2,826 research outputs found
Experimental clean combustor program, alternate fuels addendum, phase 2
The characteristics of current and advanced low-emissions combustors when operated with special test fuels simulating broader range combustion properties of petroleum or coal derived fuels were studied. Five fuels were evaluated; conventional JP-5, conventional No. 2 Diesel, two different blends of Jet A and commercial aromatic mixtures - zylene bottoms and haphthalene charge stock, and a fuel derived from shale oil crude which was refined to Jet A specifications. Three CF6-50 engine size combustor types were evaluated; the standard production combustor, a radial/axial staged combustor, and a double annular combustor. Performance and pollutant emissons characteristics at idle and simulated takeoff conditions were evaluated in a full annular combustor rig. Altitude relight characteristics were evaluated in a 60 degree sector combustor rig. Carboning and flashback characteristics at simulated takeoff conditions were evaluated in a 12 degree sector combustor rig. For the five fuels tested, effects were moderate, but well defined
Experimental clean combustor program, phase 1
Full annular versions of advanced combustor designs, sized to fit within the CF6-50 engine, were defined, manufactured, and tested at high pressure conditions. Configurations were screened, and significant reductions in CO, HC, and NOx emissions levels were achieved with two of these advanced combustor design concepts. Emissions and performance data at a typical AST cruise condition were also obtained along with combustor noise data as a part of an addendum to the basic program. The two promising combustor design approaches evolved in these efforts were the Double Annular Combustor and the Radial/Axial Combustor. With versions of these two basic combustor designs, CO and HC emissions levels at or near the target levels were obtained. Although the low target NOx emissions level was not obtained with these two advanced combustor designs, significant reductions were relative to the NOx levels of current technology combustors. Smoke emission levels below the target value were obtained
The political economy of trade policy in the KORUS FTA
This is an abridged version of the winner of the best paper award at the 2011 Seoul inter-GSIS competition at the Korean Institute for International Economic Policy (KIEP). The full and original paper can be found here
Greens-height Creeping Bentgrass cv. Emerald Evaluation of Fungicides
Evaluations of 18 fungicide treatments for control of dollar spot and brown spot, as well as effect on turf quality, were conducted in green- height creeping bentgrass cv. Emerald, at the Iowa State University Horticulture Station, Ames, IA
LuzDeploy: A Collective Action System for Installing Navigation Infrastructure for Blind People
Providing navigation assistance to people with visual impairments often requires augmenting the environment with after-market technology. However, installing navigation infrastructure in large environments requires a critical mass of trained personnel. Recruiting, training and managing participants for such a task is difficult. LuzDeploy is a computational method to recruit, instruct and orchestrate volunteers to perform physical crowdsourcing tasks. We use LuzDeploy to orchestrate volunteers to install physical infrastructure for the navigation assistance of people with visual impairments. Our system provides on-the-go enrollment so that volunteers can participate to the collective action whenever they have time, coming and leaving as needed. Providing automated instructions also allows to avoid instructing participants directly, so experts do not need to be available on-site
Unified Framework for Correlations in Terms of Local Quantum Observables
We provide a unified framework for nonsignalling quantum and classical
multipartite correlations, allowing all to be written as the trace of some
local (quantum) measurements multiplied by an operator. The properties of this
operator define the corresponding set of correlations.We then show that if the
theory is such that all local quantum measurements are possible, one obtains
the correlations corresponding to the extension of Gleason's Theorem to
multipartite systems. Such correlations coincide with the quantum ones for one
and two parties, but we prove the existence of a gap for three or more parties.Comment: 4 pages, final versio
Risk factors for vulnerable youth in urban townships in South Africa: the potential contribution of reactive attachment disorder
Reactive attachment disorder (RAD) is a psychiatric disorder developing in early or middle childhood as a consequence of significant failures in the caregiving environment. RAD results in children failing to relate socially, either by exhibiting markedly inhibited behaviour or by indiscriminate social behaviour and is associated with significant socio-behavioural problems in the longer term. This study examined RAD in South Africa, a setting with high environmental risks.
We recruited a sub-sample of 40 10-year-old children from a cohort enrolled during pregnancy for whom early attachment status was known. Children were purposefully selected to represent the four attachment categories using the data available on the strange situation procedure (SSP) at 18 months. The Manchester Child Attachment Story Task (MCAST) assessed current attachment and RAD was diagnosed using a standardised assessment package. A high proportion of the children (5/40% or 12.5%) fulfilled diagnostic criteria for RAD; all were boys and were displaying the disinhibited type. SSP classification at 18 months was not significantly associated with RAD symptoms at age of 10 years, while current MCAST classifications were. This suggests that children in this sample are at much higher risk of RAD than in high-income populations, and despite a fairly typical attachment distribution in this population at 18 months, RAD was evidenced in later childhood and associated with current attachment disorganisation.
The strengths of this research include its longitudinal nature and use of diagnostic assessments. Given increasing evidence that RAD is relatively stable over time and introduces longer term socio-behavioural risks; the high rate of RAD in this sample (12.5%) highlights potential developmental threats to children in low- and middle-income countries (LMICs). Our results should be interpreted with caution given sample size and risk of selection bias. Further research is needed to confirm these findings
The auxiliary use of LANDSAT data in estimating crop acreages: Results of the 1975 Illinois crop-acreage experiment
The author has identified the following significant results. It was found that classifier performance was influenced by a number of temporal, methodological, and geographical factors. Best results were obtained when corn was tasselled and near the dough stage of development. Dates earlier or later in the growing season produced poor results. Atmospheric effects on results cannot be independently measured or completely separated from the effects due to the maturity stage of the crops. Poor classifier performance was observed in areas where considerable spectral confusion was present
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