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Assessing Cumulative Thermal Stress in Fish During Chronic Exposure to High Temperature

Description: As environmental laws become increasingly protective, and with possible future changes in global climate, thermal effects on aquatic resources are likely to receive increasing attention. Lethal temperatures for a variety of species have been determined for situations where temperatures rise rapidly resulting in lethal effects. However, less is known about the effects of chronic exposure to high (but not immediately lethal) temperatures and even less about stress accumulation during periods of fluctuating temperatures. In this paper we present a modeling framework for assessing cumulative thermal stress in fish. The model assumes that stress accumulation occurs above a threshold temperature at a rate depending on the degree to which the threshold is exceeded. The model also includes stress recovery (or alleviation) when temperatures drop below the threshold temperature as in systems with large daily variation. In addition to non-specific physiological stress, the model also simulates thermal effects on growth.
Date: November 14, 1999
Creator: Bevelhimer, M.S. & Bennett, W.R.
Partner: UNT Libraries Government Documents Department

CASES-97 : Diurnal variation of the fair-weather PBL.

Description: The CASES-97 dataset, supplemented by data from the surrounding area and from satellite, will enable us to isolate the effects of soil moisture on boundary layer evolution.Our initial approach will be to use the integrated dataset to determine (a) the factors that contribute to PBL growth, and (b) the factors that determine the wind, temperature, and wind profiles in the growing PBL. This process will help us to consolidate the dataset and tease out remaining inconsistencies. As soon as reasonable, we want to use the dataset in mesoscale numerical models, to test and refine our conclusions. Further detail on the CASES-97 field program can be found at the World Wide Web site at: http://www.mmm.ucar.edu/cases/cases.html.
Date: November 18, 1997
Creator: Coulter, R. L.; Grossman, R. L.; Hicks, B.; Horst, T.; Klazura, G.; LeMone, M. A. et al.
Partner: UNT Libraries Government Documents Department

The importance of aerosol composition and mixing state on predicted CCN concentration and the variation of the importance with atmospheric processing of aerosol

Description: The influences of atmospheric aerosols on cloud properties (i.e., aerosol indirect effects) strongly depend on the aerosol CCN concentrations, which can be effectively predicted from detailed aerosol size distribution, mixing state, and chemical composition using Köhler theory. However, atmospheric aerosols are complex and heterogeneous mixtures of a large number of species that cannot be individually simulated in global or regional models due to computational constraints. Furthermore, the thermodynamic properties or even the molecular identities of many organic species present in ambient aerosols are often not known to predict their cloud-activation behavior using Köhler theory. As a result, simplified presentations of aerosol composition and mixing state are necessary for large-scale models. In this study, aerosol microphysics, CCN concentrations, and chemical composition measured at the T0 urban super-site in Mexico City during MILAGRO are analyzed. During the campaign in March 2006, aerosol size distribution and composition often showed strong diurnal variation as a result of both primary emissions and aging of aerosols through coagulation and local photochemical production of secondary aerosol species. The submicron aerosol composition was ~1/2 organic species. Closure analysis is first carried out by comparing CCN concentrations calculated from the measured aerosol size distribution, mixing state, and chemical composition using extended Köhler theory to concurrent CCN measurements at five supersaturations ranging from 0.11% to 0.35%. The closure agreement and its diurnal variation are studied. CCN concentrations are also derived using various simplifications of the measured aerosol mixing state and chemical composition. The biases associated with these simplifications are compared for different supersaturations, and the variation of the biases is examined as a function of aerosol age. The results show that the simplification of internally mixed, size-independent particle composition leads to substantial overestimation of CCN concentration for freshly emitted aerosols in early morning, but can reasonably predict the CCN concentration ...
Date: March 15, 2010
Creator: Wang, J.; Cubison, M.; Aiken, A.; Jimenez, J.; Collins, D.; Gaffney, J. et al.
Partner: UNT Libraries Government Documents Department

Thermal behavior of mixtures of perlite and phase change material in a simulated climate

Description: A new concept for use of phase change material (PCM) in building envelopes has been investigated. The concept is called a RCR system in analogy to an electrical circuit with a capacitor between two resistors. Here, the thermal capacitance of the PCM is sandwiched between the thermal resistance of conventional insulation. The PCM used was hydrated calcium chloride dispersed in perlite and contained in watertight test cells. One cell had a PCM/perlite ratio of 2:1 by weight; the other had a 6:1 mixture. Extruded polystyrene (XPS) was the insulation below and above the PCM. Heat-flux transducers on the top and bottom of each cell as well as thermocouples from the top to the bottom of each cell allowed them to follow closely the progression of freezing and melting in the PCM as the authors subjected the cells to both steady and diurnally varying simulated outside temperatures. Computer modeling with a transient heat conduction program was successful in proving that they understood the relevant energy transfer mechanisms and thermophysical properties. For the diurnal cycles, with twice the amount of XPS below as above the PCM, much of the energy stored during daytime by melting PCM flowed to the outside at night when it froze again. Comparisons were made to the behavior of conventional insulation. With PCM, the total daily energy flow into the conditioned space below the test cells was lower and the peak flow rate was delayed in time and decreased in magnitude.
Date: February 1997
Creator: Petrie, T. W.; Childs, P. W.; Christian, J. E.; Childs, K. W. & Shramo, D. J.
Partner: UNT Libraries Government Documents Department

Measurements of daytime and upper tropospheric water vapor profiles by Raman lidar

Description: One of the most important atmospheric constituents needed for climate and meteorological studies is water vapor. Water vapor plays an important role in driving atmospheric circulations through latent heat release and in determining the earth`s radiation budget, both through its radiative effects (water vapor is the major greenhouse gas) and cloud formation. The vertical distribution of water vapor is particularly important because it not only determines convective stability but radiative effects are also strongly altitude dependent. At present, considerable controversy exists over the nature of the vertical redistribution of water vapor in a changing climate, and particularly the distribution of water vapor in the upper troposphere. Understanding upper tropospheric moistening processes such as deep convection are therefore of prime importance in addressing the water vapor feedback question. A powerful, proven technique for the continuous measurement of nighttime water vapor profiles (in clear skies or up to the lowest cloud level) with high spatial and temporal resolution is Raman lidar. As part of the U.S. Department of Energy`s (DOE) Atmospheric Radiation Measurement (ARM) program, a high performance dual field-of-view (fov), narrowband Raman lidar system capable of both daytime and nighttime operation has been developed. In this paper, the Sandia Raman lidar system is discussed along with its application to two problems of current interest: daytime tropospheric water vapor profile measurements and upper tropospheric water vapor. We present recent measurements of upper tropospheric moisture made at the DOE Cloud and Radiation Testbed site (CART) in Oklahoma. Recent daytime measurements are also presented.
Date: March 1, 1995
Creator: Bisson, S.E. & Goldsmith, J.E.M.
Partner: UNT Libraries Government Documents Department

Defining intra- and interhour load swings

Description: Electricity consumption varies with time. These temporal variations include moment-to-moment fluctuations plus hour-to-hour changes associated with diurnal, weekly, and seasonal patterns. The problem naturally splits into two time frames: (1) fast fluctuations, on the order of seconds to minutes, and (2) slower fluctuations, on the order of an hour or longer. Fast fluctuations in aggregate load result primarily from the random movements of individual loads. Slower fluctuations result from common external causes, such as time of day, day of the week, and weather. This study empirically examines intra- and interhour load following. It develops methods to separate intra- and interhour load fluctuations, identifies the key features of each, and shows how they differ from each other.
Date: September 1, 1996
Creator: Hirst, E. & Kirby, B.
Partner: UNT Libraries Government Documents Department

Daily snow depth measurements from 195 stations in the United States

Description: This document describes a database containing daily measurements of snow depth at 195 National Weather Service (NWS) first-order climatological stations in the United States. The data have been assembled and made available by the National Climatic Data Center (NCDC) in Asheville, North Carolina. The 195 stations encompass 388 unique sampling locations in 48 of the 50 states; no observations from Delaware or Hawaii are included in the database. Station selection criteria emphasized the quality and length of station records while seeking to provide a network with good geographic coverage. Snow depth at the 388 locations was measured once per day on ground open to the sky. The daily snow depth is the total depth of the snow on the ground at measurement time. The time period covered by the database is 1893--1992; however, not all station records encompass the complete period. While a station record ideally should contain daily data for at least the seven winter months (January through April and October through December), not all stations have complete records. Each logical record in the snow depth database contains one station`s daily data values for a period of one month, including data source, measurement, and quality flags.
Date: February 1, 1997
Creator: Allison, L. J.; Easterling, D. R.; Jamason, P.; Bowman, D. P.; Hughes, P. Y. & Mason, E. H.
Partner: UNT Libraries Government Documents Department

{sup 18}O composition of CO{sub 2} and H{sub 2}O ecosystem pools and fluxes in a tallgrass prairie: Simulations and comparisons to measurements

Description: In this paper we describe measurements and modeling of 18O in CO2 and H2O pools and fluxes at a tallgrass prairie site in Oklahoma. We present measurements of the d18O value of leaf water, depth-resolved soil water, atmospheric water vapor, and Keeling plot d18O intercepts for net soil-surface CO2 and ecosystem CO2 and H2O fluxes during three periods of the 2000 growing season. Daytime discrimination against C18OO, as calculated from measured above-canopy CO2 and d18O gradients, is also presented. To interpret the isotope measurements we applied an integrated land-surface and isotope model (ISOLSM) that simulates ecosystem H218O and C18OO stocks and fluxes. ISOLSM accurately predicted the measured isotopic composition of ecosystem water pools and the d18O value of net ecosystem CO2 and H2O fluxes. Simulations indicate that incomplete equilibration between CO2 and H2O within C4 plant leaves can have a substantial impact on ecosystem discrimination. Diurnal variations in the delta18O value of above-canopy vapor had a small impact on the predicted delta18O value of ecosystem water pools, although sustained differences had a large impact. Diurnal variations in the delta18O value of above-canopy CO2 substantially affected predicted ecosystem discrimination. Leaves dominate the ecosystem 18O-isoflux in CO2 during the growing season, while the soil contribution is relatively small and less variable. However, interpreting daytime measurements of ecosystem C18OO fluxes requires accurate predictions of both soil and leaf 18O-isofluxes.
Date: November 1, 2002
Creator: Riley, William J.; Still, Christopher J.; Helliker, Brent R.; Ribas-Carbo, Miguel & Berry, Joseph A.
Partner: UNT Libraries Government Documents Department

Solar semidiurnal tidal wind oscillations above the CART site

Description: Harmonic analysis of wintertime data from 915- and 404-MHz radar wind profilers at four sites in North America has identified coherent semidiurnal wind oscillations through the entire depth of the troposphere. These winds are readily apparent above the CART site, as evidenced from analyses of data from the Haviland, KS, radar profiler. The characteristics of this wind system match the characteristics of solar semidiurnal atmospheric tides, as predicted by a simple dynamic model.
Date: March 1, 1995
Creator: Whiteman, C.D. & Bian, X.
Partner: UNT Libraries Government Documents Department

Booster's coupled bunch damper upgrade

Description: A new narrowband active damping system for longitudinal coupled bunch (CB) modes in the Fermilab Booster has recently been installed and tested. In the past, the Booster active damper system consisted of four independent front-ends. The summed output was distributed to the 18, h=84 RF accelerating cavities via the RF fan-out system. There were several problems using the normal fan-out system to deliver the longitudinal feedback RF. The high power RF amplifiers normally operate from 37 MHz to 53 MHz whereas the dampers operate around 83MHz. Daily variations in the tuning of the RF stations created tuning problems for the longitudinal damper system. The solution was to build a dedicated narrowband, Q {approx} 10, 83MHz cavity powered with a new 3.5kW solid-state amplifier. The cavity was installed in June 2002 and testing of the amplifier and damper front-end began in August 2002. A significant improvement has been made in both operational stability and high intensity beam damping. At present there are five CB modes being damped and a sixth mode module is being built. The new damper hardware is described and data showing the suppression of the coupled-bunch motion at high intensity is presented.
Date: August 14, 2003
Creator: Wildman, William A. Pellico and D. W.
Partner: UNT Libraries Government Documents Department

Scoping Study for Demand Respose DFT II Project in Morgantown, WV

Description: This scoping study describes the underlying data resources and an analysis tool for a demand response assessment specifically tailored toward the needs of the Modern Grid Initiatives Demonstration Field Test in Phase II in Morgantown, WV. To develop demand response strategies as part of more general distribution automation, automated islanding and feeder reconfiguration schemes, an assessment of the demand response resource potential is required. This report provides the data for the resource assessment for residential customers and describes a tool that allows the analyst to estimate demand response in kW for each hour of the day, by end-use, season, day type (weekday versus weekend) with specific saturation rates of residential appliances valid for the Morgantown, WV area.
Date: June 6, 2008
Creator: Lu, Shuai & Kintner-Meyer, Michael CW
Partner: UNT Libraries Government Documents Department

A study of the effect of nonrandom sampling on the estimation of exposure variability using exposure-time series from the OSHA IMIS health inspection database

Description: The objective of this study was to determine the effect of nonrandom sampling over time may have on the estimation of variability, namely the geometric standard deviation, using time series of personal exposure data.
Date: May 1, 1997
Creator: Martinez, L.T.
Partner: UNT Libraries Government Documents Department

Statistical methods for detecting ichthyoplankton density patterns that influence entrainment mortality

Description: Samples of drifting American shad eggs were collected at two transects in the Savannah River near industrial water intakes. At each transect the river was divided into four sectors that were sampled at two hour intervals over a 24 hour period. The actual risk of entrainment was approximately 35-50% lower that if the shad eggs were uniformly distributed, and the risk of entrainment was lower at one intake than the other.
Date: December 31, 1995
Creator: Paller, M.H.; Tuckfield, R.C. & Starkel, W.M.
Partner: UNT Libraries Government Documents Department

Measuring solar spectral and angle-of-incidence effects on photovoltaic modules and solar irradiance sensors

Description: Historically, two time-of-day dependent factors have complicated the characterization of photovoltaic module and array performance; namely, changes in the solar spectrum over the day and optical effects in the module that vary with the solar angle-of-incidence. This paper describes straightforward methods for directly measuring the effects of these two factors. Measured results for commercial modules, as well as for typical solar irradiance sensors (pyranometers) are provided. The empirical relationships obtained from the measurements can be used to improve the methods used for system design, verification of performance after installation, and diagnostic monitoring of performance during operation.
Date: November 1, 1997
Creator: King, D.L.; Kratochvil, J.A. & Boyson, W.E.
Partner: UNT Libraries Government Documents Department

OBSERVATIONS OF RECENT NEW PARTICLE FORMATION IN HOUSTON DURING TEXAQS-2000.

Description: Particle number size distribution measurements were conducted at a tall building site and on a research aircraft during the TexAQS-2000 study. High concentrations of nucleation mode particles were observed during the early morning hours at the same time as the top of the developing boundary layer reached the sampling altitude. Transport of primary emissions from traffic and other local sources, as well as secondary formation processes, was observed. Growth of particles from the nucleation to Aitken modes appears to significantly impact the observed diurnal variation in the number size distribution. As these particles grow to larger sizes they may become more effective at scattering radiation and could act as cloud condensation nuclei, resulting in visibility and climate effects.
Date: October 1, 2001
Creator: BUZORIUS,G.; BRECHTEL,F.; ZELENYUK,A.; IMRE,D. & ANGEVINE,W.M.
Partner: UNT Libraries Government Documents Department

An observation of direct-CP violation - {epsilon}{prime}{epsilon} result from KTeV

Description: We report the first KTeV measurement for the search of direct-CP violation by using 23% of the data sample collected in the 1996-97 fixed target run at Fermilab. The result is, Re({epsilon}{prime}/{epsilon}) = (28.0 {+-} 4.1) x 10{sup -4}, nearly 7{delta} above zero obtained by a blind analysis. This firmly establishes the long-sought ''direct-CP violation'' effect in the two-pion system ({pi}{sup +}{pi}{sup -} versus {pi}{sup 0}{pi}{sup 0}) of neutral kaon decays. Other new measurements of {Delta}m, {tau}{sub s}, {Delta}{phi} and a limit on the diurnal variation of {phi}{sub +-} for testing CPT invariance from the same data sample are also presented.
Date: December 14, 1999
Creator: Hsiung, Bob
Partner: UNT Libraries Government Documents Department

Semidiurnal solar tides in the mountain atmosphere

Description: Harmonic analysis of Doppler radar wind profiler data west of the Rocky Mountains has identified a coherent semidiurnal wind system above the wintertime boundary layer at multiple sites in the region. The unusual characteristics of this mountain wind system (its semidiurnal frequency, amplitude, phase, and direction of rotation) suggest that is is a semidiurnal solar tide. Such tides have not been previously documented in the mountain atmosphere or in the troposphere generally but, because semidiurnal signatures are well known in surface barometric traces, and large amplitude semidiurnal tides are known in the upper atmosphere, they are not unexpected. Our future research on this semidiurnal cordilleran wind system will focus on obtaining sufficient data to resolve further the vertical structure, seasonal variation, and spatial variations of the wind system. Of particular interest is the role of the Rocky Mountains and other cordilleras in modifying the global tides. It remains to be seen whether semidiurnal cordilleran circulations will be of sufficient magnitude to be observed across major arcuate-shaped east-west-oriented mountain massifs such as the Alps. There, wind systems may develop in response to pressure gradients (Frei and Davies, 1993) that form across the Alps due to differences in the amplitudes and phases of semidiurnal and diurnal pressure oscillations on the north and south sides of the mountain barrier.
Date: September 1, 1994
Creator: Whiteman, C.D. & Bian, X.
Partner: UNT Libraries Government Documents Department

Generation and mobility of radon in soil. Technical report

Description: This study has confirmed large seasonal and daily variations of Rn in soil gas, developed models for the effects of temperature and moisture on air-water Rn partition, inhibited Rn diffusion from wet soil into sparse large air-filled pores and effects of diffusion into bedrock, demonstrated that organic matter is a major host for 226Ra in soils and that organic-bound Ra largely determines the proportion of 222Rn emanated to pore space, shown that in contrast 220Rn is emanated mainly from 224Ra in Fe-oxides, detected significant disequilibrium between 226Ra and 238U in organic matter and in some recent glacial soils, demonstrated by computer models that air convection driven by temperature differences is expected in moderately permeable soils on hillsides.
Date: May 1, 1993
Creator: Rose, A. W.; Jester, W. A. & Ciolkosz, E. J.
Partner: UNT Libraries Government Documents Department

An orbit fit program for localizing errors in RHIC

Description: Many errors in an accelerator are evidenced as transverse kicks to the beam which distort the beam trajectory. Therefore, the information of the errors are imprinted in the distorted orbits, which are different from what would be predicted by the optics model. In this note, we introduce an algorithm for fitting the orbit based on an on-line optics model. By comparing the measured and fitted orbits, we first present results validating the algorithm. We then apply the algorithm and localize the location of the elusive source of vertical diurnal variations observed in RHIC. The difference of two trajectories (linear accelerator) or closed orbits (storage ring) should match exactly a betatron oscillation, which is predictable by the optics model, in an ideal machine. However, in the presence of errors, the measured trajectory deviates from prediction since the model is imperfect. Comparison of measurement to model can be used to detect such errors. To do so the initial conditions (phase space parameters at any point) must be determined which can be done by comparing the difference orbit to prediction using only a few beam position monitors (BPMs). The fitted orbit can be propagated along the beam line based on the optics model. Measurement and model will agree up to the point of an error. The error source can be better localized by additionally fitting the difference orbit using downstream BPMs and back-propagating the solution. If one dominating error source exist in the machine, the fitted orbit will deviate from the difference orbit at the same point.
Date: November 1, 2011
Creator: Liu, C.; Minty, M. & Ptitsyn, V.
Partner: UNT Libraries Government Documents Department

POPULATION DISTRIBUTION DURING THE DAY

Description: Population distribution during the day can be defined as distribution of population in an area during the daytime hours. However, a precise definition of daytime hours is challenging given the geographic variability in the length of a day or daylight hours. The US Census Bureau used "normal business hours" as the span of time to describe daytime population. Given that Censuses typically estimates residential population, it represents a nighttime population distribution. In that respect, daytime population in an area may be broadly defined as distribution of population at times other than when they are expected to be at their residences at night which extends the duration from business hours to include the evening hours as well.
Date: January 1, 2008
Creator: Bhaduri, Budhendra L.
Partner: UNT Libraries Government Documents Department

Water-bearing minerals on mars: source of observed mid-latitude water?

Description: The Odyssey spacecraft documented the existence of heterogeneously distributed hydrogen at martian mid-latitudes, suggesting that large areas of the near-equatorial highlands contain near-surface deposits of 'chemically and/or physically bound H20 and/or OH' in amounts up to 3 .8% equivalent H20. Shallow occurrences of water ice are not stable near the martian equator, making the hydrogen deposits at these latitudes somewhat enigmatic. Clay minerals and zeolites have both been proposed as possible water-bearing constituents on Mars, and both are common terrestrial alteration products of hydrovolcanic basaltic ashes and palagonitic material comparable to those that may be widespread on Mars. Smectites within martian meteorites, attributed to hydrous alteration on Mars rather than on Earth, provide direct evidence of clay minerals from Mars. In addition, new thermal emission spectrometer (TES) data provide good evidence for unspecified zeolites in martian surface dust [6] . The nature of the hydrogen-containing material observed in the equatorial martian regolith is of particular importance to the question of whether hydrous minerals have formed in the past on Mars. Also, whether these minerals exist in a hydrated (i .e., containing H2O molecules in their structures) or dehydrated state is a crucial question . The existence of hydrous minerals is also important in connection with their possible role in affecting the diurnal variation of the martian atmosphere, in their potential role in unraveling the paleohydrology and paleobiology of Mars, and in their possible use as a water resource to support exploration of the martian mid-latitudes.
Date: January 1, 2003
Creator: Bish, D. L. (David L.); Carey, J. W. (James W.) & Fialips, C. I. (Clair I.)
Partner: UNT Libraries Government Documents Department