14,466 research outputs found

    Innovation in the energy sector: advancing or frustrating climate policy goals?

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    The energy sector is well known for the relatively modest level of resource that it devotes to research and development (R&D). However, the incremental pace of energy innovation has speeded up in the last decade as measured by public sector R&D budgets, deployment of alternative technologies and novel institutional arrangements. While much of this effort has been targeted at technologies that promise to reduce carbon dioxide (CO2) emissions, there have also been major innovations that extend the fossil fuel resource base and reduce the cost of extraction. The last decade’s developments can be seen in terms of a challenge to the existing energy paradigm in parallel with a renewed innovative response focusing on conventional fuels and technologies. This paper examines this tension, by exploring the expectations of a variety of organisations in both the public and private sector regarding energy sector developments and by analysing private sector expenditure on energy research and development (R&D) and public sector budgets for energy R&D and demonstration (RD&D). Scenarios and outlook exercises that have been published since 2013 reveal a wide range of beliefs about the future development of the energy system. The contrasting views underpinning the different scenarios are reflected in divergent patterns of R&D investment between the private and public sectors. There appears to be a tension between the drive to transform energy systems, on the part of public bodies, mainly motivated by the need to combat global climate change, and private sector activity, which tends to reinforce and extend existing patterns of energy provision. The paper addresses, but not answer definitively, the key question as to whether technological change is enabling or frustrating ambitious carbon goals

    Nonlinearity and pixel shifting effects in HXRG infrared detectors

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    We study the nonlinearity (NL) in the conversion from charge to voltage in infrared detectors (HXRG) for use in precision astronomy. We present laboratory measurements of the NL function of a H2RG detector and discuss the accuracy to which it would need to be calibrated in future space missions to perform cosmological measurements through the weak gravitational lensing technique. In addition, we present an analysis of archival data from the infrared H1RG detector of the Wide Field Camera 3 in the Hubble Space Telescope that provides evidence consistent with the existence of a sensor effect analogous to the brighter-fatter effect found in Charge-Coupled Devices. We propose a model in which this effect could be understood as shifts in the effective pixel boundaries, and discuss prospects of laboratory measurements to fully characterize this effect.Comment: Accepted for publication in the Journal of Instrumentation (JINST). Part of "Precision Astronomy with Fully Depleted CCDs" (Dec 1-2, 2016), Brookhaven National Laboratory, Upton, NY, US

    Applications of the magneto-optical filter to stellar pulsation measurements

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    A proposed method of employing the Cacciani magneto-optical filter (MOF) for stellar seismology studies is described. The method relies on the fact that the separation of the filter bandpasses in the MOF can be changed by varying the level of input power to the filter cells. With the use of a simple servosystem the bandpass of a MOF can be tuned to compensate for the changes in the radial velocity of a star introduced by the orbital motion of the Earth. Such a tuned filter can then be used to record intensity fluctuations through the MOF bandpass over an extended period of time for each given star. Also, the use of a two cell version of the MOF makes it possible to alternately chop between the bandpass located in the stellar line wing and a second bandpass located in the stellar continuum. Rapid interchange between the two channels makes it possible for atmospheric-introduced noise to be removed from the time series

    A Study of Flow Separation in Transonic Flow Using Inviscid and Viscous Computational Fluid Dynamics (CFD) Schemes

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    A comparison of flow separation in transonic flows is made using various computational schemes which solve the Euler and the Navier-Stokes equations of fluid mechanics. The flows examined are computed using several simple two-dimensional configurations including a backward facing step and a bump in a channel. Comparison of the results obtained using shock fitting and flux vector splitting methods are presented and the results obtained using the Euler codes are compared to results on the same configurations using a code which solves the Navier-Stokes equations

    Tamm-Horsfall glycoprotein binds IgG with high affinity

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    Tamm-Horsfall glycoprotein binds IgG with high affinity. Tamm-Horsfall protein (THP), a monomelic glycoprotein (Mr 80 to 100 kDa), is produced by the mammalian kidney's thick ascending limb of Henle cells and excreted into the urine. The function of THP is uncertain. Here we report that a high molecular weight contaminant in sheep THP (sTHP) preparations was identified as sheep IgG by its positive reaction with donkey anti-sheep IgG antibody and with protein G. To answer the question of whether sTHP and sheep IgG co-purified because of a physical interaction between the two proteins, an enzyme-linked immunosorbent assay (ELISA) using immobilized sTHP and soluble sheep IgG was performed. Analysis of the ELISA data identified the presence of two sets of binding sites: a high affinity site (Kd 10-12 to 10-13 M) and a lower affinity site (Kd 10-10 to 10-11 M). The ELISA detected a similar high affinity interaction between human THP (hTHP) and human IgG. The binding of sheep IgG to immobilized sTHP was inhibited by soluble sTHP. These observations suggest an additional factor to be considered in studies addressing THP's potential immuno-regulatory function

    A method for the estimation of p-mode parameters from averaged solar oscillation power spectra

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    A new fitting methodology is presented which is equally well suited for the estimation of low-, medium-, and high-degree mode parameters from mm-averaged solar oscillation power spectra of widely differing spectral resolution. This method, which we call the "Windowed, MuLTiple-Peak, averaged spectrum", or WMLTP Method, constructs a theoretical profile by convolving the weighted sum of the profiles of the modes appearing in the fitting box with the power spectrum of the window function of the observing run using weights from a leakage matrix that takes into account both observational and physical effects, such as the distortion of modes by solar latitudinal differential rotation. We demonstrate that the WMLTP Method makes substantial improvements in the inferences of the properties of the solar oscillations in comparison with a previous method that employed a single profile to represent each spectral peak. We also present an inversion for the internal solar structure which is based upon 6,366 modes that we have computed using the WMLTP method on the 66-day long 2010 SOHO/MDI Dynamics Run. To improve both the numerical stability and reliability of the inversion we developed a new procedure for the identification and correction of outliers in a frequency data set. We present evidence for a pronounced departure of the sound speed in the outer half of the solar convection zone and in the subsurface shear layer from the radial sound speed profile contained in Model~S of Christensen-Dalsgaard and his collaborators that existed in the rising phase of Solar Cycle~24 during mid-2010

    The 1984 solar oscillation program of the Mount Wilson 60-foot tower

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    The instrumentation, data, and preliminary results from the summer, 1984, solar oscillation observing program which was carried out using the 60-foot tower telescope of the Mt. Wilson Observatory are described. This program was carried out with a dedicated solar oscillation observing system and obtained full-disk Dopplergrams every 40 seconds for up to 11 hours per day. Between June and September, 1984, observations were obtained with a Na magneto-optical filter on 90 different days. The data analysis has progressed to the point that spherical harmonic filter functions were employed to generate a few one-dimensional power spectra from a single day's observations

    Tackling concentrated worklessness: integrating governance and policy across and within spatial scales

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    Spatial concentrations of worklessness remained a key characteristic of labour markets in advanced industrial economies, even during the period of decline in aggregate levels of unemployment and economic inactivity evident from the late 1990s to the economic downturn in 2008. The failure of certain localities to benefit from wider improvements in regional and national labour markets points to a lack of effectiveness in adopted policy approaches, not least in relation to the governance arrangements and policy delivery mechanisms that seek to integrate residents of deprived areas into wider local labour markets. Through analysis of practice in the British context, we explore the difficulties of integrating economic and social policy agendas within and across spatial scales to tackle problems of concentrated worklessness. We present analysis of a number of selected case studies aimed at reducing localised worklessness and identify the possibilities and constraints for effective action given existing governance arrangements and policy priorities to promote economic competitiveness and inclusion
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