A new continuous planar fit method for calculating fluxes in complex, forested terrain.

The planar fit method is often recommended for long-term eddy covariance flux measurements since it offers a number of advantages over rotating into streamwise coordinates. For sites over complex, forested terrain a single planar fit may not account for complex variations in slope and canopy cover with wind direction. An alternative to the planar fit method is presented where the tilt angle is fitted as a continuous function of the wind direction. This retains many of the benefits of the planar fit method, while at the same time better representing local variations in tilt with wind direction

Continuous-Wave Cavity Ring-Down for High-Sensitivity Polarimetry and Magnetometry Measurements

We report the development of a novel variant of cavity ring-down polarimetry using a continuous-wave laser operating at 532 nm for highly precise chiroptical activity and magnetometry measurements. The key methodology of the apparatus relies upon the external modulation of the laser frequency at the frequency splitting between non-degenerate left- and right-circularly polarised cavity modes. The method is demonstrated by evaluation of the Verdet constants of crystalline CeF3 and fused silica, in addition to the observation of gas- and solution-phase optical rotations of selected chiral molecules. Specifically, optical rotations of (i) vapours of alpha-pinene and R-(+)-limonene, (ii) mutarotating D-glucose in water, and (iii) acidified L-histidine solutions, are determined. The detection sensitivities for the gas- and solution phase chiral activity measurements are ~30 microdeg and ~120 microdeg over a 30 s detection period per cavity roundtrip pass, respectively. Furthermore, the measured optical rotations for R-(+)-limonene are compared with computations performed using the Turbomole quantum chemistry package. The experimentally observed optically rotatory dispersion of this cyclic monoterpene was thus rationalised via consideration of its room temperature conformer distribution as determined by the aforementioned single-point energy calculations.Comment: 12 pages, 8 figure

Modelling Canopy Flows over Complex Terrain

Recent studies of flow over forested hills have been motivated by a number of important applications including understanding CO22 and other gaseous fluxes over forests in complex terrain, predicting wind damage to trees, and modelling wind energy potential at forested sites. Current modelling studies have focussed almost exclusively on highly idealized, and usually fully forested, hills. Here, we present model results for a site on the Isle of Arran, Scotland with complex terrain and heterogeneous forest canopy. The model uses an explicit representation of the canopy and a 1.5-order turbulence closure for flow within and above the canopy. The validity of the closure scheme is assessed using turbulence data from a field experiment before comparing predictions of the full model with field observations. For near-neutral stability, the results compare well with the observations, showing that such a relatively simple canopy model can accurately reproduce the flow patterns observed over complex terrain and realistic, variable forest cover, while at the same time remaining computationally feasible for real case studies. The model allows closer examination of the flow separation observed over complex forested terrain. Comparisons with model simulations using a roughness length parametrization show significant differences, particularly with respect to flow separation, highlighting the need to explicitly model the forest canopy if detailed predictions of near-surface flow around forests are required

Manufacturing facility for Nylon 6,6

In the case of constructing a Nylon 6,6 manufacturing facility in Calvert City, Kentucky, a continuous process that produces pellets was chosen. This process proved to be safer and more economically attractive than batch processes or processes that produced fibers. This was done by simulating the process in Aspen Plus to determine required reactor volumes, heat duties, and the product composition.The process was found to have a net present value of $61,500,000 and a discounted cash flow rate of return of 27$37,000,000 is required, along with annual operating costs of $2,000,000.Based on the preliminary design, it is suggested that this process should be continued onto the detailed design phase

Is thirty-seven years sufficient for full return of the ant biota following restoration?

Introduction: An assessment of whether rehabilitated mine sites have resulted in natural or novel ecosystems requires monitoring over considerable periods of time or the use of space-for-time substitution (chronosequence) approaches. Methods: To provide an assessment of ecosystem recovery in areas mined for bauxite in 1975, the ant fauna of one area planted with Eucalyptus resinifera, one seeded with mixed native species, one topsoiled but unrestored, and a forest reference was subjected to a ‘long-term’ study by sampling monthly and latterly annually between 1976 and 1989 using pitfall traps. These plots were resampled in 2012. A companion ‘short-term’ chronosequence study was performed in 1979 in 28 bauxite mines of various ages and restored by a range of different methods, plus three forest references. In order to examine the assertion that the observed differences between restored areas and forest references will lessen with time, sampling using comparable methods was repeated in 2012 in seven of the original plots, representing progressive advances in rehabilitation technology: planted pines; planted eastern states eucalypts; planted native eucalypts; planted eucalypts over seeded understorey; and planted eucalypts on fresh, double-stripped topsoil, plus two forest reference sites. Results: Ant and other invertebrate richness in the long-term study was initially superior in the seeded plot, with little difference between the planted and unplanted plots. It was concluded that although composition of the ant fauna had converged on that of the forest over the 14-year period, differences still persisted.The 2012 resampling revealed that ant species richness and composition had deteriorated in the seeded plot, while values in the unplanted plot, which now supported naturally colonised trees and an understorey, had increased. Differences between all rehabilitated plots and forest still persisted. As with the long-term study, the rate of fauna return and the type of ants present in the short-term study plots differed with the method of rehabilitation used, and, in 1979, no plots had converged on the forest in terms of the ant assemblage. By 2012 ant richness increased, and more so with each advance in rehabilitation technology, except for seeding, in which the understorey had collapsed. Double-stripping of topsoil resulted in the greatest improvements in ant species richness, although none of the areas had converged on the forest reference areas in terms of assemblage composition or ant functional group profiles. Furthermore, assemblage composition in the forest had changed over time, possibly due to reductions in rainfall, which further complicates rehabilitation objectives. Conclusions: It is concluded that although rehabilitation can achieve its objective of restoring diversity, the original assemblage has still not been achieved after 37 years, suggesting that a degree of novelty has been introduced into these older-style rehabilitated areas. The company’s current rehabilitation practices reflect multiple advances in their approach, lending optimism that current restoration may achieve something close to the original ecosystem, an outcome that can only be verified by extended studies like the one described here

Gamma-Ray Bursts via the Neutrino Emission from Heated Neutron Stars

A model is proposed for gamma-ray bursts based upon a neutrino burst of about 10^52 ergs lasting a few seconds above a heated collapsing neutron star. This type of thermal neutrino burst is suggested by relativistic hydrodynamic studies of the compression, heating, and collapse of close binary neutron stars as they approach their last stable orbit, but may arise from other sources as well. We present a hydrodynamic simulation of the formation and evolution of the pair plasma associated with such a neutrino burst. This pair plasma leads to the production of ~10^51 - 10^52 ergs in gamma-rays with spectral and temporal properties consistent with observed gamma-ray bursts.Comment: Final version. 30 pages, 10 figures, 6 tables, accepted for publication in The Astrophysical Journa

Evaluation of the changed properties of aquatic animals after dam construction using ecological network analysis

Dam construction results in variations of hydrology, river morphology and habitat and the biota associated with the reservoir change significantly compared to the assemblage before dam construction in order to match these changed environmental conditions. Some attempts so far have been made to ascertain the changed properties of aquatilia due to dam construction. Most of them, however, were focused on perturbances to single factors, such as rearing habitats, reproduction and migration routes, etc. Few have been done on the performance of aquatilia from the whole-ecosystem perspective. Herein, we evaluate the structural properties of aquatic animals and their complex ecological relationships within the ecosystem before and after dam construction based on ecological network analysis. This study provides a feasible way for integral ecosystem evaluation with the application of ecological network analysis to river ecosystem subjected to human disturbance

Intranasal fentanyl versus intravenous morphine in the emergency department treatment of severe painful sickle cell crises in children: study protocol for a randomised controlled trial.

BACKGROUND: Children with sickle cell disease (SCD) frequently and unpredictably present to the emergency department (ED) with pain. The painful event is the hallmark acute clinical manifestation of SCD, characterised by sudden onset and is usually bony in origin. This study aims to establish if 1.5mcg/kg of intranasal fentanyl (INF; administered via a Mucosal Atomiser Device, MAD™) is non-inferior to intravenous morphine 0.1 mg/kg in severe SCD-associated pain. METHODS/DESIGN: This study is a randomised,double-blind, double-dummy active control trial of children (weighing more than 10 kg) between 1 year and 21 years of age with severe painful sickle cell crisis. Severe pain is defined as rated seven or greater on a 0 to 10 age-appropriate numeric pain scale or equivalent. The trial will be conducted in a single tertiary urban paediatric ED in Dublin, Ireland. Each patient will receive a single active agent and a single placebo via the intravenous and intranasal routes. All clinical and research staff, patients and parents will be blinded to the treatment allocation. The primary endpoint is severity of pain scored at 10 min from administration of the study medications. Secondary endpoints include pain severity measured at 0, 5, 15, 20, 30, 60 and 120 min after the administration of analgesia, proportion of patients requiring rescue analgesia and incidence of adverse events. The trial ends at 120 min after the administration of the study drugs. A clinically meaningful difference in validated pain scores has been defined as 13 mm. Setting the permitted threshold to 50% of this limit (6 mm) and assuming both treatments are on average equal, a sample size of 30 patients (15 per group) will provide at least 80% power to demonstrate that INF is non-inferior to IV morphine with a level of significance of 0.05. DISCUSSION: This clinical trial will inform of the role of INF 1.5mcg/kg via MAD in the acute treatment of severe painful sickle cell crisis in children in the ED setting. TRIAL REGISTRATION: Current Controlled Trials ISRCTN67469672 and EudraCT no. 2011-005161-20