985 resultados para waste heat
Resumo:
Various test methods exist for measuring heat of cement hydration; however, most current methods require expensive equipment, complex testing procedures, and/or extensive time, thus not being suitable for field application. The objectives of this research are to identify, develop, and evaluate a standard test procedure for characterization and quality control of pavement concrete mixtures using a calorimetry technique. This research project has three phases. Phase I was designed to identify the user needs, including performance requirements and precision and bias limits, and to synthesize existing test methods for monitoring the heat of hydration, including device types, configurations, test procedures, measurements, advantages, disadvantages, applications, and accuracy. Phase II was designed to conduct experimental work to evaluate the calorimetry equipment recommended from the Phase I study and to develop a standard test procedure for using the equipment and interpreting the test results. Phase II also includes the development of models and computer programs for prediction of concrete pavement performance based on the characteristics of heat evolution curves. Phase III was designed to study for further development of a much simpler, inexpensive calorimeter for field concrete. In this report, the results from the Phase I study are presented, the plan for the Phase II study is described, and the recommendations for Phase III study are outlined. Phase I has been completed through three major activities: (1) collecting input and advice from the members of the project Technical Working Group (TWG), (2) conducting a literature survey, and (3) performing trials at the CP Tech Center’s research lab. The research results indicate that in addition to predicting maturity/strength, concrete heat evolution test results can also be used for (1) forecasting concrete setting time, (2) specifying curing period, (3) estimating risk of thermal cracking, (4) assessing pavement sawing/finishing time, (5) characterizing cement features, (6) identifying incompatibility of cementitious materials, (7) verifying concrete mix proportions, and (8) selecting materials and/or mix designs for given environmental conditions. Besides concrete materials and mix proportions, the configuration of the calorimeter device, sample size, mixing procedure, and testing environment (temperature) also have significant influences on features of concrete heat evolution process. The research team has found that although various calorimeter tests have been conducted for assorted purposes and the potential uses of calorimeter tests are clear, there is no consensus on how to utilize the heat evolution curves to characterize concrete materials and how to effectively relate the characteristics of heat evolution curves to concrete pavement performance. The goal of the Phase II study is to close these gaps.
Audit report on the Delaware County Solid Waste Disposal Commission for the year ended June 30, 2006
Resumo:
Audit report on the Delaware County Solid Waste Disposal Commission for the year ended June 30, 2006
Resumo:
BACKGROUND: Reactive oxygen species production increases during aging, whereas protective mechanisms such as heat shock proteins (HSPs) or antioxidant capacity are depressed. Physical activity has been hypothesized to provide protection against oxidative damage during aging, but results remain controversial. This study aimed to investigate the effect of different levels of physical activity during aging on Hsp72 expression and systemic oxidative stress at rest and in response to maximal exercise. METHODS: Plasma antioxidant capacity (Trolox equivalent antioxidant capacity, TEAC), thiobarbituric acid-reactive species (TBARS), advanced oxidized proteins products (AOPP), and Hsp72 expression in leukocytes were measured before and after maximal exercise testing in 32 elderly persons (aged 73.2 years), who were assigned to two different groups depending on their level of physical activity during the past 12 months (OLow = moderate to low level; OHigh = higher level). RESULTS: The OHigh group showed higher aerobic fitness and TEAC (both representing 120% of OLow values) as well as lower oxidative damage (50% of OLow values) and Hsp72 expression. Exercise led to a lower increase in oxidative damage in the OHigh group. Aerobic fitness was positively correlated with TEAC and negatively with lipid peroxidation (TBARS). Hsp72 expression was negatively correlated with TEAC but positively correlated with TBARS levels. CONCLUSIONS: The key finding of this study is that, in people aged 60 to 90 years, long-term high level of physical activity preserved antioxidant capacity and limited oxidative damage accumulation. It also downregulated Hsp72 expression, an adaptation potentially resulting from lower levels of oxidative damage.
Resumo:
Newsletter produced by Iowa Department of Natural Resources about energy and waste in Iowa
Resumo:
Audit report on the Butler County Solid Waste Commission for the year ended June 30, 2007
Resumo:
Audit report on the Wayne-Ringgold-Decatur County Solid Waste Management Commission for the year ended June 30, 2007
Resumo:
Audit report on the Jones County Solid Waste Management Commission for the year ended June 30, 2007
Resumo:
Special investigation of Hardin County Solid Waste Disposal Commission for the period January 1, 2002 through December 31, 2007
Resumo:
Audit report on the Shelby County Area Solid Waste Agency for the year ended June 30, 2007
Resumo:
Audit report on the Rural Iowa Waste Management Association for the year ended June 30, 2007
Resumo:
Audit report on the Pocahontas County Solid Waste Commission for the year ended June 30, 2007
Resumo:
Land plants are prone to strong thermal variations and must therefore sense early moderate temperature increments to induce appropriate cellular defenses, such as molecular chaperones, in anticipation of upcoming noxious temperatures. To investigate how plants perceive mild changes in ambient temperature, we monitored in recombinant lines of the moss Physcomitrella patens the activation of a heat-inducible promoter, the integrity of a thermolabile enzyme, and the fluctuations of cytoplasmic calcium. Mild temperature increments, or isothermal treatments with membrane fluidizers or Hsp90 inhibitors, induced a heat shock response (HSR) that critically depended on a preceding Ca(2+) transient through the plasma membrane. Electrophysiological experiments revealed the presence of a Ca(2+)-permeable channel in the plasma membrane that is transiently activated by mild temperature increments or chemical perturbations of membrane fluidity. The amplitude of the Ca(2+) influx during the first minutes of a temperature stress modulated the intensity of the HSR, and Ca(2+) channel blockers prevented HSR and the onset of thermotolerance. Our data suggest that early sensing of mild temperature increments occurs at the plasma membrane of plant cells independently from cytosolic protein unfolding. The heat signal is translated into an effective HSR by way of a specific membrane-regulated Ca(2+) influx, leading to thermotolerance.
Audit report on the Delaware County Solid Waste Disposal Commission for the year ended June 30, 2007
Resumo:
Audit report on the Delaware County Solid Waste Disposal Commission for the year ended June 30, 2007
Resumo:
Audit report on the Crawford County Area Solid Waste Agency Commission for the year ended June 30, 2007
Resumo:
Audit report on the Hardin County Sanitary Solid Waste Disposal Commission for the year ended June 30, 2007
