17 research outputs found
Acadêmicos auto-alienados: reflexões sobre a crise norte-americana da disciplina "direito e desenvolvimento" (1974) = Scholars in self-estrangement: some reflections on the crisis in law and development studies in the United States
No full textTradução de José Rodrigo Rodriguez e José Rafael Zull
Thin-film photonic crystal LEDs with enhanced directionality
No full textThe use of photonic crystals for light extraction from light-emitting diodes (LEDs)
gives the possibility to shape the farfield emission pattern. This is of particular interest
for étendue-limited LED applications that require a more directional farfield than state-
of-the-art Lambertian emitters. However, the application of a photonic crystal in a LED
results in directional emission only if the photonic crystal and the distribution of guided
modes in the LED are tuned correctly. In this thesis, red- and blue-emitting thin-film
PhC-LEDs in the AlGaInP and InGaN material systems were modelled, designed,
fabricated and characterized. The first experimental results show that light extraction
with photonic crystals from AlGaInP thin-film LEDs several microns thick is neither
directional nor more efficient than state-of-the-art LEDs with a rough surface structure.
Directional light extraction for AlGaInP PhC-LEDs is for the first time demonstrated in
much thinner devices where the photonic crystal light extraction of guided modes is
combined with the resonant-cavity effect. In an attempt to approach the ideal PhC-LED,
strong photonic crystal farfield shaping is demonstrated in InGaN thin-film LEDs of
sub-micron thickness. Analysis of their spectral farfields unexpectedly shows that high
order diffraction contributes significantly to the light extraction efficiency if the mode
absorption is sufficiently low. It is also demonstrated that directional photonic crystal
light extraction is possible in InGaN thin-film LEDs several microns thick. The
directionality stems from the modulation of the spontaneous emission caused by the
proximity of the active region to the bottom mirror. Two new concepts for enhanced
light extraction and high directionality are presented: Photonic crystals with two
dominating lattice constants are found to outperform conventional photonic crystal
LEDs. An alternative approach is the dielectric PhC-LED - FDTD simulations show
that the high extraction efficiency of LEDs with surface roughness is combined with the
higher directionality of photonic crystal light extraction
Farming system profitability and impacts of commodity price risk
No full textTake home messages
• Large gaps in profitability are possible between the best and worst systems – differences of $92-494/ha per year were found between systems at each site
• Intensity is the major factor driving good/poor economic performance of the farming system - more so than crop choice. Matching intensity to environmental potential seems to be the most important lever to optimise farming system profitability
• Increasing crop intensity increased costs and risks, but potentially higher crop income wasn’t realised over the dry run of seasons and hence has produced lower gross margins than more conservative systems
• Lower crop intensity had lower system gross returns, but because of lower inputs and costs may achieve a more favourable return on investment at lower risk when there are limited planting opportunities. These systems have achieved lower gross margins than the baseline system in all but one comparison
• Increasing legume frequency has the potential to capitalise on favourable legume prices but using long-term prices has rarely exceeded gross margins of baseline systems
• Increasing nutrient supply incurred higher costs and required favourable seasonal conditions to increase grain yields and gross margins – this rarely occurred over the experimental years (excluding Trangie 2016 and Emerald 2017 where significant crop responses were obtained)
• Systems involving crops with higher price variability (e.g. pulses, cotton) had limited downside risk but increased upside opportunities of higher economic returns. Even when comparing recent and long-term grain prices, the relative profitability ranking of systems rarely changed
• Selecting a crop system is a long-term decision with unknown future yield and prices, hence choose systems that maximise system productivity and resilience, rather than responding to current commodity prices
Vulnerability and adaptive capacity of the Granite Belt tomato industry to future increases in temperature
No full textA project funded by the Queensland Government in 2010 sought to improve the capacity of primary producers in selected horticultural industries to manage risks and identify opportunities arising from Queensland's changing and variable climate. Tomato growers in the Granite Belt in south-east Queensland documented their vulnerability to climate change, adaptation options and economically evaluated risk management responses in the supply of fresh tomatoes. The production and quality of field grown tomatoes is significantly reduced when mean monthly maximum temperatures exceed 29°C two weeks prior to flowering. Granite Belt tomato growers who took part in this extensive series of interactive climate awareness workshops were presented with (best knowledge) future climate scenarios for their Granite Belt production location. Once aware of the Tomato plants intrinsic high temperature flowering threshold they concluded that the possibility of reaching this threshold was unlikely in the medium term (i.e. by 2030). Granite Belt summer tomato production has evolved in a unique high altitude region, where mean maximum monthly temperature, both current and projected, does not exceed the maximum temperature threshold above which tomato crop yield is reduced. Growers understand that their unique high altitude location gives them a production advantage, and that their industry will benefit from projected future temperature changes. Granite Belt growers now have a better understanding of the impact of climate variables on tomato production through increased knowledge which they applied using the Horticulture Vulnerability Matrix. Discussion of projected future climate impacts and the populating of this Vulnerability Matrix was a major focus of each workshop session, and allowed growers to increase their knowledge, identify areas of vulnerability and document adaptation options necessary to build industry resilience
A summary of the economics of deep P nutrition trials in the northern grains region: where have current trials provided economic benefits?
No full textTake home messages
Yield increases of 10% or more in 21/43 site observations, whilst 30/43 observations had responses of 5% or more to 20P.
There does not appear to be a significant difference in response to P rate, with the average yield increase across 20P, 30 and 40P (combined), and 60 and 80P (combined) rates all being approximately 10%.
The majority of treatments did not create a positive return in the first two years, with 7 of 21 sites having currently returned a net benefit
Reclaiming the Imagination through Science
No full textThis thesis attempts to reclaim the imagination, defined by Ann Berthoff as the name for the active mind, by looking at brain biology as it relates to teaching and learning. The section titled Keeping Biology in Mind: The Brain as Speculative Instrument demonstrates how biological naturalism, a philosophy developed by John Searle, validates the concept of an ontologically subjective I and hence the creation of course materials based on David Kolb\u27s experiential-learning model. In addition, it discusses how biologist James Zull maps the actual structure of the brain onto Kolb\u27s model. Adding to this bottom-up theory of learning that emphasizes brain biology and subjective experience, this thesis discusses how the mind, through mental force, works in a top-down fashion to change the brain, and suggests that students can learn to take control of their own learning by applying mental force. The section titled Keeping Affect in Mind: The Biology of Intuition presents the aspect of affect known as intuition and how it fits into the discussion. The main premise of this thesis is that we can employ concepts of the brain and learning in the composition classroom to facilitate the teaching and learning of writing. The last section titled Keeping Composition in Mind: Theory into Practice is devoted to this premise on a practical level
Serial Pursuit
No full textNature Morte is pleased to announce „Serial Pursuit,“ a group exhibition in which recent works in various media by David Mabb, Manisha Parekh, Dayanita Singh and Audiobombing Crew will be brought together to present an exploration of art works created as sets or in sequences.
The highlight of the opening night will be a performance by Audiobombing Crew. Founded by Markus Zull and Stephan Ebersthäuser in 2003, the sound art collective creates serial sound loops, which are collaged together from analogue sources. The duo works with technical defects and their dynamic manipulation. By mixing Indian pop songs sourced from Bollywood musicals and spoken audio materials, the artists develop sound loops whose repetitive nature resembles the tone of ancient mantras. Audiobombing Crew live and work in Pfaffenhofen in Southern Germany. They have performed in venues such as the Kölner Philharmonie, the Schauspielhaus Düsseldorf and at Gasteig München.
In David Mabb’s works, "Rhythm 69" and "Two Squares," various wallpaper and fabric designs of William Morris are spliced together with the avant-garde art of El Lissitzky and Hans Richter. Presented as paintings arranged in formalist grids which mimic the regulative practices of industrial production, Mabb’s smash-ups of the now haute-bourgeois decorative motifs and the once radical but now sentimentalized utopian experiments are steeped in the irony implicit in negotiating a politicized art practice today. David Mabb (b.1959) lives and works in London. He has exhibited widely in both solo and group exhibitions at venues such as the Liverpool Biennial, the Delaware Centre for the Contemporary Arts, Leo Kamen Gallery in Toronto, the CIMA Gallery in Calcutta and the British Council in New Delhi.
Dayanita Singh's work "Museum of Innocence (The Madras Chapter)" is a photographic portrait of the MGR Memorial House in Chennai, India. The former private residence of M.G. Ramachandran is now a museum that commemorates the beloved Tamil actor and politician, where his personal belongings are displayed as relics. Singh uses the camera’s special ability to capture loss to create the memory of a memory held up by a lattice of formal repetition. Dayanita Singh (b. 1960) lives and works in New Delhi. Her work was included in the exhibition "Illuminazione" at this year’s Venice Biennale and she has held numerous solo exhibitions in prestigious venues such as the Hamburger Bahnhof Museum in Berlin, the Isabella Stewart Gardiner Museum in Boston, Recontres Arles in France, Frith Street Gallery in London, Fondacion Mapfre in Madrid, and Shiseido Gallery, Tokyo.
In Manisha Parekh’s new gouache paintings and graphite drawings on paper, her imagery is bio-morphic and seemingly automatic. Successive images build into a canon of identity and cultural inheritance, both Indian and international. Manisha Parekh (b. 1964) lives and works in New Delhi. Solo exhibitions of her works have been presented at Nature Morte, New Delhi; BodhiArt, New York; Berkeley Square Gallery, London; Sakshi Gallery, Mumbai; The British Council, New Delhi; and The Foundation for Indian Art, Amsterdam
