240 research outputs found

    Optimized Wide-Field Survey Telescope Using Adaptive Optics

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    We describe a new technique for ground-based telescopic surveys that can deliver a wide field of view and nearly diffraction-limited image quality. We discuss a very low cost, yet sensitive and efficient, concept to perform science previously considered from space. For ground-based telescopes with small D/r0 (aperture over turbulence cell diameter) a significant improvement in point source sensitivity can be achieved with tip-tilt correction only. However, the solid angle over which image motion is constant is typically less than an arcminute. To achieve tip-tilt correction over a larger field we propose to use a high order adaptive optics system where one pupil sub-aperture now corresponds to one isokinetic patch. The high order deformable mirror is conjugated to an atmospheric height where the tip-tilt "beams" separate from each other while the overall tip-tilt can be taken out with a tip-tilt secondary mirror conjugated to low height. One source per square arcminute with V ≤ 18^m is required for the determination of the image motion, allowing a sky coverage of more than 50%. The improvement over seeing limited observations is maximal at D/r_0 ≈ 4 with a S/N improvement of a factor of four. An inexpensive system with 500 actuators can correct a field of view of 0.4 × 0.4 deg^2. It is thus well-suited for searches of point sources, e.g. high-z SN Ia or other transient phenomena

    A Literature Review of Swine Heat Production

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    Current ASAE standards of heat and moisture production (HP, MP) for swine are primarily based on data collected nearly four decades ago. Feedstuffs, management practices, growth rate, and lean percentage of swine have changed HP and MP considerably in that time period. Literature data shows that lean percent increased 1.55% in the last 10 years, resulting in an increase in HP by approximately 15%. Data were compiled into two categories: prior to 1988, and 1988 to present. Analysis of this data revealed that HP increased 12.4% to 35.3% between the two categories, with the largest differences occurring at higher temperatures. The results also revealed lack of HP and MP data for greater than 90 kg pigs. The HP and MP standards for design of swine housing systems should be updated

    Perioperative Pleural Drainage in Liver Transplantation: A Retrospective Analysis from a High-Volume Liver Transplant Center

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    BACKGROUND Pleural effusions represent a common complication after liver transplantation (LT) and chest drain (CD) placement is frequently necessary. MATERIAL AND METHODS In this retrospective cohort study, adult LT recipients between 2009 and 2016 were analyzed for pleural effusion formation and its treatment within the first 10 postoperative days. The aim of the study was to compare different settings of CD placement with regard to intervention-related complications. RESULTS Overall, 597 patients met the inclusion criteria, of which 361 patients (60.5%) received at least 1 CD within the study period. Patients with a MELD >25 were more frequently affected (75.7% versus 56.0%, P<0.001). Typically, CDs were placed in the intensive care unit (ICU) (66.8%) or in the operating room (14.1% during LT, 11.5% in the context of reoperations). In total, 97.0% of the patients received a right-sided CD, presumably caused by local irritations. Approximately one-third (35.4%) of ICU-patients required pre-interventional optimization of coagulation. Of the 361 patients receiving a CD, 15 patients (4.2%) suffered a post-interventional hemorrhage and 6 patients (1.4%) had a pneumothorax requiring further treatment. Less complications were observed when the CD was performed in the operating room compared to the ICU: 1 out 127 patients (0.8%) versus 20 out of 332 patients (6.0%); P=0.016. CONCLUSIONS CD placement occurring in the operating room was associated with fewer complications in contrast to placement occurring in the ICU. Planned CD placement in the course of surgery might be favorable in high-risk patients

    Optimized Wide-Field Survey Telescope Using Adaptive Optics

    Get PDF
    We describe a new technique for ground-based telescopic surveys that can deliver a wide field of view and nearly diffraction-limited image quality. We discuss a very low cost, yet sensitive and efficient, concept to perform science previously considered from space. For ground-based telescopes with small D/r0 (aperture over turbulence cell diameter) a significant improvement in point source sensitivity can be achieved with tip-tilt correction only. However, the solid angle over which image motion is constant is typically less than an arcminute. To achieve tip-tilt correction over a larger field we propose to use a high order adaptive optics system where one pupil sub-aperture now corresponds to one isokinetic patch. The high order deformable mirror is conjugated to an atmospheric height where the tip-tilt "beams" separate from each other while the overall tip-tilt can be taken out with a tip-tilt secondary mirror conjugated to low height. One source per square arcminute with V ≤ 18^m is required for the determination of the image motion, allowing a sky coverage of more than 50%. The improvement over seeing limited observations is maximal at D/r_0 ≈ 4 with a S/N improvement of a factor of four. An inexpensive system with 500 actuators can correct a field of view of 0.4 × 0.4 deg^2. It is thus well-suited for searches of point sources, e.g. high-z SN Ia or other transient phenomena

    Aggressive tax planning indicators; Final Report

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    The aim of this study is to provide economic evidence of the relevance of aggressive tax planning (ATP) structures for all EU Member States. The study relies on economic indicators available at macro-level and on indicators derived from firm-level data. The objective is indeed to look at the relevance of ATP for all Member States through these two complementary angles. For each indicator, the study identifies outliers based on a consistent methodology. None of the indicators provides per se an irrefutable causality towards aggressive tax planning. However, considered together, the set of indicators shall be seen as a "body of evidence". While there are some data limitation, the study provides a broad picture of which Member States appear to be exposed to ATP structures, and how it impacts on their tax base (erosion or increase). The discussed ATP structures can be grouped into three main channels: i) ATP via interest payments, ii) ATP via royalty payments and iii) ATP via strategic transfer pricing. In addition to general indicators assessing the overall exposure to ATP, we also derive specific indicators for each of the ATP channels. In combination, these indicators allow to classify entities within multinational enterprises (MNEs) into three types: i) target entities, where the tax base is reduced ii) the lower tax entities where the tax base is increased but taxed at a lower rate, and iii) conduit entities which are in a group with ATP activities but no clear effect on the tax base is observable

    Comparison of Observed and Simulated Grow-Finish Swine Performance Under Summer Conditions

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    As a part of a National Pork Producers Council educational program, our research and extension team at the University of Kentucky was linked with an independent commercial swine producer to test the NCPIG model against observed commercial on-farm data. This experience provided improved information for model development as well as increased producer insight into the data input needs and potential benefits of modeling. Detailed production information comparisons between the NCPIG model and producer data are presented for summer time conditions to assess the validity of the NCPIG model for simulation of grow-finish swine performance. Results demonstrated that the NCPIG model accurately simulated performance
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