Wind resource in the urban environment

Renewable energy technologies, such as windturbines, have to be considered for new buildingover 1000m2 under the Energy Performance ofBuildings Directive (2002). Accurate assessment ofthe wind resource is a key component in the successof a wind installation. Designers, planners andarchitects also need wind data from urban areas tosupport low-energy building design, naturalventilation, air quality, pollution control, insuranceand wind engineering. Over the last six years instrumentation has been installed at the DublinInstitute of Technology (DIT) in two separate locationsto monitor the wind. The data has shown that thewind resource will vary quite considerably on a givensite and this is due to local variations in topography,and other factors associated with wind andturbulence in the built environment. Difficultieswere encountered in measuring the wind andturbulence on site. IEC 61400-12-1: 2005 states that“... analytical tools (anemometers presently available)offer little help in identifying the impact of thesevariables, and experimental methods encounterequally-serious difficulties.” The practical experienceof measuring wind in the urban environmentinformed the development of a prototypeanemometer that may be capable of digitallymapping accurate real-time three-dimensional dataon wind speed, wind direction and, uniquely in thefield of wind instrumentation, wind turbulence

On-line, Single Point Standardization Analysis for Measuring Hydrogen Production by Transition Metal Catalyst in Light Driven Synthesis

An automated SPS-GC-TCD has been optimized to determine hydrogen production in light driven synthesis reactions while operating in real time and being capable of multiple analysis per hour. The SPS-GC-TCD method incorporates two sample loops on a valve, one for a check standard and the other for the sample, eliminating many sources of error associated with gas sampling and allowing for automated calibration during each analytical run. Gas samples containing hydrogen in a percent volume concentration were analyzed and method detection limit (MDL), accuracy and precision measurments have been conducted. Using single point standardization, proof of concept results for the analyzer gave an MDL of 0.73% (v/v%), accuracy of 100%, and precision of 3.7% for hydrogen. These values were comparable to results obtained by a much more intensive 5-point external calibration. The automated system gave extreme improvements in reproducibility, and a detection limit of 0.25% and precision of 1.7%

Geospatial Characterization of Fluvial Wood in a Midwestern, Semi-Confined Alluvial River System

Large woody debris (LWD) has become universally recognized as a key component of the ecological and geomorphological function of river systems. The use of LWD as a restoration tool in Midwestern river systems is widespread, yet LWD-related restoration strategies are primarily supported by research from the Pacific Northwest or other physiographically similar regions. The purpose of this dissertation research was to investigate the longitudinal arrangement patterns of LWD and to characterize LWD and its effects on sediment storage within the Big River, a Midwestern river system located in the Missouri Ozarks. I adopted a multi-scale approach to analyze (1) large-scale longitudinal patterns of LWD arrangement, (2) potential geomorphic and riparian control mechanisms of LWD arrangement, (3) reach-scale characteristics of LWD, and (4) reach-scale relationships between LWD and sediment storage. The results of this research demonstrate that the longitudinal arrangement of LWD along the Big River is not random. Along many segments of the Big River, LWD density is spatially periodic. Periodicity showed a strong positive association with gravel bar spacing and meander wavelength, although there were insufficient data to statistically confirm the relationship. Furthermore, reaches that exhibited strong periodicity yielded stronger relationships between LWD density and the geomorphic/riparian independent variables tested. Analyses consistently identified valley width and sinuosity as being associated with LWD density. Wood loads in the Big River were low relative to those in streams located in the commonly studied Pacific Northwest, and high relative to other low- to mid- gradient river systems. In general, wood piece size was large relative to those of other river systems, and may suggest, along with field observations, that bank erosion is the dominant wood recruitment mechanism. Furthermore, the contribution of LWD to reach-scale sediment storage was low relative to other in-channel sediment stores. These results provide a baseline characterization of LWD for a semi-confined-meandering river system. This will help provide a directive for LWD-related management in stream restoration ventures in semi-confined meandering river systems and provide a first step toward developing more accurate models of LWD dynamics

Anomalous scattering of light on Triton

Researchers report here the discovery of an isolated region of anomalously forward scattering materials on the surface of Triton. The researchers' best-fit Hapke parameters indicate that regolith particles in the anomalous scattering region are not only less backward scattering, but also slightly lower in single scattering albedo than average materials on Triton's surface. While it might be possible to account for such differences in terms of differences in particle size and transparency, it is also possible that the anomalous region is compositionally distinct from other terrains. It is noteworthy that, for the anomalous region, there exists a distinctively strong spatial correlation between the photometric ratios at different phase angles, and that, relative to other terrains, the anomalous region reddens at a different rate with increasing phase angle

An approach to CMG steering using feedback linearization

This paper presents an approach for controlling spacecraft equipped with control moment gyroscopes. A technique from feedback linearization theory is used to transform the original nonlinear problem to an equivalent linear form without approximating assumptions. In this form, the spacecraft dynamics appear linearly, and are decoupled from redundancy in the system of gyroscopes. A general approach to distributing control effort among the available actuators is described which includes provisions for redistribution of rotors, explicit bounds in gimbal rates, and guaranteed operation at or near singular configurations. A particular algorithm is developed for systems of double-gimbal devices, and demonstrated in two examples for which existing approaches fail to give adequate performance

The Yrast Spectra of Weakly Interacting Bose-Einstein Condensates

The low energy quantal spectrum is considered as a function of the total angular momentum for a system of weakly interacting bosonic atoms held together by an external isotropic harmonic potential. It is found that besides the usual condensation into the lowest state of the oscillator, the system exhibits two additional kinds of condensate and associated thermodynamic phase transitions. These new phenomena are derived from the degrees of freedom of "partition space" which describes the multitude of different ways in which the angular momentum can be distributed among the atoms while remaining all the time in the lowest state of the oscillator

The role of delamanid in the treatment of drug-resistant tuberculosis

Tuberculosis (TB) remains a significant cause of death worldwide, and emergence of drug-resistant TB requires lengthy treatments with toxic drugs that are less effective than their first-line equivalents. New treatments are urgently needed. Delamanid, previously OPC-67863, is a novel drug of the dihydro-nitroimidazole class with potent anti-TB activity and great promise to be effective in the treatment of drug-resistant TB. This review examines the preclinical and clinical development of delamanid, reviews current guidance on its use and evaluates the opportunities and challenges for its future role in TB management.Publisher PDFPeer reviewe