9,613 research outputs found

    DEVELOPMENT OF A METHOD FOR IN-SITU TESTING OF OXYGEN CONCENTRATIONS IN COMPOST BEDDED PACK BARNS

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    Compost bedded pack barns are a relatively new type of dairy housing system that is being implemented in Kentucky. Extensive research has been done on the composting of animal manure, however, little has been done on composting animal manure in place. One of the most concerning challenges is aeration. Improper aeration can cause system failure. The ability to quickly and accurately measure the oxygen concentration would allow researchers the ability to determine which methods of tillage/aeration are most effective in compost bedded pack barns. The research in this thesis focused on the development of a method for simultaneously testing oxygen concentrations at different locations and depth in compost in-situ. A probe was developed that vertically aligned Apogee Instruments oxygen sensors (SO-120) in order to generate an oxygen profile of the compost. The probe was used to test the effect of different tillage/aeration strategies in a composted bedded pack barn. The results indicated the probe was effective at measuring the oxygen concentrations in active compost tested in laboratory conditions and it was determined that there was a significant difference in oxygen concentration with respect to depth. However, when applied in the compost bedded pack barn, large amounts of variation occurred randomly in the data, causing no difference to be detected as a result of varying tillage aeration treatments

    Enabling Assurance in the MBSE Environment

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    A number of specific benefits that fit within the hallmarks of effective development are realized with implementation of model-based approaches to systems and assurance. Model Based Systems Engineering (MBSE) enabled by standardized modeling languages (e.g., SysML) is at the core. These benefits in the context of spaceflight system challenges can include: Improved management of complex development, Reduced risk in the development process, Improved cost management, Improved design decisions. With appropriate modeling techniques the assurance community can improve early oversight and insight into project development. NASA has shown the basic constructs of SysML in an MBSE environment offer several key advantages, within a Model Based Mission Assurance (MBMA) initiative

    `t Hooft Anomaly Matching for QCD

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    I present a set of theories which display non-trivial `t Hooft anomaly matching for QCD with FF flavors. The matching theories are non-Abelian gauge theories with "dual" quarks and baryons, rather than the purely confining theories of baryons that `t Hooft originally searched for. The matching gauge groups are required to have an F±6F\pm 6 dimensional representation. Such a correspondence is reminiscent of Seiberg's duality for supersymmetric (SUSY) QCD, and these theories are candidates for non-SUSY duality. However anomaly matching by itself is not sufficiently restrictive, and duality for QCD cannot be established at present. At the very least, the existence of multiple anomaly matching solutions should provide a note of caution regarding conjectured non-SUSY dualities.Comment: 8 pages, LaTeX, version to be published in PR

    Learning To Be a Lawyer: Transition Into Practice Pilot Project

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    A law student, upon graduation, is not a finished product, a respected law school dean observed. A practicing lawyer might add: A lawyer, upon passage of the Bar examination, is not a finished product. To determine ways new lawyers can be helped in moving up the steep learning curve that separates law students from competent professionals, the State Bar of Georgia, through its Committee on the Standards of the Profession, is conducting a Transition into Practice Pilot Project

    Validation of a fornix depth measurer: a putative tool for the assessment of progressive cicatrising conjunctivitis

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    Background/aims Documentation of conjunctival forniceal foreshortening in cases of progressive cicatrising conjunctivitis (PCC) is important in ascertaining disease stage and progression. Lower fornix shortening is often documented subjectively or semi-objectively, whereas upper forniceal obliteration is seldom quantified. Although tools such as fornix depth measurers (FDMs) have been described, their designs limit upper fornix measurement. The purpose of this study was to custom-design a FDM to evaluate the upper fornix and to assess variability in gauging fornix depth. \ud \ud Methods A polymethylmethacrylate FDM was constructed using industry-standard jewellery computer software and machinery. Two observers undertook a prospective independent evaluation of central lower fornix depth in a heterogeneous cohort of patients with clinically normal and abnormal conjunctival fornices both subjectively and by using the FDM (in mm). Upper central fornix depth was also measured. Agreement was assessed using Bland–Altman plots. \ud \ud Results Fifty-one eyes were evaluated. There was 100% intraobserver agreement to within 1 mm for each observer for lower fornix measurement. The mean difference in fornix depth loss using the FDM between observer 1 and 2 was 1.19%, with 95% confidence of agreement (±2SD) of −15% to +20%. In total, 86% (44/51) of measurements taken by the two observers agreed to within 10% of total lower fornix depth (ie, ±1 mm) versus only 63% (32/51) of the subjective measurements. Mean upper fornix difference was 0.57 mm, with 95% confidence of agreement of between −2 and + 3 mm. \ud \ud Conclusions This custom-designed FDM is well tolerated by patients and shows low intraobserver and interobserver variability. This enables repeatable and reproducible measurement of upper and lower fornix depths, facilitating improved rates of detection and better monitoring of progression of conjunctival scarring

    Gravitational instabilities in a protosolar-like disc - I. Dynamics and chemistry

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    MGE gratefully acknowledges a studentship from the European Research Council (ERC; project PALs 320620). JDI gratefully acknowledges funding from the European Union FP7-2011 under grant agreement no. 284405. ACB's contribution was supported, in part, by The University of British Columbia and the Canada Research Chairs program. PC and TWH acknowledge the financial support of the European Research Council (ERC; project PALs 320620).To date, most simulations of the chemistry in protoplanetary discs have used 1 + 1D or 2D axisymmetric α-disc models to determine chemical compositions within young systems. This assumption is inappropriate for non-axisymmetric, gravitationally unstable discs, which may be a significant stage in early protoplanetary disc evolution. Using 3D radiative hydrodynamics, we have modelled the physical and chemical evolution of a 0.17 M⊙ self-gravitating disc over a period of 2000 yr. The 0.8 M⊙ central protostar is likely to evolve into a solar-like star, and hence this Class 0 or early Class I young stellar object may be analogous to our early Solar system. Shocks driven by gravitational instabilities enhance the desorption rates, which dominate the changes in gas-phase fractional abundances for most species. We find that at the end of the simulation, a number of species distinctly trace the spiral structure of our relatively low-mass disc, particularly CN. We compare our simulation to that of a more massive disc, and conclude that mass differences between gravitationally unstable discs may not have a strong impact on the chemical composition. We find that over the duration of our simulation, successive shock heating has a permanent effect on the abundances of HNO, CN and NH3, which may have significant implications for both simulations and observations. We also find that HCO+ may be a useful tracer of disc mass. We conclude that gravitational instabilities induced in lower mass discs can significantly, and permanently, affect the chemical evolution, and that observations with high-resolution instruments such as Atacama Large Millimeter/submillimeter Array (ALMA) offer a promising means of characterizing gravitational instabilities in protosolar discs.Publisher PDFPeer reviewe
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