at the NP surface, facilitate the activation of a range of aldehyde and alcohol substrates. The photocatalytic e ffi ciencies strongly depend on the Au loading, particle sizes of the AuNPs, irradiance, and wavelength of the light irradiation. Finally, a plausible reaction mechanism was proposed, and the Au/Al 2 O 3 catalysts can be reused several times without signi fi cantly losing activity. The knowledge acquired in this study may inspire further studies in new e ffi cient recyclable photocatalysts and a wide range of organic synthesis driven by sunlight.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The Global Financial Crisis (GFC) in 2008 had a significant impact on the world economy and the construction industry was no exception. This study investigates the major impacts of the 2008 GFC on the Australian construction industry and, in particular how the Australian construction contractors responded to the economic downturn. A total of 35 senior managers from the Top 100 Australian construction companies were interviewed. The findings indicate that construction companies, particularly the large ones were not affected in any significant way but are expecting some difficult financial times over the next few years and are taking actions to minimize the upcoming adverse impacts. The most common strategy adopted by Australian construction contractors is to concentrate on core business while avoiding aimless bidding. Similarly, great focus is placed on retaining human resources in order to maintain the skill set so that the company can respond quickly when market conditions improves. The research findings will provide construction contractors with insights on how to establish and sustain competitive advantages during economic slowdown and become more resilient in the future.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The Ok Tedi copper orebody consists of porphyry and skarn orebodies. The skarn orebodies, identified by different mineralogy, are the source of high intermittent fluorine levels in the mill concentrates. This paper discusses the results of the work undertaken to characterize the various fluorine-bearing minerals in samples of final copper concentrates and the distribution of fluorine amongst the minerals. Quantification of each mineral in mill feed and various flotation streams at Ok Tedi enables an understanding of the quantitative response of fluorine-bearing minerals to flotation. The metallurgical behavior of fluorine in the flotation process is also discussed.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This is a conceptual paper that seeks to explore the role of entrepreneurial marketing in promoting entrepreneurship in tertiary education. We postulate that the subject of entrepreneurship is marketed in different ways as a means of introducing (a) new learners to the subject area of entrepreneurship and (b) the wide ranging possibilities of entrepreneurship education. This research explores both the entrepreneurial marketing and the entrepreneurship literature to capture how they meet at the interface to solve the issue of appropriately marketing entrepreneurship courses within the context of university education. Whilst empirical evidence of entrepreneurial marketing has tended to concentrate on profit-making and small organizations, fewer studies have sought to understand the role of entrepreneurial marketing in public sector organizations, including the university. Although this article is exploratory in nature, it shows the benefits of utilizing the extensive research within the fields of entrepreneurial marketing and entrepreneurship to determine the value of entrepreneurship education for policymakers, universities and students.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Most histories of the Franklins concentrate on Sir John’s explorations and disappearance in the Arctic, supplemented with stories of Lady Jane’s devotion to discovering his fate. Here we present the Franklins’ musical legacy, revealing a genial and cultured presence which inspired local musicians to pay homage to the “universally beloved & respected” 4 Sir John and Lady Jane Franklin.