The chaetognatha of the Eastropic Expedition, with notes as to their possible value as indicators of hydrographic conditions

ENGLISH: The purpose of this study was to investigate the possibility that certain species of Chaetognatha found in Eastern Tropical Pacific waters can serve as biological indicators of oceanographic features. "Indicator" organisms have been found useful in identifying water types, in tracing the pattern of current systems, and in tracing the origin of moving water masses. To be of use in this type of study, the organisms must be sufficiently abundant to be readily sampled, and easily identified to species; they must also, at least partially, fulfill the additional requisites listed and discussed by Sverdrup, Johnson, and Fleming (1942, pp. 866-867). Among several groups of organisms fulfilling these requirements are the Chaetognatha. Specimens of this group of animals occurred in large numbers in the plankton samples used for this study. The works of Thomson (1947), Fraser (1942), Ritter-Zahony (1911), and Sund (1959) were used for identification. SPANISH: El objetivo de este estudio ha sido el de investigar la posibilidad de utilizar ciertas especies de quetognatos encontrados en el Pacífico Oriental Tropical como indicadoras biológicas de características oceanográficas. Organismos "indicadores" fueron encontrados útiles para la identificación de tipos de agua, el trazado del régimen de los sistemas de corrientes y la determinación del origen de masas de agua en movimiento. Para servir a este tipo de estudios, los organismos deben ser lo suficientemente abundantes como para ser fácilmente muestreados e identificados hasta la especie; también deben satisfacer, por lo menos parcialmente, los requerimientos indicados y discutidos par Sverdrup, Johnson y Fleming (1942, pags. 866-867)

Comment on "Indispensable Finite Time Correlations for Fokker-Planck Equations from Time Series Data"

Comment on "Indispensable Finite Time Correlations for Fokker-Planck Equations from Time Series Data"Comment: 2 pages, 1 figur

(WP 2010-11) The Benefits of Environmental Improvement: Estimates From Space-time Analysis

This paper develops estimates of environmental improvement based on a two-stage hedonic price analysis of the single family housing market in the Puget Sound region of Washington State. The analysis — which focuses specifically on several EPA-designated environmental hazards and involves 226,918 transactions for 177,303 unique properties that took place between January 2001 and September 2009 — involves four steps: (i) ten hedonic price functions are estimated year-by-year, one for each year of the 2000s; (ii) the hedonic estimates are used to compute the marginal implicit price of distance from air release, superfund, and toxic release sites; (iii) the marginal implicit prices, which vary through time, are used to estimate a series of implicit demand functions describing the relationship between the price of distance and the quantity consumed; and, finally (iv) the demand estimates are compared to those obtained in other research and then used evaluate the potential scale of benefits associated with some basic environmental improvement scenarios. Overall, the analysis provides further evidence that it is possible to develop a structural model of implicit demand within a single housing market and suggests that the benefits of environmental improvement are substantial

Analyzing the Function of Cartilage Replacements: A Laboratory Activity to Teach High School Students Chemical and Tissue Engineering Concepts

A cartilage tissue engineering laboratory activity was developed as part of the Exciting Discoveries for Girls in Engineering (EDGE) Summer Camp sponsored by the Women In Engineering Program (WIEP) at Purdue University. Our goal was to increase awareness of chemical engineering and tissue engineering in female high school students through a laboratory activity that incorporated a number of National Research Council learning objectives for science and engineering. This manuscript describes the context of the activity, detailed instructions to perform the activity, and a summary of the feedback. As a result of the activity, participants knew more about the chemical engineering profession and were able to form stronger and more educated opinions about their career interests

A Self-Sufficient Nitrate Groundwater Remediation System: Geobacter Sulfurreducens Microbial Fuel Cell Fed by Hydrogen from a Water Electrolyzer

Nitrate contamination of groundwater is a major problem, especially in farming areas where nitrogen-based fertilizers are used. Geobacter sulfurreducens electrodes were electrochemically evaluated for their ability to reduce nitrate with implications for groundwater remediation. G. sulfurreducens were optimized for nitrate reduction by modifying growth media during subculture. The Geobacter were then cast on Toray carbon paper electrodes and immobilized with pectin. Cyclic voltammetry demonstrated that the electrodes bioelectrocatalytically reduce nitrate with an onset potential of −0.25 V vs. SCE. Amperometry was used to evaluate nitrate concentrations between 0.5 and 270 mM. The limit of detection is 8 mM with a linear range of 20 mM to 160 mM. Evaluation by a Michaelis Menten kinetic model yields a KM of 110 ± 10 mM. The Geobacter sulfurreducens electrodes were incorporated into a nitrate reducing microbial fuel cell which was fed nitrate contaminated water by a peristaltic pump and hydrogen from a proton exchange membrane (PEM)-based water electrolysis cell and yielded a remediation rate of 6 mg/cm2/day

Reaction Mechanism for Oxygen Evolution on RuO2, IrO2, and RuO2@IrO2 Core-Shell Nanocatalysts

Iridium dioxide, IrO2, is second to the most active RuO2 catalyst for the oxygen evolution reaction (OER) in acid, and is used in proton exchange membrane water electrolyzers due to its high durability. To improve the activity of IrO2-based catalysts, we prepared RuO2@IrO2 core-shell nanocatalysts using carbon-supported Ru as the template. At 1.48 V, the OER specific activity of RuO2@IrO2 is threefold that of IrO2. While the activity volcano plots over wide range of materials have been reported, zooming into the top region to clarify the rate limiting steps of most active catalysts is important for further activity enhancement. Here, we verified theory-proposed sequential water dissociation pathway in which the O–O bond forms on a single metal site, not via coupling of two adsorbed intermediates, by fitting measured polarization curves using a kinetic equation with the free energies of adsorption and activation as the parameters. Consistent with theoretical calculations, we show that the OER activities of IrO2 and RuO2@IrO2 are limited by the formation of O adsorbed phase, while the OOH formation on the adsorbed O limits the reaction rate on RuO2

Pathways to Ultra-Low Platinum Group Metal Catalyst Loading in Proton Exchange Membrane Electrolyzers

Hydrogen is one of the world\u27s most important chemicals, with global production of about 50 billion kg/year. Currently, hydrogen is mainly produced from fossil fuels such as natural gas and coal, producing CO2. Water electrolysis is a promising technology for fossil-free, CO2-free hydrogen production. Proton exchange membrane (PEM)-based water electrolysis also eliminates the need for caustic electrolyte, and has been proven at megawatt scale. However, a major cost driver is the electrode, specifically the cost of electrocatalysts used to improve the reaction efficiency, which are applied at high loadings (\u3e3 mg/cm2 total platinum group metal (PGM) content). Core-shell catalysts have shown improved activity for hydrogen production, enabling reduced catalyst loadings, while reactive spray deposition techniques (RSDT) have been demonstrated to enable manufacture of catalyst layers more uniformly and with higher repeatability than existing techniques. Core-shell catalysts have also been fabricated with RSDT for fuel cell electrodes with good performance. Manufacturing and materials need to go hand in hand in order to successfully fabricate electrodes with ultra-low catalyst loadings (\u3c0.5 mg/cm2 total PGM content) without significant variation in performance. This paper describes the potential for these two technologies to work together to enable low cost PEM electrolysis systems

Multipartite Bound Information exists and can be activated

We prove the conjectured existence of Bound Information, a classical analog of bound entanglement, in the multipartite scenario. We give examples of tripartite probability distributions from which it is impossible to extract any kind of secret key, even in the asymptotic regime, although they cannot be created by local operations and public communication. Moreover, we show that bound information can be activated: three honest parties can distill a common secret key from different distributions having bound information. Our results demonstrate that quantum information theory can provide useful insight for solving open problems in classical information theory.Comment: four page

Building a single repository to meet all use cases: a collaboration between institution, researchers and supplier

Repositories have historically focused on a single use case, primarily the capture of traditional (text-based) open access publications, requiring separate solutions for different use cases (e.g. research data). This made capturing the variety of research outputs challenging at the University of Westminster, which engages in practice-based arts research, alongside traditional research. Building on a history of collaboration, Haplo and the University and its research community have built a single, open source repository meeting multiple use cases including text-based and non-text based outputs, portfolios and research data. Made possible through the flexible technical architecture of the Haplo platform, whose underlying technology is based on semantic web principles and meets COAR’s vision for next-generation repositories. Improvements to the repository now enable better capture and display of research outputs across disciplines. Highlights include the development of dynamic portfolios, improved support for non-text based outputs and ongoing engagement with practice-based arts researchers to understand their needs, build workflows, review metadata and build, test and implement a transformed repository

The Benefits of Environmental Improvement: Estimates From Space-time Analysis

This paper develops estimates of environmental improvement based on a two-stage hedonic price analysis of the single family housing market in the Puget Sound region of Washington State. The analysis — which focuses specifically on several EPA-designated environmental hazards and involves 226,918 transactions for 177,303 unique properties that took place between January 2001 and September 2009 — involves four steps: (i) ten hedonic price functions are estimated year-by-year, one for each year of the 2000s; (ii) the hedonic estimates are used to compute the marginal implicit price of distance from air release, superfund, and toxic release sites; (iii) the marginal implicit prices, which vary through time, are used to estimate a series of implicit demand functions describing the relationship between the price of distance and the quantity consumed; and, finally (iv) the demand estimates are compared to those obtained in other research and then used evaluate the potential scale of benefits associated with some basic environmental improvement scenarios. Overall, the analysis provides further evidence that it is possible to develop a structural model of implicit demand within a single housing market and suggests that the benefits of environmental improvement are substantial.Hedonic housing model, benefits, environmental improvement