2,722 research outputs found

    Running to Stand Still: Challenges Economists Face with Imperfect Data

    Get PDF
    Some suggest that land application of phosphorus rich poultry litter has negatively affected area waters' recreational value. However, key data are unavailable to conduct thorough economic analysis to aid in policy development. This paper examines the challenges associated with using limited economic analyses to construct policy to address this situation.Research Methods/ Statistical Methods,

    Mediating Social Anxiety and Disordered Eating: The Role of Expressive Suppression

    Get PDF
    Social anxiety and disordered eating frequently overlap, and evidence suggests that emotional suppression may be an important mediating factor. The present study examines the relationships among social anxiety, emotional suppression, and disordered eating in a nonclinical sample of 160 undergraduate women. Participants completed self-report measures for social anxiety, disordered eating, expressive suppression, depression, and negative affect. Results from mediation analyses indicate that the relationship between social anxiety and disordered eating is fully mediated by expressive suppression. Findings are consistent with a displacement theory in which unexpressed negative affect is shifted toward the body, thereby promoting symptoms of disordered eating

    Method for carbon dioxide splitting

    Get PDF
    A method for splitting carbon dioxide via a two-step metal oxide thermochemical cycle by heating a metal oxide compound selected from an iron oxide material of the general formula AxFe3-xO4, where 0≦x≦1 and A is a metal selected from Mg, Cu, Zn, Ni, Co, and Mn, or a ceria oxide compound of the general formula MaCebOc, where

    Constraints in Quantum Geometrodynamics

    Get PDF
    We compare different treatments of the constraints in canonical quantum gravity. The standard approach on the superspace of 3--geometries treats the constraints as the sole carriers of the dynamic content of the theory, thus rendering the traditional dynamical equations obsolete. Quantization of the constraints in both the Dirac and ADM square root Hamiltonian approaches leads to the well known problems of time evolution. These problems of time are of both an interpretational and technical nature. In contrast, the geometrodynamic quantization procedure on the superspace of the true dynamical variables separates the issues of quantization from the enforcement of the constraints. The resulting theory takes into account states that are off-shell with respect to the constraints, and thus avoids the problems of time. We develop, for the first time, the geometrodynamic quantization formalism in a general setting and show that it retains all essential features previously illustrated in the context of homogeneous cosmologies.Comment: 36 pages, no figures, submitted to IJMPA, Rewording, Fixed Typo

    Hybrid metal oxide cycle water splitting

    Get PDF
    Hybrid thermochemical water splitting cycles are provided in which thermally reduced metal oxides particles are used to displace some but not all of the electrical requirements in a water splitting electrolytic cell. In these hybrid cycles, the thermal reduction temperature is significantly reduced compared to two-step metal-oxide thermochemical cycles in which only thermal energy is required to produce hydrogen from water. Also, unlike the conventional higher temperature cycles where the reduction step must be carried out under reduced oxygen pressure, the reduction step in the proposed hybrid cycles can be carried out in air, allowing for thermal input by a solar power tower with a windowless, cavity receiver

    Hybrid metal oxide cycle water splitting

    Get PDF
    Hybrid thermochemical water splitting systems are disclosed that thermally reduces metal oxides particles to displace some but not all of the electrical requirements in a water splitting electrolytic cell. In these hybrid systems, the thermal reduction temperature is significantly reduced compared to two-step metal-oxide thermochemical cycles in which only thermal energy is required to produce hydrogen from water. Also, unlike conventional higher temperature systems where the reduction step must be carried out under reduced oxygen pressure, the reduction step in the proposed hybrid systems can be carried out in air, allowing for thermal input by a solar power tower with a windowless, cavity receiver

    Integrating scientific and local knowledge to inform risk-based management approaches for climate adaptation

    Get PDF
    AbstractRisk-based management approaches to climate adaptation depend on the assessment of potential threats, and their causes, vulnerabilities, and impacts. The refinement of these approaches relies heavily on detailed local knowledge of places and priorities, such as infrastructure, governance structures, and socio-economic conditions, as well as scientific understanding of climate projections and trends. Developing processes that integrate local and scientific knowledge will enhance the value of risk-based management approaches, facilitate group learning and planning processes, and support the capacity of communities to prepare for change. This study uses the Vulnerability, Consequences, and Adaptation Planning Scenarios (VCAPS) process, a form of analytic-deliberative dialogue, and the conceptual frameworks of hazard management and climate vulnerability, to integrate scientific and local knowledge. We worked with local government staff in an urbanized barrier island community (Sullivan’s Island, South Carolina) to consider climate risks, impacts, and adaptation challenges associated with sea level rise and wastewater and stormwater management. The findings discuss how the process increases understanding of town officials’ views of risks and climate change impacts to barrier islands, the management actions being considered to address of the multiple impacts of concern, and the local tradeoffs and challenges in adaptation planning. We also comment on group learning and specific adaptation tasks, strategies, and needs identified

    TIPS: a system for automated image-based phenotyping of maize tassels

    Get PDF
    Abstract Background The maize male inflorescence (tassel) produces pollen necessary for reproduction and commercial grain production of maize. The size of the tassel has been linked to factors affecting grain yield, so understanding the genetic control of tassel architecture is an important goal. Tassels are fragile and deform easily after removal from the plant, necessitating rapid measurement of any shape characteristics that cannot be retained during storage. Some morphological characteristics of tassels such as curvature and compactness are difficult to quantify using traditional methods, but can be quantified by image-based phenotyping tools. These constraints necessitate the development of an efficient method for capturing natural-state tassel morphology and complementary automated analytical methods that can quickly and reproducibly quantify traits of interest such as height, spread, and branch number. Results This paper presents the Tassel Image-based Phenotyping System (TIPS), which provides a platform for imaging tassels in the field immediately following removal from the plant. TIPS consists of custom methods that can quantify morphological traits from profile images of freshly harvested tassels acquired with a standard digital camera in a field-deployable light shelter. Correlations between manually measured traits (tassel weight, tassel length, spike length, and branch number) and image-based measurements ranged from 0.66 to 0.89. Additional tassel characteristics quantified by image analysis included some that cannot be quantified manually, such as curvature, compactness, fractal dimension, skeleton length, and perimeter. TIPS was used to measure tassel phenotypes of 3530 individual tassels from 749 diverse inbred lines that represent the diversity of tassel morphology found in modern breeding and academic research programs. Repeatability ranged from 0.85 to 0.92 for manually measured phenotypes, from 0.77 to 0.83 for the same traits measured by image-based methods, and from 0.49 to 0.81 for traits that can only be measured by image analysis. Conclusions TIPS allows morphological features of maize tassels to be quantified automatically, with minimal disturbance, at a scale that supports population-level studies. TIPS is expected to accelerate the discovery of associations between genetic loci and tassel morphology characteristics, and can be applied to maize breeding programs to increase productivity with lower resource commitment

    Building bridges: a critical analysis of university and industry collaboration to improve diverse access to elite professions

    Get PDF
    This article explores how both universities and industry can work together to improve access to graduate opportunities for disadvantaged students. Focusing on an initiative which involved students from a post-1992 university experiencing London's legal sector, this article analyses the factors which contribute to students' perceptions of their increased self-efficacy as a result of participating in the event. Utilising a focus group methodology, the article critically examines the barriers that can be imposed by students' socio-economic backgrounds which may prevent such initiatives from having a meaningful impact on diverse recruitment and fair access to higher professional occupations. Focusing in on 2 particular strands of the Triple Helix Model, this article also makes some recommendations as to how more effective bridges can be built between universities and industry to improve access for all to the elite professions

    The Polarization of the Cosmic Microwave Background Due to Primordial Gravitational Waves

    Full text link
    We review current observational constraints on the polarization of the Cosmic Microwave Background (CMB), with a particular emphasis on detecting the signature of primordial gravitational waves. We present an analytic solution to the Polanarev approximation for CMB polarization produced by primordial gravitational waves. This simplifies the calculation of the curl, or B-mode power spectrum associated with gravitational waves during the epoch of cosmological inflation. We compare our analytic method to existing numerical methods and also make predictions for the sensitivity of upcoming CMB polarization observations to the inflationary gravitational wave background. We show that upcoming experiments should be able either detect the relic gravitational wave background or completely rule out whole classes of inflationary models.Comment: 25 pages, 4 figures, review published in IJMP
    • …
    corecore