2,537 research outputs found
Seasonally loaded waste stabilisation ponds: a novel application for intermittent discharge
This research examined the use of a single facultative pond for treatment of an intermittent discharge from a UK campsite. The system was monitored over an 11-month period to determine the optimum time for discharge in terms of quality standards. The results showed that based on organic strength, discharge was possible in winter between November and March but February was the optimum to meet nutrient and suspended solids requirements. The pond showed rapid acclimatisation to the influent wastewater, with biochemical oxygen demand removal rates during the filling period of around 60 kg ha?1 day?1 and removal efficiencies of ?95% after maturation. The system proved simple to operate. A major design factor is the requirement for storage of net incoming precipitation, which may provide dilution of residual pollutants but requires additional system capacity.<br/
An Investigation of the Use of Bandwidth Criteria for Rotorcraft Handling-Qualities Specifications
The objective of this study was to investigate bandwidth concepts for deriving rotorcraft handling-qualities criteria from data obtained in two simulator experiments conducted at the Aeromechanics Laboratory. The first experiment was an investigation of the effects of helicopter vertical-thrust-response characteristics on handling qualities; the second experiment investigated the effects of helicopter yaw-control-response characteristics. In both experiments, emphasis was on low-speed Nap-of-the-Earth (NOE) tasks
Applications of Image Processing in Viticulture: A Review
The production of high quality grapes for wine making is challenging. Significant progress has been made in the automated prediction of harvest yields from images but the analysis of images to predict the quality of the harvest has yet to be fully addressed. The quality of wine produced depends in part on the quality of the grapes harvested and therefore on the presence of disease in the vineyard. There is potential for automated early detection of disease in grape crops through the development of accurate techniques for image processing. This paper presents a review of current research and highlights some of the key challenges for geo-computation (image processing, computer vision and data mining techniques) to inform the management of vineyards and highlights the key challenges for in-field image capture and analysis. An exploration of potential applications for the knowledge generated by imaging techniques is then presented. This discussion is driven by the current interest in the effect of rapid and dramatic climate change on the production of wine and focuses on how this information might be utilized to inform the design and validation of accurate predictive models
Development and evaluation of an inverse solution technique for studying helicopter maneuverability and agility
An inverse solution technique for determining the maximum maneuvering performance of a helicopter using smooth, pilotlike control inputs is presented. Also described is a pilot simulation experiment performed to investigate the accuracy of the solution resulting from this technique. The maneuverability and agility capability of the helicopter math model was varied by varying the pitch and roll damping, the maximum pitch and roll rate, and the maximum load-factor capability. Three maneuvers were investigated: a 180-deg turn, a longitudinal pop-up, and a lateral jink. The inverse solution technique yielded accurate predictions of pilot-in-the-loop maneuvering performance for two of the three maneuvers
A piloted simulation investigation of the normal load factor and longitudinal thrust required for air-to-air acquisition and tracking
A piloted simulation study was performed by the U.S. Army Aeroflighydynamics Directorate to develop insight into the maneuverability requirements for aggressive helicopter maneuvering tasks such as air-to-air combat. Both a conventional helicopter and a helicopter with auxiliary thrust were examined. The aircraft parameters of interest were the normal and longitudinal load factor envelopes. Of particular interest were the mission performance and handling qualities tradeoffs with the parameters of interest. Two air-to-air acquisition and tracking tasks and a return-to-cover task were performed to assess mission performance. Results indicate that without auxiliary thrust, the ownship normal load factor capability needs to match that of the adversary in order to provide satisfactory handling qualities. Auxiliary thrust provides significant handling qualities advantages and can be substituted to some extent for normal load factor capability. Auxiliary thrust levels as low as 0.2 thrust/weight can provide significant handling qualities advantages
Electronics and Chemistry: Varying Single Molecule Junction Conductance Using Chemical Substituents
We measure the low bias conductance of a series of substituted benzene
diamine molecules while breaking a gold point contact in a solution of the
molecules. Transport through these substituted benzenes is by means of
nonresonant tunneling or superexchange, with the molecular junction conductance
depending on the alignment of the metal Fermi level to the closest molecular
level. Electron-donating substituents, which drive the occupied molecular
orbitals up, increase the junction conductance, while electron-withdrawing
substituents have the opposite effect. Thus for the measured series,
conductance varies inversely with the calculated ionization potential of the
molecules. These results reveal that the occupied states are closest to the
gold Fermi energy, indicating that the tunneling transport through these
molecules is analogous to hole tunneling through an insulating film.Comment: 14 pages, 4 figure
The CEDAR Project
We describe the plans and objectives of the CEDAR project (Combined e-Science
Data Analysis Resource for High Energy Physics) newly funded by the PPARC
e-Science programme in the UK. CEDAR will combine the strengths of the well
established and widely used HEPDATA database of HEP data and the innovative
JetWeb data/Monte Carlo comparison facility, built on the HZTOOL package, and
will exploit developing grid technology. The current status and future plans of
both of these individual sub-projects within the CEDAR framework are described,
showing how they will cohesively provide (a) an extensive archive of Reaction
Data, (b) validation and tuning of Monte Carlo programs against these reaction
data sets, and (c) a validated code repository for a wide range of HEP code
such as parton distribution functions and other calculation codes used by
particle physicists. Once established it is envisaged CEDAR will become an
important Grid tool used by LHC experimentalists in their analyses and may well
serve as a model in other branches of science where there is a need to compare
data and complex simulations.Comment: 4 pages, 4 postscript figures, uses CHEP2004.cls. Presented at
Computing in High-Energy Physics (CHEP'04), Interlaken, Switzerland, 27th
September - 1st October 200
A Comparative Analysis of Opinion Mining and Sentiment Classification in Non-english Languages
In the past decade many opinion mining and sentiment classification studies have been carried out for opinions in English. However, the amount of work done for non-English text opinions is very limited.In this review, we investigate opinion mining and sentiment classification studies in three non-English languages to find the classification methods and the efficiency of each algorithm used in these methods. It is found that most of the research conducted for non-English has followed the methods used in the English language with onlylimited usage of language specific properties, such as morphological variations. The application domains seem to be restricted to particular fields and significantly less research has been conducted in cross domains. Keywords—Natural Language processing, Text mining, Machine Learning
Formation and Evolution of Single Molecule Junctions
We analyze the formation and evolution statistics of single molecule
junctions bonded to gold electrodes using amine, methyl sulfide and dimethyl
phosphine link groups by measuring conductance as a function of junction
elongation. For each link, maximum elongation and formation probability
increase with molecular length, strongly suggesting that processes other than
just metal-molecule bond breakage play a key role in junction evolution under
stress. Density functional theory calculations of adiabatic trajectories show
sequences of atomic-scale changes in junction structure, including shifts in
attachment point, that account for the long conductance plateau lengths
observed.Comment: 10 pages, 4 figures, submitte
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