2,016 research outputs found

    Student progress 2006: accelerated literacy NT schools

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    In 2004 the Commonwealth Government in conjunction with the Northern Territory Department of Employment Education and Training and with support from the School for Social and Policy Research, launched the National Accelerated Literacy Program. Accelerated literacy is a teaching methodology designed to accelerate students\u27 reading, writing, and comprehension skills by using narratives that are age-appropriate. At the end of the 2006 school year, there were 50 participating schools. Of these, there were 36 schools with recorded assessments. Student progress for the year showed some encouraging results

    Synthesis of phthalocyanine doped sol-gel materials

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    The synthesis of sol-gel silica materials doped with three different types of metallophthalocyanines has been studied. Homogeneous materials of good optical quality were prepared and the first optical limiting measurements of dyes in sol-gel hosts were carried out. The properties of these solid state limiters are similar to limiters based on phthalocyanine (Pc) in solution. Sol-gel silica materials containing copper, tin and germanium phthalocyanines were investigated. The initial step in all cases was to prepare silica sols by the sonogel method using tetramethoxy silane (TMOS), HCl and distilled water. Thereafter, the synthesis depended upon the specific Pc and its solubility characteristics. Copper phthalocyanine tetrasulfonic acid tetra sodium salt (CuPc4S) is soluble in water and various doping levels (1 x 10 (exp -4) M to 1 x 10 (exp -5) M) were added to the sol. The group IV Pc's, SnPc(OSi(n-hexyl)3)2 and GePc(OSi(n-hexyl)3)2, are insoluble in water and the process was changed accordingly. In these cases, the compounds were dissolved in THF and then added to the sol. The Pc concentration in the sol was 2 x 10(exp -5)M. The samples were then aged and dried in the standard method of making xerogel monoliths. Comparative nanosecond optical limiting experiments were performed on silica xerogels that were doped with the different metallophthalocyanines. The ratio of the net excited state absorption cross section (sigma(sub e)) to the ground state cross section (sigma(sub g)) is an important figure of merit that is used to characterize these materials. By this standard the SnPc sample exhibits the best limiting for the Pc doped sol-gel materials. Its cross section ratio of 19 compares favorably with the value of 22 that was measured in toluene. The GePc materials appear to not be as useful as those containing SnPc. The GePc doped solids exhibit a higher onset energy (2.5 mj and lower cross section ratio, 7. The CuPc4S sol-gel material has a still lower cross section ratio, 4, however, the tetrasulfonate groups make the dye soluble in water which greatly facilitates its incorporation into the sol-gel matrix. The nonlinear transmission of CuPc4S in a pH 2 buffer solution and in a silica xerogel were compared. It is evident that the CuPc4S preserves its optical limiting behavior in the sol-gel matrix, indicating that the fundamental excited state absorption process is essentially the same for a molecule in solution or in the solid state. Although the spectroscopic details of energy level lifetimes are unknown, the significance is that passive optical limiting has been achieved in the solid state via incorporation of a dye into an inorganic host. The only compromise occurs at the extremely high energy regime where photobleaching is observed. This is a result of the limited mobility of the dye molecules in the solid silica host relative to a liquid host. The effects of photodegradation in the xerogel are additive, whereas the solution provides a supply of fresh molecules that are free to enter the active volume between pulses

    Pseudocapacitive oxide materials for high-rate electrochemical energy storage

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    Electrochemical energy storage technology is based on devices capable of exhibiting high energy density (batteries) or high power density (electrochemical capacitors). There is a growing need, for current and near-future applications, where both high energy and high power densities are required in the same material. Pseudocapacitance, a faradaic process involving surface or near surface redox reactions, offers a means of achieving high energy density at high charge–discharge rates. Here, we focus on the pseudocapacitive properties of transition metal oxides. First, we introduce pseudocapacitance and describe its electrochemical features. Then, we review the most relevant pseudocapacitive materials in aqueous and non-aqueous electrolytes. The major challenges for pseudocapacitive materials along with a future outlook are detailed at the end

    Where Do Batteries End and Supercapacitors Begin?

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    Electrochemical measurements can distinguish between different types of energy storage materials and their underlying mechanisms

    Parallel fabrication and single-electron charging of devices based on ordered, two-dimensional phases of organically functionalized metal nanocrystals

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    A parallel technique for fabricating single-electron, solid-state capacitance devices from ordered, two-dimensional closest-packed phases of organically functionalized metal nanocrystals is presented. The nanocrystal phases were prepared as Langmuir monolayers and subsequently transferred onto Al-electrode patterned glass substrates for device construction. Alternating current impedance measurements were carried out to probe the single-electron charging characteristics of the devices under both ambient and 77 K conditions. Evidence of a Coulomb blockade and step structure reminiscent of a Coulomb staircase is presented

    Thermomagnetic-Responsive Self-Folding Microgrippers for Improving Minimally Invasive Surgical Techniques and Biopsies

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    Traditional open surgery complications are typically due to trauma caused by accessing the procedural site rather than the procedure itself. Minimally invasive surgery allows for fewer complications as microdevices operate through small incisions or natural orifices. However, current minimally invasive tools typically have restricted maneuverability, accessibility, and positional control of microdevices. Thermomagnetic-responsive microgrippers are microscopic multi-fingered devices that respond to temperature changes due to the presence of thermal-responsive polymers. Polymeric devices, made of poly(N-isopropylacrylamide-co-acrylic acid) (pNIPAM-AAc) and polypropylene fumarate (PPF), self-fold due to swelling and contracting of the hydrogel layer. In comparison, soft metallic devices feature a pre-stressed metal bilayer and polymer hinges that soften with increased temperature. Both types of microdevices can self-actuate when exposed to the elevated temperature of a cancerous tumor region, allowing for direct targeting for biopsies. Microgrippers can also be doped to become magnetically responsive, allowing for direction without tethers and the retrieval of microdevices containing excised tissue. The smaller size of stimuli-responsive microgrippers allows for their movement through hard-to-reach areas within the body and the successful extraction of intact cells, RNA and DNA. This review discusses the mechanisms of thermal- and magnetic-responsive microdevices and recent advances in microgripper technology to improve minimally invasive surgical techniques

    O’ Brien Center

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    poster abstractThe O’Brien Center for Advanced Renal Microscopy and Analysis is based around the Indiana Center for Biological Microscopy in Indianapolis (ICBM), and is supported by partnerships with Purdue University and the University of North Carolina. The Center acts as a national resource for investigators to apply state-of-the-art techniques in fluorescence microscopy to research in kidney biology and pathophysiology. Investigators have access to four microscope systems capable of multiphoton and confocal imaging and optimized for intravital imaging studies on rodents. Point-scanning and spinning-disk confocal systems are also available. Training and assistance with development of imaging protocols are available from expert staff at the ICBM. The Center emphasizes development of new and improved methods for imaging the kidney and seeks to disseminate these innovations as widely as possible amongst renal investigators. Currently, the Center is (1) developing new software for rendering, segmentation, analysis and stabilization of three-dimensional data from live imaging experiments; (2) developing new fluorescent probes and delivery methods optimized for intravital imaging studies in the kidney; and (3) exploring methods to increase the reach of multiphoton imaging in the kidney. Funding is available through the Center’s O’Brien Fellows Program to support short visits (one-two weeks) to Indianapolis for data collection, development of imaging protocols to address particular questions and for training in fluorescence microscopy and image analysis. The Center also offers instructional workshops in fluorescence microscopy and intravital imaging every two years. Current information about how to access the resources available through the Center is available at http://medicine.iupui.edu/nephrology/obrien

    A rising tide lifts all boats: the role of share and category changes in managing organic sales growth

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    The strategic objective of marketing activities is to drive business growth by promoting the firm’s products. Beyond merger and acquisition, organic growth can be targeted from two sources: Market Share Gain and Category Growth. Market share is often the focus for corporate objectives and used as a success measure. This research explores the relative impact of these two elements on firm growth across product category and addresses whether market share should be the main focus for all organisations. The study covers 39 consumer packaged goods’ categories from the UK and US, across 189 manufacturers over three to five years of data, post-2010. We show that firm growth through market share gain is likely to benefit small firms, and large firms’ growth is likely to be driven by category growth. The results provide empirical support in the area of business growth and how marketing plays a crucial role in this pursuit

    Rapid Phenotypic Assessment of Bird Cherry-oat Aphid Tolerance in Winter Wheat

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    Rhopalosiphum padi L., or the bird cherry-oat aphid, causes significant damage to winter wheat (Triticum aestivum L.) in the Great Plains. Our objective was to develop a juvenile-plant bioassay for BCO tolerance that allows rapid phenotypic characterization of tolerance in a growth chamber study using root and shoot weight measurements of 3-wk old seedlings produced in seed germination pouches. Based on preliminary results, bioassay methods were used in verification experiments conducted on one hundred and forty-nine Oklahoma, Colorado, SRPN, and CIMMYT lines indicated levels of responses to feeding (roots being greater than shoots), but both averaging around a 30 % reduction. Findings of indigenous genetic variation in six of the eight control treatments (P>0.05) further exonerated the need for control plants to curve variation by a ratio of infested-to-control. Correlation relationships between three of the four sources showed that both roots and shoots are key to finding tolerance.Department of Plant and Soil Science
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