WorldWideScience
2

Design of automatic monitoring network for the water quality management of river basin  

Energy Technology Data Exchange (ETDEWEB)

In designing automatic water quality monitoring networks for a river basin, determination of measurement locations and items is critical to the effectiveness of the total system. In this paper we studied how to decide these two design factors when a monitoring network is designed for the purpose of water quality surveillance and emergency alarm. For measurement locations, candidate sites are chosen based on the intake amount for water supply and the point sources of contamination. Then, detailed locations are decided according to the contaminant flow distance. As for measurement items, characteristics and the accident history of water pollution in the basin must be taken into account. Considering economic aspects, we proposed a two-stage measurement plan: basic components for all locations and selective ones variable for different locations. Proposed methodology is demonstrated through a case study for Nak-dong River Basin. (author). 10 refs., ...

1996-04-30

3

Regulation of Na(+)-K+ pump activity in contracting rat muscle.  

UK PubMed Central (United Kingdom)

1. In rat soleus muscle, high frequency electrical stimulation produced a rapid increase in intracellular Na+ (Na+i) content. This was considerably larger in muscles contracting without developing tension...Full Text Available

1997-09-15

4

The effects of temperature dependent viscosity and thermal conductivity on unsteady MHD convective heat transfer past a semi-infinite vertical porous moving plate with variable suction  

British Library Electronic Table of Contents (United Kingdom)

In this article, we studied the effects of variable viscosity and thermal conductivity on an unsteady two-dimensional laminar flow of a viscous incompressible conducting fluid past a semi-infinite vertical porous moving plate taking into account the effect of a magnetic field in the presence of variable suction. The fluid viscosity is assumed to vary as an inverse linear function of temperature but the thermal conductivity is assumed to vary as a linear function of temperature. It is assumed that the porous plate moves with a constant velocity in the direction of fluid flow, and the free stream velocity follows the exponentially increasing small perturbation law. The governing equations for the flow are transformed into a system of nonlinear ordinary differential equations by perturbation ...

2007-01-01

5

Diagnosis of early human myocardial ischemic damage with electron probe microanalysis  

Energy Technology Data Exchange (ETDEWEB)

We determined the Na/K x-ray intensity ratio in frozen sections of myocardial tissues obtained at autopsy from patients who died from various causes, using electron probe analysis. We have been able to distinguish between the ischemically injured and normal cells. The method is simple, fast, and dependable even when the duration of ischemia is only 30 minutes.

1983-03-01

6

Determinants of health insurance ownership among South African women  

UK PubMed Central (United Kingdom)

BackgroundStudies conducted in developed countries using economic models show that individual- and household- level variables are important determinants of health insurance ownership....Full Text Available

7

Climate change/variability implications on hydroelectricity generation in the Zambezi River Basin  

British Library Electronic Table of Contents (United Kingdom)

The study has analysed the effects of various factors on hydroelectric power generation potential to include climate change/variability, water demand, and installation of proposed hydroelectric power schemes in the Zambezi River Basin. An assessment of historical (1970?2000) power potential in relation to climate change/variability at existing hydro electric power schemes(Cahora Bassa, Kariba, Kafue Gorge and Itezhi-Tezhi) in the Zambezi River Basin was conducted. The correlation of hydroelectric power potential with climate change/variability aimed at observing the link and extent of influence of the latter on the former was investigated. In order to predict the future outlook of hydro electric power potential, General Circulation Models (GCM) were used to generate projected precipitation...

2011-01-01

8

Transport of sorbing solutes in randomly heterogeneous formations: Spatial moments, macrodispersion, and parameter uncertainty  

Energy Technology Data Exchange (ETDEWEB)

Expressions for the spatial moments and macrodispersion tensor for sorbing solutes in heterogeneous formations were presented using a probabilistic model of a fluid residence time coupled with the particle position analysis. The fluid residence time was defined as a fraction of the actual time during which the particle stayed in the mobile fluid phase of the aquifer. The fluid residence time is a random variable whose variability comes as a result of the non-equilibrium sorption properties. The sorbing solute was assumed to be governed with first-order linear kinetics. The closed-form expressions were based on the stationarity in the kinetic process and on the first-order approximation in the hydraulic conductivity field and in the fluid residence time. The non-equilibrium effects were presented as a function of the spatial variability in hydraulic conductivity and temporal ...

1993-06-01

9

Modeling of snow melting and uniform wetting front migration in a layered subfreezing snowpack  

Energy Technology Data Exchange (ETDEWEB)

A method of modeling freeze-thaw cycles of naturally deposited snowpacks is presented. The model involves the Stefan condition as an independent governing equation on the exterior moving boundary to calculate snowpack thinning, flow of water through a variably saturated layered porous medium as described by the Richards equation, and heat conduction with a phase change. The heat conduction problem was treated in two ways. Local heat conduction between a snow grain and its surrounding water film was treated by using a simple energy balance. Global heat conduction with a phase change (the Stefan problem) was introduced to calculate the space-time temperature distribution. In order to handle multiple interior moving boundaries, a specific form of the enthalpy formulation was used for heat conduction with a phase change. Changing material properties were considered ...

1994-08-01

10

The coexistence of fish species in streams: relationships between assemblage attributes and trophic and environmental variables  

British Library Electronic Table of Contents (United Kingdom)

Diet overlap and niche breadth are well-known species traits from trophic ecology that can assist in explaining how species interact and coexist as well as the ecological mechanisms that influence biodiversity. In the present study, we analyzed the relationships between these trophic variables and indicators of resource availability with some attributes of fish assemblages (species richness, Shannon diversity index, evenness, density and individual body size). The physical and chemical characteristics of the biotopes (topography, water quality and conservation of slopes) were examined to identify possible patterns. Monthly sampling using electrofishing was conducted in 2003 along five streams located in the Cuiab? River watershed. The relationships between environmental variables and attri...

2011-01-01

11

THE EFFECT OF VARIABLE THERMAL CONDUCTIVITY ON MICRO-POLAR FLUID FLOW BY CHEBYSHEV COLLOCATION METHOD  

British Library Electronic Table of Contents (United Kingdom)

In this article, the authors analyzed the effect of thermal conductivity on unsteady magnetohydrodynamic (MHD) free convection in a micro-polar fluid past a semi-infinite vertical porous plate. The fluid thermal conductivity is assumed to vary as a linear function of temperature. By using the Chebyshev collocation method in the spatial direction and the Crank-Nicolson method in the time direction, the boundary layer equations are transformed into a linear algebraic system. There are several material parameters whose affect on the flow have been studied, for instance, thermal conductivity, radiation, magnetic, micro-polar, suction (or injection) parameters, and Prandtl number. Boundary layer and Boussineq approximations have been introduced together to describe the flow field. The domain of...

2010-01-01

12

Prediction of thermal conductivity of ethylene glycol-water solutions by using artificial neural networks  

British Library Electronic Table of Contents (United Kingdom)

The objective of this study is to develop an artificial neural network (ANN) model to predict the thermal conductivity of ethylene glycol-water solutions based on experimentally measured variables. The thermal conductivity of solutions at different concentrations and various temperatures was measured using the cylindrical cell method that physical properties of the solution are being determined fills the annular space between two concentric cylinders. During the experiment, heat flows in the radial direction outwards through the test liquid filled in the annual gap to cooling water. In the steady state, conduction inside the cell was described by the Fourier equation in cylindrical coordinates, with boundary conditions corresponding to heat transfer between the solution and cooling water. ...

2009-01-01

13

Performance of bentonite/crushed rock borehole plugs  

International Nuclear Information System (INIS)

A mixture of crushed rock and bentonite is being considered as backfill and sealant for high-level nuclear waste repositories. Many variables affect the hydraulic conductivity of such a mixture, including the size and shape of the rock particles, method of mixing, water content and density of the clay, and the weight ratio of rock to clay. Mixtures of crushed basalt and bentonite have been tested to determine the relative effects of these variables. Two types of permeameters are used, 20 cm diameter stainless steel permeameters and 10 cm diameter clear PVC permeameters. Plugs are installed as a single lift or in many lifts; the water content of the clay ranged from air-dry (in most cases) to as high as 200%. Preliminary results show that a mixture of 75% crushed basalt and 25% bentonite has a hydraulic conductivity between 1 x 10/sup -9/ cm/s and 2.5 x 10/sup -8/ cm/s. In some cases, preferential flow ...

14

A model for estimating the hydraulic conductivity of granular material based on grain shape, grain size, and porosity  

Energy Technology Data Exchange (ETDEWEB)

Particle shape is an important parameter in numerous civil, environmental, and petroleum engineering applications. In ground-water flow, the shape of individual particles comprising the soil affects the soil`s pore size distribution and, hence, the important flow characteristics such as hydraulic conductivity and headloss. A model for delineating the relative importance of particle size, particle shape, and porosity, (and their interactions), in explaining the variability of hydraulic conductivity of a granular porous medium is developed and tested. Three types of porous media are considered in this work: spherical glass beads; granular sand; and irregularly shaped, shredded glass particles. A reliable method for quantifying the three-dimensional shape and packing of large samples of irregular particles based on their angle of repose is presented. The results of column experiments indicate that in the size range examined ...

1995-11-01

15

Prediction of thermal conductivity of ethylene glycol-water solutions by using artificial neural networks  

Energy Technology Data Exchange (ETDEWEB)

The objective of this study is to develop an artificial neural network (ANN) model to predict the thermal conductivity of ethylene glycol-water solutions based on experimentally measured variables. The thermal conductivity of solutions at different concentrations and various temperatures was measured using the cylindrical cell method that physical properties of the solution are being determined fills the annular space between two concentric cylinders. During the experiment, heat flows in the radial direction outwards through the test liquid filled in the annual gap to cooling water. In the steady state, conduction inside the cell was described by the Fourier equation in cylindrical coordinates, with boundary conditions corresponding to heat transfer between the solution and cooling water. The performance of ANN was evaluated by a regression analysis between the predicted and the experimental values. The ...

2009-10-15

16

Relationship between historical sea-surface temperature variability and climate change-induced coral mortality in the western Indian Ocean  

British Library Electronic Table of Contents (United Kingdom)

Many of the world's coral reefs suffered high coral mortality during the 1998 ENSO, with the highest mortality in the western Indian Ocean (WIO). A meta-analysis of field data on change in coral cover across the 1998 ENSO event was conducted for 36 major reef areas in the WIO, and relationship of the change with the historical sea-surface temperature (SST) variability investigated. WIO reefs were categorized into three major SST groups of differing coral cover change. Cover change was negatively associated with standard deviation (SD) SST until about SD 2.3, with increasing flatness of the SST frequency distributions. It increased with further increase in SD as the SST distributions became strongly bimodal in the Arabian/Persian Gulf area. The study indicates that environmental resistance/...

2010-01-01

17

Reduction of fluoroscopic exposure for the air-contrast barium enema  

Energy Technology Data Exchange (ETDEWEB)

In a fluoroscopic imaging system, image quality and patient dose are both affected by the optical system linking the image intensifier with the video camera. The effect on patient exposure of increasing the optical iris aperture size over that required for other procedures performed on the same imaging system was investigated for the air-contrast barium enema examination. Using a large-area transmission ionisation chamber to monitor the Roentgen-area-product of entrance exposure, a decrease in fluoroscopic radiation of greater than 50% was clinically documented for a fluoroscopic system utilising kVp and mA variable automatic brightness control. For this iris change, the video image was of acceptable quality for positioning and monitoring the patient, and no deleterious effect was detected in the conduct of the air-contrast exam. The availability of a variable-sized operator-selectable iris diaphragm would permit this ...

1983-11-01

18

Prioritizing areas in the native range of hygrophila for surveys to collect biological control agents  

British Library Electronic Table of Contents (United Kingdom)

Native to Southeast Asia, Hygrophila polysperma is an invasive aquatic weed of lotic habitats in the southern United States and Mexico. An increase in the number of water bodies invaded by hygrophila since 1990 suggests that current methods employed to control this weed are inadequate. Classical biological control may be a viable option for long term regulation of hygrophila in the invaded range. In this study, we used the Maximum Entropy Species Distribution Model (MaxEnt) to prioritize climatically suitable native habitats in India and Bangladesh for conducting exploratory surveys to collect biological control agents. In total, 164 point occurrences from the United States and Mexico and 20 predictor variables, including 19 bioclimatic variables and altitude, were used to predict the nati...

2011-01-01

19

Some Statistical Procedures for Evaluation of the Relative Contribution for Yield Components in irradiated populations of Peanut (Arachis hypogaea L  

International Nuclear Information System (INIS)

The present investigation was conducted at Ismaillia Research Station-Agricultural Research Center, Ismaillia Governorate, during the two successive seasons of 2000 and 2001. Two varieties of peanut (Arachis hypogaea L) namely Giza 4 and Giza 5 were treated with gamma ray doses; 10,15, 20, 25 Kr in order to induce genetic variability and to study the importance of the relative contribution of peanut yield components by employing some statistical procedures, i.e. simple correlation, multiple linear regression and stepwise regression analysis. The results showed that, there was significant positive correlation between seed yield/plant and no. of pods/plant, 100 seed weight, shelling percentage and pod yield/plant, and there was significant positive correlation between pod yield/plant and no of seed/plant,100 pod weight and 100 seed weight. The multiple linear regression analysis clearly showed that the relative contribution (R"2%) of the yield ...

2003-04-01

20

Groundwater travel time uncertainty analysis. Sensitivity of results to model geometry, and correlations and cross correlations among input parameters  

Energy Technology Data Exchange (ETDEWEB)

This study examines the sensitivity of the travel time distribution predicted by a reference case model to (1) scale of representation of the model parameters, (2) size of the model domain, (3) correlation range of log-transmissivity, and (4) cross correlations between transmissivity and effective thickness. The basis for the reference model is the preliminary stochastic travel time model previously documented by the Basalt Waste Isolation Project. Results of this study show the following. The variability of the predicted travel times can be adequately represented when the ratio between the size of the zones used to represent the model parameters and the log-transmissivity correlation range is less than about one-fifth. The size of the model domain and the types of boundary conditions can have a strong impact on the distribution of travel times. Longer log-transmissivity correlation ranges cause larger variability in the predicted travel times. ...

1985-03-01

21

Measuring back stresses in commercial alloys at elevated temperatures. [922/sup 0/K  

Energy Technology Data Exchange (ETDEWEB)

Strain transient dip tests have been conducted on two commercial heats of Alloy 800 at 922 K. Tests were conducted on both a servo-controlled hydraulic machine and a specially designed dip test machine. Using measured maximum strain changes during dips allowed unambiguous definition of a kinematic variable. The several other methods of interpreting dip test data by attempting to measure strain rates shortly after the unloading decrements were found not to be satisfactory. The nature of the instantaneous unloading strains and the strain transients following unloading are also discussed in terms of the mechanisms of deformation in Alloy 800. 9 figures, 3 tables.

1982-01-01

22

Household batteries: Evaluation of collection methods  

Energy Technology Data Exchange (ETDEWEB)

While it is difficult to prove that a specific material is causing contamination in a landfill, tests have been conducted at waste-to-energy facilities that indicate that household batteries contribute significant amounts of heavy metals to both air emissions and ash residue. Hennepin County, MN, used a dual approach for developing and implementing a special household battery collection. Alternative collection methods were examined; test collections were conducted. The second phase examined operating and disposal policy issues. This report describes the results of the grant project, moving from a broad examination of the construction and content of batteries, to a description of the pilot collection programs, and ending with a discussion of variables affecting the cost and operation of a comprehensive battery collection program. Three out-of-state companies (PA, NY) were found that accept spent batteries; difficulties in ...

1992-01-01

23

Household batteries: Evaluation of collection methods  

Energy Technology Data Exchange (ETDEWEB)

While it is difficult to prove that a specific material is causing contamination in a landfill, tests have been conducted at waste-to-energy facilities that indicate that household batteries contribute significant amounts of heavy metals to both air emissions and ash residue. Hennepin County, MN, used a dual approach for developing and implementing a special household battery collection. Alternative collection methods were examined; test collections were conducted. The second phase examined operating and disposal policy issues. This report describes the results of the grant project, moving from a broad examination of the construction and content of batteries, to a description of the pilot collection programs, and ending with a discussion of variables affecting the cost and operation of a comprehensive battery collection program. Three out-of-state companies (PA, NY) were found that accept spent batteries; difficulties in ...

1992-12-31

24

Optimisation of reactive dye removal by sequential electrocoagulation-flocculation method: comparing ANN and RSM prediction.  

Science.gov (United States)

The removal of Reactive Black 5 dye in an aqueous solution by electrocoagulation (EC) as well as addition of flocculant was investigated. The effect of operational parameters, i.e. current density, treatment time, solution conductivity and polymer dosage, was investigated. Two models, namely the artificial neural network (ANN) and the response surface method (RSM), were used to model the effect of independent variables on percentage of dye removal. The findings of this work showed that current density, treatment time and dosage of polymer had the most significant effect on percentage of dye removal (p0.8). PMID:21411950

2011-01-01

25

Responses of aquatic organisms to metal pollution in a lowland river in Flanders: A comparison of diatoms and macroinvertebrates  

International Nuclear Information System (INIS)

The role of macroinvertebrates and diatoms as indicator for metal pollution was investigated by assessing both biota along a metal gradient in the Belgian river the Dommel. Macroinvertebrates and diatoms were sampled in summer and winter and physical-chemical characteristics of the water were measured at four different sample periods and related to sediment characteristics. Although metal concentrations, except cadmium, in the water nowhere exceeded water quality standards, high metal concentrations were measured in the sediment, indicating historical contamination of the Dommel. At the sites that were situated downstream of the pollution source, high levels of conductivity and chloride were measured in the water. Redundancy Analysis (RDA) indicated pH, phosphate and zinc as the significant environmental variables explaining each respectively 7.7%, 11.6% and 22.6% of the macroinvertebrate community composition. Two clusters could be separated, ...

2008-12-15

26

Techniques for measurement of velocity in liquid-metal MHD flows  

Energy Technology Data Exchange (ETDEWEB)

Three instruments for measuring local velocities in liquid-metal MHD experiments for fusion blanket applications are being evaluated. The devices are used in room-temperature NaK experiments to measure three-dimensional flow field patterns anticipated in complex blanket geometries. Hot film anemometry, a standard technique in ordinary fluids, is being used, as well as two developmental devices. One is called the Liquid Metal Electromagnetic Velocity Instrument (LEVI), and performs essentially as a local dc electromagnetic flow meter. The third device, a Thermal Transient Anemometer (TTA) is a rugged, yet relatively simple device, which measures local velocity through the mechanism of convective heat transfer, in some ways similar to hot-film anemometry. Results are presented showing the kinds of data collected this far with each instrument. Measurements include both local velocity measurements and some preliminary frequency analyses of the fluctuating signals from ...

1986-01-01

27

Optimization of Valve Disc Using Orthogonal Array and Kriging Model  

Science.gov (United States)

A butterfly valve is a type of flow control device, typically used to regulate a fluid flowing. Currently, FEA is often used to predict the safety in the design of valve disc. Also, the study about the affection of butterfly valve's disc to the valve flow characteristics by using CFD has been done by many researchers. Along with the development of computer technique, design and analysis of computer experiments has becoming more and more important in engineering design and optimization. Hereinto Kriging model is one popular analysis approach for the purpose of creating a cheap ``meta-model'' as a surrogate to a computationally expensive simulation model. In this paper, the numerical analysis considered the strength, pressure loss coefficient and weight of valve disc simultaneously is investigated to improve the shape of a traditional butterfly valve disc. Firstly, an initial model of butterfly valve is made to evaluate the performance of the valve disc by using CFD and FEM. Then several ...

2008-10-01

28

Optimal Control of Thermo--Fluid Phenomena in Variable Domains  

Science.gov (United States)

This presentation concerns our continued research on adjoint--based optimization of viscous incompressible flows (the Navier--Stokes problem) coupled with heat conduction involving change of phase (the Stefan problem), and occurring in domains with variable boundaries. This problem is motivated by optimization of advanced welding techniques used in automotive manufacturing, where the goal is to determine an optimal heat input, so as to obtain a desired shape of the weld pool surface upon solidification. We argue that computation of sensitivities (gradients) in such free--boundary problems requires the use of the shape--differential calculus as a key ingredient. We also show that, with such tools available, the computational solution of the direct and inverse (optimization) problems can in fact be achieved in a similar manner and in a comparable computational time. Our presentation will address certain mathematical and computational aspects of ...

2008-11-01

29

CFD investigation of balcony spill plumes in atria (part II)  

Energy Technology Data Exchange (ETDEWEB)

This paper proposes an integrated method for using experimental data and CFD modeling to develop engineering correlations for atrium smoke management. Part I focused on the experimental program and validation of a CFD model of the experimental facility. Part II describes the extension of this model to a parametric study of balcony spill plumes. Smoke management in buildings during fire events often uses mechanical ventilation systems to maintain smoke layer elevation above a safe evacuation path. Design of these systems requires accurate correlations for the smoke production or mass flow rate of the buoyant fire plume. One design issue is the mass flow rate of fire plumes which spill out from a fire compartment, under a balcony and up through an atrium or other large volume. Current engineering correlations for these balcony spill plumes (BSPs) are based on a combination of one-tenth scale test data and theoretical analysis. The suitability of these correlations for real-scale designs ...

2005-07-01

30

CFD investigation of balcony spill plumes in atria (part II)  

International Nuclear Information System (INIS)

This paper proposes an integrated method for using experimental data and CFD modeling to develop engineering correlations for atrium smoke management. Part I focused on the experimental program and validation of a CFD model of the experimental facility. Part II describes the extension of this model to a parametric study of balcony spill plumes. Smoke management in buildings during fire events often uses mechanical ventilation systems to maintain smoke layer elevation above a safe evacuation path. Design of these systems requires accurate correlations for the smoke production or mass flow rate of the buoyant fire plume. One design issue is the mass flow rate of fire plumes which spill out from a fire compartment, under a balcony and up through an atrium or other large volume. Current engineering correlations for these balcony spill plumes (BSPs) are based on a combination of one-tenth scale test data and theoretical analysis. The suitability of these correlations for real-scale designs ...

31

Use of acupuncture therapy as a supplement to conventional medical treatments for acute ischaemic stroke patients in an academic medical centre in Korea  

British Library Electronic Table of Contents (United Kingdom)

Objectives: Acupuncture has served as a major complementary and alternative therapy that supplements conventional medicine and is the subject of growing public interest. This study was conducted to estimate the usage rate of acupuncture as a supplemental treatment in acute ischaemic stroke patients and to identify factors associated with the choice to use this therapy. Methods: Using the registry of stroke patients admitted to an academic medical centre in Korea, the use of acupuncture therapy was recorded and analysed, along with the patients' socio-demographic characteristics, hospital access variables, risk factors for ischaemic stroke and clinical characteristics. The data were analysed using descriptive statistics, chi-square tests and multiple logistic regression analyses. Results: O...

2011-01-01

32

Unsteady MHD micro polar flow and heat transfer over a vertical porous moving plate with variable suction  

Energy Technology Data Exchange (ETDEWEB)

The unsteady two-dimensional laminar flow of a viscous incompressible electrically conducting micro polar fluid via a porous medium past a semi-infinite vertical porous moving plate in the presence of a transverse magnetic field is studied. A uniform magnetic field acts perpendicularly to the porous surface in which absorbs the micro polar fluid with a suction velocity varying with time. The effects of material parameters on the velocity and temperature fields across the boundary layer are investigated. The method of solution can be applied for small perturbation approximation. Numerical results of velocity and temperature distributions of micro polar fluids are compared with the corresponding flow problems for a Newtonian fluid. (author)

2001-07-01

33

Reliability-based design optimization of an FPSO riser support using moving least squares response surface meta-models  

British Library Electronic Table of Contents (United Kingdom)

The paper deals with the reliability-based design optimization (RBDO) of a riser support installed on a floating production storage and offloading (FPSO) unit under operation, extreme, damaged, and one line failure cases and installation loading conditions. The optimization problem is formulated such that probabilistic thickness variables described with random characteristics are determined by minimizing the weight of the riser support structure subjected to stress constraints for the given target reliability. The initial design model is generated based on actual FPSO riser support specifications. The finite element analysis is conducted using NASTRAN, and the probabilistic optimal solutions are obtained via the moving least squares method in the context of RBDO using a response surface me...

2011-01-01

34

Reflux boiling heat removal in a scaled TMI-2 system test facility  

International Nuclear Information System (INIS)

An investigation of decay heat removal by the reflux boiling process was performed on a 1/18 linear-scaled test facility simulating the Three Mile Island (TMI-2) primary system. The objective was to clarify reflux boiling phenomena and core cooling effectiveness. Principal test variables included: core power, primary system water and gas inventories, and steam generator secondary-side coolant flow rate. Of 49 tests conducted, 43 achieved a steady-state heat rejection mode within 3 hours. Subsequent analyses identified two distinct reflux boiling modes. Based upon our current understanding, reflux boiling appears to be an effective process for removing decay heat in a broad range of the conditions investigated for a plant of the TMI configuration.

1980-06-01

35

Prevalence and Incidence of HCV Infection among Vietnam Heroin Users with Recent Onset of Injection  

British Library Electronic Table of Contents (United Kingdom)

HCV infection continues to spread at an alarming rate among IDU populations. The available evidence suggests that HCV is acquired relatively quickly following onset of injection. However, there are few prospective studies of HCV acquisition, particularly among IDU populations in resource-poor settings. A sample of young male heroin injectors with recent onset of injection (<4?years) was recruited in Hanoi, Vietnam for a prospective assessment of the early course of injection (n?=?179). Both behavioral and biological assessments (including detailed retrospective assessment of injection initiation) were conducted at baseline and repeated at 6-month intervals for a period of 16?months. Variables associated with HCV infection (p value?p value?=?0.0005). In multivariate logistic regression anal...

2010-01-01

36

Numerical simulation of shallow-water dam break flows in open channels using smoothed particle hydrodynamics  

British Library Electronic Table of Contents (United Kingdom)

SummaryA meshless numerical model is proposed to investigate shallow-water dam break flows in 1D open channels. The numerical model is to solve the shallow water equations (SWE) based on smoothed particle hydrodynamics (SPH). The concept of slice water particles (SWP) is adopted in the SPH-SWE formulation. The numerical sensitivity analysis is first performed to study the appropriate SWP number and variable smoothing length through dam break flows in an idealized 1D channel with dry/wet beds. Extensive validation by comparison with laboratory and field data is next conducted for four benchmark problems, including dam break flows through a rough flat channel, a rough bumpy channel with various downstream boundary conditions, a nonprismatic channel, and a realistic scale model of the Toce ri...

2011-01-01

37

Environmental Impact Analysis Using Hybrid Decision Support Framework: A Transportation Project Case Study  

British Library Electronic Table of Contents (United Kingdom)

An Environmental Impact Assessment (EIA) study for any project is a time- consuming process because it has a large number of dependent and independent variables that must be taken into account. Although EIAs are dependent on geo-spatial information in order to make an assessment, there are no standard rules for conducting an environmental assessment. In addition, each assessment objective is case-dependent, based on what information is available. This paper presents a new framework for the analysis phase of the Environmental Impact Assessment (EIA) for projects, based on the integration between remote sensing technology, geographic information systems, and spatial modeling. The framework comprehensively analyzes the environmental vulnerability around the project areas and its impact on the...

2010-01-01

38

Assessing vineyard water status using the reflectance based Water Index  

British Library Electronic Table of Contents (United Kingdom)

In the Mediterranean arc, vines for wine production are mainly grown without the support of irrigation. Under such conditions, site variables affecting the extent and seasonal timing of water deficits are the dominant environmental constraints for grape production. Moreover, water availability and vine water status are the factors most comprehensively determining fruit composition and, thus, wine quality. Therefore, monitoring the extent of water stress in vines might be a valuable tool for the optimisation of grape yield and quality. The objective of this study was to evaluate the feasibility of using the reflectance based Water Index (WI) to estimate vine water status at the leaf and canopy levels. The study was conducted on Vitis vinifera cv. Chardonnay potted plants submitted to contra...

2010-01-01

39

A novel medium devoid of ruminant peptone for high yield growth of Mycoplasma ovipneumoniae  

British Library Electronic Table of Contents (United Kingdom)

Mycoplasma ovipneumoniae is considered an emerging veterinary pathogen causing pneumonia in sheep and goats worldwide. Currently it has not been possible to define a growth medium that yields the maximum growth of M. ovipneumoniae within a short incubation period. Growth yields of M. ovipneumoniae in Eatons medium are variable and not as consistently high as those seen with other Mycoplasma spp. This study investigated the ability of different M. ovipneumoniae field strains to grow in various media formulations, where PPLO broth was replaced by a vegetable protein source, and comparisons were made in terms of strain viability in Eatons medium. Studies were also conducted to determine the optimal carbohydrate source for use in the M. ovipneumoniae medium. Generally, it was found that differ...

2008-01-01

41

Interactions in multiple schedules: negative induction with squirrel monkeys1  

UK PubMed Central (United Kingdom)

In Experiment I, lever pressing by squirrel monkeys was maintained under a sequence of variable-interval, multiple variable-interval variable-interval, and multiple variable-interval extinction schedules...Full Text Available

1978-11-01

42

US Army workshop on low-heat-rejection engines (4th). Sessions report for 29-31 March 1989  

Energy Technology Data Exchange (ETDEWEB)

There are a number of characteristics exhibited by ceramic materials that may provide potential benefits for the reciprocating internal combustion engine. However, the brittle nature of these materials together with a variability in strength has created difficulties in applying ceramic materials to the engine environment. Although a wide range of physical properties is available from contemporary ceramic materials, a material offering consistently high strength has yet to be developed. For sliding-contact applications, desirable characteristics include good wear resistance, low friction, ability to join metals and good heat dissipation. Test results have shown that cam/follower components with cast iron cam sliding on a silicon nitride follower exhibit very low wear rates. The application of silicon carbide to face seals has also shown substantial reductions in both friction and wear when compared with conventional materials. The use of ceramic materials for ...

1989-03-31

43

Effects of transverse magnetic field, Prandtl number and Reynolds number on non-Darcy mixed convective flow of an incompressible viscous fluid past a porous vertical flat plate in a saturated porous medium  

Energy Technology Data Exchange (ETDEWEB)

The effect of transverse magnetic field parameter (Hartmann number, Ha) Reynolds number (Re) and Prandtl number (Pr) on the mixed convection flow past a semi-infinite vertical porous plate in a non-Darcian porous medium with variable viscosity and porosity, viscous dissipation and fluid-solid thermal conductivity ratio in the presence of plate transpiration (lateral mass flux) is investigated theoretically and numerically using Keller`s implicit finite difference scheme. It is shown that the Harmann number acts as a retarding force and increases the momentum boundary layer thickness, analogous to the flow against a positive pressure gradient, simultaneously decreasing local skin friction (shear stress). The heat transfer rate is however enhanced by the magnetic field (for positive values of the Eckert number) since the fluid is heated and temperature gradients become reduced between the fluid and the plate, with important potential applications ...

1997-01-01

44

Carbon-bonded carbon fiber insulation for radioisotope space power systems  

Energy Technology Data Exchange (ETDEWEB)

A carbon-bonded carbon fiber (CBCF) insulation developed for a radioisotope heat source is made from chopped rayon fiber about 10..mu..m long, which is carbonized and bonded with phenolic resin particles. The CBCF is an excellent lightweight insulating material with a nominal density of 0.2 Mg/m/sup 3/ and a thermal conductivity of 0.24 W/(m-K) in vacuum at 2000/sup 0/C. (Several attributes that make CBCF particularly suitable for the heat source application have been identified.) These include light weight, low thermal conductivity, chemical compatibility, and hightemperature capabilities. The mechanical strength of CBCF insulation is satisfactory for the application. The basic fabrication technique was refined to eliminate undesirable large pores and cracks often present in materials fabricated by earlier techniques. Also, processing was scaled up to increase the fabrication rate by a factor of 10. The specific properties of the CBCF were ...

1985-05-01

45

Carbon-bonded carbon fiber insulation for radioisotope space power systems  

Energy Technology Data Exchange (ETDEWEB)

A carbon-bonded carbon fiber (CBCF) insulation developed for a radioisotope heat source is made from chopped rayon fiber about 10 ..mu..m in diameter and 250 ..mu..m long, which is carbonized and bonded with phenolic resin particles. The CBCF is an excellent lightweight insulating material with a nominal density of 0.2 Mg/m/sup 3/ and a thermal conductivity of 0.24 W/(m-K) in vacuum at 2000/sup 0/C. Several attributes that make CBCF particularly suitable for the heat source application have been identified. These include light weight, low thermal conductivity, chemical compatibility, and high-temperature capabilities. The mechanical strength of CBCF insulation is satisfactory for the application. The basic fabrication technique was refined to eliminate undesirable large pores and cracks often present in materials fabricated by earlier techniques. Also, processing was scaled up to increase the fabrication rate by a factor of 10. The specific ...

1985-05-01

46

The comparative uptake and interaction of several radionuclides in the trophic levels surrounding the Los Alamos Meson Physics Facility (LAMPF) waste water ponds  

International Nuclear Information System (INIS)

A study was undertaken to examine the uptake, distribution, and interaction of five activation products (Co-57, Be-7, Cs-134, Rb-83, and Mn-54) within the biotic and abiotic components surrounding the waste treatment lagoons of the Los Alamos Meson Physics Facility (LAMPF). The study attempted to ascertain where, and what specific interactions were taking place among the isotopes and the biotic/abiotic components. A statistical approach, utilizing Multivariate Analysis of Variance (MANOVA), was conducted testing the radioisotopic concentrations by (1) the trophic levels (TROPLVL) in each position sampled on the grid, (2) where sampled on the grid (TRAN), (3) where sampled with-in each grid line (PLOT), and (4) the side with which sampled (SIDE). This provided both the dependent and independent variables that would be tested. The Null Hypothesis (Ho) tested the difference in the mean values of the isotopes within/between each of the four ...

1983-05-01

47

The comparative uptake and interaction of several radionuclides in the trophic levels surrounding the Los Alamos Meson Physics Facility (LAMPF) waste water ponds  

Energy Technology Data Exchange (ETDEWEB)

A study was undertaken to examine the uptake, distribution, and interaction of five activation products (Co-57, Be-7, Cs-134, Rb-83, and Mn-54) within the biotic and abiotic components surrounding the waste treatment lagoons of the Los Alamos Meson Physics Facility (LAMPF). The study attempted to ascertain where, and what specific interactions were taking place among the isotopes and the biotic/abiotic components. A statistical approach, utilizing Multivariate Analysis of Variance (MANOVA), was conducted testing the radioisotopic concentrations by (1) the trophic levels (TROPLVL) in each position sampled on the grid, (2) where sampled on the grid (TRAN), (3) where sampled with-in each grid line (PLOT), and (4) the side with which sampled (SIDE). This provided both the dependent and independent variables that would be tested. The Null Hypothesis (Ho) tested the difference in the mean values of the isotopes within/between each of the four ...

1989-08-01

48

Variable elimination in chemical reaction networks with mass action kinetics  

CERN Document Server

We consider chemical reaction networks taken with mass action kinetics. The steady states of such a system are solutions to a system of polynomial equations. Even for small systems the task of finding the solutions is daunting. We develop an algebraic framework and procedure for linear elimination of variables. The procedure reduces the variables in the system to a set of "core" variables by eliminating variables corresponding to a set of non-interacting species. The steady states are parameterized algebraically by the core variables, and a graphical condition is given for when a steady state with positive core variables necessarily have all variables positive. Further, we characterize graphically the sets of eliminated variables that are constrained by a conservation law and show that this conservation law takes a ...

2011-01-01

49

Development and characterization of carbon-bonded carbon fiber insulation for radioisotope space power systems  

Energy Technology Data Exchange (ETDEWEB)

The General-Purpose Heat Source (GPHS), an improved radioisotope heat source, employs a unique thermal insulation material, carbon-bonded carbon fiber (CBCF), to protect the fuel capsule and to help achieve the highest possible specific power. The CBCF insulation is made from chopped rayon fiber about 10 ..mu..m in diameter and 250 ..mu..m long, which is carbonized and bonded with phenolic resin particles. The CBCF shapes, both tubes and plates, are formed in a multiple molding facility by vacuum molding a water slurry of the carbonized chopped-rayon fiber (54 wt %) and phenolic resin (46 wt %). The molded shapes are subsequently dried and cured. Final carbonization of the resin is at 1600/sup 0/C. Machining to close tolerances (+-0.08 mm) is accomplished by conventional tooling and fixturing. The resulting material is an excellent lightweight insulation with a nominal density of 0.2 Mg/m/sup 3/ and a thermal conductivity of 0.24 W(m.K) in vacuum at 2000/sup 0/C. ...

1985-06-01

50

Unsteady state heat transfer in the vertical walls of a building  

Energy Technology Data Exchange (ETDEWEB)

The unsteady state heat transfer behaviour of a vertical wall subject to the effects of uniform radiation is investigated and the dimensional analysis of combined heat transfers by conduction, convection and radiation is presented. The convective heat transfer coefficients used in the numerical model are determined experimentally by means of an assembly resembling the conditions encountered in the dwelling (variable temperatures and heat flows in time and space, wall associated with a floor, radiative flux outside the wall). In routine conditions (homogeneous wall dimensions, temperature differentials less than 40/sup 0/C), it is shown that the problem depends in practice on three parameters (instead of five) and that nomographs can give the energy accumulated in the wall as a function of its geometric and thermal charactersitics and the external conditions (type and thickness of material, changes in incident flux, convection over the height of ...

1982-12-01

51

Transient performance of FFTF [Fast Flux Test Facility] reference fuel  

International Nuclear Information System (INIS)

Fourteen irradiated Fast Flux Test Facility (FFTF) fuel pins were subjected to representative overpower transients in six flowing sodium loop experiments conducted in the TREAT reactor. The transient tests were extended to substantial overpower levels well beyond protected levels, with some tests intentionally run to failure to identify failure thresholds and characteristics. Test variables included transient ramp rate (5, 50, and 100 cents/s) and burnup (2 to 58 MWd/kg). Performance limits and failure characteristics were identified, and cladding strain and fuel melting data were obtained for development and verification of transient analysis codes. The test results demonstrated that FFTF Reference fuel pins are capable of surviving overpower levels well beyond the FFTF secondary Plant Protection System (PPS) trip limit of 1.25 times normal rated power. Based on analytical evaluations to interpolate and extrapolate test results to the full ...

1986-09-07

52

Trace metal concentrations in estuaries and coastal regions  

Energy Technology Data Exchange (ETDEWEB)

Estuaries and coastal regions are highly variable in the physical and hydrographic conditions. As a result of heavy urbanization and industrialization of the head waters of most estuaries, there are substantial localized inputs of contaminants to the estuary. These factors combined with the flushing characteristics of individual estuaries to create relatively unique features that result in variation in the typical levels of trace metals for these systems. This makes intercomparison of the estuaries difficult. Comparability among estuaries becomes even more difficult when metals analyses are conducted without proper control of field and laboratory contamination, now firmly established in the trace metal analytical literature as a prerequisite for reliable marine trace metals analysis. This paper compares the concentrations of selected trace metal (Ag, Cd, Cu, Ni, Pb, and Zn) concentrations in the waters of several major estuaries of the United ...

1994-12-31

53

Solar desalination using humidification-dehumidification processes. Part II. An experimental investigation  

Energy Technology Data Exchange (ETDEWEB)

An experimental investigation of a humidification-dehumidification desalination (HDD) process using solar energy at the weather conditions of Suez City, Egypt, is presented. A test rig is designed and constructed to conduct this investigation under different environmental and operating conditions. The test rig consists of a solar water heater (concentrator solar collector type), solar air heater (flat plate solar collector type), humidifier tower and dehumidifier exchanger. Different variables are examined including the feed water flow rate, the air flow rate, the cooling water flow rate in the dehumidifier and the weather conditions. Comparisons between the experimental results and other published results are presented. It is found that the results of the developed mathematical model by the same authors are in good agreement with the experimental results. The tested results show that the productivity of the system is strongly affected by the ...

2004-05-01

54

Solar desalination using humidification-dehumidification processes. Part II. An experimental investigation  

International Nuclear Information System (INIS)

An experimental investigation of a humidification-dehumidification desalination (HDD) process using solar energy at the weather conditions of Suez City, Egypt, is presented. A test rig is designed and constructed to conduct this investigation under different environmental and operating conditions. The test rig consists of a solar water heater (concentrator solar collector type), solar air heater (flat plate solar collector type), humidifier tower and dehumidifier exchanger. Different variables are examined including the feed water flow rate, the air flow rate, the cooling water flow rate in the dehumidifier and the weather conditions. Comparisons between the experimental results and other published results are presented. It is found that the results of the developed mathematical model by the same authors are in good agreement with the experimental results. The tested results show that the productivity of the system is strongly affected by the ...

2004-05-01

55

Solar desalination using humidification dehumidification processes. Pt. 2. An experimental investigation  

Energy Technology Data Exchange (ETDEWEB)

An experimental investigation of a humidification-dehumidification desalination (HDD) process using solar energy at the weather conditions of Suez City, Egypt, is presented. A test rig is designed and constructed to conduct this investigation under different environmental and operating conditions. The test rig consists of a solar water heater (concentrator solar collector type), solar air heater (flat plate solar collector type), humidifier tower and dehumidifier exchanger. Different variables are examined including the feed water flow rate, the air flow rate, the cooling water flow rate in the dehumidifier and the weather conditions. Comparisons between the experimental results and other published results are presented. It is found that the results of the developed mathematical model by the same authors are in good agreement with the experimental results. The tested results show that the productivity of the system is strongly affected by the ...

2004-05-01

56

Metallic glasses as new catalyst systems for energy conversion: Final report  

Energy Technology Data Exchange (ETDEWEB)

Pd-Si metallic glasses have been utilized as catalysts in the Fischer-Tropsch reaction. The glasses are selective of ethane, whereas the in-situ crystallized glasses select a range of hydrocarbons characteristic of conventional Pd catalysts. This shift in selectivity has been observed in other hydrogenation reactions. Surface crystallization caused by the reaction conditions causes variable selectivity. Crystallization in reaction conditions has been monitored by DSC. During the course of the grant we developed the use of (+)- apopinene (6,6-dimethyl-1R,5R-bicyclo(3.1.1)hept-2-ene) as a molecular probe for determining the number and kinds of active sites on metallic glass catalysts. To accomplish this we conducted many experiments for comparison on other types of catalysts. These were foils, powders, and highly dispersed metals on several different supports. The glassy surfaces appear to be three dimensionally random (hilly or rolling) with ...

1987-01-01

57

Low-severity catalytic two-stage liquefaction process: Final summary report, 1 September 1985--February 1988  

Science.gov (United States)

Hydrocarbon Research, Inc. (HRI) has been actively involved in the development of a low-severity two-stage coal liquefaction process. Since inception of the concept of low-temperature, first-stage hydrogenation followed by a higher temperature second-stage hydrocracking operation, in 1982, efforts have been concentrated on this process. This final report covers development efforts under both contracts from October 1983 to March 1988. The major objective was to reduce process severity and improve economics. Studies were conducted on Illinois No. 6 and Ohio No. 5/6 bitumen coals and included several process variable experiments, catalyst testing, use of cleaned coal and evaluation process recycle options. The total effort included 277 days onstream of continuous bench-scale operations, and data analysis and process modeling, and engineering design and economic studies are reported herein. 13 refs., 15 figs., 40 tabs.

1988-09-01

58

Investigation of the effect of process parameters on the formation and characteristics of recast layer in wire-EDM of Inconel 718  

Energy Technology Data Exchange (ETDEWEB)

Inconel 718 is a high nickel content superalloy possessing high strength at elevated temperatures and resistance to oxidation and corrosion. The non-traditional manufacturing process of wire-electrical discharge machining (EDM) possesses many advantages over traditional machining during the manufacture of Inconel 718 parts. However, certain detrimental effects are also present and are due in large part to the formation of the recast layer. An experimental investigation was conducted to determine the main EDM parameters which contribute to recast layer formation in Inconel 718. It was found that average recast layer thickness increased primarily with energy per spark, peak discharge current, and current pulse duration. Over the range of parameters tested, the recast layer was observed to be between 5 and 9 {micro}m in average thickness, although highly variable in nature. The recast material was found to possess in-plane tensile residual ...

2009-07-01

59

Implications of the Electrostatic Approximation in the Beam Frame on the Nonlinear Vlasov-Maxwell Equations for Intense Beam Propagation  

Energy Technology Data Exchange (ETDEWEB)

This paper develops a clear procedure for solving the nonlinear Vlasov-Maxwell equations for a one-component intense charged particle beam or finite-length charge bunch propagating through a cylindrical conducting pipe (radius r = r(subscript)w = const.), and confined by an applied focusing force. In particular, the nonlinear Vlasov-Maxwell equations are Lorentz-transformed to the beam frame ('primed' variables) moving with axial velocity relative to the laboratory. In the beam frame, the particle motions are nonrelativistic for the applications of practical interest, already a major simplification. Then, in the beam frame, we make the electrostatic approximation which fully incorporates beam space-charge effects, but neglects any fast electromagnetic processes with transverse polarization (e.g., light waves). The resulting Vlasov-Maxwell equations are then Lorentz-transformed back to the laboratory frame, and properties of ...

2001-11-08

60

Atomization and deposition rates in vertical annular two-phase flow  

Energy Technology Data Exchange (ETDEWEB)

The two-phase annular regime is characterized by a high velocity gas stream flowing through the core of the tube surrounded by a thin, highly agitated liquid film flowing concurrently along the tube wall. Part of the liquid may be entrained as droplets in the gas phase. The specific goals of this study were to measure fully developed rates of interchange and entrained fraction over a wide range of flow variables in the upward configuration of the annular regime, to obtain a more fundamental understanding of liquid interchange phenomena via studies of liquid film characteristics and to develop an improved design correlation for the entrained fraction. Towards this end, air-water experiments were conducted in two vertical pipe lines, 2.54 and 4.20 cm in diameter. Air velocities ranging from 20 to 120 m/s and total liquid flow rates ranging from 10 to 100 g/s were investigated. Two models for the rate of atomization, proposed by Tatterson (1975) ...

1988-01-01

61

Analysis of the relationship between the coal properties and their liquefaction characteristics by using the coal data base; Tanshu data base ni yoru tanshitsu to ekika tokusei no kaiseki  

Energy Technology Data Exchange (ETDEWEB)

The relationship between coal properties and liquefaction or gasification characteristics was analyzed by using the analysis and test results and liquefaction characteristics in the coal data base. On liquefaction reaction, the close relation between an oil yield and coal constituent composition or a coal rank is well-known. Various multivariable regression analyses were conducted by using 6 factors as variables such as calorific value, volatile component, O/C and H/C atomic ratios, exinite+vitrinite content and vitrinite reflectance, and liquefaction characteristics as variate. On liquefaction characteristics, the oil yield of dehydrated and deashed coals, asphaltene yield, hydrogen consumption, produced water and gas quantities, and oil+asphaltene yield were predicted. The theoretical gasification efficiency of each specimen was calculated to evaluate the liquefaction reaction obtained. As a result, the oil yield increased with H/C atomic ...

1996-10-28

62

Analysis of EPA`s cost-effectiveness study for the coastal oil and gas effluent limitations guidelines  

Energy Technology Data Exchange (ETDEWEB)

The US Environmental Protection Agency (EPA) conducted a cost-effectiveness (CE) analysis to estimate the incremental cost of complying with the proposed effluent limitation guidelines (ELGs) for the coastal oil and gas industry (EPA 1995a). EPA`s CE analysis calculates the pounds of each pollutant that would be removed if the chosen discharge option is selected. In 1993, EPA issued final ELGs for the offshore oil and gas industry and published an offshore CE analysis. The chemical characteristics of produced water from the offshore region are essentially the same as those of produced water from the coastal region. It was surprising, therefore, that EPA chose a much longer list of pollutants and generally stricter weighting factors for the coastal CE analysis. This report reviews the data, assumptions, and analyses used in EPA`s coastal CE analysis and identifies alternate data, assumptions, and analyses that could lead to significantly different cost-effectiveness ...

1995-05-01

63

Organization and safety in nuclear power plants  

International Nuclear Information System (INIS)

Perspectives from industry, academe, and the NRC are brought together in this report and used to develop a logical framework that links management and organization factors and safety in nuclear power plant performance. The framework focuses on intermediate outcomes which can be predicted by organizational and management factors, and which are subsequently linked to safety. The intermediate outcomes are efficiency, compliance, quality, and innovation. The organization and management factors can be classified in terms of environment, context, organizational governance, organizational design, and emergent processes. Initial empirical analyses were conducted on a limited set of hypotheses derived from the framework. One set of hypotheses concerned the relationships between one of the intermediate outcome variables, efficiency, as measured by critical hours and outage rate, and safety, as measured by 5 NRC indicators. Results of the analysis suggest ...

68

Lead-203 for skeletal imaging  

International Nuclear Information System (INIS)

... biological variability body distribution kidneys labelled compounds lead 203

70

Final report of the second dye-tracer test at the Chestnut Ridge Security Pits, Y-12 Plant, Oak Ridge, Tennessee  

Energy Technology Data Exchange (ETDEWEB)

Martin Marietta Energy Systems, Inc. (Energy Systems) manages a closed hazardous waste disposal unit, Chestnut Ridge Security Pits (CRSP), in the form of two trenches and several auger-holes, located on top of the eastern portion of Chestnut Ridge at the Department of Energy (DOE) Oak Ridge Y-12 Plant in Tennessee. The groundwater monitoring system for the unit presently consists of a network of upgradient and downgradient monitor wells. To investigate the discharge of groundwater to springs and streams. An initial dye-tracer study was conducted during the driest part of 1990. The dye was detected at some of the monitoring sites, but verification was necessary due to the proximity of some sites to extraneous dye sources. A second dye-tracer was conducted during the wet weather season. The actual test commenced during the first week of February 1992 with a 4-week baseline monitoring period to determine the inherent ...

1992-11-01

71

Final report of the second dye-tracer test at the Chesnut Ridge Security Pits, Y-12 Plant, Oak Ridge, Tennessee  

Energy Technology Data Exchange (ETDEWEB)

Martin Marietta Energy Systems, Inc. (Energy Systems) manages a closed hazardous waste disposal unit, Chestnut Ridge Security Pits (CRSP), in the form of two trenches and several auger-holes, located on top of the eastern portion of Chestnut Ridge at the Department of Energy (DOE) Oak Ridge Y-12 Plant in Tennessee. The groundwater monitoring system for the unit presently consists of a network of upgradient and downgradient monitor wells. To investigate the discharge of groundwater to springs and streams, Energy Systems, through Geraghty and Miller, Inc., conducted an initial dye-tracer study during the driest part of 1990. The dye was detected at some of the monitoring sites, but verification was necessary due to the proximity of some sites to extraneous dye sources. Based on the results of the initial study, Energy Systems recommended to the Tennessee Department of Environment and Conservation (TDEC) in the 1990 Groundwater Quality Assessment Report (GWQAR) (HSW ...

1992-11-01

72

FY 2000 Feasibility study on the environmentally-friendly coal utilization systems as part of the international project for coal utilization measures. Feasibility study on supporting introduction of the environmentally-friendly coal utilization systems in Vietnam (Model project for introduction of advanced coal preparation systems); 2000 nendo kokusai sekitan riyo taisaku jigyo chosa hokokusho. Kankyo chowagata sekitan riyo system kanosei chosa jigyo Vietnam ni okeru kankyo chowagata sekitan riyo system donyu shien jigyo (kodo sentan system donyu model jigyo kanosei chosa jigyo)  

Energy Technology Data Exchange (ETDEWEB)

The feasibility study was conducted on a model project in Vietnam, aimed at solving the environmental pollution problems resulting from use of coal by demonstrating and disseminating the Japan's environmental technologies in the Southeast Asian countries. The feasibility study was conducted for the Cua Ong Coal Preparation Enterprise, which has the largest coal preparation capacity in Vietnam and port facilities. It is treating raw coal from 10 coal mines for classification and preparation, and shipping coal of various types that meet the standards for domestic use and export. The survey results point out that unrecovered coal remains in waste water discharged from the coal preparation plants to pollute the sea area, and that quantity of the refuse increases because of the unrecovered coal it contains. The environmental technologies needed to introduce include modification to variable wave pattern type jigging ...

2001-06-01

73

Confrontation between stellar pulsation and evolution; Proceedings of the Conference (ASP Series, Vol. 11), Bologna, Italy, May 28-31, 1990  

International Nuclear Information System (INIS)

Attention is given to the folowing topics: population I and II variable stars; LP variables, the sun, and mass determination; and predegenerate and degenerate variables. Particular papers are presented on alternative evolutionary approaches to the absolute magnitude of the RR Lyrae variables; the evolution of the Cepheid stars; nonradial pulsations in rapidly rotating Delta Scuti stars; dynamical models of dust shells around Mira variables; and pulsations of central stars of planetary nebulae.

1990-05-28

74

CFD investigation of balcony spill plumes in atria  

Energy Technology Data Exchange (ETDEWEB)

Smoke management in buildings during fire events often uses mechanical ventilation systems to maintain smoke layer elevation above a safe evacuation path. Design of these systems requires accurate correlations for the smoke production rate of the buoyant fire plume. One design issue is the smoke production rate of fire plumes which spill out from a fire compartment, under a balcony and up through an atrium or other large volume. Current engineering correlations for these balcony spill plumes are based on a combination of one-tenth scale test data and theoretical analysis. Questions have arisen over the suitability of these correlations for real-scale designs. A combined program of full-scale experimentation and CFD modeling is being conducted to analyze the accuracy of these correlations. A full-scale experimental facility was constructed with a 5 m by 5 m by 15 m fire compartment connected to a four-story atrium. Propane fires in the compartment produce balcony ...

2004-07-01

75

CFD investigation of balcony spill plumes in atria  

International Nuclear Information System (INIS)

Smoke management in buildings during fire events often uses mechanical ventilation systems to maintain smoke layer elevation above a safe evacuation path. Design of these systems requires accurate correlations for the smoke production rate of the buoyant fire plume. One design issue is the smoke production rate of fire plumes which spill out from a fire compartment, under a balcony and up through an atrium or other large volume. Current engineering correlations for these balcony spill plumes are based on a combination of one-tenth scale test data and theoretical analysis. Questions have arisen over the suitability of these correlations for real-scale designs. A combined program of full-scale experimentation and CFD modeling is being conducted to analyze the accuracy of these correlations. A full-scale experimental facility was constructed with a 5 m by 5 m by 15 m fire compartment connected to a four-story atrium. Propane fires in the compartment produce balcony ...

2004-05-09

76

Variable Pathogenicity Determines Individual Lifespan in Caenorhabditis elegans  

UK PubMed Central (United Kingdom)

A common property of aging in all animals is that chronologically and genetically identical individuals age at different rates. To unveil mechanisms that influence aging variability, we identified markers...Full Text Available

2011-04-01

77

Variability In Motor Learning: Relocating, Channeling and Reducing Noise  

UK PubMed Central (United Kingdom)

Variability in motor performance decreases with practice but is never entirely eliminated, due in part to inherent motor noise. The present study develops a method that quantifies how performers...Full Text Available

2009-02-01

78

The Characterisation of Three Types of Genes that Overlie Copy Number Variable Regions  

UK PubMed Central (United Kingdom)

BackgroundDue to the increased accuracy of Copy Number Variable region (CNV) break point mapping, it is now possible to say with a reasonable degree of confidence whether a gene...Full Text Available

79

Numerical optimization of spherical variable-line-spacing grating X-ray spectrometers  

UK PubMed Central (United Kingdom)

Operation of an X-ray spectrometer based on a spherical variable-line-spacing (VLS) grating is analyzed using dedicated ray-tracing software allowing fast optimization of the grating parameters and...Full Text Available

2011-03-01

80

Intra-Individual Variability in Alzheimer's Disease and Cognitive Aging: Definitions, Context, and Effect Sizes  

UK PubMed Central (United Kingdom)

Background/AimsTo explore different definitions of intra-individual variability (IIV) to summarize performance on commonly utilized cognitive tests (Mini Mental State Exam; Clock...Full Text Available

81

Guided Cell Migration on Microtextured Substrates with Variable Local Density and Anisotropy  

UK PubMed Central (United Kingdom)

This work reports the design of and experimentation with a topographically patterned cell culture substrate of variable local density and anisotropy as a facile and efficient platform to guide...Full Text Available

2009-02-06

82

Considerable Variability in Platelet Activity among Patients with Coronary Artery Disease in Response to an Increased Maintenance Dose of Clopidogrel  

UK PubMed Central (United Kingdom)

BackgroundVariable platelet response to clopidogrel has been widely observed. Studies have shown that the mean aggregation response to clopidogrel can be changed...Full Text Available

2009-05-01

83

Comparative optimism in models involving both classical clinical and gene expression information  

UK PubMed Central (United Kingdom)

BackgroundIn cancer research, most clinical variables have already been investigated and are now well established. The use of transcriptomic variables has raised two problems: restricting...Full Text Available

84

Adaptive Thresholding for Improving Sensitivity in Single-Trial Simultaneous EEG/fMRI  

UK PubMed Central (United Kingdom)

A common approach used to fuse simultaneously recorded EEG and fMRI is to correlate trial-by-trial variability in the EEG, or variability of components derived therefrom, with the blood oxygenation...Full Text Available

87

Mira variables - Pulsation, mass loss and evolution  

International Nuclear Information System (INIS)

Recent developments in the analysis of Mira atmosphere, the determination of the pulsation mode, the problem of mass loss, and the evolution of the Mira variables are covered. Model atmospheres for Mira variables, including the opacities of the molecules expected in very late M-type atmospheres are discussed. The pulsation constant for Omicron Ceti is evaluated using T(eff) = 2900 + or - 200 K, and it is concluded that Miras are fundamental mode pulsators. The importance of molecular opacity to the driving of mass loss is evaluated, and it is pointed out that the radiation pressure on molecules is not a major factor in driving mass loss from Mira. Mass loss is considered as a factor in the calculations of the periods for Mira variables. 30 refs.

1990-05-28

88

Asymptotic functions of many variables and singular operations with Schwartz distributions  

International Nuclear Information System (INIS)

A theory of the asymptotic functions for the case of many variables is presented. It is shown that the class F(R"N) of these generalized functions is closed in respect to the linear algebraic and analytic operations, multiplication as well as a set of linear and polynomial changes of the variables. The existence in F(R"N) of analogues (consistent with the linear operations) of the Schwartz distributions with point support is proved. In terms of these analogues, some formulae for singular products and changes of variables of the Dirac #delta#-function and its derivatives #delta#"("i")(x), x is an element of R"N, are given. (author). 14 refs.

1992-10-19

89

A Simulation Model for Estimating Airport Terminal Area ...  

Science.gov (United States)

... AIR TRAFFIC, TERMINAL FLIGHT ... FLIGHT, RANDOM VARIABLES, STOCHASTIC PROCESSES ... COMPUTER PROGRAMS, QUEUEING THEORY. ...

1971-05-01

90

Variable-speed hydro evolves  

Energy Technology Data Exchange (ETDEWEB)

Success in improving hydropower project efficiency has opened more global markets for variable-speed generator technology. Manufacturers continue to test the markets as the technology evolves. The potential of variable-speed application becomes evident considering that more than 150 pumped storage plants, with a combined capacity exceeding 100,000 MW, are in operation globally.

1993-10-01

91

Tidal spin-up and magnetic braking in cataclysmic variables  

International Nuclear Information System (INIS)

Based on proposed models for the tidal spin-up and magnetic braking of stars with a convective outer envelope, it is suggested that the rotation of secondaries in cataclysmic variables is not necessarily synchronized with the orbital revolution. This may provide an explanation for the observed large range in the mass transfer rate (at the same orbital period) of cataclysmic variables above the period gap. (author).

92

Moderate deviations for stationary sequences of Hilbert valued bounded random variables  

CERN Document Server

In this paper, we derive the moderate deviation principle for stationary sequences of bounded random variables with values in a Hilbert space. The conditions obtained are expressed in terms of martingale-type conditions. The main tools are martingale approximations and a new Hoeffding inequality for non adpated sequences of Hilbert-valued random variables. Applications to Cramer-Von Mises statistics, functions of linear processes and stable Markov chains are given.

2008-01-01

93

Long-run determinants of pollution: A robustness analysis  

British Library Electronic Table of Contents (United Kingdom)

This paper examines how robust economic, political, and demographic variables are related to water and air pollution. Employing Bayesian Averaging of Classical Estimates (BACE) for a cross section of 47 countries, 34 variables and 3 proxies for air and water pollution over a period from 1980 to 2000 we confirm the environmental Kuznets curve hypothesis and highlight the relevance of variables that are not directly related to production.

2009-01-01

94

Joint distributions and tachyons  

International Nuclear Information System (INIS)

In recent years there has been a renewed interest in the treatment of quantum mechanics in terms of joint distribution functions, i.e. functions of momentum and position coordinates p and q. The author considers j.d.f. in the sense of classical probability theory of a stochastic variable. The j.d.f. is then interpreted as the probability that the variables p and q have certain values, the variables being considered as a property possessed by the object system. This formalism is used to provide a unified description of bradyons and tachyons. (Auth.).

95

EUVE Observations of Nonmagnetic Cataclysmic Variables  

Energy Technology Data Exchange (ETDEWEB)

The authors summarize EUVE's contribution to the study of the boundary layer emission of high accretion-rate nonmagnetic cataclysmic variables, especially the dwarf novae SS Cyg, U Gem, VW Hyi, and OY Car in outburst. They discuss the optical and EUV light curves of dwarf nova outbursts, the quasi-coherent oscillations of the EUV flux of SS Cyg, the EUV spectra of dwarf novae, and the future of EUV observations of cataclysmic variables.

2001-09-05

96

Circadian and circatrigintan respiratory and related intermodulations in the crab Barytelphusa guerini.  

Science.gov (United States)

Respiration and related physiologic variables in different tissues of Barytelphusa guerini and the respiration of this freshwater crab as a whole are closely synchronized in phase and in frequency along the circadian scale, in the face of large differences in circadian amplitude. A very close timing of most of the 36 variables examined in 2 separate circadian profiles and a modulation of some of these variables in added profiles as a function of lunar stage are clearly demonstrable, statistically significant and illustrative of time relations at 2 interacting frequencies. PMID:6745009

98

To Repair or to Rebuild? Analyzing Personnel Security ...  

Science.gov (United States)

... Screening Adjudication Monitoring Applicants of Information Behavior II I Conducting Investigations ... Applicants of Information Behavior Conducting ...

1988-09-01

99

Triggered instabilities in rocket motors and active combustion control for an incinerator afterburner  

Science.gov (United States)

Two branches of research are conducted in this thesis. The first deals with nonlinear combustion response as a mechanism for triggering combustion instabilities in solid rocket motors. A nonlinear wave equation is developed to study a wide class of combustion response functions to second-order in fluctuation amplitude. Conditions for triggering are derived from analysis of limit cycles, and regions of triggering are found in parametric space. Introduction of linear cross-coupling and quadratic self-coupling among the acoustic modes appears to be how the nonlinear combustion response produces triggering to a stable limit cycle. Regions of initial conditions corresponding to stable pulses were found, suggesting that stability depends on initial phase angle and harmonic content, as well as the composite amplitude, of the pulse. Also, dependence of nonlinear stability upon system parameters is considered. The second part of this thesis presents research for a ...

1999-01-01

100

The effect of nickel on irradiation hardening of pressure vessel steels  

International Nuclear Information System (INIS)

An experimental investigation of the effect of nickel content on irradiation hardening of reactor pressure vessel steels was conducted. The alloys studied, with nickel contents ranging from 0 to 1.7%, included five sets of steels representing variations in copper contents and other metallurgical variables. Various subsets of the alloys were irradiated at selected combinations of flux, fluence, and irradiation temperature. Irradiation hardening was measured by either changes in the uniaxial yield stress or diamond pyramid hardness. Higher hardening rates with increasing nickel were observed in controlled experiments on commercial-type steels containing high copper concentrations (0.4% Cu). The effect of nickel increased with increasing fluence and decreasing temperature. At high fluence (>10"1"9 n/cm"2) the hardening increased with nickel at an average rate of about 100 MPa/%Ni. There also appeared to be an influence of heat treatment on the ...

1988-06-27

101

The Second International Piping Integrity Research Group (IPIRG-2) program. Final report, October 1991--April 1996  

Energy Technology Data Exchange (ETDEWEB)

The IPIRG-2 program was an international group program managed by the US NRC and funded by organizations from 15 nations. The emphasis of the IPIRG-2 program was the development of data to verify fracture analyses for cracked pipes and fittings subjected to dynamic/cyclic load histories typical of seismic events. The scope included: (1) the study of more complex dynamic/cyclic load histories, i.e., multi-frequency, variable amplitude, simulated seismic excitations, than those considered in the IPIRG-1 program, (2) crack sizes more typical of those considered in Leak-Before-Break (LBB) and in-service flaw evaluations, (3) through-wall-cracked pipe experiments which can be used to validate LBB-type fracture analyses, (4) cracks in and around pipe fittings, such as elbows, and (5) laboratory specimen and separate effect pipe experiments to provide better insight into the effects of dynamic and cyclic load histories. Also undertaken were an uncertainty analysis to ...

1997-03-01

102

Temperature dependence of the performance of ultraviolet detectors  

Energy Technology Data Exchange (ETDEWEB)

We present the results of a comprehensive study of the temperature dependences of the quantum efficiency for ultraviolet detectors based on GaAs, GaP and 4H--SiC Schottky structures, and on Si, GaAs p-n structures. For ultraviolet detectors based on Schottky structures, the quantum efficiency increases with increasing temperature for all photon energies, even including the semiconductor intrinsic absorption region. On the other hand, for ultraviolet detectors based on p-n structures, the quantum efficiency is practically temperature independent in the semiconductor intrinsic absorption region. The change in the quantum efficiency for the GaAs and Si detectors is less than 0.01% per degree. To explain the measurements, a variable trap occupancy model is presented. Subsurface imperfections of the semiconductor cause fluctuations in the profile of the conduction band and the valence band edges. In the presence of an electric field in the ...

2003-08-21

103

Temperature dependence of the performance of ultraviolet detectors  

International Nuclear Information System (INIS)

We present the results of a comprehensive study of the temperature dependences of the quantum efficiency for ultraviolet detectors based on GaAs, GaP and 4H--SiC Schottky structures, and on Si, GaAs p-n structures. For ultraviolet detectors based on Schottky structures, the quantum efficiency increases with increasing temperature for all photon energies, even including the semiconductor intrinsic absorption region. On the other hand, for ultraviolet detectors based on p-n structures, the quantum efficiency is practically temperature independent in the semiconductor intrinsic absorption region. The change in the quantum efficiency for the GaAs and Si detectors is less than 0.01% per degree. To explain the measurements, a variable trap occupancy model is presented. Subsurface imperfections of the semiconductor cause fluctuations in the profile of the conduction band and the valence band edges. In the presence of an electric field in the ...

2003-08-21

104

Summary of the marine aerosol properties and thermal imager performance trial (MAPTIP). Professional paper  

Energy Technology Data Exchange (ETDEWEB)

This paper describes a 1993 field experiment entitled Marine Aerosol Properties and Thermal Imager Performance Trial (MAPTIP) conducted by NATO AC/243 Panel 04/RSG.8 and 04/RSG.5 in the Dutch coastal waters. Objectives were: to improve and validate vertical marine aerosol models by providing an extensive set of aerosol and meteorological measurements, within a coastal environment at different altitudes and for a range of meteorological conditions; make aerosol and meteorological observations in the first 10 m of the ocean surface with a view to extending existing aerosol models to incorporate near-surface effects; and to assess marine boundary layer effects on thermal Imaging systems. Aerosol and meteorological instruments, as well as thermal imagers and calibrated targets, were utilized. This network of instrumentation has provided a comprehensive database of aerosol size distribution profiles and relevant meteorological variables throughout ...

1995-08-01

105

Removal of H2S and SO2 by CaCO3-Based Sorbents at High Pressure  

Energy Technology Data Exchange (ETDEWEB)

The theoretical and experimental investigation of the mechanism of SO2 and H2S removal by CaCO3 -based sorbents (limestones and dolomites) in pressurized uidized-bed coal combustors (PFBC) and high pressure gasiers, respectively, is the main objective of this study. It is planned to carry out reactivity evolution experiments under simulated high pressure conditions or in high pressure thermogravimetric and, if needed, uidized- bed reactor (high pressure) arrangements. The pore structure of fresh, heat-treated, and half-calcined solids (dolomites) will be analyzed using a variety of methods. Our work will focus on limestones and dolomites whose reaction with SO2 or H2S under atmospheric conditions has been studied by us or other research groups in past studies. Several theoret- ical tools will be employed to analyze the obtained experimental data including a variable diusivity shrinking-core model and models for diusion, reaction, and structure evolution in ...

1998-02-01

106

Numerical study of natural convection in fully open tilted cavities  

Energy Technology Data Exchange (ETDEWEB)

A numerical simulation of two-dimensional laminar natural convection in a fully open tilted square cavity with an isothermally heated back wall is conducted. The remaining two walls of the cavity are adiabatic. Steady-state solutions are presented for Grashof numbers between 10{sup 2} and 10{sup 5} and for tilt angles ranging from {minus}60{degree} to 90{degree} (where 90{degree} represents a cavity with the opening facing down). The fluid properties are assumed to be constant except for the density variation with temperature that gives rise to the buoyancy forces, which is treated by the Boussinesq approximation. The fluid concerned is air with Prandtl number fixed at 0.71. The governing equations are expressed in a normalized primitive variables formulation. Numerical predictions of the velocity and temperature fields are obtained using the finite-volume-based power law (SIMPLER: Semi-Implicit Method for Pressure-Linked Equations Revised) ...

1999-09-01

107

NATURAL GAS VARIABILITY IN CALIFORNIA: ENVIRONMENTAL IMPACTS AND DEVICE PERFORMANCE EXPERIMENTAL EVALUATION OF POLLUTANT EMISSIONS FROM RESIDENTIAL APPLIANCES  

Science.gov (United States)

The effect of liquefied natural gas on pollutant emissions was evaluated experimentally with used and new appliances in the laboratory and with appliances installed in residences, targeting information gaps from previous studies. Burner selection targeted available technologies that are projected to comprise the majority of installed appliances over the next decade. Experiments were conducted on 13 cooktop sets, 12 ovens, 5 broiler burners, 5 storage water heaters, 4 forced air furnaces, 1 wall furnace, and 6 tankless water heaters. Air-free concentrations and fuel-based emission factors were determined for carbon monoxide, nitrogen oxides, nitrogen dioxide, and the number of (predominantly ultrafine) particles over complete burns?including transient effects (device warm-up and intermittent firing of burners) following ignition--and during more stable end-of-burn conditions. Formaldehyde was measured over multi-burn cycles. The baseline fuel was Northern California ...

2009-12-01

108

Human exposure to PCDDs, PCDFs, and dioxin like PCBs in Japan, 2001  

Energy Technology Data Exchange (ETDEWEB)

In our previous study, we have estimated the level of human exposure to dioxins (PCDDs, PCDFs, and Dioxin like PCBs) in Japan based on dioxins monitoring data and results of total diet studies (TDS) in fiscal 2000 (April 2000- March 2001). It has been reported that the national PCDDs/DFs emission in 2001 against the 1997 level has been reduced by approximately 77% In addition, reduction of environmental levels was reported. The enforcement of Japan's Law Concerning Special Measures against Dioxins has significant impact on the reduction of the average dioxins concentrations in the ambient air. Therefore, the transitions of Japanese dioxins exposure levels in recent years are worthy of attention. In order to determine exposure level in fiscal 2001, collection and compilation for surveillance results derived from the regular environmental monitoring under the law as well as other dioxins surveys by national and local governmental bodies were continued, and the data were ...

2004-09-15

109

High temperature electrochemical polishing of H{sub 2}S from coal gasification process streams. Quarterly progress report, January 1, 1996--March 31, 1996  

Energy Technology Data Exchange (ETDEWEB)

Coal may be used to generate electrical energy by any of several processes, most of which involve combustion or gasification. Combustion in a coal-fired boiler and power generation using a steam- cycle is the conventional conversion method; however, total energy conversion efficiencies for this type of process are only slightly over 30{percent}. Integration of a gas-cycle in the process (combined cycle) may increase the total conversion efficiency to 40{percent}. Conversion processes based on gasification offer efficiencies above 50{percent}. H{sub 2}S is the predominant gaseous contaminant in raw coal gas. Problems arise due to the corrosive nature of H{sub 2}S on metal components contained in these cycles. Because of this, H{sub 2}S concentrations must be reduced to low levels corresponding to certain power applications. An advanced process for the separation of hydrogen sulfide (H{sub 2}S) from coal gasification product streams through an electrochemical membrane is being developed ...

1996-09-01

110

Geothermal Heat Pump Profitability in Energy Services  

Energy Technology Data Exchange (ETDEWEB)

If geothermal heat pumps (GHPs) are to make a significant mark in the market, we believe that it will be through energy service pricing contracts offered by retailcos. The benefits of GHPs are ideally suited to energy service pricing (ESP) contractual arrangements; however, few retailcos are thoroughly familiar with the benefits of GHPs. Many of the same barriers that have prevented GHPs from reaching their full potential in the current market environment remain in place for retailcos. A lack of awareness, concerns over the actual efficiencies of GHPs, perceptions of extremely high first costs, unknown records for maintenance costs, etc. have all contributed to limited adoption of GHP technology. These same factors are of concern to retailcos as they contemplate long term customer contracts. The central focus of this project was the creation of models, using actual GHP operating data and the experience of seasoned professionals, to simulate the financial performance of GHPs in ...

1997-11-01

111

Formation of metal oxides by cathodic arc deposition  

Energy Technology Data Exchange (ETDEWEB)

Cathodic arc deposition is an established and industrially applied technique for the formation of nitrides (e.g. TiN); it can also be used for metal oxide thin film formation. A cathodic arc plasma source with the desired cathode material is operated in an oxygen atmosphere of appropriate pressure, and metal oxides of various stoichiometric composition can be formed on different substrates. We report here on a series of experiments on metal oxide formation by cathodic arc deposition for different applications. Black copper oxide has been deposited on accelerator components to increase the radiative heat transfer between the parts. Various metal oxides such as tungsten oxide, niobium oxide, nickel oxide and vanadium oxide have been deposited on ITO glass to form electrochromic films for window applications. Optical waveguide structures can be formed by refractive index variation using oxide multilayers. We have synthesized multilayers of Al{sub 2}O{sub 3}-Y{sub 2}O{sub 3}-Al{sub 2}O{sub ...

1995-11-01

112

Corrosion probes for fireside monitoring in coal-fired boilers  

Energy Technology Data Exchange (ETDEWEB)

Corrosion probes are being developed and combined with an existing measurement technology to provide a tool for assessing the extent of corrosion of metallic materials on the fireside in coal-fired boilers. The successful development of this technology will provide power plant operators the ability to (1) accurately monitor metal loss in critical regions of the boiler, such as waterwalls, superheaters, and reheaters; and (2) use corrosion rates as process variables. In the former, corrosion data could be used to schedule maintenance periods and in the later, processes can be altered to decrease corrosion rates. The research approach involves laboratory research in simulated environments that will lead to field tests of corrosion probes in coal-fired boilers. Laboratory research has already shown that electrochemically-measured corrosion rates for ash-covered metals are similar to actual mass loss corrosion rates. Electrochemical tests conducted ...

2005-01-01

113

Correlation of angiogenesis with "1"8F-FMT and "1"8F-FDG uptake in non-small cell lung cancer  

International Nuclear Information System (INIS)

L-[3-"1"8F]-#alpha#-methyltyrosine ("1"8F-FMT) is an amino-acid tracer for positron-emission tomography (PET). We have conducted a clinicopathologic study to elucidate the correlation of angiogenesis with "1"8F-FMT and 2-["1"8F]-fluoro-2-deoxy-D-glucose ("1"8F-FDG) uptake in patients with non-small cell lung cancer (NSCLC). Thirty-seven NSCLC patients were enrolled in this study, and two PET studies with "1"8F-FMT and "1"8F-FDG were performed. Uptake of PET tracers was evaluated with standardized uptake value. Vascular endothelial growth factor (VEGF), CD31, CD34, L-type amino acid transporter 1 (LAT1) and Ki-67 labeling index of the resected tumors were analyzed by immunohistochemical staining, and correlated with the clinicopathologic variables and the uptake of PET tracers. The median VEGF rate was 45% (range, 10-78%). High expression was seen in 30 patients (81%, 30/37). VEGF expression was statistically associated with progressively ...

2009-04-01

114

Cleat mineralization of the Scollard and Coalspur Formations coal seams, western Alberta : regional seal development and implications for CBM exploration  

Energy Technology Data Exchange (ETDEWEB)

A geological study was conducted to better understand the nature of cleat development and degree of mineralization in coal seams of the Scollard and Coalspur Formations in western Alberta. The results can be applied to equivalent formations. The source and reservoir rocks of a coalbed methane (CBM) system were described. Coal seams are basically fractured reservoirs with 7 types of cleats. The field work involved cleat minerals sampling and determining cleat attributes such as type, strike and spacing from open-cut mines and outcrops. The laboratory work involved X-Ray diffraction, scanning electron microscopy, energy dispersive microscopy, stable isotope analysis, and fluid inclusions analysis. The study showed that coal seams of the Scollard and Coalspur Formations are widespread and cleated to various degrees. The face and butt cleats strike northeast-southwest and northwest southeast respectively along the structural grain of the Laramide Orogeny. The major ...

2004-07-01

115

Attitudes toward obesity in obese persons: a matched comparison of obese women with and without binge eating.  

Science.gov (United States)

No research has compared expressions of weight bias across different subgroups of obese individuals. This study compared attitudes toward and beliefs about obesity in women with and without binge eating disorder (BED) and examined whether these attitudes are related to psychological factors. Fifty obese women with BED were compared with an age- and body mass index (BMI)-matched group of 50 obese women without BED on a battery of established measures of anti-fat attitudes and beliefs about weight controllability and psychological factors (self-esteem, depression, and eating disorder features). The ageand BMI-matched groups did not differ with respect to beliefs about obesity or attitudes toward obese persons, or in self-esteem or depression. Correlational analyses conducted separately within each group revealed that women with BED who reported more favorable attitudes towards obese persons had higher self-esteem and lower levels of depression, whereas there were no ...

2010-01-27

116

A designed screening study with prespecified combinations of factor settings  

Energy Technology Data Exchange (ETDEWEB)

In many applications, the experimenter has limited options about what factor combinations can be chosen for a designed study. Consider a screening study for a production process involving five input factors whose levels have been previously established. The goal of the study is to understand the effect of each factor on the response, a variable that is expensive to measure and results in destruction of the part. From an inventory of available parts with known factor values, we wish to identify a best collection of factor combinations with which to estimate the factor effects. Though the observational nature of the study cannot establish a causal relationship involving the response and the factors, the study can increase understanding of the underlying process. The study can also help determine where investment should be made to control input factors during production that will maximally influence the response. Because the factor combinations are observational, the ...

2009-01-01

117

On the development of a new methodology for groundwater-driven health risk assessment  

Science.gov (United States)

A methodology and hypothetical case study are presented for incorporation of uncertainty and variability into calculations of human health risk appropriate for regional, or basin-scale, groundwater management problems. Uncertainty in well water concentration is introduced through complex contaminant migration patterns in the subsurface. Variability is considered in parameters related to individual behavior patterns and biological effects and to groundwater extraction and distribution networks. A joint uncertainty and variability (JUV) analysis is used to generate a two-dimensional distribution or risk surface that spans both transport uncertainty as well as individual variability. Cuts in this distributional surface (fractiles of variability and percentiles of uncertainty) are presented and discussed. Comparisons with alternative approaches based upon deterministic transport models ...

1998-01-01

118

Simulation of the transient eddy current measurement for the characterization of depth and conductivity of a plate  

International Nuclear Information System (INIS)

A transient eddy current measurement method is presented to determine the thickness and conductivity of a conductive plate. The conductive plate is induced by an air-cored coil, the magnetic flux density along the axial is measured and the various signals corresponding to plates with different thickness and conductivity are calculated using a 3D transient eddy current simulator. Characteristic features are obtained from the transient response. A similarity-based modeling method is utilized in this study to estimate the thickness and conductivity of the conductive plate. (author)

2008-07-01

119

Fate of Mercury in Synthetic Gypsum Used for Wallboard Production  

Energy Technology Data Exchange (ETDEWEB)

This report presents and discusses results from Task 5 of the study ''Fate of Mercury in Synthetic Gypsum Used for Wallboard Production,'' performed at a full-scale commercial wallboard plant. Synthetic gypsum produced by wet flue gas desulfurization (FGD) systems on coal-fired power plants is commonly used in the manufacture of wallboard. The FGD process is used to control the sulfur dioxide emissions which would result in acid rain if not controlled. This practice has long benefited the environment by recycling the FGD gypsum byproduct, which is becoming available in increasing quantities, decreasing the need to landfill this material, and increasing the sustainable design of the wallboard product. However, new concerns have arisen as recent mercury control strategies developed for power plants involve the capture of mercury in FGD systems. The objective of this study is to determine whether any mercury is released into the atmosphere when the ...

2006-06-01

120

The implications of tolerance system interpretation on past and present dimensional variability studies  

Energy Technology Data Exchange (ETDEWEB)

Dimensional variability studies and published dimensional variability standards have been used by the foundry industry for years as an indicator of the casting process` ability to produce uniform parts. These studies are an extremely useful tool in the continuous ``dimensional dialogue`` between foundries and customers. The nature of these studies, and of the current tolerancing systems used by casting designers, leaves room for some misinterpretation and misuse of these study results. This paper contains two important discussions. The first part explains exactly what these studies represent. Following this is a brief explanation on dimensional and geometric tolerances and how they communicate dimensional requirements.

1994-12-31

121

Man-made disasters: A cross-national analysis  

British Library Electronic Table of Contents (United Kingdom)

This research investigates the impact of national culture and several institutional factors on the safety performance of society and establishes statistically significant relationships between those variables. As expected, the research results reveal that some cultural variables such as uncertainty avoidance, gender orientation and institutional variables such as the degree of law avoidance can directly influence the safety performance of the society. The findings also support the inverted u-curve (Safety Kuznet curve) hypothesis indicating even if we expect a negative trend at the beginning stage of industrialization, we can expect a positive trend in safety performance as their income level continues to improve beyond a certain point.

2011-01-01

122

Go vs. no-go - potential and limitations of continuous-variable quantum computing by measurements  

Energy Technology Data Exchange (ETDEWEB)

In this talk, we explore the feasibility of quantum computation using continuous-variable systems by means of local measurements only. In the first part of the talk, we will identify crucial limitations that arise when starting from Gaussian cluster states. This is done by resorting to a Gaussian projected entangled pair picture as well as to notions of continuous-variable quantum repeater networks. In the second part, we look at instances in which these limitations can be overcome, and how suitable encodings of qubits in oscillators and feasible non-Gaussian resource states give rise to universal schemes for quantum computing.

2010-07-01

123

Creep properties of modified 9 Cr-1 Mo steel  

Energy Technology Data Exchange (ETDEWEB)

Creep properties of modified 9 Cr-1 Mo steel, an alloy significantly improved in elevated-temperature strength over 2 1/4 Cr-1 Mo and other similar alloys, are presented here. Data are primarily on material in the normalized and tempered condition. Effects of variables such as isothermal annealing treatment, cold work, normalizing temperature, tempering temperature, notch, and biaxial stress state have also been examined. Data analysis and comparisons have shown that modified 9 Cr-1 Mo alloy is very insensitive in response to several material variables, heat treatments, and specimen design variables.

1983-01-01

124

Vascular Effects of Photodynamic and Pulsed Dye Laser Therapy Protocols  

UK PubMed Central (United Kingdom)

Background and ObjectivePulsed dye laser (PDL) treatment of cutaneous vascular lesions is associated with variable and unpredictable efficacy. Thus, alternative treatment...Full Text Available

2008-11-01

125

Variability in Melanoma Metalloproteinase Expression Profiling  

UK PubMed Central (United Kingdom)

The proteolytic activities of a disintegrin and metalloproteinase (ADAM); a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS), and matrix metalloproteinase (MMP) families play important...Full Text Available

2010-12-01

126

The role of fatigue variability in life prediction of an #alpha#+#beta# titanium alloy  

International Nuclear Information System (INIS)

The fatigue life variability of the #alpha#+#beta# titanium alloy, Ti-6Al-2Sn-4Zr-6Mo increased with decreasing stress level. The variability in life was found to be due to segregation of lives due to two failure mechanisms. A bimodal cumulative distribution model was shown to accurately describe the combined failure modes. The nominal failure processes for the two regimes were similar, with crack nucleation occurring in equiaxed #alpha#p particles, irrespective of life or stress level. However the variability in life was not controlled by the size of the crack-nucleating #alpha#p, but rather by the ability of the material to distribute deformation and avoid early crack nucleation.

2004-06-10

127

Spatial and Temporal Variability of Column Integrated Aerosol - NASA  

Science.gov (United States)

the southern Arabian Gulf region left its signature on the heterogeneous aerosol .... Arabian Gulf region, since large differences in ? may be caused by ...

128

Spatial Variability of Wave Data from Todos Santos Bay, Baja California, Mexico  

Science.gov (United States)

... and operation of marine structures and to estimate coastal sediment transport. While the timely collection and report of high ... ...

129

Organismos que causan enfermedades transmitidas por los alimentos ...  

Science.gov (United States)

... Variable, Alimentos mal enlatados, especialmente verduras enlatadas en el hogar; pescado fermentado, papas asadas en papel de aluminio, ajo envasado. ...

130

Order in Spontaneous Behavior  

UK PubMed Central (United Kingdom)

Brains are usually described as input/output systems: they transform sensory input into motor output. However, the motor output of brains (behavior) is notoriously variable, even under identical sensory...Full Text Available

131

Optimization of extraction of high-ester pectin from passion fruit peel (Passiflora edulis flavicarpa) with citric acid by using response surface methodology  

British Library Electronic Table of Contents (United Kingdom)

A central composite design was employed to optimize the extraction of pectin with citric acid. The independent variables were citric acid concentration (0.086-2.91% w/v) and extraction time (17-102min). The combined effect of these variables on the degree of esterification was investigated. Results have shown that the generated regression models adequately explained the data variation and significantly represented the actual relationship between the independent variables and the responses. Besides that, the citric acid concentration was the most important factor to affect the degree of esterification, as it exerted a significant influence on the dependent variable. Lower citric acid concentration increased the pectin degree of esterification. The surface response showed the relationships b...

2008-01-01

132

Multifractal Analysis of Multiple Ergodic Averages  

CERN Document Server

In this paper we present a complete solution to the problem of multifractal analysis of multiple ergodic averages in the case of symbolic dynamics for functions of two variables depending on the first coordinate.

2011-01-01

133

Modeling hydrologic responses to deforestation/forestation and ...  

Science.gov (United States)

Worldwide century-long forest hydrologic research has documented that deforestation and forestation (i.e. reforestation and afforestation) can have variable ...

134

Koji Mukai's Bibliography - Astrophysics Science Division Staff ...  

Science.gov (United States)

Jul 25, 2011 ... Koji Mukai's Bibliography. Invited Reviews. Mukai, K. 1994, "ASCA PV Phase Observations of Cataclysmic Variables," in "New Horizon of X-ray ...

135

Fractal dynamics in physiology: Alterations with disease and aging  

UK PubMed Central (United Kingdom)

According to classical concepts of physiologic control, healthy systems are self-regulated to reduce variability and maintain physiologic constancy. Contrary to the predictions of homeostasis, however,...Full Text Available

2002-02-19

136

Floral ontogeny of Annonaceae: evidence for high variability in floral form  

UK PubMed Central (United Kingdom)

Background and AimsAnnonaceae are one of the largest families of Magnoliales. This study investigates the comparative floral development of 15 species to understand the basis for...Full Text Available

2010-10-01

137

Enhancement of bioleaching of a spent Ni/Mo hydroprocessing catalyst by Penicillium simplicissimum  

British Library Electronic Table of Contents (United Kingdom)

Statistically based experimental designs were applied to screen and optimize the bioleaching of spent hydrocracking catalyst by Penicillium simplicissimum. Eleven factors were examined for their significance on bioleaching using a Plackett-Burman factorial design. Four significant variables (pulp density, sucrose, NaNO"3, and yeast extract concentrations) were selected for the optimization studies. The combined effect of these variables on metal bioleaching was studied using a central composite design (CCD). Second-order polynomials were established to identify the relationship between the recovery percent of the metals and the four significant variables. The optimal values of the variables for maximum metals bioleaching were as follows: pulp density (4.0%, w/v), sucrose (90g/L), NaNO"3 (2...

2011-01-01

138

Effects of wildfires on environmental variability: a comparative analysis using different spectral indices, patch metrics and thematic resolutions  

British Library Electronic Table of Contents (United Kingdom)

Knowledge on environmental variability and how it is affected by disturbances is crucial for understanding patterns of biodiversity and determining adequate conservation strategies. The aim of this study is to assess environmental variability in patches undergoing post-fire vegetation recovery, identifying trends of change and their relevant drivers. We particularly evaluate: the value of three spectral indices derived from Landsat satellite data [Normalized Burn Ratio (NBR), Normalized Difference Vegetation Index (NDVI) and Wetness Component of the Tasseled Cap Transformation (TCW)] for describing secondary succession; the effectiveness of three metrics (diversity, evenness and richness) as indicators of patch variability; and how thematic resolution can affect the perception of environme...

2010-01-01

139

Effects of Climatic Variability and Land Use on American Drylands...  

Science.gov (United States)

Wildlife Refuge, CA Rare and endangered endemic plants Diana Anderson Northern Arizona University Geomorphology Kathryn Thomas USGS, Flagstaff, AZ Vegetation dynamics John...

2011-09-30

140

ENSO affects sex ratio progeny in captive Iberian red deer despite a steady feeding regime  

British Library Electronic Table of Contents (United Kingdom)

Climate variability greatly affects animals through direct and indirect effects. Animals with slow reproductive adaptation to ecological changes such as large mammals are likely to have evolved mechanisms to anticipate early such impacts of climate variability on the environment. One of the adaptive mechanisms between reproductive costs and benefits in mammals affects parental investment through biases in sex ratio. Deer might be likely to show an early detection of climate variability because conception takes place in early autumn, but the main raising cost in deer concerns lactation, which takes place at the end of the following spring. The aim of this paper is to assess whether there is a relationship between global indices of climate variability such as El Ni?o-Southern Oscillation (EN...

2011-01-01

141

DESIGN STUDY OF CONTINUOUSLY VARIABLE ROLLER CONE - NASA Technical ...  

Science.gov (United States)

pedel preo,ure. (_PD). VSO may be developed by nor_:el epeed-o-_eter means at the output. ,haft or it may be derived ...

142

Comparing Genomes within the Species Mycobacterium tuberculosis  

UK PubMed Central (United Kingdom)

The study of genetic variability within natural populations of pathogens may provide insight into their evolution and pathogenesis. We used a Mycobacterium tuberculosis high-density...Full Text Available

2001-04-01

143

Characterizing partial upwellings ... - Lake Tahoe Validation - NASA  

Science.gov (United States)

measure meteorological variables and bulk water temper- ature. The locations of the buoys are given in Table 1. TB2 and TB3 were moved slightly farther south ...

144

Baxter Q-operator and Separation of Variables for the open SL(2,R) spin chain  

CERN Document Server

We construct the Baxter Q-operator and the representation of the Separated Variables (SoV) for the homogeneous open SL(2,R) spin chain. Applying the diagrammatical approach, we calculate Sklyanin's integration measure in the separated variables and obtain the solution to the spectral problem for the model in terms of the eigenvalues of the Q-operator. We show that the transition kernel to the SoV representation is factorized into the product of certain operators each depending on a single separated variable. As a consequence, it has a universal pyramid-like form that has been already observed for various quantum integrable models such as periodic Toda chain, closed SL(2,R) and SL(2,C) spin chains.

2003-01-01

145

Adaptive Pareto Set Estimation for Stochastic Mixed Variable ...  

Science.gov (United States)

... Direct Search (SMOMADS) and Paciencia's NMADS [45] based on Kim and de Weck's ... Todd Paciencia for his foundational contributions. ...

2009-03-01

146

A novel approach to the dynamics of Szekeres dust models  

CERN Document Server

We obtain an elegant and useful description of the dynamics of Szekeres dust models (in their full generality) by means of "quasi--local" scalar variables constructed by suitable integral distributions that can be interpreted as weighed proper volume averages of the local covariant scalars. In terms of these variables, the field equations and basic physical and geometric quantities are formally identical to their corresponding expressions in the spherically symmetric LTB dust models. Since we can map every Szekeres model to a unique LTB model, rigorous results valid for the latter models can be readily generalized to a non--spherical Szekeres geometry. The new variables lead naturally to an initial value formulation in which all scalars are expressed as scaling laws in terms of their values at an arbitrary initial space slice. These variables also yield a significant simplification of numerical work, ...

2011-01-01

147

Measurement of the charge asymmetry in top-antitop quark production with the CDF II experiment  

Energy Technology Data Exchange (ETDEWEB)

The Fermi National Laboratory (Fermilab) operates the Tevatron proton-antiproton collider at a center-of-mass energy of {radical}s = 1.96 TeV, the is therefore the only collider which is today able to produce the heaviest known particle, the top quark. The top quark was discovered at the Tevatron by the CDF and D0 collaborations in 1995. At the Tevatron, most top quarks are produced via the strong interaction, whereby quark-antiquark annihilation dominates with 85%, and gluon fusion contributes with 15%. Considering next-to-leading order (NLO) contributions in the cross section of top-antitop quark production, leads to a slight positive asymmetry in the differential distribution of the production angle {alpha} of the top quarks. This asymmetry is due to the interference of certain NLO contributions. The charge asymmetry A in the cosine of {alpha} is predicted [14] to amount to 4-6%. Information about the partonic rest frame, necessary for a measurement of A in the observable cos ...

2006-12-01

148

Influence of solar activity and environment on 10Be in recent natural archives  

Energy Technology Data Exchange (ETDEWEB)

Understanding the link between the Sun and climate is vital in the current incidence of global climate change, and 10Be in natural archives constitutes an excellent tracer for this purpose. As cosmic rays enter the atmosphere, cosmogenic isotopes like 10Be and 14C are formed. Variations in solar activity modulate the amount of incoming cosmic rays, and thereby cosmogenic isotope production. Atmospherically produced 10Be enters natural archives such as sediments and glaciers by wet and dry deposition within about a year of production. 10Be from natural archives therefore provides information on past solar activity, and because these archives also contain climate information, solar activity and climate can be linked. One remaining question is to what degree 10Be in natural archives reflects production, and to what extent the local and regional environment overprints the production signal. To explore this, 10Be was measured at annual resolution over the last 600 years in a Greenland ice ...

2009-05-15

149

A model for development of freight transport; En model for godstransportens udvikling  

Energy Technology Data Exchange (ETDEWEB)

This report describes the results of a large project conducted in a corporation between Statistics Denmark and the Danish National Environmental Research Institute. The main objective of the project has been to analyse the possibilities of prescribing the development in the Danish freight transport in a more appropriate and precise way than it is done by existing models. A secondary objective of the project was to develop a model based on the findings of the analysis. The intention was to be able to describe all areas of freight transport. The analysis has proven it impossible to improve the existing calculations in some areas of transport. Hence, the project has been narrowed down to focus exclusively on road freight transport. The developed model distinguishes itself from existing models by a much higher level of detail in the calculations. This enables the model to describe the structural relations between transport and economic activity, which has previously ...

2001-01-01

150

The onset conditions of enhancement of ice accumulation associated with heat-conducting plates located perpendicularly to heat-transfer surfaces; Part 1: Analysis for still water  

Energy Technology Data Exchange (ETDEWEB)

An analytical study of the ice-formation process associated with heat-conducting plates located perpendicularly to isothermally heated and cooled surfaces with some clearance is presented. It is proposed that the onset conditions, which describe whether the ice-volume fraction in a steady state is greater than or less than that without heat-conducting plates, are defined by the dimensionless distances between the heated/cooled walls and the heat-conducting plates. It is shown that the onset conditions are dependent on the pitch and the thickness of the heat-conducting plates and are less dependent on the thermal conductivity of the plates.

1994-07-01

151

Variable Frequency Microwave Synthesis of Silver Nanoparticles  

Energy Technology Data Exchange (ETDEWEB)

Synthesis of silver nanoparticles based on a polyol process and variable frequency microwave (VFM) was investigated. Comparing to a thermal method, the reaction by VFM radiation was much faster. The effects of silver nitrate concentration, poly(N-vinylpyrrolidone) (PVP) concentration, reaction time and reaction temperature were studied. It was found that the higher concentration of silver nitrate, longer reaction time and higher temperature increased the particle size while the higher concentration of PVP decreased the particle size.

2006-02-15

152

One-dimensional numerical simulation of free-electron laser (FEL) amplifier with incorporate variable-parameter wiggler magnets  

International Nuclear Information System (INIS)

A physical model of free-electron laser (FEL) amplifier with variable-parameter wiggler magnets for one-dimensional numerical simulation is presented and a numerical example is given. The wiggler parameters, efficiency of energy conversion between electron beam and laser field, laser intensity, phase-space distributions and energy spectrum of electrons are computed. The period of synchronous oscillation and saturation value of laser intensity agree with estimated one.

153

Flow control with variable inflow as an alternative to conventional nozzle group control - automatic control of large capacity steam turbines  

International Nuclear Information System (INIS)

In the case of large capacity steam turbines the conventional nozzle group control is, for mechanical and thermodynamic reasons, diminishing more and more in importance in favour of variable pressure control. A design for constant-pressure operation as an alternative to nozzle group control is described; this demonstrates a series of important advantages compared with the latter. (orig.).

154

Conference on climate and water. Volume 2  

Energy Technology Data Exchange (ETDEWEB)

This book contains the Proceedings of the Conference on Climate and Water under the following groupings: Impacts of climatic variability and change-resulting from the changes in hydrological variables; Aquatic environment; Terrestrial environment; Coastal zones and navigation; Urban and industrial water supply and drainage; Energy production; Intropogenic changes of climate and water management problems; Flood potential; Irrigation and land drainage.

1989-12-31

155

Conference on climate and water  

Energy Technology Data Exchange (ETDEWEB)

This book contains the Proceedings of the Conference on Climate and Water under the following groupings: Impacts of climatic variability and change-resulting from the changes in hydrological variables; Aquatic environment; Terrestrial environment; Coastal zones and navigation; Urban and industrial water supply and drainage; Energy production; Intropogenic changes of climate and water management problems; Flood potential; Irrigation and land drainage.

1989-01-01

156

Variable-speed generation enhances hydro operation  

Energy Technology Data Exchange (ETDEWEB)

Two major developments have given impetus to wider adoption of variable-speed turbine/generators in hydroelectric plants, both essentially environmental: (1) the need for stream-bed stability below river dams, and (2) the need to minimize fish damage. Also, the need to stabilize pumped-storage and generating efficiencies to match extreme changes in head levels has been a driving force. Variable-speed operation in hydro applications is relatively new to North America. In other parts of the world, it has been used in pumped-storage plants since 1971. In the US, and increasing potential exists for variable-speed hydro, considering the 30 pumped-storage plants already in operation and several river plants struggling with high head fluctuations--including four at stations operated by the Bonneville Power Administration. Several modifications to hydro-plant hardware and operating procedures are actively being considered at ...

1993-07-01

157

Intrapartum FHR monitoring and neonatal CT brain scan  

Energy Technology Data Exchange (ETDEWEB)

The effect of fetal distress on the neonatal brain was investigated by neonatal CT brain scan, FHR monitoring and mode of delivery. This study involved 11 cases of full term vertex delivery in which FHR was recorded by fetal direct ECG during the second stage labor. All infants weighed 2,500 g or more. FHR monitoring was evaluated by Hon's classification. Neonatal brain edema was evaluated by cranial CT histgraphic analysis (Nakada's method). 1) Subdural hemorrhage was noted in 6 of 7 infants delivered by vacuum extraction or fundal pressure (Kristeller's method). 2) Intracranial hemorrhage was demonstrated in all of 3 infants with 5-min. Apgar score 7 or less. 3) Two cases with prolonged bradycardia and no variability had intraventricular or intracerebral hemorrhage which resulted in severe central nervous system damage. 4) The degree of neonatal brain edema correlated with 5-min. Apgar score. 5) One case with prolonged bradycardia and ...

1982-12-01

158

Intrapartum FHR monitoring and neonatal CT brain scan  

International Nuclear Information System (INIS)

The effect of fetal distress on the neonatal brain was investigated by neonatal CT brain scan, FHR monitoring and mode of delivery. This study involved 11 cases of full term vertex delivery in which FHR was recorded by fetal direct ECG during the second stage labor. All infants weighed 2,500 g or more. FHR monitoring was evaluated by Hon's classification. Neonatal brain edema was evaluated by cranial CT histgraphic analysis (Nakada's method). 1) Subdural hemorrhage was noted in 6 of 7 infants delivered by vacuum extraction or fundal pressure (Kristeller's method). 2) Intracranial hemorrhage was demonstrated in all of 3 infants with 5-min. Apgar score 7 or less. 3) Two cases with prolonged bradycardia and no variability had intraventricular or intracerebral hemorrhage which resulted in severe central nervous system damage. 4) The degree of neonatal brain edema correlated with 5-min. Apgar score. 5) One case with prolonged bradycardia and no ...

1982-01-01

159

Thermal conductivity coefficient of steam up to 500 deg C and 500 bar  

International Nuclear Information System (INIS)

The thermal conductivity of steam has been measured as a function of temperature from 100 deg C to 515 deg C and pressure up to 500 bar using the coaxial cylinder method. Corrections to the apparent thermal conductivity data are detailed. Correlations of the thermal conductivity coefficients are given in terms of temperature and density.

161

Probing Neutron Star Evolution with Gamma Rays  

Science.gov (United States)

The research sponsored by this grant was conducted in two fields of high-energy astrophysics:

1996-01-01

163

Conductivity of doped N-carbazolyl-substituted polysilanes  

Energy Technology Data Exchange (ETDEWEB)

A series of N-carbazolyl-substituted silane homo- and copolymers has been prepared by Wurtz coupling. Doping with iodine on these copolymer films increases the electrical conductivity to the range 10{sup -6}-10{sup -3} S cm{sup -1}. The conductivity depends strongly on the composition of the copolymer; it reaches the maximum value for N-carbazolyl-substituted silane homopolymer. The effects of carbazolyl group on conductivity and charge transport mechanisms in the polymer are discussed. (orig.)

1995-08-01

166

Variability of the physical properties of tuff at Yucca Mountain, NV  

Energy Technology Data Exchange (ETDEWEB)

Lateral and vertical variabilities in the bulk and mechanical properties of silicic volcanic tuff at the potential nuclear waste repository site in Yucca Mountain, NV have been evaluated. Laboratory measurements have been performed on tuff specimens recovered from boreholes located to support the design of the Exploratory Studies Facility/North Ramp. The data include dry and saturated bulk densities, average grain density, porosity, compressional and shear wave velocities, elastic moduli, and compressional and tensional fracture strengths. Data from eight boreholes aligned in a northwest-southeast direction have been collected under the required quality assurance program. Three boreholes have penetrated the potential repository horizon. The information collected provides for an accurate appraisal of the variability of rock properties in the vicinity of the boreholes. As expected, there is substantial variability in the bulk ...

1994-12-31

167

Polyp measurement based on CT colonography and colonoscopy: variability and systematic differences  

Energy Technology Data Exchange (ETDEWEB)

To assess the variability and systematic differences in polyp measurements on optical colonoscopy and CT colonography. Gastroenterologists measured 51 polyps by visual estimation, forceps comparison and linear probe. CT colonography observers randomly assessed polyp size two-dimensionally (abdominal and intermediate window) and three-dimensionally (manually and semi-automatically). Linear mixed models were used to assess the variability and systematic differences between CT colonography and optical colonoscopy techniques. The variability of forceps and linear probe measurements was comparable and both showed less variability than measurement by visual assessment. Measurements by linear probe were 0.7 mm smaller than measurements by visual assessment or by forceps. The variability of all CT colonography techniques was lower than for measurements by forceps or visual assessment and ...

2010-06-15

168

Powertrain and apparatus using a continuously variable ratio transmission to improve fuel economy  

Energy Technology Data Exchange (ETDEWEB)

An automotive powertrain includes a conventional piston engine, a continuously variable ratio transmission, an engine speed sensor and a feedback control system. The control system adjusts both the transmission ratio and the throttle valve in the engine carburetor or fuel metering system in response to the position of the accelerator pedal and in response to the crankshaft speed as measured by the engine sensor. The transmission provides extreme overdrive gear ratios which allow the engine to be operated at wide open throttle even during moderate cruising, and, in addition, the engine carburetor or fuel metering system is calibrated to deliver to the engine a stoichiometric air-fuel mixture which is combined, before combustion, with a special proportion of recirculated exhaust gas. As a result of extensive wide open throttle engine operation with the above mentioned intake charge composition, combustion variables are optimized to produce ...

1981-07-28

169

Power correlation for vertical axis wind turbines with varying geometries  

British Library Electronic Table of Contents (United Kingdom)

Abstract In this paper, a new predictive model that can forecast the performance of a vertical axis wind turbine (VAWT) is presented. The new model includes four primary variables (rotor velocity, wind velocity, air density, and turbine power output) as well as five geometrical variables (rotor radius, turbine height, turbine width, stator spacing, and stator angle). These variables are reduced to include the power coefficient (Cp) and tip speed ratio (TSR). A power coefficient correlation for a novel VAWT (called a Zephyr Vertical axis Wind Turbine (ZVWT)) is developed. The turbine is an adaptation of the Savonius design. The new correlation can predict the turbine's performance for altered stator geometry and varying operating conditions. Numerical simulations with a rotating reference f...

2011-01-01

170

Long and Short Distance Migration in Italy: The Role of Economic, Social and Environmental Characteristics  

British Library Electronic Table of Contents (United Kingdom)

This paper analyses Italian interregional migration flows. The approach taken is to decompose labour mobility flows into short distance and long distance migration and to model the effects of economic variables, social capital and quality of life variables, and amenity variables, on the mobility behaviour of individuals. We estimate these different types of migration flows using a negative binomial model, augmented with instruments to control for potential endogeneity issues. Our findings demonstrate that long distance migration reflects a disequilibrium model of migration whereas short distance migration largely reflects an equilibrium model of migration. As such, attempts to model interregional migration in general will be mis-specified as the simultaneously-operating underlying mobility...

2011-01-01

171

Irreversible Performance of a Quantum Harmonic Heat Engine  

CERN Document Server

The unavoidable irreversible losses of power in a heat engine are found to be of quantum origin. Following thermodynamic tradition a model quantum heat engine operating by the Otto cycle is analyzed. The working medium of the model is composed of an ensemble of harmonic oscillators. A link is established between the quantum observables and thermodynamical variables based on the concept of canonical invariance. These quantum variables are sufficient to determine the state of the system and with it all thermodynamical variables. Conditions for optimal work, power and entropy production show that maximum power is a compromise between the quasistatic limit of adiabatic following on the compression and expansion branches and a sudden limit of very short time allocation to these branches. At high temperatures and quasistatic operating conditions the efficiency at maximum power coincides with the endoreversible result. The optimal ...

2006-01-01

172

Interannual relationships between Indian Summer Monsoon and Indo-Pacific coupled modes of variability during recent decades  

British Library Electronic Table of Contents (United Kingdom)

Various SST indices in the Indo-Pacific region have been proposed in the literature in light of a long-range seasonal forecasting of the Indian Summer Monsoon (ISM). However, the dynamics associated with these different indices have never been compared in detail. To this end, the present work re-examines the variabilities of ISM rainfall, onset and withdrawal dates at interannual timescales and explores their relationships with El Ni?o-Southern Oscillation (ENSO) and various modes of coupled variability in the Indian Ocean. Based on recent findings in the literature, five SST indices are considered here: Ni?o3.4 SST index in December?January both preceding [Nino(?1)] and following the ISM [Nino(0)], South East Indian Ocean (SEIO) SST in February?March, the Indian Ocean Basin (IOB) mode in ...

2011-01-01

173

Experiences in batch trajectory alignment for pharmaceutical process improvement through multivariate latent variable modelling  

British Library Electronic Table of Contents (United Kingdom)

The primary objective of batch data as trajectory alignment (or synchronization) is to standardize the data sampling per batch according to the evolution of the process, and secondarily to homogenize the samples per run. The use of an indicator variable performs both objectives well. Two examples from the pharmaceutical sector are discussed to illustrate the different ways to deal with uneven samples across batches and across variables in the same batch. Since trajectory alignment requires large time investment, a simple triage approach is proposed to assess the need to analyze the dynamics of a given process and hence perform alignment. The presented examples are representative of a broad variety of batch processes that are operated by recipe in the pharmaceutical sector. In our experienc...

2011-01-01

174

Enamel-Calibrated Lamellar Bone Reveals Long Period Growth Rate Variability in Humans  

British Library Electronic Table of Contents (United Kingdom)

Abstract Mammalian teeth exhibit incremental structures representing successive forming fronts of enamel at varying time scales, including a short daily increment called a cross striation and a long period called a stria of Retzius, the latter of which, in humans, occurs on average every 8-9 days. The number of daily increments between striae is called the repeat interval, which is the same period as that required to form one increment of bone, i.e. the lamella, the fundamental - if not archetypal - unit of bone. Lamellae of known formation time nevertheless vary in width, and thus their measures provide time-calibrated growth rate variability. We measured growth rate variability for as many as 6 years of continuously forming primary incremental lamellar bone from midshaft femur histologic...

2011-01-01

175

Dirichlet mean identities and laws of a class of subordinators  

CERN Document Server

An interesting line of research is the investigation of the laws of random variables known as Dirichlet means. However, there is not much information on interrelationships between different Dirichlet means. Here, we introduce two distributional operations, one of which consists of multiplying a mean functional by an independent beta random variable, the other being an operation involving an exponential change of measure. These operations identify relationships between different means and their densities. This allows one to use the often considerable analytic work on obtaining results for one Dirichlet mean to obtain results for an entire family of otherwise seemingly unrelated Dirichlet means. Additionally, it allows one to obtain explicit densities for the related class of random variables that have generalized gamma convolution distributions and the finite-dimensional distribution of their associated L\\'{e}vy processes. ...

2010-01-01

176

Combined inverse modeling approach and load duration curve method for variable nitrogen total maximum daily load development in an agricultural watershed  

British Library Electronic Table of Contents (United Kingdom)

Purpose Nonpoint sources (NPS) pollution has been an important cause for water quality impairment worldwide. To take the temporal variations of both NPS pollution and in-stream attenuation into consideration, an inverse modeling approach and the load duration curve (LDC) method were combined for variable nutrient total maximum daily load (TMDL) development. Methods Water quality and hydrological parameters were monitored monthly along the ChangLe River system in 2004?2008. The catchment NPS export load (EL) and TMDL for total nitrogen (TN) were estimated by the inverse format of an existing stream nutrient transport equation. The LDC method was used to describe the variability of EL, TMDL, requiring load (RLR) and percent (the ratio between the RLR and the EL, RPR) reduction, and then to s...

2011-01-01

177

Characterizing the time variability in magnetized neutrino--cooled accretion disks: signatures of the gamma-ray burst central engine  

CERN Document Server

The central engine of Gamma Ray Bursts is hidden from direct probing with photons mainly due to the high densities involved. Inferences on their properties are thus made from their cosmological setting, energetics, low-energy counterparts and variability. If GRBs are powered by hypercritical accretion onto compact objects, on small spatial scales the flow will exhibit fluctuations, which could in principle be reflected in the power output of the central engine and ultimately in the high energy prompt emission. Here we address this issue by characterizing the variability in neutrino cooled accretion flows through local shearing box simulations with magnetic fields, and then convolving them on a global scale with large scale dynamical simulations of accretion disks. The resulting signature is characteristic, and sensitive to the details of the cooling mechanism, providing in principle a discriminant for GRB central engine properties.

2010-01-01

178

Centennial climate variability in the British Isles during the mid-late Holocene  

British Library Electronic Table of Contents (United Kingdom)

Multi-millennial climate changes were relatively minor over the mid-late Holocene in the British Isles, because orbitally forced insolation changes were smaller than those at higher latitudes. Centennial climate variability is thus likely to have exerted a greater influence on the environment and human society of the region. Proxy-climate records from the British Isles covering the last 4500years are assembled and re-evaluated with the aim of identifying centennial climate variability reflected by multi-proxy indicators. The proxies include bog oak populations, peatland surface wetness, flooding episodes from fluvial deposits, speleothem annual band width and oxygen isotopes, chironomids from lake sediments and sand and dune deposition. Most proxies reflect water balance rather than temper...

2010-01-01

179

Assessing variability of water quality in a groundwater-fed perennial lake of Kashmir Himalayas using linear geostatistics  

British Library Electronic Table of Contents (United Kingdom)

This paper presents a study on Manasbal lake, which is one of the high altitude lakes in the Kashmir Valley, India. Eighteen water samples were analysed for major ions and trace elements to assess the variability of water quality of the lake for various purposes. Geostatistics, the theory of regionalized variables, was then used to enhance the dataset and estimate some missing spatial values. Results indicated that the concentration of major ions in the water samples in winter was higher than in summer. The scatter diagrams suggested the dominance of alkaline earths over the alkali elements. Three types of water were identified in the lake that are referred to as Ca?HCO3, Mg?HCO3 and hybrid types. The lake water was found to be controlled by rock?water interaction with carbonate lithology ...

2011-01-01

180

Advanced experimental design applied to damage tolerance of composite materials  

Science.gov (United States)

This paper focuses on a factorial-based design strategy. The approach provides an efficient and statistically reliable means for assessing the influence of multivariable effects. It is applied to the detection and evaluation of damage in impacted composite sandwich panels. The experimental results obtained from this test strategy are utilized to form an empirical response function. The resulting polynomial relates damage area to residual compression strength at values of independent variables for which testing did not occur. The response function also identifies nonlinear interaction effects of key variabes that cannot be easily ascertained by traditional single-variable test strategies. Independent variables evaluated include core thickness, number of face sheet plys and impact energy. The methodology presented allows the designer to predict with more confidence the damage tolerance of a composite material component, and ...

1991-01-01

181

A variable gene delivery carrier-biotinylated chitosan/polyethyleneimine  

International Nuclear Information System (INIS)

A variable gene delivery system has been developed based on conjugating chitosan to biotin through a functionalized poly(ethylene glycol) (PEG) spacer, which can be used to further bind different molecules on the outer layer of a polymer/DNA complex by streptavidin (SA)-biotin linkage. In this study, TAT-conjugated SA was used as the model molecule to prove the conjugation function of the prepared complex. In addition, low-molecular-weight poly(ethyleneimine) (PEI) was added into the polymer/DNA complex to increase the transfection efficiency. The results of the luciferase assay show that the transfection efficiency of the prepared complex was significantly correlated with the amount of PEI and was further enhanced when TAT was conjugated to the complex by SA-biotin linkage. Considered to have negligible cytotoxic effects, the variable gene delivery complex prepared in this study would be of considerable potential as carriers for in vitro ...

2010-12-01

182

A study on the pretreatment of a sugarcane bagasse sample with dilute sulfuric acid  

British Library Electronic Table of Contents (United Kingdom)

Experiments based on a 23 central composite full factorial design were carried out in 200-ml stainless-steel containers to study the pretreatment, with dilute sulfuric acid, of a sugarcane bagasse sample obtained from a local sugar?alcohol mill. The independent variables selected for study were temperature, varied from 112.5?C to 157.5?C, residence time, varied from 5.0 to 35.0 min, and sulfuric acid concentration, varied from 0.0% to 3.0% (w/v). Bagasse loading of 15% (w/w) was used in all experiments. Statistical analysis of the experimental results showed that all three independent variables significantly influenced the response variables, namely the bagasse solubilization, efficiency of xylose recovery in the hemicellulosic hydrolysate, efficiency of cellulose enzymatic saccharificatio...

2011-01-01

183

Local thermal property analysis by scanning thermal microscopy of an ultrafine-grained copper surface layer produced by surface mechanical attrition treatment  

International Nuclear Information System (INIS)

Scanning thermal microscopy (SThM) was used to map thermal conductivity images in an ultrafine-grained copper surface layer produced by surface mechanical attrition treatment (SMAT). It is found that the deformed surface layer shows different thermal conductivities that strongly depend on the grain size of the microstructure: the thermal conductivity of the nanostructured surface layer decreases obviously when compared with that of the coarse-grained matrix of the sample. The role of the grain boundaries in thermal conduction is analyzed in correlation with the heat conduction mechanism in pure metal. A theoretical approach, based on this investigation, was used to calculate the heat flow from the probe tip to the sample and then estimate the thermal conductivities at different scanning positions. Experimental results and theoretical calculation demonstrate that ...

2006-06-15

184

Water Deficit and Spatial Pattern of Leaf Development. Variability in Responses Can Be Simulated Using a Simple Model of Leaf Development1  

UK PubMed Central (United Kingdom)

We analyzed the effect of short-term water deficits at different periods of sunflower (Helianthus annuus L.) leaf development on the spatial and temporal patterns of tissue expansion...Full Text Available

1999-02-01

185

Variable domain I of nematode CLEs directs post-translational targeting of CLE peptides to the extracellular space  

UK PubMed Central (United Kingdom)

Effector proteins expressed in the esophageal gland cells of cyst nematodes are delivered into plant cells through a hollow, protrusible stylet. Although evidence indicates that effector proteins function...Full Text Available

2010-12-01

186

Transposable elements are enriched within or in close proximity to xenobiotic-metabolizing cytochrome P450 genes  

UK PubMed Central (United Kingdom)

BackgroundTransposons, i.e. transposable elements (TEs), are the major internal spontaneous mutation agents for the variability of eukaryotic genomes. To address the general issue...Full Text Available

187

Time-Referenced Effects of an Internal vs. External Focus of Attention on Muscular Activity and Compensatory Variability  

UK PubMed Central (United Kingdom)

The paralysis-by-analysis phenomenon, i.e., attending to the execution of one's movement impairs performance, has gathered a lot of attention over recent years (see Wulf, 2007,...Full Text Available

188

The Interaction between AID and CIB1 Is Nonessential for Antibody Gene Diversification by Gene Conversion or Class Switch Recombination  

UK PubMed Central (United Kingdom)

Activation-induced deaminase (AID) initiates somatic hypermutation, gene conversion and class switch recombination by deaminating variable and switch region DNA cytidines to uridines. AID is predominantly...Full Text Available

189

Temporal Stability of Urinary and Plasma Biomarkers of Tobacco Smoke Exposure among Cigarette Smokers  

UK PubMed Central (United Kingdom)

Intraindividual variability of measurements of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), nicotine, cotinine, and r-1,t-2,3,c-4-tetrahydroxy-1,2,3,4-tetrahydrophenanthrene...Full Text Available

2010-06-01

190

Seasonal and Spatial Variability of Bacterial and Archaeal Assemblages in the Coastal Waters near Anvers Island, Antarctica  

UK PubMed Central (United Kingdom)

A previous report of high levels of members of the domain Archaea in Antarctic coastal waters prompted us to investigate the ecology of Antarctic planktonic prokaryotes. rRNA hybridization...Full Text Available

1998-07-01

191

Relationship between mRNA secondary structure and sequence variability in Chloroplast genes: possible life history implications  

UK PubMed Central (United Kingdom)

BackgroundSynonymous sites are freer to vary because of redundancy in genetic code. Messenger RNA secondary structure restricts this freedom, as revealed by previous findings in...Full Text Available

192

RESPONSE LATENCY AS AN INDEX OF RESPONSE STRENGTH DURING FUNCTIONAL ANALYSES OF PROBLEM BEHAVIOR  

UK PubMed Central (United Kingdom)

Dependent variables in research on problem behavior typically are based on measures of response repetition, but these measures may be problematic when behavior poses high risk or when its occurrence...Full Text Available

2011-01-01

193

QOI10/477: The medCERTAIN Project: Rating and certification of Internet health information using medPICS  

UK PubMed Central (United Kingdom)

IntroductionHealth information on the Internet undergoes no quality control at the stage of production, thus its quality is highly variable, making it difficult...Full Text Available

194

Predictors of disability in a longitudinal sample of patients with rheumatoid arthritis.  

UK PubMed Central (United Kingdom)

Information from the Health Assessment Questionnaire (HAQ) is used to identify which variables measured in 1981 successfully predict the severity of disease in 1989 and the eight year change in severity...Full Text Available

1992-05-01

195

Practical Applications of the Bioinformatics Toolbox for Narrowing Quantitative Trait Loci  

UK PubMed Central (United Kingdom)

Dissecting the genes involved in complex traits can be confounded by multiple factors, including extensive epistatic interactions among genes, the involvement of epigenetic regulators, and the variable...Full Text Available

2008-12-01

196

Post traumatic stress symptoms and heart rate variability in Bihar flood survivors following yoga: a randomized controlled study  

UK PubMed Central (United Kingdom)

BackgroundAn earlier study showed that a week of yoga practice was useful in stress management after a natural calamity. Due to heavy rain and a rift on the banks of the Kosi river,...Full Text Available

197

OPTIMIZATION OF COMBINED SEWER OVERFLOW CONTROL SYSTEMS  

Science.gov (United States)

The highly variable and intermittent pollutant concentrations and flowrates associated with wet-weather events in combined sewersheds necessitates the use of storage-treatment systems to control pollution.An optimized combined-sewer-overflow (CSO) control system requires a manage...

198

Non-Detection of Polarized, Scattered Light from the HD 189733b Hot Jupiter  

CERN Document Server

Using the POLISH instrument, I am unable to reproduce the large-amplitude polarimetric observations of Berdyugina et al. (2008) to the >99.99% confidence level. I observe no significant polarimetric variability in the HD 189733 system, and the upper limit to variability from the exoplanet is Delta_P < 7.9 x 10^(-5) with 99% confidence in the 400 nm to 675 nm wavelength range. Berdyugina et al. (2008) report polarized, scattered light from the atmosphere of the HD 189733b hot Jupiter with an amplitude of two parts in 10^4. Such a large amplitude is over an order of magnitude larger than expected given a geometric albedo similar to other hot Jupiters. However, my non-detection of polarimetric variability phase-locked to the orbital period of the exoplanet, and the lack of any significant variability, shows that the polarimetric modulation reported by Berdyugina et al. (2008) cannot be due to the ...

2009-01-01

199

Monitoring the Simultaneous Presentation of Spatialized Speech Signals in a Virtual Acoustic Environment.  

Science.gov (United States)

The effect of spatial auditory information on a listener's ability to detect, identify, and monitor multiple simultaneous speech signals was evaluated using virtual audio technology. Factorial combinations of three variables - the number of localized spee...

1998-01-01

200

Molecular dynamics of a ?B DNA element: base flipping via cross-strand intercalative stacking in a microsecond-scale simulation  

UK PubMed Central (United Kingdom)

The sequence-dependent structural variability and conformational dynamics of DNA play pivotal roles in many biological milieus, such as in the site-specific binding of transcription factors to target...Full Text Available

2008-09-01

201

Molecular Variability of Pseudallescheria boydii, a Neurotropic Opportunist  

UK PubMed Central (United Kingdom)

The sequences of the internal transcribed spacer (ITS) ribosomal DNA (rDNA) domain data obtained by restriction fragment length polymorphism analysis with 18S rDNA and fingerprinting (M13) for clinical...Full Text Available

2000-09-01

202

Lymphoma depletion during CD20 immunotherapy in mice is mediated by macrophage Fc?RI, Fc?RIII, and Fc?RIV  

UK PubMed Central (United Kingdom)

Despite the demonstrated clinical efficacy of CD20 monoclonal antibody (mAb) for lymphoma therapy, the in vivo mechanisms of tumor depletion remain controversial and variable. To identify the molecular...Full Text Available

2008-08-15

203

Investigating the spatial variability in incidence of coronary heart disease in the Gazel cohort: the impact of area socioeconomic position and mediating role of risk factors  

UK PubMed Central (United Kingdom)

Study objectiveThe study aim was to improve our understanding of the relationships between contextual socioeconomic characteristics and coronary heart disease (CHD)...Full Text Available

2011-02-01

204

Industrial emissions cause extreme urban ozone diurnal variability  

UK PubMed Central (United Kingdom)

Simulations with a regional chemical transport model show that anthropogenic emissions of volatile organic compounds and nitrogen oxides (NOx = NO + NO2) lead to a dramatic diurnal...Full Text Available

2004-04-27

205

Incorporation of the International Spinal Cord Injury Data Set Elements into the National Institute of Neurological Disorders and Stroke (NINDS) Common Data Elements (CDEs)  

UK PubMed Central (United Kingdom)

ObjectiveTo develop consistent variable names and a common database structure for the data elements in the International Spinal Cord Injury (SCI) Data Sets.Full Text Available

2011-01-01

206

Identification of genes and haplotypes that predict rheumatoid arthritis using random forests  

UK PubMed Central (United Kingdom)

Random forest (RF) analysis of genetic data does not require specification of the mode of inheritance, and provides measures of variable importance that incorporate interaction effects. In this paper...Full Text Available

207

Human variability and susceptibility to trichloroethylene.  

UK PubMed Central (United Kingdom)

Although humans vary in their response to chemicals, comprehensive measures of susceptibility have generally not been incorporated into human risk assessment. The U.S. EPA dose-response-based risk assessments...Full Text Available

2000-05-01

208

Hominin life history: reconstruction and evolution  

UK PubMed Central (United Kingdom)

In this review we attempt to reconstruct the evolutionary history of hominin life history from extant and fossil evidence. We utilize demographic life history theory and distinguish life history variables,...Full Text Available

2008-04-01

209

High genetic variability and low local diversity in a population of arbuscular mycorrhizal fungi  

UK PubMed Central (United Kingdom)

Arbuscular mycorrhizal fungi (AMF) are ecologically important root symbionts of most terrestrial plants. Ecological studies of AMF have concentrated on differences between species; largely assuming...Full Text Available

2004-02-24

210

High Speed Cylindrical Roller Bearing Development.  

Science.gov (United States)

High speed experimental tests provided data on six parametric cylindrical roller bearings. Four bearing variables were evaluated and the results were correlated with the analytical model developed under Naval Air Propulsion Center Contract N00140-76-C-038...

1980-01-01

211

Heats (enthalpies) of formation of coals and the thermodynamic evaluation of the coal formation process  

British Library Electronic Table of Contents (United Kingdom)

An approach to the calculation of the quantity of heat consumed in the process of coal formation is presented. The variability of this parameter in a coalification series is analyzed using coals from the Kuznetsk and Tunguska Basins as an example.

2011-01-01

212

Hamiltonian BRST formalism for gauge-invariant systems with closed algebra  

International Nuclear Information System (INIS)

The systems for which the algebra of gauge transformations in the lagrangian formalism is closed, are considered. The hamiltonian BRST charge and the BRST-invariant hamiltonian are found explicitly. Their expansions in powers of the ghost variables contain, in general, an infinite number of terms. (orig.).

1991-11-01

213

Glossitis of Military Workingn> Dogs in South Vietnam: History and Clinical Characteristics.  

Science.gov (United States)

Glossitis among U.S. military working dogs in South Vietnam was characterized by variable redness and loss of papillae on the anterodorsal third of the tongue; salivation, drooling, and inappetence were the principal clinical signs. Symptomatic treatment ...

1973-01-01

214

Genome-wide linkage scan for contraction velocity characteristics of knee musculature in the Leuven Genes for Muscular Strength Study  

UK PubMed Central (United Kingdom)

The torque-velocity relationship is known to be affected by ageing, decreasing its protective role in the prevention of falls. Interindividual variability in this torque-velocity relationship is partly...Full Text Available

2008-09-01

215

Genome size and wing parameters in passerine birds  

UK PubMed Central (United Kingdom)

Despite their status as the most speciose group of terrestrial vertebrates, birds exhibit the smallest and least variable genome sizes among tetrapods. It has been suggested that this is because powered...Full Text Available

2009-01-07

216

Genetic architecture of voluntary exercise in an advanced intercross line of mice  

UK PubMed Central (United Kingdom)

Exercise is essential for health, yet the amount, duration, and intensity that individuals engage in are strikingly variable, even under prescription. Our focus was to identify the locations and effects...Full Text Available

2010-07-01

217

Feature Selection and Classification of MAQC-II Breast Cancer and Multiple Myeloma Microarray Gene Expression Data  

UK PubMed Central (United Kingdom)

Microarray data has a high dimension of variables but available datasets usually have only a small number of samples, thereby making the study of such datasets interesting and challenging. In the task...Full Text Available

218

Experimental evaluation of angularly-variable fiber geometry for targeting depth-resolved reflectance from layered epithelial tissue phantoms  

Science.gov (United States)

The aim of the present study focuses on experimentally demonstrating the efficacy of using angularly-variable fiber geometry to achieve the desired tissue-layer selection and probing depths with the further objective of enhancing the sensitivity and specificity of spectral diagnosis in stratified architectures that resemble human cervical epithelia. The morphological and biochemical features of epithelial tissue vary in accordance with tissue depths; consequently, the accuracy of spectroscopic diagnosis of epithelial dysplasia may be enhanced by probing the optical properties of this tissue. When correlated to cellular dysplasia, layer-specific changes in tissue optical properties may be deciphered by reflectance spectroscopy coupled with angularly-variable fiber geometry. This study addresses the utility of using such angularly-variable fiber geometry for resolving spatially-specific spectral signatures of tissue ...

2007-03-01

219

Effect of Wastewater Treatment Plant Effluent on Microbial Function and Community Structure in the Sediment of a Freshwater Stream with Variable Seasonal Flow?  

UK PubMed Central (United Kingdom)

We investigated the effects of wastewater treatment plant (WWTP) discharge on the ecology of bacterial communities in the sediment of a small, low-gradient stream in South Australia. The quantification...Full Text Available

2008-05-01

220

EFFECT OF THE DIGENEAN PARASITE PROTEROMETRA MACROSTOMA ON HOST MORPHOLOGY IN THE FRESHWATER SNAIL ELIMIA LIVESCENS  

Science.gov (United States)

... 1984; Martin-Mora et al., 1995), and parasitism (Rothschild and Rothschild, 1939; Pesigan et al., 1958; Moose, 1963; Pan, ... effects of digeneans are variable; they may enhance (Rothschild and Rothschild...

221

Do the Obese Have Lower Body Temperatures? A New Look at a Forgotten Variable in Energy Balance  

UK PubMed Central (United Kingdom)

Understanding the pathogenesis of obesity is now more important than ever, given the remarkable world-wide epidemic. This paper explores the potential role of core temperature in energy balance, and...Full Text Available

2009-01-01

222

Dimensionless energy confinement scaling in W7-AS  

International Nuclear Information System (INIS)

Energy confinement in W7-AS has been analyzed in terms of dimensionally exact form free functions employing Bayesian probability theory. The confinement function was set up as a linear combination of dimensionally exact power law terms as already proposed very early by Connor and Taylor. Generation of this expansion basis is dictated by the basic plasma model which one assumes. Based upon data accumulated in W7-AS, which contains the energy content for a wide variety of variable settings, predictions for single variable scans are made. The scaling functions for density and power scans, respectively, are in quantitative agreement with data collected in W7-AS. The result of a single variable scan is therefore already hidden in the data obtained for arbitrary variable choices and can be extracted from the latter by a proper data analysis. Furthermore, the optimal model for the description of the global ...

1999-12-01

223

Detrended Fluctuation Analysis of Intracranial Pressure Predicts Outcome Following Traumatic Brain Injury  

UK PubMed Central (United Kingdom)

Detrended fluctuation analysis (DFA) is a recently developed technique suitable for describing scaling behavior of variability in physiological signals. The purpose of this study is to explore...Full Text Available

2008-11-01

224

Determinants of output in group and solo medical practice.  

UK PubMed Central (United Kingdom)

Certain structural and environmental factors other than technical combination of resources and firm size are hypothesized to affect medical practice output. Four groups of variables related to physician...Full Text Available

1976-01-01

225

Climate models and scenarios  

Energy Technology Data Exchange (ETDEWEB)

In recent years the modelling of interannual climate variability has been studied, the atmospheric energy and water cycles, and climate simulations with the ECHAM3 model. In addition, the climate simulations of several models have been compared with special emphasis in the area of northern Europe

1996-12-31

226

Cangrelor increases the magnitude of platelet inhibition and reduces interindividual variability in clopidogrel-pretreated subjects  

UK PubMed Central (United Kingdom)

BackgroundInadequate platelet inhibition despite aspirin and clopidogrel therapy during and after a percutaneous coronary intervention is associated with an impaired clinical outcome....Full Text Available

2009-05-01

227

Calibration of the solar UV radiometers in Finland  

Energy Technology Data Exchange (ETDEWEB)

In this report, the main emphasis is given to (1) the problems associated with the basic calibration of the spectroradiometer and (2) the year-to-year variability of the calibrations of the solar UV network radiometers. Also, the results from intercomparisons of the Brewer and OL 742 spectroradiometers are included

1996-12-31

228

CYP1B1 mutations in Spanish patients with primary congenital glaucoma: phenotypic and functional variability  

UK PubMed Central (United Kingdom)

PurposeTo analyze the contributions of cytochrome P4501B1 (CYP1B1) mutations to primary congenital glaucoma (PCG) in Spanish patients.MethodsWe...Full Text Available

229

Boundary value problem for an elliptic equation with rapidly oscillating coefficients in a rectangle  

British Library Electronic Table of Contents (United Kingdom)

An elliptic equation in a rectangle with coefficients depending on a fast variable and with its period being a small parameter is considered. An asymptotic expansion of the solution up to an arbitrary degree of the small parameter is constructed and substantiated by applying the two-scale expansion method.

2011-01-01

230

Average uncertainty as a determinant of observing behavior1  

UK PubMed Central (United Kingdom)

After discrimination training on a multiple variable-interval extinction schedule of food reinforcement, pigeons were placed on the uncued or mixed version of the same schedule and allowed to make...Full Text Available

1974-09-01

231

Automatic stenosis detection and quantification in renal arteriography.  

UK PubMed Central (United Kingdom)

Visual assessment of the degree of renal artery stenosis on renal arteriography has a large inter- and intraobserver variability. This degree is usually estimated by the ratio between the most narrowed...Full Text Available

1997-01-01

232

Assessing spatio-temporal variability of risk surfaces using residential history data in a case control study of breast cancer  

UK PubMed Central (United Kingdom)

BackgroundMost analyses of spatial clustering of disease have been based on either residence at the time of diagnosis or current residence. An underlying assumption in these analyses...Full Text Available

233

Aspirin and Clopidogrel Response Variability  

UK PubMed Central (United Kingdom)

Antiplatelet resistance has been proposed as a possible mechanism to explain recurrent cardiovascular events in patients who have coronary artery disease and who are undergoing dual antiplatelet therapy....Full Text Available

2008-01-01

234

Analytical study on analysis methods of several random variables for seismic nonlinear responses of reactor buildings  

International Nuclear Information System (INIS)

In the case wherein nonlinear seismic response analyses are carried out, the response values vary due to the variations in materials and modeling. In this paper, nonlinear analyses of several random variables are carried out using: i. a conventional method; ii. a two-point estimation method (i. and ii. are simplified methods); and iii. Monte Carlo simulation (detailed method) to examine the variability of the response in the excessive nonlinear range for seismic responses of shear walls. The analyses are performed to a PWR-3 loop type reactor building which is one of the most typical reactor buildings in Japan. The variations are considered in specified compressive strength of concrete, concrete damping factor, shear wave velocity of soil and shapes of shear stress-strain relation curves of shear walls. As the results by the two simplified methods closely matched the Monte Carlo simulation results, the appropriateness for applying the ...

1993-08-15

235

Absolute CD4+ T-Lymphocyte Count as a Surrogate Marker of Pediatric HIV Disease Progression  

UK PubMed Central (United Kingdom)

BackgroundTraditionally in pediatric HIV, the CD4+ T-lymphocyte percent is used in monitoring disease progression due to the variability in absolute CD4+ T-lymphocyte...Full Text Available

2008-07-01

236

A new evolutionary scenario for the Mycobacterium tuberculosis complex  

UK PubMed Central (United Kingdom)

The distribution of 20 variable regions resulting from insertion-deletion events in the genomes of the tubercle bacilli has been evaluated in a total of 100 strains of Mycobacterium tuberculosis,...Full Text Available

2002-03-19

237

A new VCAN/versican splice acceptor site mutation in a French Wagner family associated with vascular and inflammatory ocular features  

UK PubMed Central (United Kingdom)

PurposeTo detail the highly variable ocular phenotypes of a French family affected with an autosomal dominantly inherited vitreoretinopathy and to identify the disease gene.MethodsSixteen...Full Text Available

238

A Latent Variable Approach for Meta-Analysis of Gene Expression Data from Multiple Microarray Experiments  

UK PubMed Central (United Kingdom)

BackgroundWith the explosion in data generated using microarray technology by different investigators working on similar experiments, it is of interest to combine results across...Full Text Available

239

A Computational Framework Discovers New Copy Number Variants with Functional Importance  

UK PubMed Central (United Kingdom)

Structural variants which cause changes in copy numbers constitute an important component of genomic variability. They account for 0.7% of genomic differences in two individual genomes, of which...Full Text Available

240

Variable-dispersion electron spectrometer for the SCA/FEL  

International Nuclear Information System (INIS)

A variable-dispersion electron spectrometer is being installed for use by the Stanford Superconducting Accelerator in conjunction with its Free Electron Laser program. The system has been designed to operate with electron beam energies from 20 MeV to 200 MeV, with a maximum energy resolution of 0.01% FWHM. The maximum energy acceptance is approximately #+-# 5%, as determined by the bending magnet aperture. Resolution is controlled by adjusting the focal conditions at the entrance to a 90 degree bending magnet, while the dispersion is controlled by changing the magnitude and polarity of the field in a quadrupole magnet which immediately follows the bending magnet. 4 refs., 5 figs.

1989-06-01

241

United States Air Force Academy (USAFA) Vertical Axis Wind Turbine. Final report May 77-Sep 80  

Science.gov (United States)

This report describes the design, fabrication, installation and testing of a small variable-speed vertical axis wind turbine (VAWT). This VAWT is unique in its installation using hand tools only; unconventional and simple support system; and variable speed operation under microprocessor control. Initial testing confirmed that the turbine can be controlled by commanded alternator field modulation. Further studies will be directed toward determination of an optimum control algorithm.

1980-09-01

242

The effects of aircraft engine pollutant emission measurement variability on engine certification policy  

Science.gov (United States)

Divergence between aircraft engine emission regulations proposed by EPA and ICAO is discussed. Every engine, upon entering service, requires a certificate as to its compliance with emission standards. It is shown that despite the large variability in the measurements, it is possible to devise a certification procedure requiring the testing of one engine only. Statistical modeling of such a test at the 5% significance level is described. Values of the parameter standard deviation/mean recommended as certification standards for various pollutants are given. Features of a rational certification scheme to be formulated are outlined.

1978-10-01

243

Separation of variables for the quantum SL(2,R) spin chain  

CERN Document Server

We construct representation of the Separated Variables (SoV) for the quantum SL(2,R) Heisenberg closed spin chain and obtain the integral representation for the eigenfunctions of the model. We calculate explicitly the Sklyanin measure defining the scalar product in the SoV representation and demonstrate that the language of Feynman diagrams is extremely useful in establishing various properties of the model. The kernel of the unitary transformation to the SoV representation is described by the same "pyramid diagram" as appeared before in the SoV representation for the SL(2,C) spin magnet. We argue that this kernel is given by the product of the Baxter Q-operators projected onto a special reference state.

2003-01-01

244

Product identification in industrial batch fermentation using a variable forgetting factor  

British Library Electronic Table of Contents (United Kingdom)

For reliable operation and the optimization of production, industrial fermentation processes require appropriate tools for monitoring the process in real time. This work presents the structure and operation of a soft sensor for the on-line monitoring of biomass and product concentration during salinomycin and bacitracin fermentation in an industrial, 80-m^3 batch reactor; moreover it provides a tool for evaluation of batch production verified in industrial application. The process estimation algorithm consists of decoupled growth and product models, which ensures an unbiased convergence of the estimator and the robustness of the model. The production of secondary metabolites is described with a non-structured model upgraded with a variable forgetting factor that demonstrated a successful e...

2011-01-01

245

Method and system for controlling the idle speed of an internal combustion engine at variable ignition timing  

Energy Technology Data Exchange (ETDEWEB)

The idle speed of an internal combustion engine is controlled in response to a variable ignition timing control signal from a microcomputer. The microcomputer derives this control signal as a function of the magnitude of engine speed variation which occurs during engine idle periods to cause the ignition timing to vary quickly in response to a transitory engine load variation. An auxiliary air delivery system may be advantageously incorporated in the idle speed control system to cooperate with the ignition timing control in response to the engine speed variation.

1984-05-08

246

Less BOP running with variable bore rams  

Energy Technology Data Exchange (ETDEWEB)

The marine ram-type blowout preventer deployed from an offshore drilling rig has one serious disadvantage, its inaccessibility. A development to promote reliability of the subsea ram-type preventer and reduce the excess running and pulling to charge out rams, is the variable bare ram (VBR). Unlike the standard ram, the VBR has the ability to pack off a range of pipe sizes. Interest in VBR's has been revived and research and development in this equipment goes on at each of three manufacturer's facilities in Houston.

1984-04-01

247

Inclusive photoproduction of D{sup *{+-}} mesons at next-to-leading order in the general-mass variable-flavor-number scheme  

Energy Technology Data Exchange (ETDEWEB)

We discuss the inclusive production of D{sup *{+-}} mesons in {gamma}p collisions at DESY HERA, based on a calculation at next-to-leading order in the general-mass variable-flavor-number scheme. In this approach, MS subtraction is applied in such a way that large logarithmic corrections are resummed in universal parton distribution and fragmentation functions and finite mass terms are taken into account. We present detailed numerical results for a comparison with data obtained at HERA and discuss various sources of theoretical uncertainties. (orig.)

2009-02-15

248

Evolution of the white dwarf mass and spin in cataclysmic variables  

International Nuclear Information System (INIS)

We consider the spin-up of the white dwarf in non-magnetic cataclysmic variables (CVs) during secular evolution. If this is unresisted, CVs are quenched as boundary-layer emitters once the binary period has decreased by #approx# 1 hr. Angular momentum loss in nova explosions may, however, prevent the star reaching breakup. If the explosions remove (1 + #epsilon#) x the mass accreted between outbursts, values 0.5 < #approx# #epsilon# < #approx# 1 allow CVs to be modest boundary-layer emitters for most of their lifetimes. Spectral effects will limit their detection as soft X-ray sources. (author).

249

Energy productivity in the industrial sector: an econometric analysis  

Energy Technology Data Exchange (ETDEWEB)

Energy productivity and energy intensity within the industrial sector of the economy are examined. Results suggest that relative prices and other economic factors can explain much of the variation in both energy productivity and energy intensity for manufacturing and mining and for the industrial sector as a whole. Cyclical factors, seasonal factors and trend variables are also useful in explaining variation in these data, both for annual and monthly time series. Of the variables examined, it appears that the relative price of energy is a highly significant factor in accounting for the difference between actual industrial energy intensity and that which might have been expected had pre-1973 trends continued.

1983-01-01

250

Effects of variable hardness, ph, alkalinity, suspended clay, and humics on the chemical speciation and aquatic toxicity of copper  

Science.gov (United States)

The effects of variable hardness, pH, alkalinity, humics, and suspended clay on the chemical speciation of copper and its toxicity to fathead minnow larvae in Lake Superior water were investigated. Two proposed methods (toxicity factors and chemical speciation) for predicting LC50 values in specific natural waters from laboratory toxicity data and the average site specific values of general water quality parameters were evaluated. The accuracy of the cupric ion-selective electrode in determining CU/sup +2/ activities in ambient and chemically altered Lake Superior water was also determined.

1986-03-01

251

Coherent state quantum key distribution with multi letter phase-shift keying  

International Nuclear Information System (INIS)

We present a protocol for quantum key distribution using discrete modulation of coherent states of light. Information is encoded in the variable phase of coherent states which can be chosen from a regular discrete set ranging from binary to continuous modulation similar to phase-shift keying in classical communication. Information is decoded by simultaneous homodyne measurement of both quadratures and requires no active choice of basis. The protocol utilizes either direct or reverse reconciliation both with and without postselection. We analyze the security of the protocol and show how to enhance it by the optimal choice of all variable parameters of the quantum signal.

2010-05-01

252

Assessment of primary production and optical variability in shelf and slope waters near Cape Hatteras, North Carolina. Final project report  

Energy Technology Data Exchange (ETDEWEB)

In this project we determined primary production and optical variability in the shelf and slope waters off of Cape Hatteras, N.C. These processes were addressed in conjunction with other Ocean Margins Program investigators, during the Spring Transition period and during Summer. We found that there were significant differences in measured parameters between Spring and Summer, enabling us to develop seasonally specific carbon production and ecosystem models as well as seasonal and regional algorithm improvements for use in remote sensing applications.

2001-02-12

253

A finite-dimensional fermionic TQFT  

CERN Document Server

A fermionic - based on Grassmann--Berezin calculus of anticommuting variables - topological quantum field theory (TQFT) is considered, mainly in three dimensions. It is defined for piecewise-linear manifolds and, for a given triangulation, deals only with a finite number of variables. Despite its simple nature, it can distiguish between lens spaces L(7,1) and L(7,2). And despite its origin from a kind of Reidemeister torsion, it does this without using nontrivial representations of the fundamental group. Also, symbolic calculations are presented giving strong evidence of existence of similar theory in four dimensions.

2011-01-01

254

A comment on: ''The solution to the forward-bias puzzle''  

British Library Electronic Table of Contents (United Kingdom)

Pippenger (2011) recently proposed a solution to the longstanding forward-bias puzzle. He argues that the puzzling estimates obtained using the standard equation for the efficient markets hypothesis are due to omitted variable bias. He identifies the missing variables as the future change in the forward exchange rate and the future interest differential. When these are added to the standard equation, he finds a one-to-one relationship between the future change in the spot rate and the forward premium. However, we argue that his equation can only test covered interest parity and offers no insight into the forward-bias puzzle.

2011-01-01

255

Stochastic analysis of contaminant transport: One-dimensional non-reactive and reactive cases  

Energy Technology Data Exchange (ETDEWEB)

A reliability approach for probabilistic modeling of one-dimensional non-reactive and reactive transport in porous media provides two important quantitative results: (1) an estimate of the probability that dimensionless concentration equals or exceeds some specified level and, (2) the sensitivity of the probabilistic outcome to likely changes in each uncertain variable. The reliability approach is particularly attractive because it can incorporate various marginal probability density functions (PDF) for any of the uncertain variables. In this work uncertain variables include: groundwater flow velocity, diffusion coefficient, dispersivity, distribution coefficient, porosity and bulk density. The primary objective is to examine how the probabilistic outcome is influenced by choice of marginal PDF, correlation and magnitude of uncertainty for the variables. Because little information exists concerning the ...

1990-12-03

256

Using a Computer to Conduct Utilization and Quality of Care Review in a Prepaid Medical Care Network  

UK PubMed Central (United Kingdom)

This paper describes how a computerized MIS is used to assist HMO management to conduct utilization and quality of care review activities in a prepaid medical care network. The HMO is a ‘network’...Full Text Available

1982-11-02

257

Spontaneous radiation of atomic oscillator, situated near ideally conducting cone surface  

International Nuclear Information System (INIS)

The line width of atom, situated near ideally conducting point or inside cone cavity in ideal conductor is analyzed. It is shown that the effect of point is decreased according to decreasing of its aperture angle

1998-01-01

258

Exercise-induced airways constriction 1  

UK PubMed Central (United Kingdom)

Airway conductance was measured in a body plethysmograph at different lung volumes before and after graded exercise. In 14 out of 19 patients, mostly asthmatics, airway conductance fell significantly...Full Text Available

1972-03-01

259

Detrusor overactivity is associated with downregulation of large-conductance calcium- and voltage-activated potassium channel protein  

UK PubMed Central (United Kingdom)

Large-conductance voltage- and calcium-activated potassium (BK) channels have been shown to play a role in detrusor overactivity (DO). The goal of this study was to determine whether bladder outlet...Full Text Available

2010-06-01

260

Design of Composite Structures for Reliability and Damage Tolerance.  

Science.gov (United States)

A summary of research conducted during the first year is presented. The research objectives were sought by conducting two tasks: (1) investigation of probabilistic design techniques for reliability-based design of composite sandwich panels, and (2) examin...

1999-01-01

262

The effect of the shear rate-dependent thermal conductivity of non-Newtonian fluids on the heat transfer in a pipe flow  

Science.gov (United States)

The present study investigates the effect of the shear rate-dependent thermal conductivity of non-Newtonian fluids on the heat transfer enhancement in a pipe flow. The constant heat flux as thermal boundary condition was adopted in the thermally developed region. The present analytical results show the heat transfer enhancement over those of a shear rate-independent thermal conductivity fluid. The heat transfer coefficient ratio (h/h{sub 0}) linearly increase with the non-dimensional average velocity difference which is the product of the shear rate-dependence of the thermal conductivity and wall-shear rate.

1996-09-01

263

The effect of the precursor nanopowder size on the thermoelectric properties of nanostructured Bi-Sb-Te bulk materials  

International Nuclear Information System (INIS)

This paper presents the effect of precursor powder size on the thermoelectric properties of sintered nanostructured bulk materials. The transport properties of the nanostructured bulk show a dramatic size effect. There are a lower thermal and electrical conductivity for the bulk with smaller nanopowders. The dimensionless figure-of merit values (ZT) of almost all the samples are much lower than those of the list reported data in the paper because the decrease in the thermal conductivity is counteracted by the reduction in the electrical conductivity and the Seebeck coefficient. The combination route of hydro/solvothermal synthesis and spark-plasma-sintering method provide a well controlled way to significantly reduce the thermal conductivity.

2010-12-15

264

The Future of Airborne Forces in the Objective Force  

Science.gov (United States)

... operations. Of these two divisions, only the paratroopers of the 82nd Airborne Division can conduct a strategic forcible entry into a ...

2003-04-07

265

REVIEW OF US METEOROLOGICAL ROCKET NETWORK ...  

Science.gov (United States)

... more and better sensors to be ... all the continuously incoming data, which ... RANGE RECEIVER THERMAL CONDUCTIVITY ,# PRESSURE SENSOR ...

2011-05-14

266

Lithium ionic conductivity in LiI?Li2S?La2O2Sm (m=1, 2) composite electrolyte by solid state reaction  

British Library Electronic Table of Contents (United Kingdom)

New lithium ion composite electrolyte, LiI?Li2S?La2O2Sm (m=1, 2) was synthesized from the binary Li2S?LaOI system through solid state reaction. The lithium ion conductive property was investigated by AC impedance spectroscopy. And the highest conductivity of the obtained electrolyte at room temperature was found to be 3.0?10?6?S cm?1. The notable ionic conduction was attributed to the in situ formed amorphous LiI.

2008-01-01

267

Lack of oscillations in Dual-Phase-Lagging heat conduction for a porous slab subject to imposed heat flux and temperature  

Energy Technology Data Exchange (ETDEWEB)

This study shows that the physical conditions necessary for thermal waves to materialize in Dual-Phase-Lagging porous media conduction are not attainable in a porous slab subject to a combination of constant heat flux and temperature (Neumann and Dirichlet) boundary conditions. It is demonstrated that the approximate equivalence between Dual-Phase-Lagging (DuPhlag) heat conduction model and the Fourier heat conduction in porous media subject to Lack of Local Thermal Equilibrium (La Lotheq) that suggested the possibility of thermal oscillations and resonance reveals a condition that cannot be fulfilled because of physical constraints. (author)

2005-07-01

270

Electrical conductivity of pyrolyzed polyacrylonitrile  

Energy Technology Data Exchange (ETDEWEB)

Using ultrapure samples of polyacrylonitrile (PAN) of 485,000 or 150,000 average molecular weight solution cast in dimethylformamide, the dc conductivity (sigma) of pyrolyzed PAN (PANP) films has been studied for pyrolysis temperatures (T/ sub p/) of 280 to 435/sup 0/C. Conductivity measurements made during pyrolysis indicate the onset of a dramatic increase in sigma for T/sub p/ of 390 to 435/sup 0/C. Conductivities as high as 5 (ohm-cm)/sup -1/ have been observed for T/sub p/ < 435/sup 0/C.

1981-01-01

271

Effect of isopropyl alcohol on the surface localization and recombination of conduction-band electrons in Degussa P25 TiO_2. A pulse-radiolysis time-resolved microwave conductivity study  

International Nuclear Information System (INIS)

Conduction-band electrons, formed by pulse radiolysis of Degussa P25 TiO_2 particles, have been monitored by time-resolved microwave conductivity and found to undergo equilibrium localization and eventual recombination at the particle surface. In the presence of isopropyl alcohol recombination is retarded due to surface hole scavenging. The particle bulk can then be pumped with mobile electrons, which survive for seconds.

272

Conducting the Breakthrough: Unnecessary Operation or US ...  

Science.gov (United States)

... German Seventh Army. The Goodwood offensive by the British to the ... well. General P. Wood of tne Fourth Armored Division, rea ...

1991-05-03

273

COMBUSTIBLE AMMUNITION FOR SMALL ARMS. 1. ...  

Science.gov (United States)

... Research on development of combustible cartridge cases for small arms was conducted in Germany during World War II. ...

1960-05-01

275

A Study of the Geographic Origin, Education, and Experience ...  

Science.gov (United States)

... by starting and remaining in that size hotel. Another early study, conducted by Nailon (1968) sampled three general managers ...

1993-04-01

276

Thermal conductivity of simple molecular substances at crystal-liquid phase transition  

International Nuclear Information System (INIS)

By the example of CH2Cl2, CF2Cl2, CHF2Cl, C2F6, C2H6, SF6 and C6H12 we have investigated the isobaric thermal conductivity jump at crystal-liquid phase transition. It is shown that the reduction in the thermal conductivity at melting derives from the degree of orientational ordering of the crystals at pre-melting point.

2009-01-01

277

Conductive, spin-cast carbon films from polyacrylonitrile  

Energy Technology Data Exchange (ETDEWEB)

Polyacrylonitrile films have been spin cast and pyrolyzed to produce thin (500--1500 A) carbon films. These films have higher electrical conductivities than films produced by other methods at similar temperatures. The conductivity can be varied by at least four orders of magnitude by changing the pyrolysis temperature. Ultraviolet, infrared, and Raman spectroscopies were used to investigate the chemical structure of the films during different stages of processing.

1987-05-18

278

Conductance quantization in ferromagnetic Ni nano-constriction  

Energy Technology Data Exchange (ETDEWEB)

The conductance in ferromagnetic Ni nano-wire is quantized in units of 2e{sup 2}/h in the absence of magnetic field, while the units switch to e{sup 2}/h in the magnetic field. The fractional units of 0.7e{sup 2}/h and 1.4e{sup 2}/h with and without magnetic field appear under the application of high bias-voltage. The spin polarization and bias-voltage play an important role in the electric conduction.

2002-02-01

279

43 CFR 3251.12 - What action will BLM take on my Notice of Intent to Conduct Geothermal Resource Exploration...  

Science.gov (United States)

...take on my Notice of Intent to Conduct Geothermal Resource Exploration Operations? ...INTERIOR MINERALS MANAGEMENT (3000) GEOTHERMAL RESOURCE LEASING Exploration Operations...take on my Notice of Intent to Conduct Geothermal Resource Exploration Operations?...

2010-10-01

280

The effects of counter cation on lithium ion conductivity: In the case of the perovskite-type titanium oxides of La2/3?x Li3xTiO3 and LaTiO3  

British Library Electronic Table of Contents (United Kingdom)

We performed hybrid-DFT calculations for La2/3?xLi3xTiO3 (LLT) with lithium ion conductivity, in order to investigate the detailed lithium ion conductive mechanism from the viewpoint of molecular orbital (MO) method. It was concluded that the very ionic lithium ion in bottleneck accelerates the lithium ion conduction. The calculated MO shows no chemical bonding between lithium ion and other ions. In comparison with the perovskite-type trivalent titanium oxide of LaTiO3, the effect of the titanium's reduction was also investigated. We showed the possibility of the high lithium conductivity in LaTiO3.

2009-01-01

281

Formation of pentagonal Cu nano wires  

Energy Technology Data Exchange (ETDEWEB)

The development of nano/molecular devices will require atomic-sized electrical contacts or nano metric conductors for wiring. As metal nano wires exhibit quantized conductance at room temperature, quantum transport effects will play an important role in the practical implementation of nano devices. As copper is currently used as interconnecting metal in standard microelectronics, the characterization of Cu nano wire properties deserves special attention. In this work, we show a detailed study of structural and electronic properties of atomic-sized Cu wires. In particular, we have established a complete correlation between the conductance and the structure by associating real-time atomic resolution transmission electron microscopy imaging with molecular dynamic simulations, conductance measurements and conductance calculations. Our study has revealed the structural relaxation of Cu wires forming a ...

2004-07-01

282

Lithium ion conductive polymer electrolyte by side group rotation  

Energy Technology Data Exchange (ETDEWEB)

Ionic conductive materials are of much interest as an electrolyte for solid-state lithium batteries. Poly(alkylene oxide) and lithium salt complex exhibits high ionic conductivity in terms of its high solubility for lithium salts. However, the temperature dependency of its ionic conductivity is quite large and non-linear, the ionic conductivity drops down at low temperature, especially below glass transition temperature of the polymer. Because its ionic conductive mechanism is derived from its segmental motion of polymer main chain. A novel ionic conductive material, poly[2,6-dimethoxy-N-(4-vinylphenyl)benzamide] is synthesized and confirm ionic conductivity even below glass transition temperature. Ionic conductivity of the polymer with lithium ditrifluoromethylsulfonate imide complex shows 10{sup -5}Scm{sup -1} from 0 ...

2005-08-26

283

Thermodynamics and stability of the mixed-conducting Sr-Fe-Co-O system.  

Energy Technology Data Exchange (ETDEWEB)

Mixed-conducting Sr-Fe-Co oxides have potential applications in dense ceramic membranes for high-purity oxygen separation and/or methane conversion to produce syngas (CO + H{sub 2}), because of their combined high electronic/ionic conductivity and significant oxygen permeability. We studied the crystal structure and microstructure of the system in X-ray diffraction experiments and by using scanning electron microscopy, respectively. Thermogravimetric analysis was conducted on the SrFeCo{sub 0.5}O{sub x} sample in environments of various oxygen partial pressures (pO{sub 2}). Conductivity increased while weight decreased with increasing temperature. Activation energy decreased while conductivity increased with increasing pO{sub 2}. The pO{sub 2}-dependent conducting behavior of the SrFeCo{sub 0.5}O{sub x} system can be understood by considering the ...

1999-04-28

284

Thermal conductivity of leaf compost used in biofilters: An experimental and theoretical investigation  

International Nuclear Information System (INIS)

Thermal conductivity is an important property that governs the behaviour of leaf compost biofilters used in treating gaseous pollutants. Measurements were carried out for the thermal conductivity (K) of 44 samples of leaf compost, covering wide ranges of the volume fractions of water (#xi#_w), solids (#xi#_s) and air (#xi#_a), at 20 deg. C using an unsteady state thermal probe. The results indicated that the compost thermal conductivity increased with an increase in #xi#_w, with a decrease in #xi#_a, and with an increase in the degree of saturation (defined as the volumetric fraction of water in the total void space). The predictions from the Woodside-Messmer quadratic parallel (QP) model for the thermal conductivity of leaf compost were higher than the experimental values. A simple linear relationship was developed between the thermal conductivity and the degree of saturation, ...

2005-07-01

285

Single-Electrode Transient Behavior for Electric Double Layer Capacitor Composed of Nano-Porous Carbon Electrode; Kasseitan denki 2jyuso kyapasita no tankyoku jyuhoden katei ni taisuru sokudoronteki kento  

Energy Technology Data Exchange (ETDEWEB)

Single-electrode transient behavior was measured mainly during the discharging process for a model cell of electric double layer capacitor with nano-porous carbon electrodes and reference electrode. Apparent conductivity in the cell, which we call `effective conductivity,` is determined with approximation of current in transient behavior to a one-dimensional electrophoretic model. A comparison of effective conductivity with conductivity of bulk solution suggests an interesting mechanism of transfer of electrolyte ions. The difference in transient behavior between various electrolyte ions was not conspicuous in spite of distinctive differences in conductivity of each bulk solution. The large pore diameter of the carbon electrode results in rapid transient behavior and such an electrode should be suitable for rapid charge and discharge. The effect of origin of carbon electrode is ...

1997-07-10

286

Kapitza conductance of the (100) surface of copper  

International Nuclear Information System (INIS)

Measurements of the Kapitza conductance to liquid helium II across the (100) surface of single crystals of copper are presented. The temperature range of these measurements was 1.6-- 2.1 K. The sample surfaces were subjected to several different treatments. Some surfaces were cleaned by low-energy argon ion bombardment, annealed in an ultrahigh-vacuum system, and preserved under vacuum until purified liquid helium was admitted. Other surfaces were intentionally damaged by machining and/or exposure to the atmosphere. The conductance after these latter treatments was found to be about a factor of three higher than that of the more ideally cleaned and annealed surfaces, and a significant difference in the temperature dependence of the conductance was also observed. Conductances were reproducible for similarly treated surfaces and correlated with surface damage determined by x-ray diffraction. The ...

287

Ionic conductivity enhancement for lithium solid electrolyte; Lithium ion dodensei kotai denkaishitsu no dodensei kojo kiko no kaimei  

Energy Technology Data Exchange (ETDEWEB)

For the development of high ionic conductive solid electrolyte, LiTi2(PO4)3 (LTP), one of the promising inorganic solid electrolyte, was synthesized to investigate an effect of additional lithium salt on the ion conductivity. Lithium salt added LTP composite electrolyte sintered at 900{degree}C exhibited highest conductivity, which was two order magnitude higher than pure LTP. Effects of lithium salt addition are as follows. Conductivity of the composite electrolyte provided larger sintering temperature dependence than the pure LTP. From X-ray diffraction analysis, structures and compositions were resemble between two composite electrolytes. Byproducts except LTP provided rather low conductivity. It was suggested that melted constitution in the composite can affect the sintering improvement by the additional lithium salt at temperatures over 800 {degree}C. From the observation of ...

1996-08-01

288

Variability and spectral modeling of the hard X-ray emission of GX 339-4 in a bright low/hard state  

CERN Document Server

We study the high-energy emission of the Galactic black hole candidate GX 339-4 using INTEGRAL/SPI and simultaneous RXTE/PCA data. By the end of January 2007, when it reached its peak luminosity in hard X-rays, the source was in a bright hard state. The SPI data from this period show a good signal to noise ratio, allowing a detailed study of the spectral energy distribution up to several hundred keV. As a main result, we report on the detection of a variable hard spectral feature (>150 keV) which represents a significant excess with respect to the cutoff power law shape of the spectrum. The SPI data suggest that the intensity of this feature is positively correlated with the 25 - 50 keV luminosity of the source and the associated variability time scale is shorter than 7 hours. The simultaneous PCA data, however, show no significant change in the spectral shape, indicating that the source is not undergoing a canonical state transition. We ...

2010-01-01

289

The Oak Ridge Y-12 Plant biological monitoring and abatement program for East Fork Poplar Creek  

Energy Technology Data Exchange (ETDEWEB)

In May 1985, a National Pollutant Discharge Elimination System permit was issued for the Oak Ridge Y-12 Plant, a nuclear weapons components production facility located in Oak Ridge, Tennessee, and operated by Martin Marietta Energy Systems, Inc., for the US Department of Energy. As a condition of the permit, a Biological Monitoring and Abatement Program (BMAP) was developed to demonstrate that the effluent limitations established for the Oak Ridge Y-12 Plant protect the classified uses of the receiving stream (East Fork Poplar Creek), in particular, the growth and propagation of fish and aquatic life, as designated by the Tennessee Department of Health and Environment. A second purpose for the BMAP is to document the ecological effects resulting from implementation of a water pollution control program that will include construction of nine new wastewater treatment facilities over the next 4 years. Because of the complex nature of the effluent discharged to East Fork Poplar Creek and ...

1989-10-01

290

THE ACTIVITY AND VARIABILITY OF THE SUN AND SUN-LIKE STARS. II. CONTEMPORANEOUS PHOTOMETRY AND SPECTROSCOPY OF BRIGHT SOLAR ANALOGS  

International Nuclear Information System (INIS)

We present 14 years of contemporaneous photometric and spectroscopic observations of 28 solar analog stars, taken with the Tennessee State University Automatic Photometric Telescopes at Fairborn Observatory and the Solar-Stellar Spectrograph at Lowell Observatory. These are the best observed and most nearly Sun-like of the targets in our magnitude-limited (V #<=# 7.5) sample. The correlations between luminosity and activity reveal the expected inverse activity-brightness correlations for active stars. Strong direct correlations between activity and brightness are not prevalent for the less active solar age stars, but are precision limited. The Sun does not appear to have unusually low photometric variability when compared with the most Sun-like inactive solar analogs. We present evidence that the activity index R'_H_K is not a good discriminant of Maunder Minimum candidate stars. On the basis of a star that appears to have transitioned from a ...

2009-07-01

291

Stable isotopes of authigenic minerals in variably-saturated fractured tuff  

Energy Technology Data Exchange (ETDEWEB)

Identifying stable isotope variation and mineralogical changes in fractured rock may help establish the history of climatic and geomorphological processes that might affect the isolation properties of a waste repository site. This study examines the use of the stable isotope ratios of oxygen ({sup 18}O/{sup 16}O) and carbon ({sup 13}C/{sup 12}C) in authigenic minerals as hydrogeochemical tools tracing low-temperature rock-water interaction in variably-saturated fractured stuff. Isotopic compositions of fracture-filling and rock matrix minerals in the Apache Leap tuff, near Superior, Arizona were concordant with geothermal temperatures and in equilibrium with water isotopically similar to present-day meteoric water and groundwater. Oxygen and carbon isotope ratios of fracture-filling, in unsaturated fractured tuff, displayed an isotopic gradient believed to result from near-surface isotopic enrichment due to evaporation rather than the effects of rock-water ...

1988-11-01

292

Sequence of Potentials Lying Between the U(5) and X(5) Symmetries  

CERN Document Server

Starting from the original collective Hamiltonian of Bohr and separating the beta and gamma variables as in the X(5) model of Iachello, an exactly soluble model corresponding to a harmonic oscillator potential in the beta-variable (to be called X(5)-$\\beta^2$) is constructed. Furthermore, it is proved that the potentials of the form $\\beta^{2n}$ (with n being integer) provide a ``bridge'' between this new X(5)-$\\beta^2$ model (occuring for n=1) and the X(5) model (corresponding to an infinite well potential in the beta-variable, materialized for n going to infinity. Parameter-free (up to overall scale factors) predictions for spectra and B(E2) transition rates are given for the potentials $\\beta^2$, $\\beta^4$, $\\beta^6$, $\\beta^8$, corresponding to E(4)/E(2) ratios of 2.646, 2.769, 2.824, and 2.852 respectively, compared to the E(4)/E(2) ratios of 2.000 for U(5) and 2.904 for X(5). Hints about nuclei showing this ...

2004-01-01

293

Remodeling of the free electron laser with the L-band linac at Osaka University  

International Nuclear Information System (INIS)

The far infrared free electron laser (FEL) has been being developed since 1990 using the L-band electron linac at the Institute of Scientific and Industrial Research, Osaka University. The first lasing was obtained in 1994 at wavelengths from 32 to 40 #mu#m. The FEL is now being modified suitable for user experiments. The wiggler with a fixed magnet gap used in the original FEL has been remodeled to make the magnet gap variable. In order to optimize the variable range of the gap, the gain and the diffraction loss were calculated. The peak gain is calculated to be 270% and the diffraction loss to be 22% at 150 #mu#m. The wavelength is expected to be variable from 25 up to at least 150 #mu#m. The two bending magnets in the optical resonator have been remodeled and the vacuum chambers with larger vertical sizes for them have been newly made so that the diffraction loss in these parts becomes smaller than that in the vacuum ...

1997-02-28

294

Relationships between bone structure in the iliac crest and bone structure and strength in the lumbar spine.  

Science.gov (United States)

The purpose of this study was to examine the relationship between histomorphometric variables of cancellous bone structure and ultimate compressive strength (UCS) in the second lumbar vertebra (L2) and to determine whether structural variables in the iliac crest are predictive of the same variables and of UCS in L2. At autopsy, 7.5 mm diameter cores were removed from the iliac crest and from L2 of 29 subjects who had died suddenly without bone disease. Cancellous bone volume (BV/TV, %) was significantly lower in L2 than in iliac crest due to lower trabecular number (Tb.N, per mm) and thickness (Tb.Th, microns). There were significant correlations between iliac crest and L2 for BV/TV, Tb.N and trabecular separation (Tb.Sp, microns), but not for Tb.Th. BV/TV was negatively correlated, and Tb.Sp was positively correlated with age at both sites. Tb.Th was not significantly correlated with age in the iliac crest, but a ...

1993-03-01

295

Optimal control of the free boundary in a two-phase Stefan problem  

Science.gov (United States)

We present an optimal control approach for the solidification process of a melt in a container. The process is described by a two phase Stefan problem with the free boundary (interface between the two phases) modelled as a graph. We control the evolution of the free boundary using the temperature on the container wall. The control goal consists in tracking a prescribed evolution of the free boundary. We achieve this goal by minimizing a appropriate cost functional. The resulting minimization problem is solved numerically by a steepest descent method with step size control, where the gradient of the cost functional is expressed in terms of the adjoint variables. Several numerical examples are presented which illustrate the performance of the method. The novelty of the approach presented consists in using a sharp interface model for the control of the free boundary. This guarantees direct access to the free boundary as optimization variable in ...

2007-05-01

296

Epidemiologic studies of coronary heart disease and stroke in Japanese men living in Japan, Hawaii, and California: demographic, physical, dietary, and biochemical characteristics  

International Nuclear Information System (INIS)

These summary descriptive data of ethnically similar cohorts of indigenous and migrant Japanese males have shown similarities or slight differences in characteristics wholly or largely genetically determined, such as blood groups, stature, and skeletal size. Differences have been noted in characteristics largely environmental or behavioral, such as diet and cigarette smoking habit, as well as in characteristics determined by a varying mixture of genetic and environmental influences, such as weight, blood pressure, glucose tolerance, and serum lipid and uric acid levels. Detailed analyses of the distributions of laboratory variables, of dietary data obtained by different methods, and of correlations among laboratory, dietary, physical, and demographic variables are currently in progress. Also part of the study plan are determinations of disease prevalence from evaluation of examination, laboratory, and electrocardiographic findings, of disease ...

297

Development, field testing and implementation of automated hydraulically controlled, variable volume loading systems for reciprocating compressors  

Energy Technology Data Exchange (ETDEWEB)

Automated, variable volume unloaders provide the ability to smoothly load/unload reciprocating compressors to maintain ideal operations in ever-changing environments. Potential advantages provided by this load control system include: maximizing unit capacity, optimizing power economy, maintaining low exhaust emissions, and maintaining process suction and discharge pressures. Obstacles foreseen include: reliability, stability, serviceability and automation integration. Results desired include: increased productivity for the compressor and its operators, increased up time, and more stable process control. This presentation covers: system design features with descriptions of how different types of the devices were developed, initial test data, and how they can be effectively operated; three actual-case studies detailing the reasons why automated, hydraulically controlled, variable volume, head-end unloaders were chosen over other types of ...

2003-07-01

298

Advanced fuzzy logic controllers design and evaluation for buildings' occupants thermal-visual comfort and indoor air quality satisfaction  

Energy Technology Data Exchange (ETDEWEB)

The aim of this paper is to present and evaluate control strategies for adjustment and preservation of air quality, thermal and visual comfort for buildings' occupants while, simultaneously, energy consumption reduction is achieved. Fuzzy PID, fuzzy PD and adaptive fuzzy PD control methods are applied. The inputs to any controller are: the PMV index affecting thermal comfort, the CO{sub 2} concentration affecting indoor air quality and the illuminance level affecting visual comfort. The adaptive fuzzy PD controller adapts the inputs and outputs scaling factors and is based on a second order reference model. More specifically, the scaling factors are modified according to a sigmoid type function, in such a way that the measured variable to be as closer as possible to the reference model. The adaptive fuzzy PD controller is compared to a non-adaptive fuzzy PD and to an ON-OFF one. The comparison criteria are the energy required and the controlled ...

2001-07-01

299

Abundance of West Nile virus mosquito vectors in relation to climate and landscape variables.  

Science.gov (United States)

It is currently unclear if the potential for West Nile virus transmission by mosquito vectors in the eastern United States is related to landscape or climate factors or both. We compared abundance of vector species between urban and suburban neighborhoods of Henrico County, VA, in relation to the following factors: temperature, precipitation, canopy cover, building footprint, and proximity to drainage infrastructure. Mosquitoes were collected throughout the 2005, 2006, and 2007 seasons and tested for West Nile virus (WNV) in pools of 10-50. Test results of mosquito pools were compared to average site abundance from 37 sites in Henrico County, VA; abundance was then examined in relation to ecological variables. Urban infrastructure was positively correlated with the abundance of Culex pipiens L./Cx. restuans, and our findings implicate combined sewer overflow systems as large contributors to Culex vector populations. No measure of urbanization examined in our study ...

2011-06-01

300

A variability study of the first catalog of gamma-ray sources on the 2.3 years AGILE data archive  

Science.gov (United States)

AGILE pointed observations performed from July 9, 2007 to October 30, 2009 are a recent, high quality gamma-ray data archive for monitoring studies of medium to high brightness gamma-ray sources in the 30 MeV -50 GeV energy range. We present a variability study of the 1AGL sources over the complete AGILE pointed Observation Blocks (OBs) dataset. The first AGILE Gamma-Ray Imaging Detector (GRID) catalog (Pittori et al. 2009) included a significance-limited (4 sigma) sample of 47 sources (1AGL), detected with a conservative analysis over a first-year non-uniform sky coverage dataset. In this analysis we used data of an improved full Field of View (FOV) event filter, on a much larger (about 27.5 months) observation dataset, analyzing each OB separatedly. This data processing resulted in an improved source list as compared to the 1AGL one. We present here some results on the variability of some of these sources.

2010-01-01

301

A dynamic approach to the Environmental Kuznets Curve hypothesis  

Energy Technology Data Exchange (ETDEWEB)

The Environmental Kuznets Curve (EKC) hypothesis states that pollution levels increase as a country develops, but begin to decrease as rising incomes pass beyond a turning point. In EKC analyses, the relationship between environmental degradation and income is usually expressed as a quadratic function with the turning point occurring at a maximum pollution level. Other explanatory variables have been included in these models, but income regularly has had the most significant effect on indicators of environmental quality. One variable consistently omitted in these relationships is the price of energy. This paper analyzes previous models to illustrate the importance of prices in these models and then includes prices in an econometric EKC framework testing energy/income and CO{sub 2}/income relationships. These long-run price/income models find that income is no longer the most relevant indicator of environmental quality or energy demand. Indeed, ...

1999-02-01

302

A dynamic approach to the Environmental Kuznets Curve hypothesis  

International Nuclear Information System (INIS)

The Environmental Kuznets Curve (EKC) hypothesis states that pollution levels increase as a country develops, but begin to decrease as rising incomes pass beyond a turning point. In EKC analyses, the relationship between environmental degradation and income is usually expressed as a quadratic function with the turning point occurring at a maximum pollution level. Other explanatory variables have been included in these models, but income regularly has had the most significant effect on indicators of environmental quality. One variable consistently omitted in these relationships is the price of energy. This paper analyzes previous models to illustrate the importance of prices in these models and then includes prices in an econometric EKC framework testing energy/income and CO_2/income relationships. These long-run price/income models find that income is no longer the most relevant indicator of environmental quality or energy demand. Indeed, we ...

1999-02-01

303

Wind systems life cycle cost analysis: a description and users manual. [LIFECC  

Energy Technology Data Exchange (ETDEWEB)

This report describes the LIFECC computer program developed for the purpose of calculating the cost of energy produced by wind systems according to the principles of life cycle costing (LCC). Following a brief explanation of the LCC concept and its advantages, input variables to the program and their importance to various program users, including manufacturers and designers, utilities, various institutions and consumers, are explained. A detailed user's guide to the program is then provided, together with a sensitivity analysis which discusses the impact of key variables on wind system cost of energy and the importance of cash flow to the wind system purchaser. Sample cases of program output and an LIFECC program listing are provided.

1982-07-01

304

What explains default risk premium during the financial crisis? Evidence from Japan  

British Library Electronic Table of Contents (United Kingdom)

As is well documented, subprime mortgage markets carried significant default risk. This paper investigates the relationship between default risk premium, stock market conditions and macroeconomic variables during the financial crisis. Using iTraxx Japan Credit Default Swap (CDS) index spreads covering the period from March 2006 to November 2009, we employ a time-varying dynamic factor model with Markov regime switching to generate regime probabilities for default risk. We analyze the sensitivity of default risk premium changes to stock market conditions and macroeconomic variables by using two-state Markov switching models: a crisis regime sparked by rising loan defaults in the sub-prime mortgage market, and a non-crisis regime. We found strong evidence that the relationship between defaul...

2011-01-01

305

Variable structure system based logic fuzzy control of bridge vibration using fail-safe magnetorheological fluid dampers  

Science.gov (United States)

This paper presents a semi-active vibration control of a scaled two-span bridge structure. Magneto-rheological fluid dampers are utilized as the semi-active energy absorbing deices and a bridge vibration control system is developed. Closed-loop control system based on fuzzy logic is used to suppress the bridge deck motion under random excitations. The sufficient condition for the closed-loop stability of the fuzzy control system is derived from the variable structure system theory. It is demonstrated that this stable fuzzy control system can significantly reduce the relative deck displacement using about 55 percent less power compared to passive-on state, while the absolute deck acceleration is relatively unaffected.

2002-06-01

306

Understanding Formulation Systems—A Six Sigma Approach  

British Library Electronic Table of Contents (United Kingdom)

The broad use of Six Sigma in the improvement of all types of processes has provided new insight for how to design, analyze, and interpret formulation studies and mixture experiments. Experience has shown that, consistent with the Pareto principle, there are typically three to six key variables that have major effects on the performance of the process. Identifying these key variables increases your ability to control and optimize the process. Applying this concept to formulation studies suggests that we should be searching for those critical few components that are driving the performance of the product formulation. This thinking changes how we approach both the design and analysis phases of product formulation studies, including the reassessment of formulations in use today. A review of t...

2011-01-01

307

Two-boson algebra and quantum computing with Josephson-like systems  

Energy Technology Data Exchange (ETDEWEB)

Our investigation concerns the class of Josephson-like systems, sharing the same nonlinear Hamiltonian. Among the latter a Josephson junction with an external biasing circuit is considered. We diagonalize the fully nonlinear Hamiltonian (in the superconductive regime of the junction) in the Fock space of the TBHA (two-boson Heisenberg algebra) and prove that such algebra leads quite naturally to the theoretical realization of codewords and logical operators: the codewords are defined as the even and odd coherent states of the TBHA, while the logical operators are expressed in terms of operators in the same algebra. Our theoretical construction corresponds to a continuous variable quantum computation scheme; the continuous variables are identified in terms of the physical operators of the junction. The link between this scheme and the technique of fermionization of bosonic systems is also discussed.

2005-12-01

308

To Get Overall Shapes and New Data of the 120-Cell and the 600-Cell  

CERN Document Server

This research will be helpful for people to display the 2-dimensiona projective models of 4-variable actual problems in many fields, in order to investigate deeply those actual problems. By using the theory of N-dimensional finite rotation group of the regular polytopes, the author established the 2-dimensional projective model of 4-dimensional rectangular coordinate system, and deduced a transformation matrix, and adopt it to display successfully the 2-dimensional overall shapes of two most complicated regular polytopes 120-Cell and 600-Cell. In the meantime, the author calculated all the vertex coordinates and determine the joint relationships between adjacent vertices of the regular polytopes 120-Cell and 600-Cell. Also, this provided a pattern for displaying the 2-dimensional projective model of 4-variable actual problem.

2009-01-01

309

Three dimensional simulation of compressible and incompressible flows through the finite element method; Simulacao tridimensional de escoamentos compressiveis e incompressiveis atraves do metodo dos elementos finitos  

Energy Technology Data Exchange (ETDEWEB)

Although incompressible fluid flows can be regarded as a particular case of a general problem, numerical methods and the mathematical formulation aimed to solve compressible and incompressible flows have their own peculiarities, in such a way, that it is generally not possible to attain both regimes with a single approach. In this work, we start from a typically compressible formulation, slightly modified to make use of pressure variables and, through augmenting the stabilising parameters, we end up with a simplified model which is able to deal with a wide range of flow regimes, from supersonic to low speed gas flows. The resulting methodology is flexible enough to allow for the simulation of liquid flows as well. Examples using conservative and pressure variables are shown and the results are compared to those published in the literature, in order to validate the method. (author)

2004-11-15

310

Technologies for Saving Energy in Railway Operation: General Discussion on Energy Issues Concerning Railway Technology  

British Library Electronic Table of Contents (United Kingdom)

Early technical history of electric supply to electric railways is briefly reviewed as an introduction to the following seven papers included in this special issue on technologies for saving energy in railway operation. Continuous power supply played a significant role in the early history of railway technologies. The variable voltage variable frequency (VVVF) power electronic technology had also a substantial impact on railway traction systems after 1980s. VVVF technology made it possible to have more efficient drives, downsize rolling stocks, and develop regenerative brakes. Because detailed discussions on each technical development are presented in the following papers, the general remarks of those technologies made in this introduction provide logical links to the ideas presented in th...

2010-01-01

311

Spatial and seasonal variability in cetacean distribution in the fjords of northern Patagonia, Chile  

British Library Electronic Table of Contents (United Kingdom)

Viddi, F. A., Hucke-Gaete, R., Torres-Florez, J. P., and Ribeiro, S. 2010. Spatial and seasonal variability in cetacean distribution in the fjords of northern Patagonia, Chile. - ICES Journal of Marine Science, 67: 959-970. Compared with other Chilean coastal areas, little is known about the diversity and distribution of cetaceans in northern Patagonian fjords. Between December 2000 and November 2001, surveys on platforms of opportunity were undertaken in southern Chile to evaluate species richness and the spatial and seasonal distribution of cetaceans. Nine species were recorded, blue, humpback, and minke whales, Peales dolphin, Chilean dolphin, killer whale, false killer whale, bottlenose dolphin, and Cuviers beaked whale. The pattern of cetacean distribution displayed significant season...

2010-01-01

312

Solution of free vibration equations of semi-rigid connected Reddy?Bickford beams resting on elastic soil using the differential transform method  

British Library Electronic Table of Contents (United Kingdom)

The literature regarding the free vibration analysis of Bernoulli?Euler and Timoshenko beams under various supporting conditions is plenty, but the free vibration analysis of Reddy?Bickford beams with variable cross-section on elastic soil with/without axial force effect using the Differential Transform Method (DTM) has not been investigated by any of the studies in open literature so far. In this study, the free vibration analysis of axially loaded and semi-rigid connected Reddy?Bickford beam with variable cross-section on elastic soil is carried out by using DTM. The model has six degrees of freedom at the two ends, one transverse displacement and two rotations, and the end forces are a shear force and two end moments in this study. The governing differential equations of motion of the r...

2011-01-01

313

Satellite monitoring of climatic factors regulating phytoplankton variability in the Arabian (Persian) Gulf  

British Library Electronic Table of Contents (United Kingdom)

Possible factors regulating phytoplankton variability in the Arabian (Persian) Gulf were analyzed on the basis of satellite observations and meteorological data (1997-2009), including remotely-sensed chlorophyll a concentration (CHL), sea surface temperature, wind, solar radiation, precipitation, and aerosols. Shallow waters of northwestern Gulf influenced by Shatt Al-Arab River discharge were more productive than open Gulf waters, although seasonal CHL patterns in this and other shallow regions looked unrealistic likely because the CHL signal was obscured by bottom reflection. Therefore our further analyses focused on the open Gulf waters, which show a subtropical seasonal CHL cycle with maximum in winter and minimum in spring-summer. This cycle, however, was decoupled from the seasonal e...

2010-01-01

314

Risk of sperm competition does not influence copulatory behavior in the promiscuous meadow vole (Microtus pennsylvanicus)  

British Library Electronic Table of Contents (United Kingdom)

It is not clear whether males in all mammalian species adjust their copulatory behavior when faced with risk of sperm competition (RSC). Previous work on meadow voles, Microtus pennsylvanicus, indicated that males increase their sperm expenditure but not the number of ejaculations in the presence of odors of a conspecific male. The present study follows up on this work and asks whether male meadow voles modify any aspect of their copulatory behavior when they face a RSC. We examined 46 variables of copulatory behavior and found that the presence of odors from a conspecific male did not affect any of these variables. Thus, male meadow voles, unlike some other species of mammals, do not adjust their copulatory behavior when exposed to cues associated with an elevated RSC.

2007-01-01

315

Rapid optical variability of TeV blazars  

British Library Electronic Table of Contents (United Kingdom)

Abstract In this first systematic attempt to characterize the intranight optical variability (INOV) of TeV-detected blazars, we have monitored a well-defined set of nine TeV blazars on total 26 nights during 2004-10. In this R- or V-band-monitoring programme only one blazar was monitored per night and the minimum duration was close to 4-h, the average being 5.3 h per night. Using the CCD for strictly simultaneous photometry of the blazar and nearby reference stars (N-star photometry), an INOV detection threshold of -1-2-per cent was achieved in the densely sampled differential light curves derived from our data. We have further expanded the sample by including another 13 TeV blazars, taking advantage of the availability in the literature of INOV data, including those published earlier in o...

2011-01-01

316

Pd based membrane reactor for ultra pure hydrogen production through the dry reforming of methane. Experimental and modeling studies  

British Library Electronic Table of Contents (United Kingdom)

A dense Pd-Ag membrane reactor (MR) with 100% hydrogen selectivity packed with either Rh/La2O3 or Rh/La2O3-SiO2 as catalysts was used to carry out the dry reforming of methane. The membrane reactor simulation was performed using a well-known reactor model. For this purpose, we employed the equations derived from complete kinetic studies of the dry reforming of methane reaction in connection with both catalysts. In addition, we developed the kinetic equation for the reverse water gas shift reaction (RWGS). The combination of detailed kinetic studies with the measured permeation flux for the Pd-Ag membrane allowed a complete comparison between experimental and simulated operation variables. The variables studied for both catalysts were methane conversion and hydrogen permeation as a function...

2011-01-01

317

Partition Functions of Normal Factor Graphs  

CERN Document Server

One of the most common types of functions in mathematics, physics, and engineering is a sum of products, sometimes called a partition function. After "normalization," a sum of products has a natural graphical representation, called a normal factor graph (NFG), in which vertices represent factors, edges represent internal variables, and half-edges represent the external variables of the partition function. In physics, so-called trace diagrams share similar features. We believe that the conceptual framework of representing sums of products as partition functions of NFGs is an important and intuitive paradigm that, surprisingly, does not seem to have been introduced explicitly in the previous factor graph literature. Of particular interest are NFG modifications that leave the partition function invariant. A simple subclass of such NFG modifications offers a unifying view of the Fourier transform, tree-based reparameterization, loop calculus, and ...

2011-01-01

318

On the disrupted magnetic braking model for the period gap of cataclysmic variables  

International Nuclear Information System (INIS)

The disrupted magnetic braking theory for the period gap of cataclysmic variable systems is used to study the binary evolution of low-mass main-sequence-like stars with white dwarf companions. The model is able to reproduce the observed location and width of the gap provided that the average mass transfer rates above the upper edge of the gap are greater than about 1.9 x 10 to the -9th solar masses/yr. For the case of angular momentum loss by magnetic braking, the slope of the mass transfer rate with respect to orbital period is shown to range from 3.4 to 3.7. For the evolutionary sequences considered, the He-3 abundance at the surface of the secondary exceeds 0.0015 after the complete mixing phase, resulting in modifications in the nuclear burning development of nova explosions. 31 refs.

319

Neural integrated control for a free-floating space robot with suddenly changing parameters  

British Library Electronic Table of Contents (United Kingdom)

Because the state of a free-floating space robot model is uncertain and sudden changes in the model parameters might undermine the stability of the system, this paper proposes a control strategy based on a variable structure neural integrated controller. This scheme does not need a precise space robot model, making use of the radial basis function neural network ability approach to learn about an uncertain model. The network weights are adjusted online in real-time. During the early period of the control phase and parameter changes, the variable structure controller compensates for the uncertain model which the neural network could not learn well. It also creates global asymptotic stability for the whole closed-loop system. Simulation results show that the controller can handle bad changea...

2011-01-01

320

Multiobjective design of Work-In-Process buffer for scheduling repetitive building projects  

British Library Electronic Table of Contents (United Kingdom)

Variability in production is one of the largest factors that negatively impacts construction project performance. A common construction practice to protect production systems from variability is the use of buffers (Bf). Construction practitioners and researchers have proposed buffering approaches for different production situations, but these approaches have faced practical limitations in their application. A multiobjective analytic model (MAM) is proposed to develop a graphical solution for the design of Work-In-Process (WIP) Bf in order to overcome these practical limitations to Bf application, being demonstrated through the scheduling of repetitive building projects. Multiobjective analytic modeling is based on Simulation?Optimization (SO) modeling and Pareto Fronts concepts. Simulation...

2009-01-01

321

Moral Judgments Recruit Domain-General Valuation Mechanisms to Integrate Representations of Probability and Magnitude  

British Library Electronic Table of Contents (United Kingdom)

Summary Many important moral decisions, particularly at the policy level, require the evaluation of choices involving outcomes of variable magnitude and probability. Many economic decisions involve the same problem. It is not known whether and to what extent these structurally isomorphic decisions rely on common neural mechanisms. Subjects undergoing fMRI evaluated the moral acceptability of sacrificing a single life to save a larger group of variable size and probability of dying without action. Paralleling research on economic decision making, the ventromedial prefrontal cortex and ventral striatum were specifically sensitive to the "expected moral value" of actions, i.e., the expected number of lives lost/saved. Likewise, the right anterior insula was specifically sensitive to outcome p...

2010-01-01

322

Modelling the impacts of weather and climate variability on crop productivity over a large area: A new super-ensemble-based probabilistic projection  

British Library Electronic Table of Contents (United Kingdom)

Estimates of climate change impacts are plague with uncertainties from many physical, biological, and social-economic processes. Among the urgent research priorities, more comprehensive assessments of impacts that better represent the uncertainties are needed. Here, we develop a new super-ensemble-based probabilistic projection approach to account for the uncertainties from CO2 emission scenarios, climate change scenarios, and biophysical processes in impact assessment model. We demonstrate the approach in addressing the probabilistic changes of maize production in the North China Plain in future. The new process-based general crop model, MCWLA [Tao, F., Yokozawa, M. Zhang, Z., 2009. Modelling the impacts of weather and climate variability on crop productivity over a large area: a new proc...

2009-01-01

323

Learning Undirected Graphical Models with Structure Penalty  

CERN Document Server

In undirected graphical models, learning the graph structure and learning the functions that relate the predictive variables (features) to the responses given the structure are two topics that have been widely investigated in machine learning and statistics. Learning graphical models in two stages will have problems because graph structure may change after considering the features. The main contribution of this paper is the proposed method that learns the graph structure and functions on the graph at the same time. General graphical models with binary outcomes conditioned on predictive variables are proved to be equivalent to multivariate Bernoulli model. The reparameterization of the potential functions in graphical model by conditional log odds ratios in multivariate Bernoulli model offers advantage in the representation of the conditional independence structure in the model. Additionally, we impose a structure penalty on groups of ...

2011-01-01

324

Issues in the use of short-term radon concentration measurements for estimating long-term exposures  

International Nuclear Information System (INIS)

Short-duration measurements have been widely used to screen for exposures to elevated radon concentrations in individual houses or at state or regional levels. However, a number of factors, including spatial and temporal variability in radon concentrations, must be considered before comparison to concentration guidelines can be made. Daily variations in radon concentration can lead to inherent measurement uncertainties ranging from 20 to 100+ percent. Differences in radon concentration due to seasonal effects and/or sampling location are also variable, and do not appear to be regionally consistent. Winter/summer concentration ratios, for example, have been observed to vary by as much as a factor of 10 in basements and by a factor of 5 in first floors. In this paper the implications of these uncertainties on the use of short-term sampling for inferring long-term exposures are discussed.

1990-02-19

325

Ignition delay as determined in a variable-compression ratio direct-injection diesel engine  

Energy Technology Data Exchange (ETDEWEB)

A variable-compression ratio, direct-injection diesel engine (VCR) has been designed and assembled at Southwest Research Institute with the intention of examining the current procedures for rating the ignition quality of diesel fuels and the meaning of ignition delay as an indicator of ignition and combustion quality. Using a slightly modified ASTM D 613 procedure, the engine has been used to rate the ignition quality of 43 different test fuels. The ratings obtained in the VCR engine are compared to the corresponding rating obtained using the standard cetane rating procedure. Some of the problems associated with the standard procedure became apparent during these experiments. The experimental results are discussed in terms of the problems and the advantages of a proposed VCR-based rating procedure.

1987-01-01

326

Hydrothermal faunal assemblages and habitat characterisation at the Eiffel Tower edifice (Lucky Strike, Mid-Atlantic Ridge)  

British Library Electronic Table of Contents (United Kingdom)

Abstract The Eiffel Tower edifice is situated in the Lucky Strike hydrothermal vent field at a mean depth of 1690-m on the Mid-Atlantic Ridge (MAR). At this 11-m-high hydrothermal structure, different faunal assemblages, varying in visibly dominant species (mussels and shrimp), in mussel size and in density of mussel coverage, were sampled biologically and chemically. Temperature and sulphide (-S) were measured on the different types of mussel-based assemblages and on a shrimp-dominated assemblage. Temperature was used as a proxy for calculating total concentrations of CH4. Based on the physico-chemical measurements, two microhabitats were identified, corresponding to (i) a more variable habitat featuring the greatest fluctuations in environmental variables and (ii) a second, more stable, ...

2011-01-01

327

Genetic algorithm approach for the determination of the electrical parameters of railway traction lines  

British Library Electronic Table of Contents (United Kingdom)

The problem of electrical parameters identification in complex systems, and in particular in electric railway traction systems, is considered. Parameters are determined by an indirect approach: only the terminal variables (voltages and currents and, impedance and admittance, which can be readily calculated) are measured and the per-unit-length electrical parameters are determined using a multiconductor transmission line model of the track section under test. It will be shown that some parameters cannot be measured directly, that they are not constant with frequency and that they may depend on other external conditions. An indirect method for parameters identification is proposed through an adaptive algorithm (AA), so that the calculated terminal variables match the measured ones. The AA is...

2008-01-01

328

Experimental assessment of energy storage via variable speed compressor  

British Library Electronic Table of Contents (United Kingdom)

In this study, usage of a variable speed refrigeration system in latent heat thermal energy storage (LHTES) system is investigated to increase energy storage efficiency. Four different compressor speed control cases are compared to obtain a constant heat transfer fluid (HTF) temperature at the inlet of the energy storage tank. These control cases are (i) control with evaporation temperature, (ii) control with ethylene glycol temperature at the outlet section of evaporator, (iii) control with suction pressure of the compressor and (iv) on/off control. By means of the experimental analysis the best control strategy is obtained as control with Case (ii), in terms of stability of inlet temperature of heat transfer fluid, variations of energy efficiency of LHTES and coefficient of performance (...

2011-01-01

329

Evaluation and optimization of organosolv pretreatment using combined severity factors and response surface methodology  

British Library Electronic Table of Contents (United Kingdom)

In this study, ethanol organosolv pretreatment was investigated and optimized for the pretreatment of empty palm fruit bunch using (1) response surface methodology based on three-variable central composite design and (2) the combined severity parameters. The reaction parameters studied were sulfuric acid concentration (0.5-2.0%), reaction temperature (160-200^oC) and residence time (45-90min). Both models provide valuable and complementary informations: using combined severity parameters, very good predictions were obtained concerning xylan and lignin extraction whereas central composite design is the best model for glucose production. The optimal values of the variables were as the followings: sulfuric acid 2.0% w/w, 160^oC, 78min and the experimental values (96.0%) concerning glucose and...

2011-01-01

330

Effects of heat loss as percentage of fuel's energy, friction and variable specific heats of working fluid on performance of air standard Otto cycle  

British Library Electronic Table of Contents (United Kingdom)

The objective of this study is to analyze the effects of heat loss characterized by a percentage of the fuel's energy, friction and variable specific heats of working fluid on the performance of an air standard Otto cycle with a restriction of maximum cycle temperature. A more realistic and precise relationship between the fuel's chemical energy and the heat leakage that is based on a pair of inequalities is derived through the resulting temperature. The variations in power output and thermal efficiency with compression ratio, and the relations between the power output and the thermal efficiency of the cycle are presented. The results show that the power output as well as the efficiency where maximum power output occurs will increase with increase of the maximum cycle temperature. The temp...

2008-01-01

331

Dynamic construction of outage lists for safety analysis of power transmission lines. Dynamische Erstellung von Ausfallisten fuer die Sicherheitsanalyse elektrischer Energieuebertragungssysteme  

Energy Technology Data Exchange (ETDEWEB)

An adaptive contingency selection process is set up which produces outage lists in order to guarantee on-line network security control. The quality index system used so far did not detect and reveal all critical variables due to observation problems in the mapping of two functions. The new process uses the results of the outage simulation computing of the system status just past for the drawing up of an up-to-date outage list. A linear correcting function transform the G{sub 2}-values of the standard quality index method - which still incorporate the observation problem effect - into improved values G. Studies which use data from realstic high-voltage networks prove that the detection of critical variables is far superior to ordinary methods. (orig.).

1990-04-23

332

Covariance of quantum general relativity from Ashtekar variables  

CERN Document Server

In this paper we examine the relationship between covariance and unitarity for quantum gravity in Ashtekar variables. A usual description would discard half of the original Lorentz group, in exchange for the resulting simplifications of general relativity. We start by quantizing a trivial SL(2,C) gauge theory resulting in a nonunitary covariant theory. By the addition of a total time derivative we transform this into a unitary theory of the Ashtekar description of gravity with complete accountability of the degrees of freedom. We find that covariance on the spacetime level bears a direct relationship to covariance on the level ofthe quantum fields themselves. This procedure can in principle be applied to any totally constrained system, and bears a resemblance to the Gupta--Bleuler method. Finally, we make some observation regarding the loop representation of the SL(2,C) connection.

2008-01-01

333

Challenges in presenting high dimensional data to aid in triage in the DARPA virtual soldier project.  

Science.gov (United States)

One of the goals of the DARPA Virtual Soldier Project is to aid the field medic in the triage of a casualty. In Phase I, we are currently collecting 12 baseline experimental physiological variables and a cardiac gated Computed Tomography (CT) imagery for use in an prototyping a futuristic electronic medical record, the "Holomer". We are using physiological models and Kalman filtering to aid in diagnosis and predict outcomes in relation to cardiac injury. The physiological modeling introduces another few hundred variables. Reducing the complexity of the above into easy-to-read text to aid in the triage by the field medic is the challenge with multiple display solutions. A description of the possible techniques follows. PMID:15718701

2005-01-01

334

Bioprocess control from a multivariate process trajectory.  

Science.gov (United States)

A multivariate bioprocess control approach, capable of tracking a pre-set process trajectory correlated to the biomass or product concentration in the bioprocess is described. The trajectory was either a latent variable derived from multivariate statistical process monitoring (MSPC) based on partial least squares (PLS) modeling, or the absolute value of the process variable. In the control algorithm the substrate feed pump rate was calculated from on-line analyzer data. The only parameters needed were the substrate feed concentration and the substrate yield of the growth-limiting substrate. On-line near-infrared spectroscopy data were used to demonstrate the performance of the control algorithm on an Escherichia coli fed-batch cultivation for tryptophan production. The controller showed good ability to track a defined biomass trajectory during varying process dynamics. The robustness of the control was high, despite significant external ...

2003-09-05

335

Biodynamic modelling of the accumulation of Ag, Cd and Zn by the deposit-feeding polychaete Nereis diversicolor: Inter-population variability and a generalised predictive model  

British Library Electronic Table of Contents (United Kingdom)

Biodynamic parameters of the ragworm Nereis diversicolor from southern Spain and south England were experimentally derived to assess the inter-population variability of physiological parameters of the bioaccumulation of Ag, Cd and Zn from water and sediment. Although there were some limited variations, these were not consistent with the local metal bioavailability nor with temperature changes. Incorporating the biodynamic parameters into a defined biodynamic model, confirmed that sediment is the predominant source of Cd and Zn accumulated by the worms, accounting in each case for 99% of the overall accumulated metals, whereas the contribution of dissolved Ag to the total accumulated by the worm increased from about 27 to about 53% with increasing dissolved Ag concentration. Standardised va...

2010-01-01

336

An economic planning tool for geothermal energy projects  

Energy Technology Data Exchange (ETDEWEB)

Three geothermal direct heat applications were examined to derive a set of cost estimates from which one could determine the effect of changes in system parameters (temperature, flow, load, etc.) on the cost of heat. For each application, a set of resource characteristics and system inputs were chosen to best represent a site specific baseline condition. The baseline estimated cost of heat was calculated along with other cost estimates representing optimistic and pessimistic conditions, bracketing the range any input variable might reasonably take. Regression equations based upon these cost estimates were developed for each application to quantitatively relate changes in cost to changes in the input variables. These three equations and their accompanying nomographs serve as easily understandable planning tools for direct heat geothermal energy projects.

1980-12-01

337

A variable step-down conversion ratio switched capacitor DC-DC converter for energy harvesting systems working in intermittent mode  

International Nuclear Information System (INIS)

Energy harvesting systems stimulate the development of power management for low power consumption applications. Improving the converter efficiency of power management circuits has become a significant issue in energy harvesting system design. This paper presents a variable step-down conversion ratio switched capacitor (SC) DC-DC converter to advance the converter efficiency of charge on the stored capacitor in a wireless monitoring system of orthopedic implants. The converter is designed to work at 1 MHz switching frequency and achieves 15 to 2 V conversion. Measurement results show that the converter efficiency can reach 42% including all circuit power consumption, which is much higher than previous work. (semiconductor integrated circuits)

2009-12-01

338

12-month follow-up of first-episode psychosis in Finland and Spain-differential significance of social adjustment-related variables  

British Library Electronic Table of Contents (United Kingdom)

Abstract Objective:- This study explored 12-month outcome and its associations to social adjustment-related variables in patients with first-episode non-affective psychosis in Finland and Spain. Methods:- Forty-nine Finnish and 37 Spanish patients were evaluated at admission on various characteristics of social adjustment. Outcome was measured for 68 (79%) patients by the Brief Psychiatric Rating Scale, Global Assessment Scale, and Grip on Life. Results:- One-fourth of the patients experienced psychotic symptoms at follow-up. Sixty per-cent of the patients showed good global functioning and Grip on Life. In both patient groups, poor earlier global functioning, weak social network, poor Grip on Life, and psychological dependence on family of origin were associated with poor outcome. In the ...

2011-01-01

339

Importance of the planning activities, cutting, handling and analysis of the nuclei of oil well drilling; Importancia de las actividades de planificacion, corte, manejo y analisis de los nucleos de perforacion de pozos petroleros  

Energy Technology Data Exchange (ETDEWEB)

In the geologic formation where the oil deposits are located, diverse types of rocks perform functions as structural elements, storage containers for hydrocarbon water and calorific energy, as well as impermeable barriers and transport means of the energy and the fluids. Among the most important properties that are used to describe these functions are the porosity, the permeability, the compressibility of the pores volume, the formation resistivity factor, the saturation exponent, the velocity of acoustic waves P and S, the relative permeability, the capillary pressures, the elastic constants and other mechanical properties, the thermal expansion, coefficient, the thermal conductivity, the thermal diffusivity and the specific heat. The execution of an ample variety of activities related to the stages of exploration, location, evaluation and development of the oil deposits, depends strongly on having a good knowledge of the magnitude and the spatial ...

2007-07-01

340

Glass Furnace Combustion and Melting Research Facility.  

Energy Technology Data Exchange (ETDEWEB)

The need for a Combustion and Melting Research Facility focused on the solution of glass manufacturing problems common to all segments of the glass industry was given high priority in the earliest version of the Glass Industry Technology Roadmap (Eisenhauer et al., 1997). Visteon Glass Systems and, later, PPG Industries proposed to meet this requirement, in partnership with the DOE/OIT Glass Program and Sandia National Laboratories, by designing and building a research furnace equipped with state-of-the-art diagnostics in the DOE Combustion Research Facility located at the Sandia site in Livermore, CA. Input on the configuration and objectives of the facility was sought from the entire industry by a variety of routes: (1) through a survey distributed to industry leaders by GMIC, (2) by conducting an open workshop following the OIT Glass Industry Project Review in September 1999, (3) from discussions with numerous glass engineers, scientists, and executives, and (4) ...

2004-08-01

341

Studies on the electronic structure of some cubic intermetallic compounds of dysprosium following the self-consistent augmented-plane-wave method  

International Nuclear Information System (INIS)

The energy bands and the nature of the conduction electrons have been studied for two intermetallic compounds of dysprosium, i.e, DyZn and DyRh, following the self-consistent augmented-plane-wave (APW) method. The convergence of energy was found to be rapid for DyZn because the shell of 3d"1"0 electrons for Zn lies below the conduction band. The Fermi energies (E/sub F/) have been calculated to be 0.421 and 0.477 Ry for DyZn and DyRh, respectively. The densities and the numbers of conduction electrons inside and outside the APW spheres in each of these compounds are calculated, and it is shown that the character of conduction electrons inside the APW sphere of Dy is predominantly of d type. In order to see the accuracy of these results, self-consistent calculations were done for DyZn for different choices of the exchange potentials, and the calculated number of conduction electrons ...

342

Possible two-gap superconductivity in NdFeAsO{sub 0.9}F{sub 0.1} probed by point-contact Andreev-reflection spectroscopy  

Energy Technology Data Exchange (ETDEWEB)

Systematic studies of the NdFeAsOF superconducting energy gap using point-contact Andreev-reflection (PCAR) spectroscopy are presented. At low temperatures the PCAR conductance spectra show a pair of gap-like peaks at about {+-} (4-7) mV and in most cases also a pair of humps at around {+-} 10 mV. Fits to the s-wave two-gap model of the PCAR conductance allowed to determine two superconducting energy gaps in the system. However, the energy-gap features disappear at T* = 15-20 K, much below the particular T{sub c} of the junction under study. At T* a zero-bias conductance (ZBC) peak emerges, which at higher temperatures usually overwhelms the spectrum with an intensity significantly higher than the conductance signal at lower temperatures. Possible causes of this unexpected temperature effect are discussed. In some cases the conductance spectra show just a reduced ...

2009-01-15

343

New method for determining the energy gap of a superconductor using the maximum in differential conductance of electron tunneling spectrum  

Energy Technology Data Exchange (ETDEWEB)

A new method for determining the energy gap of a superconductor using the maximum in the differential conductance curve of electron tunneling spectrum is given in this paper. The V/sub max//kT versus ..delta../kT curve was calculated from tunneling theory. V/sub max/, the voltage of the conductance maximum, can be measured from electron tunneling spectrum. ..delta../kT can be found from this curve, then the energy gap ..delta.. can be calculated. This method is simple, fast and accurate. The accuracy almost approaches that of the curve fitting method.

1986-02-01

344

Ion funnel with extended mass range and reduced conductance limit aperture  

Energy Technology Data Exchange (ETDEWEB)

An improved ion funnel design is disclosed that decreases the axial RF (parasite) fields at the ion funnel exit. This is achieved by addition of one or more compensation electrodes after the conductance limit electrode. Various RF voltage profiles may be applied to the various electrodes minimizing the parasite axial potential wells. The smallest RF aperture that serves as the conductance limiting electrode is further reduced over standard designs. Overall, the ion funnel improves transmission ranges of both low m/z and high m/z ions, reducing RF activation of ions and decreasing the gas load to subsequent differential pumping stages.

2008-04-01

345

In situ monitoring of grouted electrolytes  

Energy Technology Data Exchange (ETDEWEB)

Cement-based composites are widely used in applications which demand long-term service life. One important example is in immobilization matrices for low-level radioactive and other hazardous wastes, which demands long-term retention and durability. The authors describe conductivity measurements of grouts flooded with water and in contact with a sink that consists of pure water. The conductivity measurements were designed and carried out in parallel with present quality verification methods and standard leach tests of the nuclear waste management industry. For the first time, the authors show that the method of replacing intrusive chemical analysis with conductivity measurements of the leaching samples yields equivalent results.

1996-04-01

346

Theoretical study of the electronic structure of some cubic intermetallic compounds of dysprosium using the augmented plane wave method  

International Nuclear Information System (INIS)

The energy bands and the nature of the conduction electrons have been studied for three intermetallic compounds of dysprosium. e.g., DyZn, DyCu and DyRh, following the augmented plane wave method. Density of states results are given and have implications for the stability of the structure of the intermetallic compounds of dysprosium. The charge densities and the number of conduction electrons inside and outside the APW spheres in each of these compounds are calculated; it is shown that the character of conduction electrons within the Dy APW sphere is principally of d type for all the compounds. The consequence of the predominance of d electron in the conduction bands on the various physical parameters is discussed. (author).

347

The thermal conductivity jump at crystal-liquid phase transition in CHCl3, C6H6, and CCl4: the action of rotational molecular motions  

International Nuclear Information System (INIS)

The thermal conductivity of liquid CHCl3, C6H6, and CCl4 is measured by a steady-state method under saturated vapor pressure in the temperature regions corresponding to pre-crystallization temperatures. The experimental results obtained are used to investigate the isobaric thermal conductivity jump ? ?p at the crystal-liquid phase transition in CHCl3, C6H6, and CCl4. The contributions of the phonon-phonon and phonon-rotational interaction to the total thermal resistance in solid and liquid state are specified using a modified method of reduced coordinates. The decrease in the thermal conductivity at the crystal-liquid phase transition, ? ?p, is explained by a combined effect of variations in positional distribution of molecules and in the form of rotational molecular motion.

2009-04-01

348

The thermal conductivity jump at crystal-liquid phase transition in CHCl3, C6H6, and CCl4: the action of rotational molecular motion  

Science.gov (United States)

The thermal conductivity of liquid CHCl3, C6H6, and CCl4 is measured by a steady-state method under saturated vapor pressure in the temperature regions corresponding to pre-crystallization temperatures. The experimental results obtained are used to investigate the isobaric thermal conductivity jump ??p at the crystal-liquid phase transition in CHCl3, C6H6, and CCl4. The contributions of the phonon-phonon and phonon-rotational interaction to the total thermal resistance in solid and liquid state are specified using a modified method of reduced coordinates. The decrease in the thermal conductivity at the crystal-liquid phase transition, ??p, is explained by a combined effect of variations in positional distribution of molecules and in the form of rotational molecular motion.

2009-04-01

349

The Theater JFACC Construct: Creating Disunity of Command ...  

Science.gov (United States)

... WHS- Washington Headquarters Service ... paper will advocate assignment of a Commander, Air Force Forces for all Joint Task Forces conducting ...

2009-04-01

350

Tackling the Steroid Issue: Squeezing Out the Juice  

Medline Plus

... Neglect (12) Co-Occurring Disorders (75) Conduct Disorders (3) D Dementia (2) Depression (51) Driving While Intoxicated (17) ...

351

Synthesis and electrochemical properties of lithium ion conductive glass, Li[sub 3]PO[sub 4]-Li[sub 2]S-SiS[sub 2  

Energy Technology Data Exchange (ETDEWEB)

As a continuation of our previous study, further experiments were performed on Li[sub 3]PO[sub 4]-Li[sub 2]S-SiS[sub 2] lithium ion conductive glass. In the present study, we employed a twin roller for quenching process instead of liquid nitrogen. We found that the glass forming region expands by twin roller technique and conductivity up to 1.5x10[sup -3] S/cm was achieved. Structural analysis on the glass revealed that Li[sub 3]PO[sub 4] doping changes the glass structure of Li[sub 2]S-SiS[sub 2], thereby enhancing the electrical conductivity

1994-02-01

352

Study of the Electron Beam Dynamics in the Fermi @ Elettra Linac  

Energy Technology Data Exchange (ETDEWEB)

A study of the electron beam dynamics in the linac is conducted for the FERMI free electron laser (FEL) founded for construction at the Sincrotrone Trieste.

2006-07-19

353

Study of the Electron Beam Dynamics in the FERMI @ ELETTRALinac  

Energy Technology Data Exchange (ETDEWEB)

A study of the electron beam dynamics in the linac is conducted for the FERMI free electron laser (FEL) founded for construction at the Sincrotrone Trieste

2006-06-17

354

SECTION 3.0 TRIAL CONDUCT  

Science.gov (United States)

... adverse events and potential major events. 3.2.2.4 Clinical Events Committee (CEC) The independent CEC (cardiologists and neurologists ...

355

Preliminary study on improvement of cementitious grout thermal conductivity for geothermal heat pump applications  

Energy Technology Data Exchange (ETDEWEB)

Preliminary studies were preformed to determine whether thermal conductivity of cementitious grouts used to backfill heat exchanger loops for geothermal heat pumps could be improved, thus improving efficiency. Grouts containing selected additives were compares with conventional bentonite and cement grouts. Significant enhancement of grout alumina grit, steel fibers, and silicon carbide increased the thermal conductivity when compared to unfilled, high solids bentonite grouts and conventional cement grouts. Furthermore, the developed grouts retained high thermal conductivity in the dry state, where as conventional bentonite and cement grouts tend to act as insulators if moisture is lost. The cementitious grouts studied can be mixed and placed using conventional grouting equipment.

1996-06-01

356

Postcards from Mars - Astrobiology - NASA  

Science.gov (United States)

Jan 4, 2004 ... By 11:30, imaging specialists had assembled a 360-degree panorama of ... engineers will conduct a comprehensive assessment of its health. ...

357

Planar QED at finite temperature and density: Hall conductivity, Berry's phases and minimal conductivity of graphene  

CERN Document Server

We study 1-loop effects for massless Dirac fields in two spatial dimensions, coupled to homogeneous electromagnetic backgrounds, both at zero and at finite temperature and density. In the case of a purely magnetic field, we analyze the relationship between the invariance of the theory under large gauge transformations, the appearance of Chern-Simons terms and of different Berry's phases. In the case of a purely electric background field, we show that the effective Lagrangian is independent of the chemical potential and of the temperature. More interesting: we show that the minimal conductivity, as predicted by the quantum field theory, is the right multiple of the conductivity quantum and is, thus, consistent with the value measured for graphene, with no extra factor of pi in the denominator.

2009-01-01

359

N88-21509 - NASA Technical Report Server (NTRS)  

Science.gov (United States)

problem similar to the Stefan problem in heat conduction [19]. ..... as the Stefan problem. Although the Stefan problem and the creep rupture ...

360

Molecular Genetics and Carcinogenesis Section  

Science.gov (United States)

The Molecular Genetics and Carcinogenesis Section conducts studies using human epithelial cells to assess: activation of proto-oncogenes by chemical and physical carcinogens; inactivation and dysregulation of tumor suppressor genes by chemical and physical

361

Magnetohydrodynamic structure of a plasmoid in fast ... - NASA  

Science.gov (United States)

We set a symmetric boundary at x=200 and a conducting wall at z=150. The domain of 0200. 0150 is resolved by 60004500 grid cells. Harris sheet ...

362

Irradiation of Langmuir-Blodgett multilayer preparations of phospholipids and a fatty acid. Pt. 1; Effect of UV radiation  

Energy Technology Data Exchange (ETDEWEB)

Langmuir-Blodgett (LB) preparations containing stacked monolayers of phospholipids or stearic acid were irradiated with UV light and the electric conductance perpendicular to the planes of the monolayers was measured. There was no observable change of conductance when LB preparations of stearic acid were irradiated. For LB preparations of phospholipids, a rise of conductance, dependent on dose rate, was observed, reaching an equilibrium level after a few hours. After irradiation the conductance fell with a temperature-dependent time constant, and eventually reached a final level a little above the initial value. A three-state model is proposed for the LB phospholipid preparations. This suggests that the absorption of one photon raises a molecule from the ground to an excited state; and the absorption of a second photon carries it into a damaged but repairable or metastable state. (author).

1992-12-01

363

Ionic conduction in polyether-based lithium arylfluorosulfonimide ionic melt electrolytes  

Energy Technology Data Exchange (ETDEWEB)

We report synthesis, characterization and ion transport in polyether-based ionic melt electrolytes consisting of Li salts of low-basicity anions covalently attached to polyether oligomers. Purity of the materials was investigated by HPLC analysis and electrospray ionization mass spectrometry. The highest ionic conductivity of 7.1 x 10{sup -6} S/cm at 30 deg. C was obtained for the sample consisting of a lithium salt of an arylfluorosulfonimide anion attached to a polyether oligomer with an ethyleneoxide (EO) to lithium ratio of 12. The conductivity order of various ionic melts having different polyether chain lengths suggests that at higher EO:Li ratios the conductivity of the electrolytes at room temperature is determined in part by the amount of crystallization of the polyether portion of the ionic melt.

2009-10-01

364

Ionic conduction in polyether-based lithium arylfluorosulfonimide ionic melt electrolytes  

International Nuclear Information System (INIS)

We report synthesis, characterization and ion transport in polyether-based ionic melt electrolytes consisting of Li salts of low-basicity anions covalently attached to polyether oligomers. Purity of the materials was investigated by HPLC analysis and electrospray ionization mass spectrometry. The highest ionic conductivity of 7.1 x 10-6 S/cm at 30 deg. C was obtained for the sample consisting of a lithium salt of an arylfluorosulfonimide anion attached to a polyether oligomer with an ethyleneoxide (EO) to lithium ratio of 12. The conductivity order of various ionic melts having different polyether chain lengths suggests that at higher EO:Li ratios the conductivity of the electrolytes at room temperature is determined in part by the amount of crystallization of the polyether portion of the ionic melt.

2009-10-01

366

Gender and Conduct Problems Predict Peer Functioning Among Children with Attention-Deficit/Hyperactivity Disorder  

British Library Electronic Table of Contents (United Kingdom)

Children with attention-deficit/hyperactivity disorder (ADHD) often have poor relationships with peers. However, research on this topic has predominantly focused on boys. This study considered child gender, ADHD status, and dimensionally assessed conduct problems as predictors of peer relationship difficulties. Participants were 125 children (ages 6-10; 67% male), 63 with clinical diagnoses of ADHD and 62 non-ADHD comparison youth. Conduct problems were reported by teachers and observed in a lab playgroup. Peer relationships were assessed by parent report, teacher report, and peer sociometric nominations in the playgroup. Results suggested that children with ADHD, as well as those with high conduct problems, displayed more impaired peer relationships than did comparison children and those ...

2011-01-01

367

Electrorheological RayleighTaylor instability at the interface between a porous layer and thin shell with poorly conducting couple stress fluid  

British Library Electronic Table of Contents (United Kingdom)

This paper is concerned with the study of the Electrorheological RayleighTaylor instability (ERTI) at the interface between a densely packed saturated poorly conducting couple stress porous layer accelerated by a lighter poorly conducting couple stress fluid in a thin shell in the presence of a transverse electric field and laser radiation. A simple theory based on fully developed flow approximations is used to derive the dispersion relation for the growth rate of ERTI. The cutoff and the maximum wave numbers and the corresponding maximum frequencies are obtained. It is shown that the effects of couple stress parameter and the electric field reduce the growth rate considerably compared to a non-conducting fluid in the absence of an electric field. These are favorable to control the surface...

2011-01-01

368

Effects of sputtering pressure on the characteristics of lithium ion conductive lithium phosphorous oxynitride thin film  

British Library Electronic Table of Contents (United Kingdom)

Lithium phosphorous oxynitride(Lipon) thin films as a lithium ion conductive electrolyte were prepared by radio frequency reactive sputtering in N2 plasma. The properties of the amorphous Lipon solid electrolyte were investigated as a function of N2 pressure during reactive sputtering. The ionic conductivity and the electrochemical stability of Lipon thin films improved drastically as the N2 pressure decreased. The ionic conductivity closed to 10?6 S cm?1 and obtained a stability window of 1.0?5.0 V with an N2 pressure of 5 mTorr, where the number of nitrogen bonds between the phosphate groups were more than those formed at higher pressure. It was possible to fabricate the Li//LiCoO2 complete thin film battery using this Lipon solid electrolyte, which exhibited excellent discharge characte...

2006-01-01

369

Effect of Macrolide Usage on Emergence of Erythromycin-Resistant Campylobacter Isolates in Chickens?  

UK PubMed Central (United Kingdom)

In this work we conducted both in vitro and in vivo experiments to examine the development and mechanisms of erythromycin (Ery) resistance in Campylobacter jejuni and Campylobacter...Full Text Available

2007-05-01

370

Dynamic clamp with StdpC software  

UK PubMed Central (United Kingdom)

Dynamic clamp is a powerful method that allows the introduction of artificial electrical components into target cells to simulate ionic conductances and synaptic inputs. This method is based...Full Text Available

2011-03-01

372

Density: Sea Water Mixing and Sinking - Aquarius - NASA  

Science.gov (United States)

density is slightly higher, its electrical conductivity is much higher, and it is slightly ... Sea water has characteristic properties (e.g. density) that are independent of ...

373

Cuba's response to the HIV epidemic.  

UK PubMed Central (United Kingdom)

BACKGROUND: Cuba's response to the human immunodeficiency virus (HIV) epidemic has been to conduct mass testing of the population to ascertain seroprevalence, to enforce mandatory relative quarantine...Full Text Available

1991-05-01

374

Conductivity studies on commercially available proton-conducting membranes with different equivalent weight  

Energy Technology Data Exchange (ETDEWEB)

Two perfluorosulfonic acid membranes, Nafion{sup R} 105 and Nafion{sup R} 115 with the same thickness but different equivalent weights (EW = 1000 g/eq. resp. 1100 g/eq.) were characterised by conductivity measurements at different water vapour activities in the temperature range of 25-70{sup o}C. The results demonstrate that a lower membrane equivalent weight opens the possibility to obtain the needed proton conductivity at lower water vapour activity. This is especially important for those fuel cell applications, in which the cell is operated without external humidification of the fuel gases. (author) 5 figs., 5 refs.

1999-08-01

375

CDC - Men's Health A-Z - Workplace Safety and Health (Occupational...  

Science.gov (United States)

Curriculums The Epilepsy Foundation, in partnership with CDC, is conducting a national education and outreach program to educate and train law enforcement officers, police...

2011-09-03

376

Biomarker studies in northern Bohemia.  

UK PubMed Central (United Kingdom)

Studies were conducted in northern Bohemia to simultaneously evaluate personal exposures to air pollution in the form of respirable particles containing polycyclic aromatic hydrocarbons (PAHs) and biomarkers...Full Text Available

1996-05-01

377

A tuberculin skin test survey among Ghanaian school children  

UK PubMed Central (United Kingdom)

BackgroundGhana has not conducted a national tuberculin survey or tuberculosis prevalence survey since the establishment of the National Tuberculosis Control Programme. The primary...Full Text Available

378

A Cultural Resources Survey Testing, and Geomorphic ...  

Science.gov (United States)

... Aerial photographs were provided by Mr. Grover P. ... Dr. Beverely J. Watkins conducted the records search and wrote the historic research. x,/ ...

1987-04-01

379

Use of ceramic porous membranes in molten carbonate fuel cells  

Energy Technology Data Exchange (ETDEWEB)

The diffusion of alkali vapours in the anode compartment of a DIR-MCFC produces the deactivation of the internal reforming catalyst. Sets of ceramic porous membranes purposed to limit the diffusion have been manufactured by different techniques and the influence of the preparation technique and of the preparative variables on the morphological characteristics of the membranes structures has been studied.

1996-12-31

380

Thin film adhesion by nanoindentation-induced superlayers. Final report  

Energy Technology Data Exchange (ETDEWEB)

This work has analyzed the key variables of indentation tip radius, contact radius, delamination radius, residual stress and superlayer/film/interlayer properties on nanoindentation measurements of adhesion. The goal to connect practical works of adhesion for very thin films to true works of adhesion has been achieved. A review of this work titled ''Interfacial toughness measurements of thin metal films,'' which has been submitted to Acta Materialia, is included.

2001-06-01

381

Thin Wall Iron Castings  

Energy Technology Data Exchange (ETDEWEB)

Results of an investigation made to develop methods of making iron castings having wall thicknesses as small as 2.5 mm in green sand molds are presented. It was found that thin wall ductile and compacted graphite iron castings can be made and have properties consistent with heavier castings. Green sand molding variables that affect casting dimensions were also identified.

2001-10-31

382

The Philadelphia Marriott: A convention center flagship hotel  

Energy Technology Data Exchange (ETDEWEB)

This article describes the state-of-the-art HVAC system at the Philadelphia Marriott Hotel. Thermal comfort and indoor air quality are emphasized. The system uses a hybrid gas absorption/electric centrifugal chilled water plant, variable flow pumping, water-side economizers to provide free cooling, central air handling units with air-side economizers and flow monitoring equipment.

1997-01-01

383

Technical and economical analysis methodology for small power distribution systems; Metodo de analisis tecnico-economico de pequenas obras de distribucion  

Energy Technology Data Exchange (ETDEWEB)

This paper propose to show the technical and economic aspects of the implementation of small power distribution systems in small rural properties in some locations of Argentina. This paper presents a concrete methodology, with a rational cost composition and introduces project variables. 4 figs.

1986-12-31

384

Stein method for invariant measures of diffusions via Malliavin calculus  

CERN Document Server

Given a random variable $F$ regular enough in the sense of the Malliavin calculus, we are able to measure the distance between its law and almost any continuous probability law on the real line. The bounds are given in terms of the Malliavin derivative of $F$. Our approach is based on the theory of It\\^o diffusions and the stochastic calculus of variations. Several examples are considered in order to illustrate our general results.

2011-01-01

385

Solar astrophysics  

Energy Technology Data Exchange (ETDEWEB)

This book comprises an up-to-date description of the astrophysical characteristics of the sun, including modern techniques used in solar research. Provides an historical background of solar research and techniques and covers the necessary astrophysics for solar studies, energy generation in the interior, the convection zone, the non- thermally heated layers, and solar wind are described in detail. Also considers the sun in relation to other stars, including information on its variable outputs of light, charged particles, and fields.

1990-01-01

386

Process optimization for saccharification of cellulose by acid hydrolysis  

Energy Technology Data Exchange (ETDEWEB)

Cellulose raw materials costs must be considered in order to obtain a minimized hexose cost. In recognition of this fact, it may be economically advantageous to operate at less than maximum hexose concentration in the reactor and to recycle unreacted cellulose. The objective of this article is to optimize a cellulose-recycle reactor system for producing hexose at minimum cost. A sensitivity analysis of the important variables in the mathematical model of this system is also discussed.

1980-01-01

387

Problems of the radiometric level measurement in large bins  

Energy Technology Data Exchange (ETDEWEB)

After a brief survey of the known level measurement methods the particularities of the radiometric measurement of the still utilisable residual volume of a bulk material in a large bin are discussed. At constant angle of repose the measurement in a suitably positioned plane of measurement suffices, at variable angle of repose two planes of measurement are required. The probable working ranges for a 1300-t lime bin are estimated.

1984-01-01

388

Physical therapy applications of MR fluids and intelligent control  

Science.gov (United States)

Resistance exercise has been widely reported to have positive rehabilitation effects for patients with neuromuscular and orthopaedic conditions. This paper presents an optimal design of magneto-rheological fluid dampers for variable resistance exercise devices. Adaptive controls for regulating the resistive force or torque of the device as well as the joint motion are presented. The device provides both isometric and isokinetic strength training for various human joints.

2005-05-01

389

Petroleum waxes in solvent systems  

Energy Technology Data Exchange (ETDEWEB)

Wax appearance temperature (WAT) of three petroleum waxes in different solvent systems under varying thermal conditions has been determined. It is observed that this temperature mainly is a function of the concentration of the wax and the solubility parameter ([delta]) of the solvent taken. This dependence of WAT has been quantified in terms of these variables in the form of mathematical equation and nomographs. (orig.)

1994-01-01

390

Optimal choice of cupola furnace nominal operating point  

Science.gov (United States)

One of the main goals in the operation of a cupola furnace is to keep the molten iron properties within prescribed bounds while maintaining the most economical operation for the cupola. In this paper the authors present a procedure to obtain the nominal values for the manipulated process variables. The nominal values are calculated by solving a constrained nonlinear programming optimization problem. Two different optimization problems are discussed and examples for using the procedure are presented.

1998-08-01

391

Multidipole magnetic fields for plasma confinement  

Energy Technology Data Exchange (ETDEWEB)

Plasma confinement by permanent magnets has been studied. An analytic formula for the field of a single bar magnet has been obtained. Generalization to various configurations of multidipole fields has also been found. Any two-dimensional field may now be completely described by a simple function of complex variables in closed form. Vector potential has also been obtained by integrating over a prescribed Riemann surface. The confinement of plasma by multidipole fields then becomes obvious through conservation principles.

1983-07-01

392

Model development for the determination of the influence of management on plant risk  

Energy Technology Data Exchange (ETDEWEB)

This paper outlines the development of an organizational model which will be used to determine the influence of supervisory and management functions in a nuclear power plant (NPP) on risk. A theoretical conceptualization, derived from the empirical literature, is used to describe the organizational structure of NPPs. The parameters and variables associated with this dynamic, process-oriented model are detailed. Applications of the model and preliminary insights derived from this conceptualization are discussed.

1988-01-01

393

Mathematical two-dimensional model for three-phase filtering of compressible fluids  

Energy Technology Data Exchange (ETDEWEB)

A mathematical model is proposed for three-phase filtering which is a particular case of a more general model of filtering multiple component mixtures and makes it possible to describe three-phase filtering flows under conditions where the pressure of saturation is variable in time and in space. In the proposed model, the system of unknown functions is selected so that it makes it possible to trace fairly simply the pressure of saturation and to compute the corresponding equation coefficients.

1982-01-01

394

Mathematical and physical model of steam-water mixture flow in horizontal steam generator  

International Nuclear Information System (INIS)

A mathematical and physical model was constructed describing the hydrodynamics of the two-phase mixture in the horizontal steam generator. The HP 9830 A desk-top calculator was used for the computations. The output variable of the solution was the level shape. A quantitative and qualitative comparison was made of the results of computations and experimental data. (author).

1982-10-01

395

Matching Vehicle Responses Using the Model-Following Control Method  

Science.gov (United States)

The Variable Dynamic Testbed Vehicle (VDTV) is presently being developed by the National Highway Traffic Safety Administration (NHTSA). It is being designed to have a steer-by-wire front steering system and an independent rear steering system. These steering systems enable the VDTV to emulate the directional control characteristics of a broad range of passenger vehicles.

1997-01-01

396

MACHO observations of Type II cepheids and RV Tauri Stars in the LMC  

Science.gov (United States)

We report the of the existence of RV Tauri stars in the Large Magellanic Cloud (LMC). This class of variable star has hitherto been unidentified in the Magellanic Clouds. In light and color curve behavior the RV Tauri stars appear to be an extension of the Type II Cepheids to longer periods. A single period-luminosity-color relationship is seen to describe both the Type II Cepheids and the RV Tauri stars in the LMC.

1996-07-01

397

Long-range correlation analysis of earthquake-related geochemical variations recorded in Central Italy  

Energy Technology Data Exchange (ETDEWEB)

The long-range correlation properties in the hourly time variability of geochemical signals measured in a 70 m depth well at Triponzo (Umbria region), are investigated by the detrended fluctuation analysis (DFA). DFA is a data processing method that allows for the detection of scaling behaviors in observational time series even in the presence of non-stationarities. The procedure adopted has allowed for the unambiguous identification of possible correlations among the recorded signals and local earthquakes.

2004-07-01

398

Investigation of a thermoplastic-powder metallurgy process for the fabrication of porous niobium rods  

International Nuclear Information System (INIS)

The feasibility of using a thermoplastic-powder metallurgy technique for the fabrication of porous niobium rods was investigated. Some early problems were overcome to successfully extrude the polymer coated niobium powder into long lengths. The effects of certain process variables were investigated. Residual porosity and extrusion pressure were found to be regulated by the polymer fraction. The procedures for taking the extruded polystyrene--niobium rods through the heat treatments to the final, tin infiltrated stage are explained.

1976-04-30

399

Integrability and symmetric spaces  

Energy Technology Data Exchange (ETDEWEB)

It is shown that a sufficient condition for a model describing the motion of a particle on a coset space to possess a Fundamental Poisson bracket Relation, and consequently charges in involution, is that it must be a symmetric space. The conditions, a Hamiltonian, or any functions of the canonical variables, has to satisfy in order to commute with these charges, are studied. It is show that, for the case of the noncompact symmetric spaces, these conditions lead to an algebraic structure which lays an important role in the construction of conserved quantities.

1989-01-01

400

Infinitesimal symmetries and conservation laws of the DNLSE hierarchy and the Noether's theorem  

Energy Technology Data Exchange (ETDEWEB)

The hierarchy of integrable nonlinear equations associated with the quadratic bundle is considered. The expressions for the solution of linearization of these equations and their conservation law in the terms of solutions of corresponding Lax pairs are found. It is shown for the first member of the hierarchy that the conservation law is connected with the solution of linearized equation due to the Noether's theorem. The local hierarchy and three nonlocal ones of the infinitesimal symmetries and conservation laws explicitly expressed through the variables of the nonlinear equations are derived. (author)

2007-08-15

401

Improve control with software monitoring technologies  

Energy Technology Data Exchange (ETDEWEB)

Multiple linear regression, principal component analysis, partial least squares, polynomial regression and artificial neural networks are popular techniques for process modeling. An industrial case study illustrates some of these technologies, with an emphasis on artificial neural networks. Experience with this and other projects indicates that while neural network models, combined with partial least squares when necessary, are an excellent tool for modeling, linear techniques may also be appropriate in some cases. Regardless of the specific method used, software analyzers are an attractive lower-cost alterative to hardware options in some monitoring applications. From a fundamental point of view, the result of chemical analysis can be considered as the dependent variable(s) of a process system having a number of independent variables. The independent variables are the causes and the chemical analysis is the effect. If the ...

1996-09-01

402

Howard Hughes Medical Institute dose assessment survey  

Energy Technology Data Exchange (ETDEWEB)

Biomedical science researchers often express frustration that health physics practices vary widely between individual institutions. A survey examining both internal and external dose assessment practices was devised and mailed to fifty institutions supporting biomedical science research. The results indicate that health physics dose assessment practices and policies are highly variable. Factors which may contribute to the degree of variation are discussed. 2 tabs.

1996-12-01

403

Haplotyping and copy number estimation of the highly polymorphic human beta-defensin locus on 8p23 by 454 amplicon sequencing  

UK PubMed Central (United Kingdom)

BackgroundThe beta-defensin gene cluster (DEFB) at chromosome 8p23.1 is one of the most copy number (CN) variable regions of the human genome. Whereas individual DEFB CNs have been...Full Text Available

404

Fuzzy risk analysis for safeguards and network security  

Science.gov (United States)

Analyzing the risk of a safeguards system, in particular the security of a computer network based on the notion of fuzzy sets and linguistic variables, addresses concerns such as complexity and inherent imprecision in estimating the possibility of loss or compromise. Automated risk analysis allows the risk to be determined for an entire system based on estimates for lowest level components and the component weight. In addition, for each component (asset) we select the most effective combination of protection mechanisms against a given set of threats.

1992-01-01

405

Evolution of a horizontal branch Population II star with total mass 0.63 Msub solar  

Science.gov (United States)

The theoretical evolution of a horizontal branch star of Population II is followed through the helium burning in the core phase and is compared with the results given by other investigators. The m- fluence of different physics and interpolation schemes in the opacity tables is discussed. Some thoughts are given on the explanation of the erratic period variations observed in some of the RR Lyrae variables in the globular clusters. (auth)

1973-01-01

406

Estimating Regional Spatial and Temporal Variability of PM2.5 Concentrations Using Satellite Data, Meteorology, and Land Use Information  

UK PubMed Central (United Kingdom)

BackgroundStudies of chronic health effects due to exposures to particulate matter with aerodynamic diameters ≤ 2.5 μm (PM2.5) are often limited by sparse...Full Text Available

2009-06-01

407

Entangling optical and microwave cavity modes by means of a nanomechanical resonator  

CERN Document Server

We propose a scheme able to generate stationary continuous variable entanglement between an optical and a microwave cavity mode by means of their common interaction with a micro-mechanical resonator. We show that when both cavities are intensely driven one can generate bipartite entanglement between any pair of the tripartite system, and that, due to entanglement sharing, optical-microwave entanglement is efficiently generated at the expense of microwave-mechanical and opto-mechanical entanglement.

2011-01-01

408

Energy efficient fuzzy based combined variable refrigerant volume and variable air volume air conditioning system for buildings  

Energy Technology Data Exchange (ETDEWEB)

Energy conservative building design has triggered greater interests in developing flexible and sophisticated air conditioning systems capable of achieving enhanced energy-savings potential without sacrificing the desired thermal comfort and indoor air quality (IAQ). This research work greatly aimed at achieving enhanced energy conservation, good thermal comfort and better IAQ for space conditioning with the application of combined variable refrigerant volume (VRV) and variable air volume (VAV) air conditioning (A/C) systems. Experimental investigation on the proposed combined air conditioning system with the application of intelligent fuzzy logic controller was performed for summer and winter climatic conditions to substantiate the energy-savings capability. The proposed system experimentally analyzed under fixed ventilation, demand controlled ventilation (DCV) and combined DCV and economizer cycle (EC) ventilation techniques effectively ...

2010-04-15

409

Effects of several variables on whole effluent toxicity test performance and interpretation  

Energy Technology Data Exchange (ETDEWEB)

Protocol changes and options contained within US Environmental Protection Agency whole effluent toxicity tests represent variables that have the potential to affect bioassay performance and interpretation of results. Variables evaluated in this study include: the change in allowable age in the Pimephales promelas acute bioassay from up to 90 d to a maximum of 14 d, age-specific acute responses of P. promelas among the allowable ages of 1 to 14 d, change in the chronic growth endpoint definition from final mass to biomass, differences between hemacytometer and fluorometer measurements in the Selenastrum capricornutum protocol, and options for statistical interpretation of species sensitivity in multiple test/species screening bioassays. Clear age-related sensitivity and precision differences were observed in acute responses of P. promelas. Results obtained using the younger age classes were typically more variable in studies ...

2000-01-01

410

Effect of environmental variables on localized corrosion of high-performance container materials  

Energy Technology Data Exchange (ETDEWEB)

Electrochemical cyclic potentiodynamic polarization (CPP) experiments were performed on several candidate high-performance waste package container materials to evaluate their susceptibility to localized corrosion in aqueous environments relevant to the potential underground high-level nuclear waste repository. This paper presents the results of this study showing the effects of chloride ion (Cl) concentrations, pH, temperature, and electrochemical potential scan rate on the pitting corrosion behavior of these materials.

1997-01-01

411

Dynamics of Axial Separation in Long Rotating Drums  

Energy Technology Data Exchange (ETDEWEB)

We propose a continuum description for the axial separation of granular materials in a long rotating drum. The model, operating with two local variables, concentration difference and the dynamic angle of repose, describes both initial transient traveling wave dynamics and long-term segregation of the binary mixture. Segregation proceeds through ultraslow logarithmic coarsening. {copyright} {ital 1999} {ital The American Physical Society}

1999-06-01

412

Diversion of the Immune Response to Neisseria gonorrhoeae from Th17 to Th1/Th2 by Treatment with Anti-Transforming Growth Factor ? Antibody Generates Immunological Memory and Protective Immunity  

UK PubMed Central (United Kingdom)

ABSTRACTThe immune response to Neisseria gonorrhoeae is poorly understood, but its extensive antigenic variability and resistance to complement are thought to allow it...Full Text Available

413

Discordant expression and variable numbers of neighboring GGA- and GAA-rich triplet repeats in the 3' untranslated regions of two groups of messenger RNAs encoded by the rat polymeric immunoglobulin receptor gene.  

UK PubMed Central (United Kingdom)

An unusual S1-nuclease sensitive microsatellite (STMS) has been found in the single copy, rat polymeric immunoglobulin receptor gene (PIGR) terminal exon. In Fisher rats, elements within or beyond the...Full Text Available

1995-04-11

414

Differential decay of parent-of-origin-specific genomic sharing in cystic fibrosis-affected sib pairs maps a paternally imprinted locus to 7q34  

UK PubMed Central (United Kingdom)

Cystic fibrosis (CF) is a monogenic disease characterized by a high variability of disease severity and outcome that points to the role of environmental factors and modulating genes that shape the course...Full Text Available

2010-05-01

415

Crop improvement of field vegetables  

Environmental Research Database

DescriptionThe main objective of the project is to develop a range of underpinning plant resources together with information about the level of genetic variability they represent, in a form suitable for use in crop improvement research in vegetable brassicas, lettuce and onion. The proposed research addresses Defra's requirement for a crop improvement programme to underpin research programmes aimed at Pest and Disease Control, Plant Nutrition and Quality in field vegetables at HRI. We will produc [continued...

2009-01-31

416

Conventional and unconventional political participation  

Energy Technology Data Exchange (ETDEWEB)

A non-recursive model is proposed and empirically tested with data of opponents of nuclear power. In explaining conventional and unconventional participation the theory of collective action is applied and modified in two respects: the perceived influence on the elimination of collective evils are taken into account; the selective incentives considered are non-material ones. These modifications proved to be valid: the collective good variables and non-material incentives were important determinants for the two forms of participation. Another result was that there is a reciprocal causal relationship between conventional and unconventional participation.

1985-01-01

417

Computer modeling in the design and evaluation of electric and hybrid vehicles  

Energy Technology Data Exchange (ETDEWEB)

This demonstration project uses modern simulation techniques to illustrate the important technologies and design variables that an auto-designer would consider in production a high efficiency, low emissions vehicle. Simulation and modeling techniques use the idea of capturing the relationships between real components of the systems with mathematical equations. These equations are then solved on a computer to simulate the behavior or performance of the system under various conditions. In the current demonstration project, we focus on many variations of a hydrogen-powered vehicle.

1996-08-16

418

Comments on possible preferential order-disorder in A-15 compounds based upon Nb  

International Nuclear Information System (INIS)

The possible existence of preferential B-site disorder in A-15 compounds recently claimed on the basis of x-ray powder diffraction data but questioned from the viewpoint of known phase diagrams is examined for some Nb-based compounds of this type. It is concluded that x-ray powder data do not allow the determination of both order and compositional variables as suggested, and the latter must therefore be determined by some other method. (author).

419

Canonical Gravity with Fermions  

CERN Document Server

Canonical gravity in real Ashtekar-Barbero variables is generalized to allow for fermionic matter. The resulting torsion changes several expressions in Holst's original vacuum analysis, which are explicitly displayed here. This in turn requires adaptations to the known canonical (loop) quantization of gravity coupled to fermions, which is discussed on the basis of the classical analysis.

2007-01-01

420

Assessment of the Compositional Variability of RP-1 and RP-2 with the Advanced Distillation Curve Approach.  

Science.gov (United States)

RP-1 is a long-established hydrocarbon fuel that continues to be widely used as the kerosene component in rocket propulsion systems. The desire in recent years to use rocket motors many times, rather than a single time, has led to reformulations of RP-1. ...

2010-01-01

421

Application of artificial neural network to direct coal liquefaction research  

Energy Technology Data Exchange (ETDEWEB)

The catalytic liquefaction of a Chinese bituminous coal was simulated by artificial neural network. Three liquefaction variables, catalyst loading, reaction temperature and reaction time were used as inputs and tetrohydrofuran (THF) conversion and toluene (T) conversion were used as outputs. The artificial neural network, trained by the experimental data, could represent the liquefaction process, with a mean squared deviation of less than 0.025. 7 refs.,1 fig., 3 tabs.

1998-07-01

422

AMMONIA ABSORPTION/AMMONIUM BISULFATE REGENERATION PILOT PLANT FOR FLUE GAS DESULFURIZATION  

Science.gov (United States)

The report gives results of a pilot-plant study of the ammonia absorption/ammonium bisulfate regeneration process for removing SO2 from the stack gas of coal-fired power plants. Data were developed on the effects of such operating variable in the absorption of SO2 by ammoniacal l...

423

Sources of competitive advantage and business performance in the European meat processing industry  

DEFF Research Database (Denmark)

1. The aim of the paper is to investigate the relative importance of three sets of sources of competitive advantages on business performance in a specific industry context, ie the European meat processing industry. The three sets of competitive sources are Firm Specific Advantages (FSAs), Localizational Specific Advantages (LSAs) and Relationship Specific Advantages (RSAs). Based on a literature study, each set of competitive advantages is briefly described in terms of their theoretical antecedents. Seven hypotheses are formulated regarding the direct as well as the indirect relationships between the FSAs, LSAs and RSAs and business performance. Also, the direction of causality between the various sets of explanatory variables is considered. The hypotheses are combined in a structural modelling of firm competition. 2. Data and measurements are derived from a survey in the European meat processing industry in which 133 meat processors from 10 EU countries agreed to ...

1999-01-01

424

Zirconia-ceria: additive influence on the sintering and electric conductivity  

International Nuclear Information System (INIS)

Iron oxide as sintering aid to Ce-TZP ceramics produces a beneficial effect on the tetragonal phase stabilization. It was found that ceria powder particle size of 2,0 #mu#m turns the grain-boundary electrical conductivity higher than ceria powder of smaller grain size. (author)

1996-12-08

425

Tunneling spectroscopy of anisotropic superconductors  

Energy Technology Data Exchange (ETDEWEB)

Tunneling spectroscopy of normal-insulator-superconductor junction is investigated theoretically. In anisotropic superconductors, differently from the case of isotropic superconductor, the effective pair potentials felt by quasiparticles depend on the direction of their motion. By taking this effect into account, it is shown that the conductance spectra strongly depend on the crystal orientation. Using Green`s function method, local density of states (LDOS) in superconductor is also calculated. The close relation between conductance spectra and LDOS is presented. The calculation is compared with experimental spectra of high-{Tc} superconductors.

1996-12-31

426

Selective Expression in Carotid Body Type I Cells of a Single Splice Variant of the Large Conductance Calcium- and Voltage-activated Potassium Channel Confers Regulation by AMP-activated Protein Kinase*  

UK PubMed Central (United Kingdom)

Inhibition of large conductance calcium-activated potassium (BKCa) channels mediates, in part, oxygen sensing by carotid body type I cells. However, BKCa channels remain active...Full Text Available

2011-04-08

427

Report of the Government Industrial Research Institute, Osaka, No. 388, February 1993. High lithium ion conductive solid electrolytes  

Energy Technology Data Exchange (ETDEWEB)

Research investigating applicability of lithium salts for solid electrolyte batteries was described. The studies included determinations of lithium ion conductivities in solid electrolyte systems based on Li4SiO4, LiTi2(PO4)3, and ceramic materials. Research on all solid state lithium cells utilizing TiS2 NiPS3 electrodes was also reported.

1993-01-01

428

Indium-cadmium-oxide films having exceptional electrical conductivity and optical transparency: Clues for optimizing transparent conductors  

UK PubMed Central (United Kingdom)

Materials with high electrical conductivity and optical transparency are needed for future flat panel display, solar energy, and other opto-electronic technologies. InxCd1-xO...Full Text Available

2001-06-19

429

In-plane resolved in-situ measurements of the membrane resistance in PEFCs  

Energy Technology Data Exchange (ETDEWEB)

The conductivity of the membrane is a limiting factor for the efficiency and power density of PEFCs. Because this conductivity is strongly dependent on the membrane hydration, water management is an important aspect of PEFC optimisation. Single cell model experiments were made in order to determine the in-plane hydration of a Nafion{sup R} membrane under fuel cell conditions as function of the gas humidities. (author) 4 fig., 3 refs.

1999-08-01

430

Evaluation of an eastern shale oil residue as an asphalt additive  

Energy Technology Data Exchange (ETDEWEB)

An evaluation of eastern shale oil (ESO) residue as an asphalt additive to reduce oxidative age-hardening and moisture susceptibility was conducted. Rheological and infrared analyses of the unaged and aged asphalts and blends were then conducted to evaluate oxidative age-hardening. 18 refs., 5 figs., 6 tabs.

1996-11-01

431

Effects of bladder outlet obstruction on properties of Ca2+-activated K+ channels in rat bladder  

UK PubMed Central (United Kingdom)

In this study, we investigated the effects of bladder outlet obstruction (BOO) on the expression and function of large conductance (BK) and small conductance (SK) Ca2+-activated K+...Full Text Available

2010-05-01

432

Effect of wet-dry cycling on swelling and hydraulic conductivity of GCLs  

Energy Technology Data Exchange (ETDEWEB)

Atterberg limits, free swell, and hydraulic conductivity tests were conducted to assess how wet-dry cycling affects the plasticity and swell of bentonite, and the hydraulic conductivity of geosynthetic clay liners (GCLs) hydrated with deionized (DI) water (pH 6.5), tap water (pH 6.8), and 0.0125-M CaCl{sub 2} solution (pH 6.2). The plasticity of bentonite hydrated with DI water increased during each wetting cycle, whereas the plasticity of bentonite hydrated with tap water and CaCl{sub 2} decreased during each wetting cycle. Wet-dry cycling in DI water and tap water had little effect on swelling of the bentonite, even after seven wet-dry cycles. However, swelling decreased dramatically after two wetting cycles with CaCl{sub 2} solution. Hydraulic conductivity of GCL specimens remained low during the first four wetting cycles ({approximately}1 x 10{sup {minus}9} cm/s). However, within five to eight ...

2000-01-01

433

Dielectric dispersion and conductivity of moisture-containing amorphous polymers  

British Library Electronic Table of Contents (United Kingdom)

The effect of the moisture content in amorphous polymers (PS, PVC, PMMA) on their electro-physical properties is considered. Analytical relationships describing the inflence of the external-field frequency and environmental relative humidity on the conductivity of the polymers are given. For the use of these polymers as active elements of moisture sensors, the moisture-resistive effect is estimated.

2011-01-01

434

Calculation of the thermal load of a high voltage cable with forced circulation of oil with the help of modeling on an analog computer  

Energy Technology Data Exchange (ETDEWEB)

Equations are compiled for thermal balance in which for simplification, no consideration is made for heat conductivity along the axis of the cable and dependence of losses, heat capacitance and heat conductivity on temperature. Equations are modeled on a transistor analog calculator 42 TA. The solution to the task on the computer produced values of maximum temperature on the cable and coordinates of the point of maximum overheating. Using the analog model, one can study other parameters of the thermal mode.

1980-01-01

435

Thermal conductivity of sintered lithium orthosilicate compacts  

International Nuclear Information System (INIS)

The design of solid breeder blankets is strongly affected by the low values of thermal conductivity and density of ceramic breeder pebble beds. A significant rise of both quantities would enhance the thermal performance and lead to an increased tritium breeding ratio. In order to improve these quantities pretreated lithium orthosilicate pebble material was dry pressed and subsequently sintered. The thermal conductivity of cylindrical pellets was determined by the heat pulse method using a laser flash device. A pebble bed characteristic sample was also investigated in order to check the measurement accuracy in comparison with previous results. Furthermore, two samples of low density cellular ceramics were also prepared by infiltration of polymer foams with a ceramic slurry. The thermal conductivity results show that the values are affected both by the particle size and the sample density. Thermal ...

2009-04-30

436

Promising electrolyte materials for the coming lithium secondary batteries. Lithium ion conductive inorganic solid electrolytes; Jisedai lithium niji denchiyo denkaishitsu. Muki kotai denkaishitsu  

Energy Technology Data Exchange (ETDEWEB)

This paper describes inorganic solid electrolytes from a viewpoint of electrolytes for lithium batteries. Lithium ion conductive inorganic solid electrolytes are largely divided into crystalline and amorphous substances. Crystalline substances are known as LiI and Li3N, and also oxygen acid salt. However, when considering application to a battery, its large grain boundary resistance and electrochemical instability would be a problem. Lithium ion conductive amorphous solid electrolytes are divided into an oxide system and a sulfide system. Since most of them do not contain transition metal elements, they are stable against electrochemical reduction, and ions move isotropically in electrolyte. Therefore, ion conduction paths across the grain boundaries may be connected more easily, forming an electrolyte with low grain boundary resistance. As a result of the efforts of the authors in searching new additives substituting LiI, ...

1997-11-05

437

Preliminary study on the thermal conductivity and flammability of WPC based on some tropical woods  

Energy Technology Data Exchange (ETDEWEB)

Selected local woods and their wood-polymer combinations or composites (WPC) were tested for their thermal conductivity and their fire resistance. WPC were prepared by polymerizing monomers ''in situ'' in oven dried woods by gamma radiation. The monomers included acrylonitrile (AN), 60% styrene-40% acrylonitrile (STAN), methyl methacrylate (MMA), 95% methyl methacrylate-5% dioxane (MD), and vinylidene chloride (VDC). A reduction in thermal conductivity was exhibited by all the composites prepared. W-PAN showed the greatest reduction in thermal conductivity and W-PSTAN in general showed the least. An explanation is suggested for this behaviour. The polymers PMMA and PMD were found to enhance flammability of the woods while PVDC, PAN, and PSTAN imparted fire resistance to the woods. Of the six local woods studied, Ramin-and-Keruing-polymer composites showed the highest flammable tendencies ...

1985-01-01

438

Matrix diffusion studies by electrical conductivity methods. Comparison between laboratory and in-situ measurements  

Energy Technology Data Exchange (ETDEWEB)

Traditional laboratory diffusion experiments in rock material are time consuming, and quite small samples are generally used. Electrical conductivity measurements, on the other hand, provide a fast means for examining transport properties in rock and allow measurements on larger samples as well. Laboratory measurements using electrical conductivity give results that compare well to those from traditional diffusion experiments. The measurement of the electrical resistivity in the rock surrounding a borehole is a standard method for the detection of water conducting fractures. If these data could be correlated to matrix diffusion properties, in-situ diffusion data from large areas could be obtained. This would be valuable because it would make it possible to obtain data very early in future investigations of potentially suitable sites for a repository. This study compares laboratory electrical ...

1998-09-01

439

High lithium ion conductive Li7La3Zr2O12 by inclusion of both Al and Si  

British Library Electronic Table of Contents (United Kingdom)

High lithium-ion (Li^+) conductive garnet-structured lanthanum lithium zirconate (LLZ) solid electrolyte is prepared by incorporation of appropriate amounts of silicon (Si) and aluminum (Al). The resultant pelletized LLZ obtains total Li^+ conductivity of 6.8x10^-^4Scm^-^1 at 298K. This improved conductivity is nearly identical with the bulk Li^+ conductivity of the LLZ reported earlier, suggesting that the grain boundary resistance is effectively reduced by the incorporation of Si and Al. Microanalyses by transmission electron microscopy coupled with energy-dispersive X-ray microanalysis and electron energy-loss spectroscopy revealed the presence of amorphous Li-Al-Si-O with nano crystalline LiAlSiO4 at grain boundaries. Fast lithium-ion transport around the amorphous Li-Al-Si-O/LiAlSiO4 ...

2011-01-01

440

Characteristics of ionic liquid-based electrolytes for chip type aluminum electrolytic capacitors  

Energy Technology Data Exchange (ETDEWEB)

Since ionic liquids (ILs) possess several attractive properties, including chemical and thermal stability, nonflammability, high ionic conductivity, and negligible vapor pressure, a new electrolyte system based on ILs has been proposed for chip type aluminum electrolytic capacitors. Four ILs based on imidazolium/pyrrolidinium cations and maleate/phthalate anions have been synthesized and their thermal stabilities have been examined. The 25wt.% solutions of the four ILs in gamma-butyrolactone (GBL) solvent were prepared as electrolytes of chip type aluminum electrolytic capacitors. The conductivity, sparking voltage and thermal stability of these electrolytes have been systematically investigated. The results revealed that the four IL-based electrolytes exhibited high conductivity. Furthermore, the conductivity of maleate anion-based electrolytes is higher than that of phthalate anion-based electrolytes, ...

2006-06-19

441

Enhancement of electrical conductivity of ion-implanted polymer films  

Energy Technology Data Exchange (ETDEWEB)

The electrical conductivity of ion-implanted films of Nylon 66, Polypropylene (PP), Poly(tetrafluoroethylene) (Teflon) and mainly Poly (ethylene terephthalate) (PET) was determined by DC measurements at voltages up to 4500 V and compared with the corresponding values of pristine films. Measurements were made at 21/sup 0/C +/- 1/sup 0/C and 65 +/- 2% RH. The electrical conductivity of PET films implanted with F/sup +/, Ar/sup +/, or As/sup +/ ions at energies of 50 keV increases by seven orders of magnitude as the fluence increases from 1 x 10/sup 18/ to 1 x 10/sup 20/ ions/m/sup 2/. The conductivity of films implanted with As/sup +/ was approximately one order greater than those implanted with Ar/sup +/, which in turn was approximately one-half order greater than those implanted with F/sup +/. The conductivity of the most conductive film approx.1 S/m) was almost 14 orders of ...

1985-01-01

442

Andreev reflection and order parameter symmetry in heavy-fermion superconductors: the case of CeCoIn5  

International Nuclear Information System (INIS)

We review the current status of Andreev reflection spectroscopy on the heavy fermions, mostly focusing on the case of CeCoIn5, a heavy-fermion superconductor with a critical temperature of 2.3 K. This is a well-established technique to investigate superconducting order parameters via measurements of the differential conductance from nanoscale metallic junctions. Andreev reflection is clearly observed in CeCoIn5 as in other heavy-fermion superconductors. Considering the large mismatch in Fermi velocities, this observation seemingly appears to disagree with the Blonder-Tinkham-Klapwijk (BTK) theory. The measured Andreev signal is highly reduced to the order of maximum ?13% compared to the theoretically predicted value (100%). The background conductance exhibits a systematic evolution in its asymmetry over a wide temperature range from above the heavy-fermion coherence temperature down to well below the superconducting transition temperature. ...

2009-03-11

443

Xylem traits mediate a trade-off between resistance to freeze-thaw-induced embolism and photosynthetic capacity in overwintering evergreens  

British Library Electronic Table of Contents (United Kingdom)

Summary - Hydraulic traits were studied in temperate, woody evergreens in a high-elevation heath community to test for trade-offs between the delivery of water to canopies at rates sufficient to sustain photosynthesis and protection against disruption to vascular transport caused by freeze-thaw-induced embolism. - Freeze-thaw-induced loss in hydraulic conductivity was studied in relation to xylem anatomy, leaf- and sapwood-specific hydraulic conductivity and gas exchange characteristics of leaves. - We found evidence that a trade-off between xylem transport capacity and safety from freeze-thaw-induced embolism affects photosynthetic activity in overwintering evergreens. The mean hydraulically weighted xylem vessel diameter and sapwood-specific conductivity correlated with susceptibility to...

2011-01-01

444

Thermal conductivity of sintered lithium orthosilicate compacts  

British Library Electronic Table of Contents (United Kingdom)

The design of solid breeder blankets is strongly affected by the low values of thermal conductivity and density of ceramic breeder pebble beds. A significant rise of both quantities would enhance the thermal performance and lead to an increased tritium breeding ratio. In order to improve these quantities pretreated lithium orthosilicate pebble material was dry pressed and subsequently sintered. The thermal conductivity of cylindrical pellets was determined by the heat pulse method using a laser flash device. A pebble bed characteristic sample was also investigated in order to check the measurement accuracy in comparison with previous results. Furthermore, two samples of low density cellular ceramics were also prepared by infiltration of polymer foams with a ceramic slurry. The thermal cond...

2009-01-01

445

Thermal and radiation losses in a linear device  

Energy Technology Data Exchange (ETDEWEB)

An analysis is presented of the electron temperature in a linear device which includes the effect of thermal conduction, heat flux limit, radiation, and end plugs. It is found that the thermal conduction and the heat flux limit are dominant in the initial phase of cooling, while the later phase is almost completely controlled by radiation that spatially homogenizes the temperature distribution. In the case of bremsstrahlung, within the frame of the present model, the temperature decays to zero in a finite time. This process takes the form of a cooling wave that moves from the ends of the column to the center. Impurities cause a milder, exponential decay, which is still much faster than the algebraic conduction decay. The thermal effectiveness of the end plugs is described by a convective transfer coefficient h/sub p/. Its scaling law (in terms of the coupled plamsa-plug system) reveals that a very high plug-plasma density ...

1980-11-01

446

Stem growth habit affects leaf morphology and gas exchange traits in soybean  

British Library Electronic Table of Contents (United Kingdom)

Backgrounds and Aims The stem growth habit, determinate or indeterminate, of soybean, Glycine max, varieties affects various plant morphological and developmental traits. The objective of this study is to identify the effect of stem growth habit in soybean on the stomatal conductance of single leaves in relation to their leaf morphology in order to better understand the ecological and agronomic significance of this plant trait. Methods The stomatal conductance of leaves on the main stem was measured periodically under favourable field conditions to evaluate gmax, defined as the maximum stomatal conductance at full leaf expansion, for four varieties of soybean and their respective determinate or indeterminate near isogenic lines (NILs). Leaf morphological traits including stomatal density, ...

2009-01-01

447

Soliton microdynamics and thermal conductivity of uranium nitride at high temperatures  

British Library Electronic Table of Contents (United Kingdom)

The microdynamics of soliton waves and localized modes of nonlinear vibrations of the acoustic and optical types in uranium nitride has been investigated. It has been shown that, with an increase in the excitation energy in the spectral gap between the bands of optical and acoustic phonons, the energies of solitons increase, whereas the energies of local modes decrease. The previously experimentally observed unidentified quasi-resonant features, which shift in the gap with variations in the temperature, can represent the revealed soliton waves and local modes. The microdynamics of heat conduction of uranium nitride has been studied for the stochastic generation of soliton waves and local modes in the case of spatially distant energy absorption. The thermal conductivity coefficient determin...

2011-01-01

448

SI/SIGE NANOWIRE ARRAYS FOR THERMOELECTRICITY  

Environmental Research Database

ObjectivesFor thermoelectricity both low thermal conductivity and high electrical conductivity are required. High electrical conductivity should be established via a high carriers concentration and a high mobility.~%~The aim of this feasibility study is to investigate a method of modulation doping of Si nanowires in order to generate high carrier concentrations without the need for impurity doping, thus retaining high mobilities.~%~~%~The objectives are (in chronological order):~%~- reduction of the wire [continued...]DescriptionIn recent years, the increasing dependence of society on fossil fuels for socio-economical development has become a cause of great concern. The possibility of a reduced availability of fossil fuels, and the effect of these fuels on climate change, have encouraged research into alternative energy sources. Many of these alternatives are old ideas, implemented using modern techniques. ...

2008-01-30

449

Properties of the passive films on cold worked stainless steels in conditions of susceptibility to stress corrosion cracking  

International Nuclear Information System (INIS)

Passive films, formed on annealed and cold worked AISI 304 stainless steel in hot chloride media, were examined using polarization resistance and impedance measurements. The obtained results show the influence of cold work on film conductivity, which can be correlated to conditions of susceptibility to stress corrosion cracking. Capacitance measurements, using the Mott-Schottky approach, revealed that a change from n to p type semi-conductivity is associated to susceptible conditions with an increase in the doping density estimated for cold worked samples in the presence of chloride. It is assumed that p-type semi-conductivity of the passive film together with the position of the flat band potential has a strong influence on the dissolution processes at the corrosion potential. Based on this analysis the influence of plastic deformation, at the dislocation scale, is discussed. (authors)

2004-01-01

450

Picosecond pulse-conductivity technique applied to study excess-electron reactions in hydrocarbon mixtures  

Energy Technology Data Exchange (ETDEWEB)

To measure electron reactions on a picosecond timescale the investigators developed a picosecond pulse-conductivity technique, which makes use of the electron fine-structure pulses of our LINAC (pulse width 25 vs FWHM) to produce excess electrons and now detects changes in sample conductance under optimum conditions with an instrumental response of 18 ps. This resolution is in agreement with a theoretical estimate. This technique has been successfully applied to study excess electron reactions in solvents covering a mobility range from 0.24 to 100 cm/sup 2/V/sup -1/s/sup -1/; extension to lower mobility liquids seem possible.

1983-01-01

451

Numerical heat transfer studies of the fatty acids for different heat exchanger materials on the performance of a latent heat storage system  

Energy Technology Data Exchange (ETDEWEB)

Theoretical investigations of fatty acids as a phase change material (PCM) for energy storage system have been conducted in this study. The selected fatty acids were capric acid, lauric acid, myristic acid, palmitic acid and stearic acid. For the two-dimensional simulation model based on the enthalpy approach, calculations have been made for the melt fraction with conduction only. Glass, stainless steel, tin, aluminium mixed, aluminium and copper were used as heat exchanger materials in the numerical calculations. Theoretical results show that capric acid was found good compatibility with latent heat storage system. The large value of thermal conductivity of heat exchanger materials did not make significant contribution on the melt fraction. (author)

2005-11-01

452

Numerical evaluation of effective unsaturated hydraulic properties for fractured rocks  

Energy Technology Data Exchange (ETDEWEB)

To represent a heterogeneous unsaturated fractured rock by its homogeneous equivalent, Monte Carlo simulations are used to obtain upscaled (effective) flow properties. In this study, we present a numerical procedure for upscaling the van Genuchten parameters of unsaturated fractured rocks by conducting Monte Carlo simulations of the unsaturated flow in a domain under gravity-dominated regime. The simulation domain can be chosen as the scale of block size in the field-scale modeling. The effective conductivity is computed from the steady-state flux at the lower boundary and plotted as a function of the averaging pressure head or saturation over the domain. The scatter plot is then fitted using van Genuchten model and three parameters, i.e., the saturated conductivity K{sub s}, the air-entry parameter {alpha}, the pore-size distribution parameter n, corresponding to this model are considered as the effective K{sub s}, ...

2009-01-01

453

Nonlinear conductivity with an extremely small threshold electric field in the organic conductor (TSM-TTP)(I3)5/3  

Science.gov (United States)

(TSM-TTP)(I3)5/3 is a 1/6 -filled one-dimensional system composed of an extended donor molecule which has two tetrathiafulvalene (TTF) units in a molecule, where TSM-TTP is 2,5-bis[4,5-bis(methylseleno)-1,3-dithiol-2-ylidene]-1,3,4,6-tetrathiapentalene. Nonlinear conductivity is observed in the insulating state below 20K , and the metallic state is restored above a very small threshold electric field of 0.3V/cm at 4.2K . The extremely sensitive nonlinearity is ascribed to the inhomogeneous insulating state generated by the weak and disordered anion potentials on the otherwise highly conducting intramolecular charge order state in the double-TTF molecule.

2007-06-01

454

Mixed convection in a horizontal rectangular channel - Experimental and numerical velocity distributions  

Science.gov (United States)

Mixed convection in a rectangular channel (width/height = 2) with bottom-heated and top-cooled sections is studied by laser Doppler anemometry in nitrogen at Ra = 22,200 and Re = 18.75, 36, and 54. At the lower Re values, symmetry breaking is observed in steady but spatially oscillating flows that prevail over a certain distance from the leading edge of the differentially heated section. Further downstream, unsteady flows are found even for Re = 18.75. Numerical models are used to investigate the effects of adiabatic, conducting (with a conductive-convective heat transfer coefficient), and perfectly conducting side walls; channel tilts and Prandtl number dependence. Good agreement between calculations and experiment is obtained for longitudinal convective roll velocities. The transverse velocities are found to be independent of Re.

1992-06-01

455

Ionically conductive thin polymer films prepared by plasma polymerization. Pt. 7. Preparation and characterization of solid polymer electrolyte having fixed carboxylic acid groups with single mobile species  

Energy Technology Data Exchange (ETDEWEB)

Ultra-thin, uniform, pinhole-free solid polymer electrolyte films having a fixed carboxylic ester group of approximately 1 {mu}m thickness were prepared by polymerization of methyl acrylate and tris(2-methoxyethoxy)vinylsilane in a glow discharge plasma. The carboxylic ester group of the plasma polymer were transformed to lithium carboxylate groups by treatment with lithium iodide. This process give a single lithium ion conductive film. These solid polymer electrolyte films showed ionic conductivities of the order of 10{sup -8} S cm{sup -1} (10{sup 4} {omega} cm{sup 2} resistance per unit area) at room temperature. (orig.).

1990-08-01

456

Ionically conductive thin polymer films prepared by plasma polymerization  

International Nuclear Information System (INIS)

Ultrathin solid polymer electrolyte membranes containing sulfonic ester groups were prepared by polymerization of methyl benzenesulfonate and octamethylcyclotetrasiloxane in a glow discharge plasma. The sulfonic ester groups of the plasma polymer were transformed to lithium sulfonate groups by treatment with lithium iodide. Hybridization of this plasma polymer containing the lithium sulfonate groups with poly(ethylene oxide) (average Mw 300) resulted in the formation of a single lithium ion conductive film. The hybrid polymer electrolyte films were about 1 #mu#m thick, pinhole-free, adherent to various substrates, and showed ionic conductivities at 60 degrees C of the order of 10"- "6 S cm"- "1 (10"2 #OMEGA# cm"2 resistance per unit area of as-prepared solid polymer electrolyte). This material shows promise for electrochemical applications such as all solid-state lithium batteries, sensors, and electrochemical display devices.

457

Electrolytic membrane formation of fluoroalkyl polymer using a UV-radiation-based grafting technique and sulfonation  

Science.gov (United States)

A sulfonated fluoroalkyl graft polymer (FGP) membrane was prepared as a polymer electrolyte. First, the FGP membrane was grafted with styrene under UV irradiation. The grafted FGP was then sulfonated to functionalize it for proton conductivity. The grafting degree of the membrane increased with increasing grafting time during UV irradiation. The proton conductivity of the membrane increased with increasing grafting degree. The swelling ratio was independent of the grafting time, however, the water uptake increased with increasing grafting degree. Based on these results, it was found that the UV-initiated styrene grafting occurred along the membrane thickness direction. Moreover, the membrane was embedded within the glass fibers of the composite. This composite electrolytic membrane had 1.15 times the proton conductivity of a Nafion 117 membrane.

2011-03-01

458

Effective thermal conductivity and thermal contact resistance of gas diffusion layers in proton exchange membrane fuel cells. Part 2: Hysteresis effect under cyclic compressive load  

British Library Electronic Table of Contents (United Kingdom)

Heat transfer through the gas diffusion layer (GDL) is a key process in the design and operation of a PEM fuel cell. The analysis of this process requires the determination of the effective thermal conductivity as well as the thermal contact resistance between the GDL and adjacent surfaces/layers. The Part 1 companion paper describes an experimental procedure and a test bed devised to allow separation of the effective thermal conductivity and thermal contact resistance, and presents measurements under a range of static compressive loads. In practice, during operation of a fuel cell stack, the compressive load on the GDL changes. In the present study, experiments are performed on Toray carbon papers with 78% porosity and 5% PTFE under a cyclic compressive load. Results show a significant hy...

2010-01-01

459

Effective thermal conductivity and thermal contact resistance of gas diffusion layers in proton exchange membrane fuel cells. Part 1: Effect of compressive load  

British Library Electronic Table of Contents (United Kingdom)

Heat transfer through the gas diffusion layer (GDL) is a key process in the design and operation of a PEM fuel cell. The analysis of this process requires determination of the effective thermal conductivity as well as the thermal contact resistance associated with the interface between the GDL and adjacent surfaces/layers. In the present study, a custom-made test bed that allows the separation of effective thermal conductivity and thermal contact resistance in GDLs under vacuum and ambient conditions is described. Measurements under varying compressive loads are performed using Toray carbon paper samples with a porosity of 78% for a range of thicknesses. The measurements are complemented by compact analytical models that achieve good agreement with experimental data. A key finding is that ...

2011-01-01

460

Dose dependence of semiconductor material conductivity as a means of high fluence dosimetry  

Energy Technology Data Exchange (ETDEWEB)

Dose dependences of conductivity at a temperature of 78 K for InSb and InAs single crystals under reactor fast neutron, 50 MeV proton and 80 MeV alpha particle irradiation up to fluence of 10{sup 17} cm{sup -2} are considered. Special attention is given to non-trivial, but little known semi-conductor characteristics in terms of {sigma}(F) dependence at large fluences, and also to the versatility of such dependence for all semiconductors. The behaviour of semiconductor materials conductivity dependence on fluence presented here may be used for semiconductor dosemeters characterisitic variation forecasting under large fluence measurements and in radiation emergency dosimetry. (author).

1996-12-31

461

Differences in morphology, gas exchange and root hydraulic conductance before planting in Pinus canariensis seedlings growing under different fertilization and light regimes  

British Library Electronic Table of Contents (United Kingdom)

As the main forestry species in the Canary Islands (Spain), Pinus canariensis is frequently used in afforestation programs. Several nursery techniques are commonly employed to modify its morphology and physiology with the aim of improving post-planting survival and growth. In this work, we studied how fertilization and light regime treatments applied during the nursery period modify biomass allocation patterns and produce effects in gas exchange and root hydraulic conductance. Seedlings were grown for a 6-month period in the nursery under two light regimes (full sunlight and 40% PAR reduction), and three fertilization levels were applied in each light regime. Morphology, biomass allocation patterns, leaf gas exchange and hydraulic conductance of the whole root system were evaluated. Fertil...

2010-01-01

462

Determining effective soil formation thermal properties from field data using a parameter estimation technique  

Energy Technology Data Exchange (ETDEWEB)

A one-dimensional thermal model is derived to describe the temperature field around a vertical borehole heat exchanger (BHEx) for a geothermal heat pump. The inlet and outlet pipe flows are modeled as one, and an effective heat capacity is added to model the heat storage in the fluid and pipes. Parameter estimation techniques are then used to estimate various parameters associated with the model, including the thermal conductivity of the soil and of the grout which fills the borehole and surrounds the u-tube. The model is validated using test data from an experimental rig containing sand with known thermal conductivity. The estimates of the sand thermal conductivity derived from the model are found to be in good agreement with independent measurements.

1998-11-01

463

Determining Effective Soil Formation Thermal Properties From Field Data Using A Parameter Estimation Technique  

Energy Technology Data Exchange (ETDEWEB)

A one-dimensional thermal model is derived to describe the temperature field around a vertical borehole heat exchanger (BHEX) for a geothermal heat pump. The inlet and outlet pipe flows are modeled as one, and an effective heat capacity is added to model the heat storage in the fluid and pipes. Parameter estimation techniques are then used to estimate various parameters associated with the model, including the thermal conductivity of the soil and the grout that fills the borehole and surrounds the U-tube. The model is validated using test data from an experimental rig containing sand with known thermal conductivity. The estimates of the sand's thermal conductivity derived from the model are found to be in good agreement with independent measurements.

1999-01-01

464

Cumulative effects of in utero administration of mixtures of reproductive toxicants that disrupt common target tissues via diverse mechanisms of toxicity  

British Library Electronic Table of Contents (United Kingdom)

Summary Although risk assessments are typically conducted on a chemical-by-chemical basis, the 1996 Food Quality Protection Act required the US Environmental Protection Agency to consider cumulative risk of chemicals that act via a common mechanism of toxicity. To this end, we are conducting studies with mixtures of chemicals to elucidate mechanisms of joint action at the systemic level with the goal of providing a framework for assessing the cumulative effects of reproductive toxicants. Previous mixture studies conducted with antiandrogenic chemicals are reviewed briefly and two new studies are described. In all binary mixture studies, rats were dosed during pregnancy with chemicals, singly or in pairs, at dosage levels equivalent to approximately one-half of the ED50 for hypospadias or e...

2010-01-01

465

Wind turbulence used as searching signal for MPPT in variable-speed wind energy conversion systems  

Energy Technology Data Exchange (ETDEWEB)

The control problem associated to a class of horizontal-axis fixed-pitch variable-speed low-power wind energy conversion systems, working in the partial load region, consisting in the energy conversion maximization, is approached here under the assumption that the wind turbine model and its parameters are poorly known. Using a new approach derived from the optimum seeking methods category, generically called Maximum Power Point Tracking (MPPT), the proposed control solution aims at driving the average position of the operating point near to optimality. Instead of inducing sinusoidal search signals, the wind turbulence is here used as search disturbance. The high-speed shaft's average rotational speed is slowly adjusted using the Fast Fourier Transform processing of some available measures from the system as an estimate of the operating point's position/distance to optimality. Numerical simulations are used for preliminary checking the control law ...

2009-01-15

466

Updated user's guide for SAMMY: multilevel R-matrix fits to neutron data using Bayes' equation  

International Nuclear Information System (INIS)

In 1980 the multilevel multichannel R-matrix code SAMMY was released for use in analysis of neutron data at the Oak Ridge Electron Linear Accelerator. Since that time, SAMMY has undergone significant modifications: (1) User-friendly options have been incorporated to streamline common operations and to protect a run from common user errors, (2) The Reich-Moore formalism has been extended to include an optional logarithmic parameterization of the external R-matrix, for which any or all parameters may be varied, (3) the ability to vary sample thickness, effective temperature, matching radius, and/or resolution-broadening parameters has been incorporated, (4) to avoid loss of information (i.e. computer round-off errors) between runs, the ''covariance file'' now includes precise values for al variables, (5) Unused but correlated variables may be included in the analysis. Because of these and earlier changes, the 1980 SAMMY manual is now hopelessly ...

467

The composite absolute penalties family for grouped and hierarchical variable selection  

CERN Document Server

Extracting useful information from high-dimensional data is an important focus of today's statistical research and practice. Penalized loss function minimization has been shown to be effective for this task both theoretically and empirically. With the virtues of both regularization and sparsity, the $L_1$-penalized squared error minimization method Lasso has been popular in regression models and beyond. In this paper, we combine different norms including $L_1$ to form an intelligent penalty in order to add side information to the fitting of a regression or classification model to obtain reasonable estimates. Specifically, we introduce the Composite Absolute Penalties (CAP) family, which allows given grouping and hierarchical relationships between the predictors to be expressed. CAP penalties are built by defining groups and combining the properties of norm penalties at the across-group and within-group levels. Grouped selection occurs for nonoverlapping groups. Hierarchical ...

2009-01-01

468

Stochastic-convective transport with nonlinear reaction: Mathematical framework  

Energy Technology Data Exchange (ETDEWEB)

A stochastic-convective reactive (SCR) transport method is developed for one-dimensional steady transport in physically heterogeneous media with nonlinear degradation. The method is free of perturbation amplitude limitations and circumvents the difficulty of scale dependence of phenomenological parameters by avoiding volume-averaged specifications of diffusive/dispersive fluxes. The transport system is conceptualized as an ensemble of independent convective-reactive streamlines, each characterized by a randomized convective velocity (or travel time). Dispersive effects are treated as a component of the randomness in the streamline velocity ensemble, so no explicit expression for hydrodynamic dispersive flux is written in the streamline transport equation. The expected value of the transport over the stream tube ensemble is obtained as an average of solutions to the reactive convection equation according to the stream tube (travel time) probability distribution function. In this way, ...

1995-11-01

469

Solid oxide fuel cell simulation and design optimization with numerical adjoint techniques  

Science.gov (United States)

This dissertation reports on the application of numerical optimization techniques as applied to fuel cell simulation and design. Due to the "multi-physics" inherent in a fuel cell, which results in a highly coupled and non-linear behavior, an experimental program to analyze and improve the performance of fuel cells is extremely difficult. This program applies new optimization techniques with computational methods from the field of aerospace engineering to the fuel cell design problem. After an overview of fuel cell history, importance, and classification, a mathematical model of solid oxide fuel cells (SOFC) is presented. The governing equations are discretized and solved with computational fluid dynamics (CFD) techniques including unstructured meshes, non-linear solution methods, numerical derivatives with complex variables, and sensitivity analysis with adjoint methods. Following the validation of the fuel cell model in 2-D and 3-D, the results of the sensitivity ...

2008-01-01

470

Should high-level nuclear waste be disposed of at geographically dispersed sites?  

Energy Technology Data Exchange (ETDEWEB)

Consideration of the technical feasibility of Yucca Mountain in Nevada as the site for a high-level nuclear waste repository has led to an intense debate regarding the economic, social, and political impacts of the repository. Impediments to the siting process mean that the nuclear waste problem is being resolved by adhering to the status quo, in which nuclear waste is stored at scattered sites near major population centers. To assess the merits of alternative siting strategies--including both the permanent repository and the status quo- we consider the variables that would be included in a model designed to select (1) the optimal number of disposal facilities, (2) the types of facilities (e.g., permanent repository or monitored retrievable facility), and (3) the geographic location of storage sites. The objective function in the model is an all-inclusive measure of social cost. The intent of the exercise is not to demonstrate the superiority of any single disposal ...

1992-07-01

471

SYVAC3 manual  

Energy Technology Data Exchange (ETDEWEB)

SYVAC3 (Systems Variability Analysis Code, generation 3) is a computer program that implements a method called systems variability analysis to analyze the behaviour of a system in the presence of uncertainty. This method is based on simulating the system many times to determine the variation in behaviour it can exhibit. SYVAC3 specializes in systems representing the transport of contaminants, and has several features to simplify the modelling of such systems. It provides a general tool for estimating environmental impacts from the dispersal of contaminants. This report describes the use and structure of SYVAC3. It is intended for modellers, programmers, operators and reviewers who deal with simulation codes based on SYVAC3. From this manual they can learn how to link a model with SYVAC3, how to set up an input file, and how to extract results from output files. The manual lists the subroutines of SYVAC3 that are available for use by models, and ...

2000-07-01

472

Rotation periods of late-type stars in the young open cluster IC 2602  

CERN Document Server

We present the results of a monitoring campaign aimed at deriving rotation periods for a representative sample of stars in the young (30 Myr) open cluster IC 2602. Rotation periods were derived for 29 of 33 stars monitored. The periods derived range from 0.2d (one of the shortest known rotation periods of any single open cluster star) to about 10d (which is almost twice as long as the longest period previously known for a cluster of this age). We are able to confirm 8 previously known periods and derive 21 new ones, delineating the long period end of the distribution. Despite our sensitivity to longer periods, we do not detect any variables with periods longer than about 10d. The combination of these data with those for IC 2391, an almost identical cluster, leads to the following conclusions: 1) The fast rotators in a 30 Myr cluster are distributed across the entire 0.5 < B-V < 1.6 color range. 2) 6 stars in our sample are slow rotators, with periods longer ...

1999-01-01

473

Quark and Gluon Tagging at the LHC  

CERN Document Server

Being able to distinguish light-quark jets from gluon jets on an event-by-event basis could significantly enhance the reach for many new physics searches at the Large Hadron Collider. Through an exhaustive search of existing and novel jet substructure observables, we find that a multivariate approach can filter out over 95% of the gluon jets while keeping more than half of the light-quark jets. Moreover, a combination of two simple variables, the charge track multiplicity and the pT-weighted linear radial moment (girth), can achieve similar results. While this pair appears very promising, our study is only Monte Carlo based, and other discriminants may work better with real data in a realistic experimental environment. To that end, we explore many other observables constructed using different jet sizes and parameters, and highlight those that deserve further theoretical and experimental scrutiny. Additional information, including distributions of around 10,000 ...

2011-01-01

474

Quantum Teleportation with Continuous Variables: a survey  

CERN Document Server

Very recently we have assisted to a new development of quantum information, the so-called continuous variable (CV) quantum information theory. Such a further development has been mainly due to the experimental and theoretical advantages offered by CV systems, i.e., quantum systems described by a set of observables, like position and momentum, which have a continuous spectrum of eigenvalues. According to this novel trend, quantum information protocols like quantum teleportation have been suitably extended to the CV framework. Here, we briefly review some mathematical tools relative to CV systems and we consequently develop the concepts of quantum entanglement and teleportation in the CV framework, by analogy with the qubit-based approach. Some connections between teleportation fidelity and entanglement properties of the underlying quantum channel are inspected. Next, we face the study of CV quantum teleportation networks where more users share a multipartite state ...

2006-01-01

475

Proactive product and process qualification in steam turbine development; Proaktive Produkt- und Prozessqualifikation in der Dampfturbinenentwicklung  

Energy Technology Data Exchange (ETDEWEB)

Proactive qualification is today an integral part of the development process for steam turbines used in steam and combined cycle power plants. By providing experimentally based `random` variables, such as the steam path efficiency and blading reliability, it makes a valuable contribution to the economic `random` variables of the power plant, e.g. the rate of return, as viewed by the customer. One of the areas in which proactive product and process qualification plays an important role is the development of LP steam paths. (orig.) [Deutsch] Die proaktive Qualifikation ist heute fester Bestandteil des Entwicklungsprozesses bei Dampfturbinen, die fuer den Einsatz in Dampf- und Kombikraftwerken bestimmt sind. Sie leistet mit Hilfe experimentell ermittelter `Zufalls`-Variablen, wie z.B. Wirkungsgrad der Fluten und Zuverlaessigkeit der Beschaufelungen, einen wertvollen Beitrag zu den fuer die Kunden wichtigen wirtschaftlichen `Zufalls`-Variablen des ...

1998-10-01

476

On the stability of Innovar, a neuroleptic analgesic, for cardiovascular experiments.  

Science.gov (United States)

The effects of 0.2 and 0.5 mL/kg Innovar (a neuroleptic analgesic) on cardiovascular functions and reflexes in rabbits were measured. We recorded the effects of Innovar on arterial pressure, heart rate, respiration rate, ventricular contractility, arterial oxygen tension, as well as the drug's effects on the bradycardia and vasoconstrictor response to cigarette smoke stimulation of the nose (the so-called "nasopharyngeal reflex"). In animals given 0.2 mL/kg Innovar, all steady state cardiovascular variables had returned to pre-Innovar levels in 45 min, as had the efficacy of the nasopharyngeal reflex. In animals given 0.5 mL/kg Innovar, all steady state cardiovascular variables, except PaO2, were slightly but significantly depressed for up to 135 min after injection. The nasopharyngeal reflex returned to normal within 90 min. Because of the calmative and analgesic effects of Innovar, and its only moderate effects on cardiovascular functions and ...

1981-11-01

477

Numerical analysis of reaction-diffusion effects on species mixing rates in turbulent premixed methane-air combustion  

Energy Technology Data Exchange (ETDEWEB)

The scalar mixing time scale, a key quantity in many turbulent combustion models, is investigated for reactive scalars in premixed combustion. Direct numerical simulations (DNS) of three-dimensional, turbulent Bunsen flames with reduced methane-air chemistry have been analyzed in the thin reaction zones regime. Previous conclusions from single step chemistry DNS studies are confirmed regarding the role of dilatation and turbulence-chemistry interactions on the progress variable dissipation rate. Compared to the progress variable, the mixing rates of intermediate species is found to be several times greater. The variation of species mixing rates are explained with reference to the structure of one-dimensional premixed laminar flames. According to this analysis, mixing rates are governed by the strong gradients which are imposed by flamelet structures at high Damkoehler numbers. This suggests a modeling approach to estimate the mixing rate of ...

2010-03-15

478

Natural climate variability as indicated by glaciers and implications for climate change: a modeling study  

Energy Technology Data Exchange (ETDEWEB)

Glacier fluctuations exclusively due to internal variations in the climate system are simulated using downscaled integrations of the ECHAM4/OPYC coupled general circulation model (GCM). A process-based modeling approach using a mass balance model of intermediate complexity and a dynamic ice flow model considering simple shearing flow and sliding are applied. Multi-millennia records of glacier length fluctuations for Nigardsbreen (Norway) and Rhonegletscher (Switzerland) are simulated using auto-regressive processes determined by statistically downscaled GCM experiments. Return periods and probabilities of specific glacier length changes using GCM integrations excluding external forcings such as solar irradiation changes, volcanic or anthropogenic effects are analyzed and compared to historical glacier length records. Preindustrial fluctuations of the glaciers as far as observed or reconstructed, including their advance during the ''Little Ice Age'', ...

2001-08-01

479

Multi-objective optimization of a dimpled channel for heat transfer augmentation  

Energy Technology Data Exchange (ETDEWEB)

Staggered arrays of dimples printed on opposite surfaces of a cooling channel is formulated numerically and optimized with hybrid multi-objective evolutionary algorithm and Pareto optimal front. As Pareto optimal front produces a set of optimal solutions, the trends of objective functions with design variables are predicted by hybrid multi-objective evolutionary algorithm. The problem is defined by three non-dimensional geometric design variables composed of dimpled channel height, dimple print diameter, dimple spacing, and dimple depth, to maximize heat transfer rate compromising with pressure drop. Twenty designs generated by Latin hypercube sampling were evaluated by Reynolds-averaged Navier-Stokes solver and the evaluated objectives were used to construct Pareto optimal front through hybrid multi-objective evolutionary algorithm. The optimum designs were grouped by k-means clustering technique and some of the clustered points were evaluated ...

2008-12-15

480

Multi-objective optimization of a dimpled channel for heat transfer augmentation  

Science.gov (United States)

Staggered arrays of dimples printed on opposite surfaces of a cooling channel is formulated numerically and optimized with hybrid multi-objective evolutionary algorithm and Pareto optimal front. As Pareto optimal front produces a set of optimal solutions, the trends of objective functions with design variables are predicted by hybrid multi-objective evolutionary algorithm. The problem is defined by three non-dimensional geometric design variables composed of dimpled channel height, dimple print diameter, dimple spacing, and dimple depth, to maximize heat transfer rate compromising with pressure drop. Twenty designs generated by Latin hypercube sampling were evaluated by Reynolds-averaged Navier-Stokes solver and the evaluated objectives were used to construct Pareto optimal front through hybrid multi-objective evolutionary algorithm. The optimum designs were grouped by k-means clustering technique and some of the clustered points were evaluated ...

2008-12-01

481

Models of continuous-variable quantum computing  

Energy Technology Data Exchange (ETDEWEB)

We discuss strictly efficient models for measurement-based quantum computing using physical continuous variables, such as field modes of light. Such measurement-based quantum computing (MBQC) provides a promising paradigm for quantum computation as it does not require performing unitary gates during the computation, but rather appropriate readout. Here, we introduce novel schemes for which the resource state can be reasonably and efficiently prepared, and which notably do not require having infinite squeezing or mean energy available. What is more, error correction techniques are implementable, as the logical information is stored in finite-dimensional objects grasping correlations of the quantum states. Using the ideas of computational tensor networks we discuss how to sequentially prepare suitable physical resource states with cavity QED or with non-linear optics and how to efficiently implement a computational universal set of quantum operations with feasible ...

2009-07-01

482

Microprocessor system controlling gas-carburizing process  

Energy Technology Data Exchange (ETDEWEB)

This report introduces a microprocessor system composed of a Z-80 single-board computer controlling a gas-carburizing process. The system has 7 analogical input and output signals 24 switch signal-input and 12 switch signal-output signals, which are applicable for temperature, carbon potential, and mechanical-movement control of multipurpose sealed furnaces, or for mutiple-zone temperature, carbon potential, and mechanical-movement control of continuous gas carburizing furnaces; or for distributed control of pit-type carburizing furnaces. The setpoints of variables, such as treating time, temperature, carbon potential of carburizing period, carbon potential of diffusion period, depth of carburizing layer, P.I.D. etc., are entered by keyboard and stored into memories, and actual values are displayed by digital tubes. Furthermore, the fault of thermocouple, oxygen probe, or infrared CO/sub 2/ analyzer; carbon potential, or temperature exceeding the setting value; ...

1986-01-01

483

High frequency VLBI observations of the scatter broadened quasar B2005+403  

CERN Document Server

The quasar B2005+403 located behind the Cygnus region, is a suitable object for studying the interplay between propagation effects, which are extrinsic to the source and source intrinsic variability. On the basis of VLBI experiments performed at 1.6, 5, 8, 15, 22, and 43GHz between 1992-2003 and parallel multi-frequency monitoring of the total flux density, we investigated the variability of total flux density and source structure. Below 8 GHz, the point-like VLBI source is affected by scatter-broadening of the turbulent interstellar medium, which is located along the line of sight and likely associated with the Cygnus region. We present and discuss the measured frequency dependence of the source size, which shows a power-law with slope of -1.91+/-0.05. From the measured scattering angle at 1GHz of 77.1+/-4.0mas a SM=0.43+/-0.04 m^{-20/3} kpc is derived, consistent with the general properties of the ISM in this direction. The decreasing effect ...

2006-01-01

484

Generational Structure of Models with Dynamical Symmetry Breaking  

CERN Document Server

In models with dynamical electroweak symmetry breaking, this breaking is normally communicated to quarks and leptons by a set of vector bosons with masses generated via sequential breaking of a larger gauge symmetry. In reasonably ultraviolet-complete theories of this type, the number of stages of breaking of the larger gauge symmetry is usually equal to the observed number of quark and lepton generations, $N_{gen.}=3$. Here we investigate the general question of how the construction and properties of these models depend on $N_{gen.}$, regarded as a variable. We build and analyze models with illustrative values of $N_{gen.}$ different from 3 (namely, $N_{gen.}=1,2,4$) that exhibit the necessary sequential symmetry breaking down to a strongly coupled sector that dynamically breaks electroweak symmetry. Our results for variable $N_{gen.}$ show that one can robustly obtain, for this latter sector, a theory with a gauge coupling that is large but ...

2010-01-01

485

Estimates of the width of the wetting zone along a fracture subjected to an episodic infiltration event in variably saturated, densely welded tuff  

Energy Technology Data Exchange (ETDEWEB)

A central issue to be addressed within the Nevada Nuclear Waste Storage Investigations (NNWSI) is the role which fractures will play as the variably saturated, fractured rock mass surrounding the waste package responds to heating, cooling, and episodic infiltration events. Understanding the role of fractures during such events will, in part, depend on our ability to make geophysical measurements of perturbations in the moisture distribution in the vicinity of fractures. In this study we first examine the details of the perturbation in the moisture distribution in and around a fracture subjected to an episodic infiltration event, and then integrate that behavior over the scale at which moisture measurements are likely to be made during the Engineered Barrier Design Test of the NNWSI project. To model this system we use the TOUGH hydrothermal code and fracture and matrix properties considered relevant to the welded ash flow tuff found in the Topopah Spring member at ...

1988-05-31

486

Effective per-capita dose as a yardstick for medical radiation exposure of the population - a supplement or an alternative to the genetically significant dose  

International Nuclear Information System (INIS)

The genetically significant dose (GSD) is an index variable which exclusively allows to describe the genetic risk in the progeny of a population due to the application of ionizing radiation and radioactive substances in one part of this population. It may result in wrong interpretation of population exposure at increasing incidence of examinations in a population involving ionizing radiation and radioactive drugs at simultaneously increasing application of alternative methods in children and adolescents owing to the fact that it indicates a downward trend although somatic exposure of this population has increased. Therefore, it is recommended to state both the GSD and the level of somatic radiation exposure of the population taken from the individual sources for the comparison and assessment of radiation exposure from various sources in future. Although the somatically significant dose constitutes the suitable variable complementary to GSD in ...

1984-06-01

487

Effect of site wind properties on wind-electric conversion costs  

Energy Technology Data Exchange (ETDEWEB)

The unit cost of energy production of wind generators is examined by means of a model of the turbine power curve and the Weibull model of wind probability function, by applying the usual economic equations. The analysis is carried out in terms of dimensionless variables whose range of variability is defined by examining the data of 80 modern commercial wind turbines; likewise, the economic parameters are based on the present state of costs. The unit cost decreases asymptotically when alpha (ratio between mean wind speed and cut-in speed) - increases and shows a lower limit of 2 to 5 Ecent/kWh. This cost depends both on the value of the machine parameter {phi} (ratio between nominal and cut-in speed) and on the basic prices. The effect of the Weibull shape parameter kappa is different according to the values of {alpha} and {phi}: with low {alpha} and high {phi} the unit cost increases along with {kappa} (that is with the regularity of the ...

2004-12-01

488

Dynamics of the Intertropical Convergence Zone of the East Pacific.  

Science.gov (United States)

The dynamical factors controlling the mean state and variability of the east Pacific intertropical convergence zone (ITCZ) and the associated cross-equatorial boundary layer flow are investigated using observations from the East Pacific Investigation of Climate (EPIC2001) project. The tropical east Pacific exhibits a southerly boundary layer flow that terminates in the ITCZ. This flow is induced by the strong meridional sea surface temperature (SST) gradient in the region. Away from the equator and from deep convection, it is reasonably well described on a day-to-day basis by an extended Ekman balance model. Variability in the strength and northward extent of this flow is caused by variations in free-tropospheric pressure gradients that either reinforce or oppose the pressure gradient associated with the SST gradient. These free-tropospheric gradients are caused by easterly waves, tropical cyclones, and the Madden Julian oscillation.Convergence ...

2006-02-01

489

Consistency of the phenomenological theories of wave-type heat transport with the hydrodynamics of a phonon gas  

International Nuclear Information System (INIS)

Various phenomenological theories of wave-type heat transport, which can be interpreted as the models of an isotropic rigid heat conductor with an internal vector state variable, have been proposed in the literature with the objective to describe the second sound propagation in dielectric crystals. The aim of this paper is to analyze the relation between these phenomenological approaches and the phonon gas hydrodynamics. The four-moment phonon gas hydrodynamics based on the maximum entropy closure of the moment equations with nonlinear isotropic phonon dispersion relation is considered for this purpose. We reformulate the equations of this hydrodynamics in terms of energy and quasi-momentum as the primitive fields and subsequently demonstrate that, from the macroscopic point of view, they can be understood as describing the reference model of an isotropic rigid heat conductor with quasi-momentum playing the role of the internal vector state ...

2010-09-24

490

Cheng cycle cogeneration system; Cheng cycle system cogeneration setsubi  

Energy Technology Data Exchange (ETDEWEB)

This paper presents the Cheng cycle system featured by variable heating/generation ratio for effective operation of cogeneration systems (CGS). In this system, a superheater and reheating burner are added to an exhaust heat recovery (EHR) boiler for conventional gas turbine CGSs, while additional injection steam piping is attached to a gas turbine. Steam is injected through manifolds mounted on the periphery of a combustion chamber, and hot gas mixture of steam and air in a combustion chamber is expanded in a turbine and converted to motive power. This technology thus can improve efficiency and output power, and can operate variably CGSs corresponding to heating and generation demands. This technology has been promoted by introducing the technology of middle class Cheng cycle CGS with 4MW class gas turbine from IPT Co., U.S.A. The first system of 6400 kW is now under production for start of operation in 1996. Its EHR boiler is featured by ...

1996-03-29

491

Cataclysmic Variables and a Candidate Helium White Dwarf in the Globular Cluster NGC 6397  

CERN Document Server

We have used HST/FOS to study faint UV stars in the core of the nearby globular cluster NGC 6397. We confirm the presence of a 4th cataclysmic variable (CV) in NGC 6397 (CV 4), and we use the photometry of Cool et al. (1998) to present evidence that CVs 1--4 all have faint disks and probably low accretion rates. By combining these results with new UV spectra of CV 1 and the published spectra of Grindlay et al. (1995) we present new evidence that CVs 1--3 may be DQ Her systems, and we show that CV 4 may either be a dwarf nova or another magnetic system. Another possibility is that the CVs could be old novae in hibernation between nova eruptions. We also present the first spectrum of a member of a new class of UV bright stars in NGC 6397. These faint, hot stars do not vary, unlike the CVs, and are thus denoted as ``non-flickerers'' (NFs). Like the CVs, their spatial concentration is strongly concentrated toward the cluster center. Using stellar atmosphere models we ...

1999-01-01

492

Atmospheric carbon dioxide measurements in the remote global troposphere, 1981-1984  

Energy Technology Data Exchange (ETDEWEB)

The carbon dioxide concentration has been measured in air samples collected approximately once per week at 22 globally distributed sites during 1981-1984. All samples were analyzed on the same non-dispersive infrared analyzer apparatus. The measured concentrations are directly traceable to the WMO primary CO/sub 2/ standards. Samples which do not contain well-mixed, regionally representative air or which have been contaminated during or subsequent to sampling, have been identified. The selected data have been analyzed using an objective curve fitting method which enables improved estimation of uncertainties associated with derived parameters. The latitudinal distribution of annual mean CO/sub 2/ concentration at the network sites shows significant interannual variability possibly related to the 1982-1983 El NinoSouthern Oscillation event. No evidence was found for significant interannnual variations or trend in the phase or amplitude of the seasonal cycle. ...

1988-01-01

493

Analysis of complex systems using neural networks  

Energy Technology Data Exchange (ETDEWEB)

The application of neural networks, alone or in conjunction with other advanced technologies (expert systems, fuzzy logic, and/or genetic algorithms), to some of the problems of complex engineering systems has the potential to enhance the safety, reliability, and operability of these systems. Typically, the measured variables from the systems are analog variables that must be sampled and normalized to expected peak values before they are introduced into neural networks. Often data must be processed to put it into a form more acceptable to the neural network (e.g., a fast Fourier transformation of the time-series data to produce a spectral plot of the data). Specific applications described include: (1) Diagnostics: State of the Plant (2) Hybrid System for Transient Identification, (3) Sensor Validation, (4) Plant-Wide Monitoring, (5) Monitoring of Performance and Efficiency, and (6) Analysis of Vibrations. Although specific examples described ...

1992-01-01

494

Analysis of complex systems using neural networks  

Energy Technology Data Exchange (ETDEWEB)

The application of neural networks, alone or in conjunction with other advanced technologies (expert systems, fuzzy logic, and/or genetic algorithms), to some of the problems of complex engineering systems has the potential to enhance the safety, reliability, and operability of these systems. Typically, the measured variables from the systems are analog variables that must be sampled and normalized to expected peak values before they are introduced into neural networks. Often data must be processed to put it into a form more acceptable to the neural network (e.g., a fast Fourier transformation of the time-series data to produce a spectral plot of the data). Specific applications described include: (1) Diagnostics: State of the Plant (2) Hybrid System for Transient Identification, (3) Sensor Validation, (4) Plant-Wide Monitoring, (5) Monitoring of Performance and Efficiency, and (6) Analysis of Vibrations. Although specific examples described ...

1992-12-31

495

A regional evaluation of coal quality in the foothills/mountains region of Alberta  

Energy Technology Data Exchange (ETDEWEB)

This report is the conclusion of a three-part series that describes and attempts to explain regional coal quality variations within the foothills/mountains region of Alberta. Proximate and ultimate analysis variables, plus some vitrinite reflectance and maceral analyses, are examined for the Jurassic-Lower Cretaceous Kootenay Group, Lower Cretaceous Luscar Group, the Lower Paleocene Coalspur Formation, and the Upper Paleocene Obed-Marsh coal-bearing units. The study has two major components: a statistical analysis and mapping of coal quality data provided by the Energy Resources Conservation Board; and a 'geologic models' section, in which regional and local in-seam coal quality variations are examined from a geological perspective. The first component is designed to describe, characterize, and set limits for the coal quality variables, while the second component should provide from a geological perspective, insight as to why ...

1989-01-01

496

A Permeability Model for Coal and Other Fractured, Sorptive-Elastic Media  

Energy Technology Data Exchange (ETDEWEB)

This paper describes the derivation of a new equation that can be used to model the permeability behavior of a fractured, sorptive-elastic media, such as coal, under variable stress conditions commonly used during measurement of permeability data in the laboratory. The model is derived for cubic geometry under biaxial or hydrostatic confining pressures. The model is also designed to handle changes in permeability caused by adsorption and desorption of gases from the matrix blocks. The model equations can be used to calculate permeability changes caused by the production of methane from coal as well as the injection of gases, such as carbon dioxide, for sequestration in coal. Sensitivity analysis of the model found that each of the input variables can have a significant impact on the outcome of the permeability forecast as a function of changing pore pressure; thus, accurate input data are essential. The permeability model can also be used as a ...

2006-10-01

497

3-dimensional observations of atmospheric variables during the field campaign COPS  

Energy Technology Data Exchange (ETDEWEB)

The Convective and Orographically-induced Precipitation Study (COPS) has the aim to advance the quality of forecasts of orographically-induced precipitation in complex terrain. COPS is a Research and Development Project of the World Weather Research Program and considered to be one of the largest field campaigns on quantitative precipitation forecasting that has been performed so far. A network of state-of-the-art active and passive remote sensing systems was combined with in total 10 airborne platforms, Meteosat rapid scans and dense networks of standard meteorological instruments during the three months long field phase (June-August, 2007) in south-western Germany/eastern France to observe atmospheric variables in the three spatial dimensions and in time. By the University of Hohenheim, two novel ground-based mobile scanning lidar systems were deployed: a scanning rotational Raman lidar which provides combined measurements of the field of atmospheric temperature ...

2008-05-01