Simulations of small-scale explosive events on the Sun

Small-scale explosive events or microflares occur throughout the chromospheric network of the Sun. They are seen as sudden bursts of highly Doppler shifted spectral lines of ions formed at temperatures in the range 2x10^4 - 5x10^5 K. They tend to occur near regions of cancelling photospheric magnetic fields and are thought to be directly associated with magnetic field reconnection. Recent observations have revealed that they have a bi-directional jet structure reminiscent of Petschek reconnection. In this paper compressible MHD simulations of the evolution of a current sheet to a steady Petschek, jet-like configuration are computed using the Versatile Advection Code. We obtain velocity profiles that can be compared with recent ultraviolet line profile observations. By choosing initial conditions representative of magnetic loops in the solar corona and chromosphere, it is possible to explain the fact that jets flowing outward into the corona are more extended and appear before jets flowing towards the chromosphere. This model can reproduce the high Doppler shifted components of the line profiles but the brightening at low velocities, near the centre of the bi-directional jet, cannot be explained by this simple MHD model.Comment: 16 pages, 8 figures. To be published in Solar Physic

Two-directional-flow, axial-motion-joint flow liner

Flow liner eliminates high-cycle fatigue in ducts carrying cryogenic fluids. It is capable of handling two-directional, high-velocity cryogenic liquid flow with a 3-inch axial motion without binding within a 25-inch length

Civics and citizenship education in NSW secondary schools : case studies of the impact of authoritative expert content and multimedia technology in the classroom

This study examines teachers’ perspectives and experiences with civics and citizenship education (CCE) in secondary school classrooms in NSW. It investigates the pedagogical approaches of teachers of History and Geography in CCE and the ways in which technology is used in teaching practice. It is a study based on qualitative research methods and design. The research methodology adopts a multiple case study approach that incorporates an action research orientation. Sixteen teachers participated in the study in five NSW secondary schools. The research findings revealed that teachers approached CCE with reference to the NSW syllabus in a diverse range of ways. These approaches were categorised as follows: empathetic, rights and responsibilities based, values based, community based, and critically inquiring. While teachers tended to adopt a mix of these approaches in classroom teaching practice, the above approaches were discemable. Teaching approaches to CCE depended on several factors including school context, levels of student literacy and language skills, access to technology, and length of teaching experience. The research revealed the complex nature of the challenges facing CCE teachers in response to changing contemporary local, national and international events. The findings identify a continuing need for pre-service training, inservice training and professional development in CCE for secondary school teachers. Data gathered on teachers’ use of technology in classroom teaching showed differences in the pedagogical approaches adopted by CCE teachers in different schools. Differences in teaching approaches were shaped by teachers’ access to equipment and facilities, communication networks, and maintenance and support of technology for classroom teaching. The ‘digital divide’ revealed by the data influenced the ways in which participating teachers approached the use of technology for classroom teaching. The wider opportunities that existed in some schools to engage technology appeared to extend teacher’s ability to build knowledge of content and teaching (KCT) and knowledge of students and content (KSC) with respect to the use of technology. Limited and unequal access to technology for classroom teaching practice holds implications for the development of teachers’ pedagogical content knowledge (PCK). A technological ‘digital divide’ has the potential to be mirrored in a ‘pedagogical divide’ in approaches to teaching with varied possibilities and outcomes for teachers and students in different schools. In addition to investigating existing teaching practice, in secondary schools this study explored different pedagogical approaches to CCE in the classroom. The action research orientation adopted relied on the earlier investigation of classroom practice with participating teachers. The methods that were applied combined authoritative expert content (AEC), instructional strategies, and video technology. The study explored the perceived impact of these methods on teacher knowledge and student knowledge in classroom settings. The research design facilitated the use of AEC in classrooms with participating teachers and over 800 secondary school students from 2002- 2005. Participating teachers perceived student involvement with AEC in the classroom as beneficial to student motivation and knowledge building in civics and citizenship within the NSW syllabus. The impact of AEC on teacher knowledge suggested an enhancement of teacher content knowledge with particular emphasis on specialised content knowledge (SCK) in CCE. Teacher’s participation in the study was perceived to have enhanced pedagogical content knowledge (PCK) in CCE to some extent. The pedagogical methods based on AEC and the use of video technology demonstrated a capacity to stimulate learning and build knowledge through collaborative teaching partnerships in CCE

The relationship between industrial law and discrimination law in the determination of women's wage rates within the Australian wage fixing system

This thesis broadly reviews the developments which have occurred in relation to the implementation of equal pay principles within the Australian wage fixing process up until March 1991. Although updated references have been included in relation to certain events occurring since this date, an analysis of the Industrial Relations Commission's decision in the National Wage Case, April 1991 is not included in this study. It is worth noting that several issues relevant to wage discrimination were raised in this recent National Wage Case decision chiefly through submissions presented by the Australian Federation of Business and Professional Women. These submissions called for a work skills value inquiry to review all aspects of skill evaluation, including those with a bearing on the relative evaluation of male and female work. The Commission declined to convene such an inquiry, expressing the view that current wage fixing principles already provided ample scope for the review of any specific instances where work typically performed by women was claimed to be undervalued. The Commission confirmed that the 1972 equal pay principles of the Australian Conciliation and Arbitration Commission would continue to apply to special instances, and invited parties appearing before the Commissioner in individual cases to raise any issue they consider inconsistent with the provisions of Section 93 of the Industrial Relations Act 1988 fCtM. Significantly the Commission acknowledged that enterprise bargaining - especially bargaining for overaward payments - placed those sectors of the labour force where women predominate at a relative disadvantage. The above developments suggest that the application of equal pay principles will remain an issue relevant to industrial wage setting policy and practice into the 1990's

Do Voluntary Pollution Reduction Programs (VPRs) Spur Innovation in Environmental Technology

In the context of the EPA's 33/50 program, we study whether a VPR can prompt firms to develop new environmental technologies that yield future emission reduction benefits. Because pollutant reductions generally require costly reformulations of products and/or production processes, environmental over-compliance induced by a VPR may potentially spur environmental innovation that can reduce these costs. Conversely, a VPR may induce a participating firm to divert resources from environmental research to environmental monitoring and compliance activities that yield short-term benefits in reduced emissions. We find evidence that higher rates of 33/50 program participation are associated with significant reductions in the number of successful environmental patent applications four to six years after the program ended; these results suggest a negative relationship between the 33/50 program and longer-run environmental innovation.Research and Development/Tech Change/Emerging Technologies,

International Product Differentiation Through a Country Brand: An Economic Analysis of National Branding as a Marketing Strategy for Agricultural Products

branding, marketing, Agribusiness, Agricultural and Food Policy, Food Consumption/Nutrition/Food Safety,

Energy spectra of 3He-rich solar energetic particles associated with coronal waves

In addition to their anomalous abundances, 3He-rich solar energetic particles (SEPs) show puzzling energy spectral shapes varying from rounded forms to power laws where the later are characteristics of shock acceleration. Solar sources of these particles have been often associated with jets and narrow CMEs, which are the signatures of magnetic reconnection involving open field. Recent reports on new associations with large-scale EUV waves bring new insights on acceleration and transport of 3He-rich SEPs in the corona. We examined energy spectra for 32 3He-rich SEP events observed by ACE at L1 near solar minimum in 2007-2010 and compared the spectral shapes with solar flare signatures obtained from STEREO EUV images. We found the events with jets or brightenings tend to be associated with rounded spectra and the events with coronal waves with power laws. This suggests that coronal waves may be related to the unknown second stage mechanism commonly used to interpret spectral forms of 3He-rich SEPs.Comment: Presented at 15th Annual International Astrophysics Conference "The Science of Ed Stone". Accepted for publication in Journal of Physics: Conference Serie

International Product Differentiation through a Country Brand: An Economic Analysis of National Branding as a Marketing Strategy for Agricultural Products

Trade policy initiatives of developed country governments are in flux. Governments’ need for new trade policy measures has arisen partly because of constraints imposed on the use of export subsidies by the Agreement on Agriculture reached as part of the Uruguay Round of General Agreement on Tariffs and Trade in 1994. Further disciplines on export subsidies and other policy measures may be agreed on in the Doha Round of World Trade Organization (WTO) negotiations, accentuating the need for new policy measures. While the Doha Round may not successfully reach an agreement, the current modalities show provisional agreement on the elimination of multiple forms of export subsidies. There is provisional agreement on more stringent restrictions on the use of export credit programs. Controls on exporting state trading agencies’ ability to subsidize exports are tentatively agreed (Furtan, 2005). Food aid, which can also be used to circumvent disciplines on export subsidies, is also likely to be subject to WTO disciplines.International Relations/Trade,

Jets or high velocity flows revealed in high-cadence spectrometer and imager co-observations?

We report on active region EUV dynamic events observed simultaneously at high-cadence with SUMER/SoHO and TRACE. Although the features appear in the TRACE Fe ix/x 171A images as jets seen in projection on the solar disk, the SUMER spectral line profiles suggest that the plasma has been driven along a curved large scale magnetic structure, a pre-existing loop. The SUMER observations were carried out in spectral lines covering a large temperature range from 10^4 K to 10^6 K. The spectral analysis revealed that a sudden heating from an energy deposition is followed by a high velocity plasma flow. The Doppler velocities were found to be in the range from 90 to 160 km/s. The heating process has a duration which is below the SUMER exposure time of 25 s while the lifetime of the events is from 5 to 15 min. The additional check on soft X-ray Yohkoh images shows that the features most probably reach 3 MK (X-ray) temperatures. The spectroscopic analysis showed no existence of cold material during the events