The value of a desk study for building a national river obstacle inventory

This study evaluates two desk‐based approaches for building an inventory of man‐made river obstacles. The creation of a river obstacle inventory is a vital first step in developing a prioritization process for obstacle removal and/or modification. In this study, a desktop geographical information system analysis of two rivers and their tributary network was undertaken, using two different approaches. The first involved analysing historical maps, satellite imagery, and Ordnance Survey Ireland Discovery Series maps and producing a geo‐referenced layer of all the potential river obstacles. The second involved developing a geo‐referenced layer of potential river obstacles based on the intersections between elements of the transport network (roads and railways) and river systems. To determine the effectiveness of the desk studies, the located obstacles were cross‐referenced with actual obstacles verified through a field survey. The desk studies identified several thousand potential obstacles. The study utilizing a range of maps consistently located a greater number of actual obstacles than the desk study based on intersections between the transport and river networks. The results indicate that desk‐based research offers an efficient and effective method for locating river obstacles and can guide subsequent field surveys aimed at confirming the presence of obstacles. This is particularly useful for eliminating from study large stretches of rivers that would otherwise need to be walked to confirm the presence, or otherwise, of potential river obstacles. In this regard, desk‐based exercises can offer opportunities to save on both time and cost in larger river assessments.     

Low-dimensional, hinged bar-code metal oxide layers and free-standing, ordered organic nanostructures from turbostratic vanadium oxide

Both low-dimensional bar-coded metal oxide layers, which exhibit molecular hinging, and free-standing organic nanostructures can be obtained from unique nanofibers of vanadium oxide (VO(x)). The nanofibers are successfully synthesized by a simple chemical route using an ethanolic solution of vanadium pentoxide xerogel and dodecanethiol resulting in a double bilayered laminar turbostratic structure. The formation of vanadium oxide nanofibers is observed after hydrothermal treatment of the thiol-intercalated xerogel, resulting in typical lengths in the range 2-6 microm and widths of about 50-500 nm. We observe concomitant hinging of the flexible nanofiber lamina at periodic hinge points in the final product on both the nanoscale and molecular level. Bar-coded nanofibers comprise alternating segments of organic-inorganic (thiols-VO(x)) material and are amenable to segmented, localized metal nanoparticle docking. Under certain conditions free-standing bilayered organic nanostructures are realized.     

The predominance of economic development in the support for large-scale wind farms in the U.S. Great Plains

Wind energy is one of the fastest growing sources of power generation in the world. While general public and political support for wind energy is often high, siting wind farms frequently raises concerns in local communities, and individual projects often fail because of effective public opposition. This paper presents the results of a postal and online survey questionnaire that explores public perceptions of wind energy in two of the most important states for wind development, Texas and Iowa. The goal is a better understanding of public reactions to large-scale wind developments as a prerequisite of more widespread use of renewable energy resources. We found a high level of public support for wind energy, with more than two-thirds of respondents being in favor of building more wind farms either in their community or within the U.S. as a whole. Given that the majority of respondents had a very high level of concern for the general environment, we also found that almost two-thirds of respondents counter-intuitively indicated that producing electricity using fossil fuels is not detrimental to the environment, and that they had little concern for global climate change. Our results suggest that arguing for more renewable sources of energy based on reducing our carbon footprint is less persuasive in these communities than simply approaching it from the perspective of wind being a clean and safe source of energy. More than two-thirds of respondents felt their county had benefited economically from the wind farms and that they were a source of job creation in the county. Support for wind power in these communities is associated far more with socioeconomic factors than foundational aesthetic or moral values, with wind farms perceived as the vehicle that will reverse economic decline.     

Electroanalytical behavior of poly-L-lysine dendrigrafts at the interface between two immiscible electrolyte solutions

In this work, the electrochemical behavior of nonredox-active poly-L-lysine dendrigraft molecules of four different generations was investigated at the interface between two immiscible electrolyte solutions (ITIES). The influence of the dendrigraft generation on the electrochemical response, sensitivity of the calibration curves, and limit of detection was studied. Cyclic voltammetry at the ITIES revealed that the sensitivity increased (1840 to 25?800 nA μM(-1)) and the limit of detection decreased (11.10 to 0.65 μM) as the dendrigraft generation increased from generation G2 through to generation G5, respectively. The results are compared to those for protein voltammetry at the ITIES. Our studies suggest that the sensitivity expected for a synthetic ionized macromolecule can be predicted on the basis of its net charge and its diffusion coefficient. However, electrochemistry at the ITIES demonstrates a greater sensitivity toward proteins, which is attributed to their tertiary structure.     

Public attitudes of wind energy in Texas: Local communities in close proximity to wind farms and their effect on decision-making

Wind energy is now recognized as an important energy resource throughout the world. Within the United States, the state of Texas currently has the largest wind energy capacity with 8797 total megawatts and an additional 660 MW under construction. With this rapid growth, it is important to achieve a better understanding of how wind energy is being perceived by the public.     

State and local economic impacts from wind energy projects: Texas case study

This paper uses the Jobs and Economic Development Impacts (JEDI) model to estimate economic impacts from 1398 MW of wind power development in four counties in west Texas. Project-specific impacts are estimated at the local level (i.e., within a 100-mile radius around the wind farms) and at the state level. The primary economic policy question addressed is how investment in wind energy affects the state and local communities where the wind farms are built. During the four-year construction phase approximately 4100 FTE (full time equivalents) jobs were supported with turbine and supply chain impacts accounting for 58% of all jobs generated. Total lifetime economic activity to the state from the projects equated to more than $1.8 billion, or $1.3 million per MW of installed capacity. The total economic activity to the local communities was also substantial, equating to nearly $730 million over the assumed 20-year life cycle of the farms, or $0.52 million per MW of installed capacity. Given the current level of impacts observed, and the potential for increased impacts via greater utilization of instate manufacturing capacity and the development of trained wind industry specific laborers, Texas appears to be well positioned to see increasing impacts from continued wind development.     

Direct Comparison between Five Different Microchannels,Part 2: Experimental Description and Flow Friction Measurement

Abstract

Part one of this paper ^[1] Eason, C., Dalton, T., O'Mathúna, C., Slattery, O. and Davies, M. 2005. Direct Comparison between Five Different Microchannels, Part 1: Channel Manufacture and Measurement. Heat Transfer Engineering Journal, vol. 26(no. 3): pp. 00–00.  [Google Scholar] investigates the manufacture of five types of microchannels produced by wet and dry etching in silicon and precision mechanical sawing in silicon and thermoset plastic. This paper describes the experimental equipment and methods used to measure the pressure flow characteristics of the manufactured channels. A test system has been built to test each sample using the same inlet and outlet manifolds, pressure tappings, pumping system, and instrumentation. The measured pressure flow behavior was compared with theoretical values calculated from macroscale theory. Error analysis was carried out in order to determine the overall accuracy of the experimental work and determine the significance of any experimental deviation from theoretical values. An area compensation term is introduced to account for the difference in cross-section between the measured actual channels and the rectangles/trapeziums that share their overall dimensions.     

Spatial Variability in Secondary Metabolites of the Indo-Pacific Sponge Stylissa massa

Chemical diversity represents a measure of selective pressures acting on genotypic variability. In order to understand patterns of chemical ecology and biodiversity in the environment, it is necessary to enhance our knowledge of chemical diversity within and among species. Many sponges produce variable levels of secondary metabolites in response to diverse biotic and abiotic environmental factors. This study evaluated intra-specific variability in secondary metabolites in the common Indo-Pacific sponge Stylissa massa over various geographic scales, from local to ocean basin. Several major metabolites were quantified in extracts from sponges collected in American Samoa, Pohnpei, Saipan, and at several sites and depths in Guam. Concentrations of several of these metabolites varied geographically across the Pacific basin, with American Samoa and Pohnpei exhibiting the greatest differences, and Guam and Saipan more similar to each other. There were also significant differences in concentrations among different sites and depths within Guam. The crude extract of S. massa exhibited feeding deterrence against the omnivorous pufferfish Canthigaster solandri at natural concentrations, however, none of the isolated compounds was deterrent at the maximum natural concentrations observed, nor were mixtures of these compounds, thus emphasizing the need for bioassay-guided isolation to characterize specific chemical defenses. Antibacterial activity against a panel of ecologically relevant pathogens was minimal. Depth transplants, predator exclusion, and UV protection experiments were performed, but although temporal variability in compound concentrations was observed, there was no evidence that secondary metabolite concentration in S. massa was induced by any of these factors. Although the reasons behind the variability observed in the chemical constituents of S. massa are still in question, all sponges are not created equal from a chemical standpoint, and these studies provide further insights into patterns of chemical diversity within S. massa.     

Effective hydrodynamic shaping of sample streams in a microfluidic parallel-plate flow-assay device: matching whole blood dynamic viscosity

We report the development of an aqueous buffer system tailored to the fluidic and hemodynamic requirements of our recently reported microfluidic platelet dynamic assay device, which uses hydrodynamic focusing to "shape" a blood sample into a thin flowing layer adjacent to its protein-functionalized surface. By matching the dynamic viscosity of whole blood (3.13 ± 0.08 mPa·s, from healthy donors), the selected buffer minimizes interfacial fluid mixing and better controls shear rate within the device, permitting platelet/protein-surface interaction assays with as little as 50 μL of whole blood. Buffers containing the viscosity-enhancing components bovine serum albumin (BSA), gelofusine/glycine, or histopaque (Ficoll gradient solution) were found not to activate platelets when incubated with blood at concentrations up to 50%, as assessed by flow cytometry quantitation of P-selectin expression and αIIbβ (3) activation. In contrast, glycerol-based buffer activated platelets (two-fold increase in P-selectin levels) at concentrations as low as 10% by volume. BSA- and gelofusine/glycine-based buffers were problematic in preparation and use, and therefore, were not used beyond initial characterization. The histopaque solution selected as the best choice for flow studies stabilizes sample contact with the device's thrombogenic surface, does not activate platelets, and does not interfere with the action of agonists added to deliberately activate platelets.