5,446 research outputs found

    Experiences with and interpretation of standard test methods of building energy analysis tools

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    The authors separately apply ANSI/ASHRAE Standard 140-2001 to the simulation program TRNSYS, comparing not only their results but the differences in their simulation assumptions and in their interpretations of the Standard's test cases. Results of the application are presented for all three authors, showing that there is a significant amount of leeway within a complex simulation tool such asTRNSYS for users of different backgrounds to apply their own common simulating practices and still fall comfortably within the range of acceptability specified by such Standards. Included in the application results are results of sensitivity tests that demonstrate the relative importance of assumption differences

    Converging on a recommended set of interpretations and assumptions in applying standard tests to energy analysis tools

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    The authors, having individually applied ANSI/ASHRAE Standard 140-2001 to the simulation program TRNSYS in a previous project, compare their results, simulation assumptions, and interpretations of the Standard's test cases to arrive at a conformed set of recommended practices. Sensitivities to individual assumptions are investigated and results of applying the conformed set of assumptions are presented

    Reducing bias and quantifying uncertainty in watershed flux estimates: the R package loadflex

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    Many ecological insights into the function of rivers and watersheds emerge from quantifying the flux of solutes or suspended materials in rivers. Numerous methods for flux estimation have been described, and each has its strengths and weaknesses. Currently, the largest practical challenges in flux estimation are to select among these methods and to implement or apply whichever method is chosen. To ease this process of method selection and application, we have written an R software package called loadflex that implements several of the most popular methods for flux estimation, including regressions, interpolations, and the special case of interpolation known as the period-weighted approach. Our package also implements a lesser-known and empirically promising approach called the “composite method,” to which we have added an algorithm for estimating prediction uncertainty. Here we describe the structure and key features of loadflex, with a special emphasis on the rationale and details of our composite method implementation. We then demonstrate the use of loadflex by fitting four different models to nitrate data from the Lamprey River in southeastern New Hampshire, where two large floods in 2006–2007 are hypothesized to have driven a long-term shift in nitrate concentrations and fluxes from the watershed. The models each give believable estimates, and yet they yield different answers for whether and how the floods altered nitrate loads. In general, the best modeling approach for each new dataset will depend on the specific site and solute of interest, and researchers need to make an informed choice among the many possible models. Our package addresses this need by making it simple to apply and compare multiple load estimation models, ultimately allowing researchers to estimate riverine concentrations and fluxes with greater ease and accuracy

    Micro mechanics of the critical state line at high stresses

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    A critical state line is presented for a crushable numerical soil, which is parallel to the isotropic normal compression line. A previous theory for the normal compression line, which correctly predicts the slope as a function of the size-effect on particle strength is extended to justify the slope of the critical state line. The micro mechanics behind critical states are examined, leading to a theory for a relationship between the volume of smallest particles and mean effective stress. A unique relationship exists for crushed states, leading to a two-dimensional interpretation of the state boundary surface for soils looser than critical

    Simulation synergy : expanding TRNSYS capabilities and usability

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    Developers of simulation packages are now able to take advantage of the increase in available desktop computing power to expand the capabilities and usability of their programs. This paper will illustrate these opportunities by discussing the different techniques the developers of the TRNSYS software package have used to try and create a synergy between TRNSYS and external programs and between the developers and users of the program

    The Police as Victims of Their Own Misconceptions

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    Statutory Authority for Bankruptcy Judges to Conduct Jury Trials: Fact Or Fiction

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    Quasar x-ray spectra revisited

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    A sample of 45 quasars observed by the Imaging Proportional Counter (IPC) on the Einstein satellite is used to re-examine the relationship between the soft (0.2-3.5 keV) X-ray energy index and radio-loudness. We found the following: (1) the tendency for radio-loud quasars to have systematically flatter X-ray slopes than radio-quiet quasars (RQQ's) is confirmed with the soft X-ray excess having negligible effect; (2) there is a tendency for the flatness of the X-ray slope to correlate with radio core-dominance for radio-loud quasars, suggesting that a component of the X-ray emission is relativistically beamed; (3) for the RQQ's the soft X-ray slopes, with a mean of approximately 1.0, are consistent with the slopes found at higher energies (2-10 keV) although steeper than those observed for Seyfert 1 galaxies (also 2-10 keV) where the reflection model gives a good fit to the data; (4) the correlation of FeII emission line strength with X-ray energy index is confirmed for radio-quiet quasars using a subset of 18 quasars. The radio-loud quasars show no evidence for a correlation. This relation suggests a connection between the ionizing continuum and the line emission from the broad emission line region (BELR) of radio-quiet quasars, but in the opposite sense to that predicted by current photoionization models; and (5) the correlations of X-ray slope with radio core dominance and FeII equivalent width within the radio-loud and radio-quiet sub-classes respectively imply that the observed wide range of X-ray spectral slopes is real rather than due to the large measuring uncertainties for individual objects

    Statutory Authority for Bankruptcy Judges to Conduct Jury Trials: Fact Or Fiction

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    El distrito de Chilca, perteneciente a la provincia de Huancayo, lugar donde se realizó la investigación, tiene antecedentes de haber sufrido daños por movimientos sísmicos, los cuales fueron originados por la presencia de la falla geológica del Huaytapallana, que en la actualidad se encuentra en un silencio sísmico de 50 años. En las últimas décadas, la población del distrito de Chilca y su necesidad de tener una vivienda, fue aumentando exponencialmente. Al no contar con los recursos económicos suficientes, optan por construir de manera personal o la realizan mediante terceras personas, que no cuentan con conocimientos adecuados para la construcción de una vivienda. Para la investigación se realizó el Análisis de la Vulnerabilidad Sísmica usando tres metodologías: Método cualitativo – ATC 21, Método de la Asociación Colombiana de Ingeniería Sísmica y Método de INDECI. Métodos que permiten la evaluación de la vulnerabilidad sísmica de las viviendas. Así mismo, se contrastó los límites de distorsión de entrepiso (deriva) de una vivienda de albañilería mediante un análisis estático sísmico, y también la resistencia última de los muros de una vivienda de adobe. Ambos análisis fueron contrastados por la Norma E.0.30, Diseño Sismoresistente, y Norma E0.80, Diseño y Construcción con tierra reforzada
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