Hydration heat of alkali activated fine-grained ceramic

NASA Astrophysics Data System (ADS)

Jerman, Miloš; Černý, Robert

2017-07-01

Early-age hydration heat of alkali activated ceramic dust is studied as a function of silicate modulus. A mixture of sodium hydroxide and water glass is used as alkali activator. The measurements are carried out using a large-volume isothermal heat flow calorimeter which is capable of detecting even very small values of specific heat power. Experimental results show that the specific hydration heat power of alkali activated fine-ground ceramic is very low and increases with the decreasing silicate modulus of the mix.

Using Powerpoint Animations to Teach Operations Management Techniques and Concepts

ERIC Educational Resources Information Center

Treleven, Mark D.; Penlesky, Richard J.; Callarman, Thomas E.; Watts, Charles A.; Bragg, Daniel J.

2014-01-01

This article examines the value of using complex animated PowerPoint presentations to teach operations management techniques and concepts. To provide context, literature covering the use of PowerPoint animations in business education is briefly reviewed. The specific animations employed in this study are identified and their expected benefits to…

Multi-objective Decision Based Available Transfer Capability in Deregulated Power System Using Heuristic Approaches

NASA Astrophysics Data System (ADS)

Pasam, Gopi Krishna; Manohar, T. Gowri

2016-09-01

Determination of available transfer capability (ATC) requires the use of experience, intuition and exact judgment in order to meet several significant aspects in the deregulated environment. Based on these points, this paper proposes two heuristic approaches to compute ATC. The first proposed heuristic algorithm integrates the five methods known as continuation repeated power flow, repeated optimal power flow, radial basis function neural network, back propagation neural network and adaptive neuro fuzzy inference system to obtain ATC. The second proposed heuristic model is used to obtain multiple ATC values. Out of these, a specific ATC value will be selected based on a number of social, economic, deregulated environmental constraints and related to specific applications like optimization, on-line monitoring, and ATC forecasting known as multi-objective decision based optimal ATC. The validity of results obtained through these proposed methods are scrupulously verified on various buses of the IEEE 24-bus reliable test system. The results presented and derived conclusions in this paper are very useful for planning, operation, maintaining of reliable power in any power system and its monitoring in an on-line environment of deregulated power system. In this way, the proposed heuristic methods would contribute the best possible approach to assess multiple objective ATC using integrated methods.

Factors influencing specific fuel use in Nebraska

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shelton, D.P.; Von Bargen, K.

1981-01-01

Fuel use data relating to agricultural field operations were collected and analyzed during the Nebraska fuel use survey. The farms surveyed had a mean size of 598 ha and a mean total tractor power rating of 221 kW. Mean operating depth, field speed, and tractor power rating were determined for the major field operations. Mean field speeds were generally in agreement with commonly accepted values. Total annual fuel energy use increased with increasing farm size. Over 87 percent of this energy was used from April through October. Even though total fuel energy was increased, specific fuel energy use decreased withmore » increasing farm size. Specific fuel use for field operations was influenced by the size of area worked, operation depth, field speed, and tractor power rating.« less

Optical rogue-wave-like extreme value fluctuations in fiber Raman amplifiers.

PubMed

Hammani, Kamal; Finot, Christophe; Dudley, John M; Millot, Guy

2008-10-13

We report experimental observation and characterization of rogue wave-like extreme value statistics arising from pump-signal noise transfer in a fiber Raman amplifier. Specifically, by exploiting Raman amplification with an incoherent pump, the amplified signal is shown to develop a series of temporal intensity spikes whose peak power follows a power-law probability distribution. The results are interpreted using a numerical model of the Raman gain process using coupled nonlinear Schrödinger equations, and the numerical model predicts results in good agreement with experiment.

Site of maxima of conductivity, temperatures, density of the current and specific capacity of the thermal emission in the HFI-discharge

NASA Astrophysics Data System (ADS)

Gerasimov, A.; Kirpichnikov, A.; Sabirova, F.; Gainullin, R.

2017-11-01

On the basis of theoretical analysis of distributions of the conductivity, current density and specific power of heat release in the high-frequency induction discharge, a law of crowding of maxima of these values has been established.

Dielectric properties, optimum formulation and microwave baking conditions of chickpea cakes.

PubMed

Alifakı, Yaşar Özlem; Şakıyan, Özge

2017-03-01

The aim of this study was to correlate dielectric properties with quality parameters, and to optimize cake formulation and baking conditions by response surface methodology. Weight loss, color, specific volume, hardness and porosity were evaluated. The samples with different DATEM (0.4, 0.8 and 1.2%) and chickpea flour concentrations (30, 40 and 50%) were baked in microwave oven at different power (300, 350, 400 W) and baking times (2.50, 3.0, 3.50 min). It was found that microwave power showed significant effect on color, while baking time showed effect on weight loss, porosity, hardness, specific volume and dielectric properties. Emulsifier level affected porosity, specific volume and dielectric constant. Chickpea flour level affected porosity, color, hardness and dielectric properties of cakes. The optimum microwave power, baking time, DATEM level and chickpea flour level were found as 400 W, 2.84 min, 1.2% and 30%, respectively. The comparison between conventionally baked and the microwave baked cakes at optimum points showed that color difference, weight loss, specific volume and porosity values of microwave baked cakes were less than those of conventionally baked cakes, on the other hand, hardness values were higher. Moreover, a negative correlation between dielectric constant and porosity, and weight loss values were detected for microwave baked samples. A negative correlation between dielectric loss factor and porosity was observed. These correlations indicated that quality characteristics of a microwave baked cake sample can be assessed from dielectric properties. These correlations provides understanding on the behavior of food material during microwave processing.

[BIOETHICS: THE ABILITY TO UNDERSTAND MAN, THE POWER TO STANDARDIZE THE FACTS].

PubMed

Tzitzis, Stamatios

2015-07-01

Bioethics is both theoria and praxis. It procceds by tactics which accompany dynamics of science and mobility of ethics, concerning values specific to spaces, periods and cultures. In this perspective, bioethics, with its normative requirements, is situated beyond gouvernmental policy. The rules related to bioethics contains meta-values. Value imposed to a fact by légal rules is an existential meta-value, because there are already values that surround the nature of this fact the the morality this nature contains.

Highly conductive and porous activated reduced graphene oxide films for high-power supercapacitors.

PubMed

Zhang, Li Li; Zhao, Xin; Stoller, Meryl D; Zhu, Yanwu; Ji, Hengxing; Murali, Shanthi; Wu, Yaping; Perales, Stephen; Clevenger, Brandon; Ruoff, Rodney S

2012-04-11

We present a novel method to prepare highly conductive, free-standing, and flexible porous carbon thin films by chemical activation of reduced graphene oxide paper. These flexible carbon thin films possess a very high specific surface area of 2400 m(2) g(-1) with a high in-plane electrical conductivity of 5880 S m(-1). This is the highest specific surface area for a free-standing carbon film reported to date. A two-electrode supercapacitor using these carbon films as electrodes demonstrated an excellent high-frequency response, an extremely low equivalent series resistance on the order of 0.1 ohm, and a high-power delivery of about 500 kW kg(-1). While higher frequency and power values for graphene materials have been reported, these are the highest values achieved while simultaneously maintaining excellent specific capacitances and energy densities of 120 F g(-1) and 26 W h kg(-1), respectively. In addition, these free-standing thin films provide a route to simplify the electrode-manufacturing process by eliminating conducting additives and binders. The synthetic process is also compatible with existing industrial level KOH activation processes and roll-to-roll thin-film fabrication technologies. © 2012 American Chemical Society

The Power Behind the Controversy: Understanding Local Policy Elites' Perceptions on the Benefits and Risks Associated with High Voltage Power Line Installation in the State of Arkansas

NASA Astrophysics Data System (ADS)

Moyer, Rachael M.

Following a proposal for the installation of high voltage power lines in northwest Arkansas, a controversial policy debate emerged. Proponents of the transmission line argue that such an installation is inevitable and necessary to efficiently and reliably support the identified electric load in the region. Opponents claim that the lines will degrade the natural environment and hamper the tourism-based local economy in affected regions, notably in Ozark Mountain areas. This study seeks to understand how local policy elites perceive the benefits and risks associated with proposed transmission lines, which is a critical step in comprehending the formation and changes of related government policies. First, based upon the dual process theory of judgment, this study systematically investigates the triadic relationships between (a) more profound personal value predispositions, (b) affects and feelings, and (c) perceived benefits and risks related to the proposed installation of high voltage power lines among local policy elites in the state of Arkansas. Next, this study focuses more specifically on the role of value predispositions, specific emotional dimensions of affect heuristics, and perceptions pertaining to high voltage power line risks and benefits. Using original data collected from a statewide Internet survey of 420 local leaders and key policymakers about their opinions on the related issues, other factors claimed by previous literature, including trust, knowledge level, and demographic characteristics are considered. Analytical results suggest that grid-group cultural predispositions, as deeply held core values within local policy elites' individual belief systems, both directly and indirectly -- through affective feelings -- shape perceived utility associated with the installation of high voltage power lines. Recognizing that risk perceptions factor into policy decisions, some practical considerations for better designing policy addressing controversial issues of this nature.

Aligned carbon nanotube/zinc oxide nanowire hybrids as high performance electrodes for supercapacitor applications

NASA Astrophysics Data System (ADS)

Al-Asadi, Ahmed S.; Henley, Luke Alexander; Wasala, Milinda; Muchharla, Baleeswaraiah; Perea-Lopez, Nestor; Carozo, Victor; Lin, Zhong; Terrones, Mauricio; Mondal, Kanchan; Kordas, Krisztian; Talapatra, Saikat

2017-03-01

Carbon nanotube/metal oxide based hybrids are envisioned as high performance electrochemical energy storage electrodes since these systems can provide improved performances utilizing an electric double layer coupled with fast faradaic pseudocapacitive charge storage mechanisms. In this work, we show that high performance supercapacitor electrodes with a specific capacitance of ˜192 F/g along with a maximum energy density of ˜3.8 W h/kg and a power density of ˜ 28 kW/kg can be achieved by synthesizing zinc oxide nanowires (ZnO NWs) directly on top of aligned multi-walled carbon nanotubes (MWCNTs). In comparison to pristine MWCNTs, these constitute a 12-fold of increase in specific capacitance as well as corresponding power and energy density values. These electrodes also possess high cycling stability and were able to retain ˜99% of their specific capacitance value over 2000 charging discharging cycles. These findings indicate potential use of a MWCNT/ZnO NW hybrid material for future electrochemical energy storage applications.

High Conductivity Carbon-Carbon Heat Pipes for Light Weight Space Power System Radiators

NASA Technical Reports Server (NTRS)

Juhasz, Albert J.

2008-01-01

Based on prior successful fabrication and demonstration testing of a carbon-carbon heat pipe radiator element with integral fins this paper examines the hypothetical extension of the technology via substitution of high thermal conductivity composites which would permit increasing fin length while still maintaining high fin effectiveness. As a result the specific radiator mass could approach an ultimate asymptotic minimum value near 1.0 kg/m2, which is less than one fourth the value of present day satellite radiators. The implied mass savings would be even greater for high capacity space and planetary surface power systems, which may require radiator areas ranging from hundreds to thousands of square meters, depending on system power level.

Predictability of lesion durability for AF ablation using phased radiofrequency: Power, temperature, and duration impact creation of transmural lesions.

PubMed

Hocini, Mélèze; Condie, Cathy; Stewart, Mark T; Kirchhof, Nicole; Foell, Jason D

2016-07-01

Long-term clinical outcomes for atrial fibrillation ablation depend on the creation of durable transmural lesions during pulmonary vein isolation and on substrate modification. Focal conventional radiofrequency (RF) ablation studies have demonstrated that tissue temperature and power are important factors for lesion formation. However, the impact and predictability of temperature and power on contiguous, transmural lesion formation with a phased RF system has not been described. The purpose of this study was to determine the sensitivity, specificity, and predictability of power and temperature to create contiguous, transmural lesions with the temperature-controlled, multielectrode phased RF PVAC GOLD catheter. Single ablations with the PVAC GOLD catheter were performed in the superior vena cava of 22 pigs. Ablations from 198 PVAC GOLD electrodes were evaluated by gross examination and histopathology for lesion transmurality and contiguity. Lesions were compared to temperature and power data from the phased RF GENius generator. Effective contact was defined as electrodes with a temperature of ≥50°C and a power of ≥3 W. Eighty-five percent (168 of 198) of the lesions were transmural and 79% (106 of 134) were contiguous. Electrode analysis showed that >30 seconds of effective contact identified transmural lesions with 85% sensitivity (95% confidence interval [CI] 78%-89%), 93% specificity (95% CI 76%-99%), and 99% positive predictive value (95% CI 94%-100%). Sensitivity for lesion contiguity was 95% (95% CI 89%-98%), with 62% specificity (95% CI 42%-78%) and 90% positive predictive value (95% CI 83%-95%). No char or coagulum was observed on the catheter or tissue. PVAC GOLD safely, effectively, and predictably creates transmural and contiguous lesions. Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

MW-assisted synthesis of LiFePO 4 for high power applications

NASA Astrophysics Data System (ADS)

Beninati, Sabina; Damen, Libero; Mastragostino, Marina

LiFePO 4/C was prepared by solid-state reaction from Li 3PO 4, Fe 3(PO 4) 2·8H 2O, carbon and glucose in a few minutes in a scientific MW (microwave) oven with temperature and power control. The material was characterized by X-ray diffraction, scanning electron microscopy and by TGA analysis to evaluate carbon content. The electrochemical characterization as positive electrode in EC (ethylene carbonate)-DMC (dimethylcarbonate) 1 M LiPF 6 was performed by galvanostatic charge-discharge cycles at C/10 to evaluate specific capacity and by sequences of 10 s discharge-charge pulses, at different high C-rates (5-45C) to evaluate pulse-specific power in simulate operative conditions for full-HEV application. The maximum pulse-specific power and, particularly, pulse efficiency values are quite high and make MW synthesis a very promising route for mass production of LiFePO 4/C for full-HEV batteries at low energy costs.

Evaluation of High-Performance Space Nuclear Electric Generators for Electric Propulsion Application

NASA Technical Reports Server (NTRS)

Woodcock, Gordon; Kross, Dennis A. (Technical Monitor)

2002-01-01

Electric propulsion applications are enhanced by high power-to-mass ratios for their electric power sources. At multi-megawatt levels, we can expect thrust production systems to be less than 5 kg/kWe. Application of nuclear electric propulsion to human Mars missions becomes an attractive alternative to nuclear thermal propulsion if the propulsion system is less than about 10 kg/kWe. Recent references have projected megawatt-plus nuclear electric sources at specific mass values from less than 1 kg/kWe to about 5 kg/kWe. Various assumptions are made regarding power generation cycle (turbogenerator; MHD (magnetohydrodynamics)) and reactor heat source design. The present paper compares heat source and power generation options on the basis of a parametric model that emphasizes heat transfer design and realizable hardware concept. Pressure drop (important!) is included in the power cycle analysis, and MHD and turbogenerator cycles are compared. Results indicate that power source specific mass less than 5 kg/kWe is attainable, even if peak temperatures achievable are limited to 1500 K. Projections of specific mass less than 1 kg/kWe are unrealistic, even at the highest peak temperatures considered.

Accumulation and transfer of 137Cs and 90Sr in the plants of the forest ecosystem near the Ignalina Nuclear Power Plant.

PubMed

Lukšienė, B; Marčiulionienė, D; Gudelienė, I; Schönhofer, F

2013-02-01

The radioecological state of the forest ecosystem in the vicinity of the Ignalina Power Plant prior to decommissioning was analysed with specific emphasis on (137)Cs and (90)Sr activity concentrations in plant species growing in two reference sampling sites (Tilze and Grikiniskes). In the period of 1996-2008 the mean contamination of plants with (137)Cs was from 45 to 119 Bq/kg and with (90)Sr - from 3 to 42 Bq/kg. Measured (137)Cs TF values for soil-root transfer mainly ranged between 1.0-1.4, except for Calamagrostis arundinacea which had a TF value of 0.1. On average, the (137)Cs TF value from root to shoot was 1.7 fold higher than for soil to root transfer. (90)Sr TF values (soil-root) were in the range of 1.2-1.8 but for Calluna vulgaris it was 0.2. The mean root to shoot TF value for (90)Sr was 7.7 fold higher. These results indicate the higher (90)Sr bioavailability than that of (137)Cs in the forested area. The Grikiniskes reference site is located nearby the Ignalina NPP, specifically the heated water outlet channel, which results in altered microclimatic conditions. These specific microclimatic conditions result in relationships between (137)Cs TF (soil-root) values and pH, moisture and organic matter content in the soil at Grikiniskes which appear to be different to those at the Tilze reference sampling site. Copyright © 2012 Elsevier Ltd. All rights reserved.

Assessment of exposure to radio frequency electromagnetic fields from smart utility meters in GB; part II) numerical assessment of induced SAR within the human body.

PubMed

Qureshi, Muhammad R A; Alfadhl, Yasir; Chen, Xiaodong; Peyman, Azadeh; Maslanyj, Myron; Mann, Simon

2018-04-01

Human body exposure to radiofrequency electromagnetic waves emitted from smart meters was assessed using various exposure configurations. Specific energy absorption rate distributions were determined using three anatomically realistic human models. Each model was assigned with age- and frequency-dependent dielectric properties representing a collection of age groups. Generalized exposure conditions involving standing and sleeping postures were assessed for a home area network operating at 868 and 2,450 MHz. The smart meter antenna was fed with 1 W power input which is an overestimation of what real devices typically emit (15 mW max limit). The highest observed whole body specific energy absorption rate value was 1.87 mW kg -1 , within the child model at a distance of 15 cm from a 2,450 MHz device. The higher values were attributed to differences in dimension and dielectric properties within the model. Specific absorption rate (SAR) values were also estimated based on power density levels derived from electric field strength measurements made at various distances from smart meter devices. All the calculated SAR values were found to be very small in comparison to International Commission on Non-Ionizing Radiation Protection limits for public exposure. Bioelectromagnetics. 39:200-216, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Optimization of power and energy densities in supercapacitors

NASA Astrophysics Data System (ADS)

Robinson, David B.

Supercapacitors use nanoporous electrodes to store large amounts of charge on their high surface areas, and use the ions in electrolytes to carry charge into the pores. Their high power density makes them a potentially useful complement to batteries. However, ion transport through long, narrow channels still limits power and efficiency in these devices. Proper design can mitigate this. Current collector geometry must also be considered once this is done. Here, De Levie's model for porous electrodes is applied to quantitatively predict device performance and to propose optimal device designs for given specifications. Effects unique to nanoscale pores are considered, including that pores may not have enough salt to fully charge. Supercapacitors are of value for electric vehicles, portable electronics, and power conditioning in electrical grids with distributed renewable sources, and that value will increase as new device fabrication methods are developed and proper design accommodates those improvements. Example design outlines for vehicle applications are proposed and compared.

Flight measured and calculated exhaust jet conditions for an F100 engine in an F-15 airplane

NASA Technical Reports Server (NTRS)

Hernandez, Francisco J.; Burcham, Frank W., Jr.

1988-01-01

The exhaust jet conditions, in terms of temperature and Mach number, were determined for a nozzle-aft end acoustic study flown on an F-15 aircraft. Jet properties for the F100 EMD engines were calculated using the engine manufacturer's specification deck. The effects of atmospheric temperature on jet Mach number, M10, were calculated. Values of turbine discharge pressure, PT6M, jet Mach number, and jet temperature were calculated as a function of aircraft Mach number, altitude, and power lever angle for the test day conditions. At a typical test point with a Mach number of 0.9, intermediate power setting, and an altitude of 20,000 ft, M10 was equal to 1.63. Flight measured and calculated values of PT6M were compared for intermediate power at altitudes of 15500, 20500, and 31000 ft. It was found that at 31000 ft, there was excellent agreement between both, but for lower altitudes the specification deck overpredicted the flight data. The calculated jet Mach numbers were believed to be accurate to within 2 percent.

Simulation program for estimating statistical power of Cox's proportional hazards model assuming no specific distribution for the survival time.

PubMed

Akazawa, K; Nakamura, T; Moriguchi, S; Shimada, M; Nose, Y

1991-07-01

Small sample properties of the maximum partial likelihood estimates for Cox's proportional hazards model depend on the sample size, the true values of regression coefficients, covariate structure, censoring pattern and possibly baseline hazard functions. Therefore, it would be difficult to construct a formula or table to calculate the exact power of a statistical test for the treatment effect in any specific clinical trial. The simulation program, written in SAS/IML, described in this paper uses Monte-Carlo methods to provide estimates of the exact power for Cox's proportional hazards model. For illustrative purposes, the program was applied to real data obtained from a clinical trial performed in Japan. Since the program does not assume any specific function for the baseline hazard, it is, in principle, applicable to any censored survival data as long as they follow Cox's proportional hazards model.

Reactive power compensator

DOEpatents

El-Sharkawi, Mohamed A.; Venkata, Subrahmanyam S.; Chen, Mingliang; Andexler, George; Huang, Tony

1992-01-01

A system and method for determining and providing reactive power compensation for an inductive load. A reactive power compensator (50,50') monitors the voltage and current flowing through each of three distribution lines (52a, 52b, 52c), which are supplying three-phase power to one or more inductive loads. Using signals indicative of the current on each of these lines when the voltage waveform on the line crosses zero, the reactive power compensator determines a reactive power compensator capacitance that must be connected to the lines to maintain a desired VAR level, power factor, or line voltage. Alternatively, an operator can manually select a specific capacitance for connection to each line, or the capacitance can be selected based on a time schedule. The reactive power compensator produces control signals, which are coupled through optical fibers (102/106) to a switch driver (110, 110') to select specific compensation capacitors (112) for connections to each line. The switch driver develops triggering signals that are supplied to a plurality of series-connected solid state switches (350), which control charge current in one direction in respect to ground for each compensation capacitor. During each cycle, current flows from ground to charge the capacitors as the voltage on the line begins to go negative from its positive peak value. The triggering signals are applied to gate the solid state switches into a conducting state when the potential on the lines and on the capacitors reaches a negative peak value, thereby minimizing both the potential difference and across the charge current through the switches when they begin to conduct. Any harmonic distortion on the potential and current carried by the lines is filtered out from the current and potential signals used by the reactive power compensator so that it does not affect the determination of the required reactive compensation.

Reactive Power Compensator.

DOEpatents

El-Sharkawi, M.A.; Venkata, S.S.; Chen, M.; Andexler, G.; Huang, T.

1992-07-28

A system and method for determining and providing reactive power compensation for an inductive load. A reactive power compensator (50,50') monitors the voltage and current flowing through each of three distribution lines (52a, 52b, 52c), which are supplying three-phase power to one or more inductive loads. Using signals indicative of the current on each of these lines when the voltage waveform on the line crosses zero, the reactive power compensator determines a reactive power compensator capacitance that must be connected to the lines to maintain a desired VAR level, power factor, or line voltage. Alternatively, an operator can manually select a specific capacitance for connection to each line, or the capacitance can be selected based on a time schedule. The reactive power compensator produces control signals, which are coupled through optical fibers (102/106) to a switch driver (110, 110') to select specific compensation capacitors (112) for connections to each line. The switch driver develops triggering signals that are supplied to a plurality of series-connected solid state switches (350), which control charge current in one direction in respect to ground for each compensation capacitor. During each cycle, current flows from ground to charge the capacitors as the voltage on the line begins to go negative from its positive peak value. The triggering signals are applied to gate the solid state switches into a conducting state when the potential on the lines and on the capacitors reaches a negative peak value, thereby minimizing both the potential difference and across the charge current through the switches when they begin to conduct. Any harmonic distortion on the potential and current carried by the lines is filtered out from the current and potential signals used by the reactive power compensator so that it does not affect the determination of the required reactive compensation. 26 figs.

A Systems Model for Power Technology Assessment

NASA Technical Reports Server (NTRS)

Hoffman, David J.

2002-01-01

A computer model is under continuing development at NASA Glenn Research Center that enables first-order assessments of space power technology. The model, an evolution of NASA Glenn's Array Design Assessment Model (ADAM), is an Excel workbook that consists of numerous spreadsheets containing power technology performance data and sizing algorithms. Underlying the model is a number of databases that contain default values for various power generation, energy storage and power management and distribution component parameters. These databases are actively maintained by a team of systems analysts so that they contain state-of-art data as well as the most recent technology performance projections. Sizing of the power subsystems can be accomplished either by using an assumed mass specific power (W/kg) or energy (Wh/kg) or by a bottoms-up calculation that accounts for individual component performance and masses. The power generation, energy storage and power management and distribution subsystems are sized for given mission requirements for a baseline case and up to three alternatives. This allows four different power systems to be sized and compared using consistent assumptions and sizing algorithms. The component sizing models contained in the workbook are modular so that they can be easily maintained and updated. All significant input values have default values loaded from the databases that can be over-written by the user. The default data and sizing algorithms for each of the power subsystems are described in some detail. The user interface and workbook navigational features are also discussed. Finally, an example study case that illustrates the model's capability is presented.

Estimating sensitivity and specificity for technology assessment based on observer studies.

PubMed

Nishikawa, Robert M; Pesce, Lorenzo L

2013-07-01

The goal of this study was to determine the accuracy and precision of using scores from a receiver operating characteristic rating scale to estimate sensitivity and specificity. We used data collected in a previous study that measured the improvements in radiologists' ability to classify mammographic microcalcification clusters as benign or malignant with and without the use of a computer-aided diagnosis scheme. Sensitivity and specificity were estimated from the rating data from a question that directly asked the radiologists their biopsy recommendations, which was used as the "truth," because it is the actual recall decision, thus it is their subjective truth. By thresholding the rating data, sensitivity and specificity were estimated for different threshold values. Because of interreader and intrareader variability, estimated sensitivity and specificity values for individual readers could be as much as 100% in error when using rating data compared to using the biopsy recommendation data. When pooled together, the estimates using thresholding the rating data were in good agreement with sensitivity and specificity estimated from the recommendation data. However, the statistical power of the rating data estimates was lower. By simply asking the observer his or her explicit recommendation (eg, biopsy or no biopsy), sensitivity and specificity can be measured directly, giving a more accurate description of empirical variability and the power of the study can be maximized. Copyright © 2013 AUR. Published by Elsevier Inc. All rights reserved.

Out of Control!? How Loss of Self-Control Influences Prosocial Behavior: The Role of Power and Moral Values

PubMed Central

Joosten, Anne; van Dijke, Marius; Van Hiel, Alain; De Cremer, David

2015-01-01

Lack of self-control has been suggested to facilitate norm-transgressing behaviors because of the operation of automatic selfish impulses. Previous research, however, has shown that people having a high moral identity may not show such selfish impulses when their self-control resources are depleted. In the present research, we extended this effect to prosocial behavior. Moreover, we investigated the role of power in the interaction between moral identity and self-control depletion. More specifically, we expected that power facilitates the externalization of internal states, which implies that for people who feel powerful, rather than powerless, depletion decreases prosocial behavior especially for those low in moral identity. A laboratory experiment and a multisource field study supported our predictions. The present finding that the interaction between self-control depletion and moral identity is contingent upon people’s level of power suggests that power may enable people to refrain from helping behavior. Moreover, the findings suggest that if organizations want to improve prosocial behaviors, it may be effective to situationally induce moral values in their employees. PMID:26024380

Out of control!? How loss of self-control influences prosocial behavior: the role of power and moral values.

PubMed

Joosten, Anne; van Dijke, Marius; Van Hiel, Alain; De Cremer, David

2015-01-01

Lack of self-control has been suggested to facilitate norm-transgressing behaviors because of the operation of automatic selfish impulses. Previous research, however, has shown that people having a high moral identity may not show such selfish impulses when their self-control resources are depleted. In the present research, we extended this effect to prosocial behavior. Moreover, we investigated the role of power in the interaction between moral identity and self-control depletion. More specifically, we expected that power facilitates the externalization of internal states, which implies that for people who feel powerful, rather than powerless, depletion decreases prosocial behavior especially for those low in moral identity. A laboratory experiment and a multisource field study supported our predictions. The present finding that the interaction between self-control depletion and moral identity is contingent upon people's level of power suggests that power may enable people to refrain from helping behavior. Moreover, the findings suggest that if organizations want to improve prosocial behaviors, it may be effective to situationally induce moral values in their employees.

Thermoelectric power of PrMg3

NASA Astrophysics Data System (ADS)

Isikawa, Yosikazu; Somiya, Kazuya; Koyanagi, Huruto; Mizushima, Toshio; Kuwai, Tomohiko; Tayama, Takashi

2010-01-01

PrMg3 is supposed to be one of the strongly correlated electron systems originated from the hybridization between the Pr 4f and conduction electrons, because the gigantic electronic specific heat coefficient C/T was observed at low temperatures. However, a typical behaviour of - ln T dependence was not observed in the temperature dependence of the electrical resistivity. The thermoelectric power S is a powerful tool to investigate the density of states at the Fermi energy. We measured carefully the thermoelectric power of PrMg3 in the temperature range between 2 and 300 K. S is extremely small, ranged within ±1 μV/K over the whole temperature. The value of S/T at low temperature limit was also significantly smaller than expected from the specific heat results. We therefore conclude that the density of state at the Fermi level is not enhanced in PrMg3.

Optimization of diesel engine performance by the Bees Algorithm

NASA Astrophysics Data System (ADS)

Azfanizam Ahmad, Siti; Sunthiram, Devaraj

2018-03-01

Biodiesel recently has been receiving a great attention in the world market due to the depletion of the existing fossil fuels. Biodiesel also becomes an alternative for diesel No. 2 fuel which possesses characteristics such as biodegradable and oxygenated. However, there are facts suggested that biodiesel does not have the equivalent features as diesel No. 2 fuel as it has been claimed that the usage of biodiesel giving increment in the brake specific fuel consumption (BSFC). The objective of this study is to find the maximum brake power and brake torque as well as the minimum BSFC to optimize the condition of diesel engine when using the biodiesel fuel. This optimization was conducted using the Bees Algorithm (BA) under specific biodiesel percentage in fuel mixture, engine speed and engine load. The result showed that 58.33kW of brake power, 310.33 N.m of brake torque and 200.29/(kW.h) of BSFC were the optimum value. Comparing to the ones obtained by other algorithm, the BA produced a fine brake power and a better brake torque and BSFC. This finding proved that the BA can be used to optimize the performance of diesel engine based on the optimum value of the brake power, brake torque and BSFC.

A novel method for pair-matching using three-dimensional digital models of bone: mesh-to-mesh value comparison.

PubMed

Karell, Mara A; Langstaff, Helen K; Halazonetis, Demetrios J; Minghetti, Caterina; Frelat, Mélanie; Kranioti, Elena F

2016-09-01

The commingling of human remains often hinders forensic/physical anthropologists during the identification process, as there are limited methods to accurately sort these remains. This study investigates a new method for pair-matching, a common individualization technique, which uses digital three-dimensional models of bone: mesh-to-mesh value comparison (MVC). The MVC method digitally compares the entire three-dimensional geometry of two bones at once to produce a single value to indicate their similarity. Two different versions of this method, one manual and the other automated, were created and then tested for how well they accurately pair-matched humeri. Each version was assessed using sensitivity and specificity. The manual mesh-to-mesh value comparison method was 100 % sensitive and 100 % specific. The automated mesh-to-mesh value comparison method was 95 % sensitive and 60 % specific. Our results indicate that the mesh-to-mesh value comparison method overall is a powerful new tool for accurately pair-matching commingled skeletal elements, although the automated version still needs improvement.

Study of electromagnetic radiation pollution in an Indian city.

PubMed

Dhami, A K

2012-11-01

Electromagnetic radiation emitted by cell phone towers is a form of environmental pollution and is a new health hazard, especially to children and patients. The present studies were taken to estimate the microwave/RF pollution by measuring radiation power densities near schools and hospitals of Chandigarh city in India. The cell phone radiations were measured using a handheld portable power density meter TES 593 and specific absorption rates were estimated from the measured values. These values of electromagnetic radiation in the environment were compared with the levels at which biological system of humans and animals starts getting affected. The values were also compared with the international exposure limits set by the International Commission on Non-Ionizing Radiation Protection (ICNIRP). The highest measured power density was 11.48 mW/m(2) which is 1,148% of the biological limit. The results indicated that the exposure levels in the city were below the ICNIRP limit, but much above the biological limit.

Efficiencies of power plants, quasi-static models and the geometric-mean temperature

NASA Astrophysics Data System (ADS)

Johal, Ramandeep S.

2017-02-01

Observed efficiencies of industrial power plants are often approximated by the square-root formula: 1 - √ T -/ T +, where T +( T -) is the highest (lowest) temperature achieved in the plant. This expression can be derived within finite-time thermodynamics, or, by entropy generation minimization, based on finite rates for the processes. In these analyses, a closely related quantity is the optimal value of the intermediate temperature for the hot stream, given by the geometric-mean value: √ T +/ T -. In this paper, instead of finite-time models, we propose to model the operation of plants by quasi-static work extraction models, with one reservoir (source/sink) as finite, while the other as practically infinite. No simplifying assumption is made on the nature of the finite system. This description is consistent with two model hypotheses, each yielding a specific value of the intermediate temperature, say T 1 and T 2. The lack of additional information on validity of the hypothesis that may be actually realized, motivates to approach the problem as an exercise in inductive inference. Thus we define an expected value of the intermediate temperature as the equally weighted mean: ( T 1 + T 2)/2. It is shown that the expected value is very closely given by the geometric-mean value for almost all of the observed power plants.

Fitness Testing Athletes

PubMed Central

Cumming, Gordon R.

1970-01-01

Fitness testing of athletes can be subdivided into tests of body build, strength, aerobic power, and tests specific to the athletic event. World class athletes seem to fall into specific body types for the individual events. The top athlete usually has very little of the endomorphic characteristics and should be lean. Strength testing should be used more frequently as weight and isometric training techniques are used by many athletes and coaches without specific goals. The aerobic power of many national class athletes may be only 10-30 percent above that of the general population, and high values were found only in cyclists and distance runners. It is emphasized that the scores of fitness tests are specific for each test and do not necessarily correlate at all with athletic performance which is also specific. Despite this limitation, fitness tests do have a place in athletics and should be utilized more fully and with more understanding by coaches and athletes. Imagesp48-a PMID:20468546

Real-time identification of residential appliance events based on power monitoring

NASA Astrophysics Data System (ADS)

Yang, Zhao; Zhu, Zhicheng; Wei, Zhiqiang; Yin, Bo; Wang, Xiuwei

2018-03-01

Energy monitoring for specific home appliances has been regarded as the pre-requisite for reducing residential energy consumption. To enhance the accuracy of identifying operation status of household appliances and to keep pace with the development of smart power grid, this paper puts forward the integration of electric current and power data on the basis of existing algorithm. If average power difference of several adjacent cycles varies from the baseline and goes beyond the pre-assigned threshold value, the event will be flagged. Based on MATLAB platform and domestic appliances simulations, the results of tested data and verified algorithm indicate that the power method has accomplished desired results of appliance identification.

An Exploratory Study of Thermoelectrostatic Power Generation for Space Flight Applications

NASA Technical Reports Server (NTRS)

Beam, Benjamin H.

1960-01-01

A study has been made of a process in which a solar heating cycle is combined with an electrostatic cycle for generating electrical power for space vehicle applications. The power unit, referred to as a thermoelectrostatic generator, is a thin film, solid dielectric capacitor alternately heated by solar radiation and cooled by radiant emission. The theory of operation to extract electrical power is presented. Results of an experiment to illustrate the principle are described. Estimates of the performance of this type of device in space in the vicinity of earth are included. Values of specific power of several kilowatts per kilogram of generator weight are calculated for such a device employing polyethylene terephthalate dielectric.

Functional specifications for AI software tools for electric power applications. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Faught, W.S.

1985-08-01

The principle barrier to the introduction of artificial intelligence (AI) technology to the electric power industry has not been a lack of interest or appropriate problems, for the industry abounds in both. Like most others, however, the electric power industry lacks the personnel - knowledge engineers - with the special combination of training and skills AI programming demands. Conversely, very few AI specialists are conversant with electric power industry problems and applications. The recent availability of sophisticated AI programming environments is doing much to alleviate this shortage. These products provide a set of powerful and usable software tools that enablemore » even non-AI scientists to rapidly develop AI applications. The purpose of this project was to develop functional specifications for programming tools that, when integrated with existing general-purpose knowledge engineering tools, would expedite the production of AI applications for the electric power industry. Twelve potential applications, representative of major problem domains within the nuclear power industry, were analyzed in order to identify those tools that would be of greatest value in application development. Eight tools were specified, including facilities for power plant modeling, data base inquiry, simulation and machine-machine interface.« less

Cluster-based adaptive power control protocol using Hidden Markov Model for Wireless Sensor Networks

NASA Astrophysics Data System (ADS)

Vinutha, C. B.; Nalini, N.; Nagaraja, M.

2017-06-01

This paper presents strategies for an efficient and dynamic transmission power control technique, in order to reduce packet drop and hence energy consumption of power-hungry sensor nodes operated in highly non-linear channel conditions of Wireless Sensor Networks. Besides, we also focus to prolong network lifetime and scalability by designing cluster-based network structure. Specifically we consider weight-based clustering approach wherein, minimum significant node is chosen as Cluster Head (CH) which is computed stemmed from the factors distance, remaining residual battery power and received signal strength (RSS). Further, transmission power control schemes to fit into dynamic channel conditions are meticulously implemented using Hidden Markov Model (HMM) where probability transition matrix is formulated based on the observed RSS measurements. Typically, CH estimates initial transmission power of its cluster members (CMs) from RSS using HMM and broadcast this value to its CMs for initialising their power value. Further, if CH finds that there are variations in link quality and RSS of the CMs, it again re-computes and optimises the transmission power level of the nodes using HMM to avoid packet loss due noise interference. We have demonstrated our simulation results to prove that our technique efficiently controls the power levels of sensing nodes to save significant quantity of energy for different sized network.

Determining the Optimum Power Load in Jump Squat Using the Mean Propulsive Velocity

PubMed Central

Loturco, Irineu; Nakamura, Fabio Yuzo; Tricoli, Valmor; Kobal, Ronaldo; Cal Abad, Cesar Cavinato; Kitamura, Katia; Ugrinowitsch, Carlos; Gil, Saulo; Pereira, Lucas Adriano; González-Badillo, Juan José

2015-01-01

The jump squat is one of the exercises most frequently used to improve lower body power production, which influences sports performance. However, the traditional determination of the specific workload at which power production is maximized (i.e., optimum power load) is time-consuming and requires one-repetition maximum tests. Therefore, the aim of this study was to verify whether elite athletes from different sports would produce maximum mean propulsive power values at a narrow range of mean propulsive velocities, resulting in similar jump heights. One hundred and nine elite athletes from several individual/team sport disciplines underwent repetitions at maximal velocity with progressive loads, starting at 40% of their body mass with increments of 10% to determine the individual optimum power zone. Results indicated that regardless of sport discipline, the athletes’ optimum mean propulsive power was achieved at a mean propulsive velocity close to 1.0 m.s−1 (1.01 ± 0.07 m.s−1) and at a jump height close to 20 cm (20.47 ± 1.42 cm). Data were narrowly scattered around these values. Therefore, jump squat optimum power load can be determined simply by means of mean propulsive velocity or jump height determination in training/testing settings, allowing it to be implemented quickly in strength/power training. PMID:26444293

A performance-oriented power transformer design methodology using multi-objective evolutionary optimization

PubMed Central

Adly, Amr A.; Abd-El-Hafiz, Salwa K.

2014-01-01

Transformers are regarded as crucial components in power systems. Due to market globalization, power transformer manufacturers are facing an increasingly competitive environment that mandates the adoption of design strategies yielding better performance at lower costs. In this paper, a power transformer design methodology using multi-objective evolutionary optimization is proposed. Using this methodology, which is tailored to be target performance design-oriented, quick rough estimation of transformer design specifics may be inferred. Testing of the suggested approach revealed significant qualitative and quantitative match with measured design and performance values. Details of the proposed methodology as well as sample design results are reported in the paper. PMID:26257939

A performance-oriented power transformer design methodology using multi-objective evolutionary optimization.

PubMed

Adly, Amr A; Abd-El-Hafiz, Salwa K

2015-05-01

Transformers are regarded as crucial components in power systems. Due to market globalization, power transformer manufacturers are facing an increasingly competitive environment that mandates the adoption of design strategies yielding better performance at lower costs. In this paper, a power transformer design methodology using multi-objective evolutionary optimization is proposed. Using this methodology, which is tailored to be target performance design-oriented, quick rough estimation of transformer design specifics may be inferred. Testing of the suggested approach revealed significant qualitative and quantitative match with measured design and performance values. Details of the proposed methodology as well as sample design results are reported in the paper.

Tip clearance effects on loads and performances of semi-open impeller centrifugal pumps at different specific speeds

NASA Astrophysics Data System (ADS)

Boitel, G.; Fedala, D.; Myon, N.

2016-11-01

Relevant industrial standards or customer's specifications could strictly forbid any device adjusting the axial rotor/stator position, so that tip clearance between semi-open impeller and casing might become a result of the pump machining tolerances and assembling process, leading to big tip clearance variations compared to its nominal value. Consequently, large disparities of global performances (head, power, efficiency) and axial loads are observed with high risk of both specifications noncompliance and bearing damages. This work aims at quantifying these variations by taking into account tip clearance value and pump specific speed. Computational Fluid Dynamics is used to investigate this phenomenon by means of steady simulations led on a semi-open centrifugal pump numerical model including secondary flows, based on a k-omega SST turbulence model. Four different specific speed pump sizes are simulated (from 8 to 50, SI units), with three tip clearances for each size on a wide flow range (from 40% to 120% of the best efficiency point). The numerical results clearly show that head, power and efficiency increase as the tip clearance decreases for the whole flow range. This effect is more significant when the specific speed is low. Meanwhile, the resulting axial thrust on the impeller is very sensitive to the tip clearance and can even lead to direction inversion.

Grid-connected distributed solar power systems

NASA Astrophysics Data System (ADS)

Moyle, R.; Chernoff, H.; Schweizer, T.

This paper discusses some important, though often ignored, technical and economic issues of distributed solar power systems: protection of the utility system and nonsolar customers requires suitable interfaced equipment. Purchase criteria must mirror reality; most analyses use life-cycle costing with low discount rates - most buyers use short payback periods. Distributing, installing, and marketing small, distributed solar systems is more costly than most analyses estimate. Results show that certain local conditions and uncommon purchase considerations can combine to make small, distributed solar power attractive, but lower interconnect costs (per kW), lower marketing and product distribution costs, and more favorable purchase criteria make large, centralized solar energy more attractive. Specifically, the value of dispersed solar systems to investors and utilities can be higher than $2000/kw. However, typical residential owners place a value of well under $1000 on the installed system.

PROFESSIONALISM IN THE ARMED FORCES

DTIC Science & Technology

2017-04-06

basic American values from liberalism to conservatism" to permit " American military leaders to combine the political power which society thrusts upon...and civil societies is psychological more than physical.66 Quoting Epictetus, she notes the Stoic’s assertion "In our power are moral character and...the professional status conferred by the society he secures.6 Thesis In this paper I will analyze the specific failing of Rudolph Höss to meet

Determination of appropriate DC voltage for switched mode power supply (SMPS) loads

NASA Astrophysics Data System (ADS)

Setiawan, Eko Adhi; Setiawan, Aiman; Purnomo, Andri; Djamal, Muchlishah Hadi

2017-03-01

Nowadays, most of modern and efficient household electronic devices operated based on Switched Mode Power Supply (SMPS) technology which convert AC voltage from the grid to DC voltage. Based on theory and experiment, SMPS loads could be supplied by DC voltage. However, the DC voltage rating to energize electronic home appliances is not standardized yet. This paper proposed certain method to determine appropriate DC voltage, and investigated comparison of SMPS power consumption which is supplied from AC and DC voltage. To determine the appropriate DC voltage, lux value of several lamps which have same specification energized by using AC voltage and the results is using as reference. Then, the lamps were supplied by various DC voltage to obtain the trends of the lux value to the applied DC voltage. After that, by using the trends and the reference lux value, the appropriate DC voltage can be determined. Furthermore, the power consumption on home appliances such as mobile phone, laptop and personal computer by using AC voltage and the appropriate DC voltage were conducted. The results show that the total power consumption of AC system is higher than DC system. The total power (apparent power) consumed by the lamp, mobile phone and personal computer which operated in 220 VAC were 6.93 VA, 34.31 VA and 105.85 VA respectively. On the other hand, under 277 VDC the load consumption were 5.83 W, 19.11 W and 74.46 W respectively.

Methods for Analyzing the Economic Value of Concentrating Solar Power with Thermal Energy Storage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Denholm, Paul; Jorgenson, Jennie; Miller, Mackay

2015-07-20

Concentrating solar power with thermal energy storage (CSP-TES) provides multiple quantifiable benefits compared to CSP without storage or to solar photovoltaic (PV) technology, including higher energy value, ancillary services value, and capacity value. This report describes modeling approaches to quantifying these benefits that have emerged through state-level policymaking in the United States as well as the potential applicability of these methods in China. The technical potential for CSP-TES in China is significant, but deployment has not yet achieved the targets established by the Chinese government. According to the 12th Five Year Plan for Renewable Energy (2011-2015), CSP was expected tomore » reach 1 GW by 2015 and 3 GW by 2020 in China, yet as of December 2014, deployment totaled only 13.8 MW. One barrier to more rapid deployment is the lack of an incentive specific to CSP, such as a feed-in tariff. The 13th Five Year Plan for Solar Generation (2016-2020), which is under development, presents an opportunity to establish a feed-in tariff specific to CSP. This report, produced under the auspices of the U.S.-China Renewable Energy Partnership, aims to support the development of Chinese incentives that advance CSP deployment goals.« less

Physical Fitness Percentiles of German Children Aged 9–12 Years: Findings from a Longitudinal Study

PubMed Central

Golle, Kathleen; Muehlbauer, Thomas; Wick, Ditmar; Granacher, Urs

2015-01-01

Background Generating percentile values is helpful for the identification of children with specific fitness characteristics (i.e., low or high fitness level) to set appropriate fitness goals (i.e., fitness/health promotion and/or long-term youth athlete development). Thus, the aim of this longitudinal study was to assess physical fitness development in healthy children aged 9–12 years and to compute sex- and age-specific percentile values. Methods Two-hundred and forty children (88 girls, 152 boys) participated in this study and were tested for their physical fitness. Physical fitness was assessed using the 50-m sprint test (i.e., speed), the 1-kg ball push test, the triple hop test (i.e., upper- and lower- extremity muscular power), the stand-and-reach test (i.e., flexibility), the star run test (i.e., agility), and the 9-min run test (i.e., endurance). Age- and sex-specific percentile values (i.e., P10 to P90) were generated using the Lambda, Mu, and Sigma method. Adjusted (for change in body weight, height, and baseline performance) age- and sex-differences as well as the interactions thereof were expressed by calculating effect sizes (Cohen’s d). Results Significant main effects of Age were detected for all physical fitness tests (d = 0.40–1.34), whereas significant main effects of Sex were found for upper-extremity muscular power (d = 0.55), flexibility (d = 0.81), agility (d = 0.44), and endurance (d = 0.32) only. Further, significant Sex by Age interactions were observed for upper-extremity muscular power (d = 0.36), flexibility (d = 0.61), and agility (d = 0.27) in favor of girls. Both, linear and curvilinear shaped curves were found for percentile values across the fitness tests. Accelerated (curvilinear) improvements were observed for upper-extremity muscular power (boys: 10–11 yrs; girls: 9–11 yrs), agility (boys: 9–10 yrs; girls: 9–11 yrs), and endurance (boys: 9–10 yrs; girls: 9–10 yrs). Tabulated percentiles for the 9-min run test indicated that running distances between 1,407–1,507 m, 1,479–1,597 m, 1,423–1,654 m, and 1,433–1,666 m in 9- to 12-year-old boys and 1,262–1,362 m, 1,329–1,434 m, 1,392–1,501 m, and 1,415–1,526 m in 9- to 12-year-old girls correspond to a “medium” fitness level (i.e., P40 to P60) in this population. Conclusions The observed differences in physical fitness development between boys and girls illustrate that age- and sex-specific maturational processes might have an impact on the fitness status of healthy children. Our statistical analyses revealed linear (e.g., lower-extremity muscular power) and curvilinear (e.g., agility) models of fitness improvement with age which is indicative of timed and capacity-specific fitness development pattern during childhood. Lastly, the provided age- and sex-specific percentile values can be used by coaches for talent identification and by teachers for rating/grading of children’s motor performance. PMID:26544848

Identifying the location of the OMP separatrix in DIII-D using power accounting

DOE PAGES

Stangeby, Peter C.; Canik, John M.; Elder, J. D.; ...

2015-08-07

In order to identify reliable scalings for the scrape-off layer (SOL) power width it is necessary to know the location of the separatrix in divertor tokamaks as accurately as possible, specifically its location at the outside midplane (OMP) the standard reference location. Two methods are described which use power accounting to improve the accuracy of identifying the location of the OMP separatrix. The first uses the infrared-measured deposited power profile at the outer target as the primary input, the 'more » $$P_{{\\rm SOL}}^{{\\rm exhaust}}$$ method'. The second uses the measured power input to the SOL, obtained by subtracting the power radiated from inside the separatrix from the total heating power, the ' $$P_{{\\rm SOL}}^{{\\rm input}}$$ method'. Furthermore, these two power accounting methods are illustrated with the examples of 21 H-mode DIII-D discharges. High spatial resolution Thomson scattering measured profiles of ne and Te for the main SOL near the OMP are also used as primary input to the analysis; only between-edge localized mode data are used here. The Thomson profiles are used to calculate the electron parallel conducted heat flux profiles which are then matched to the measured $$P_{{\\rm SOL}}^{{\\rm exhaust}}$$ and $$P_{{\\rm SOL}}^{{\\rm input}}$$ by adjusting the location of the OMP separatrix relative to that of the Thomson data. For these attached discharges, it is found that the values of $$R_{{\\rm sep}}^{{\\rm omp}}$$ given by the two power accounting methods agree to within ~1 mm of each other and also to within ~1 mm of the values given by the 'standard DIII-D method' described by Porter et al (1998 Phys. Plasmas 5 1410). Lastly, the shifted $$R_{{\\rm sep}}^{{\\rm omp}}$$ results in only modest changes to the values of ne and Te at the OMP separatrix relative to the 'standard' values, increasing $$n_{{\\rm e}}^{{\\rm sep}}$$ by 8% and $$T_{{\\rm e}}^{{\\rm sep}}$$ by 20%.« less

Relation of Fuel-Air Ratio to Engine Performance

NASA Technical Reports Server (NTRS)

Sparrow, Stanwood W

1925-01-01

The tests upon which this report is based were made at the Bureau of Standards between October 1919 and May 1923. From these it is concluded that: (1) with gasoline as a fuel, maximum power is obtained with fuel-air mixtures of from 0.07 to 0.08 pound of fuel per pound of air; (2) maximum power is obtained with approximately the same ratio over the range of air pressures and temperatures encountered in flight; (3) nearly minimum specific fuel consumption is secured by decreasing the fuel content of the charge until the power is 95 per cent of its maximum value. Presumably this information is of most direct value to the carburetor engineer. A carburetor should supply the engine with a suitable mixture. This report discusses what mixtures have been found suitable for various engines. It also furnishes the engine designer with a basis for estimating how much greater piston displacement an engine operating with a maximum economy mixture should have than one operating with a maximum power mixture in order for both to be capable of the same power development.

Low-Radiation Cellular Inductive Powering of Rodent Wireless Brain Interfaces: Methodology and Design Guide.

PubMed

Soltani, Nima; Aliroteh, Miaad S; Salam, M Tariqus; Perez Velazquez, Jose Luis; Genov, Roman

2016-08-01

This paper presents a general methodology of inductive power delivery in wireless chronic rodent electrophysiology applications. The focus is on such systems design considerations under the following key constraints: maximum power delivery under the allowable specific absorption rate (SAR), low cost and spatial scalability. The methodology includes inductive coil design considerations within a low-frequency ferrite-core-free power transfer link which includes a scalable coil-array power transmitter floor and a single-coil implanted or worn power receiver. A specific design example is presented that includes the concept of low-SAR cellular single-transmitter-coil powering through dynamic tracking of a magnet-less receiver spatial location. The transmitter coil instantaneous supply current is monitored using a small number of low-cost electronic components. A drop in its value indicates the proximity of the receiver due to the reflected impedance of the latter. Only the transmitter coil nearest to the receiver is activated. Operating at the low frequency of 1.5 MHz, the inductive powering floor delivers a maximum of 15.9 W below the IEEE C95 SAR limit, which is over three times greater than that in other recently reported designs. The power transfer efficiency of 39% and 13% at the nominal and maximum distances of 8 cm and 11 cm, respectively, is maintained.

A New Weighted Injury Severity Scoring System: Better Predictive Power for Pediatric Trauma Mortality.

PubMed

Shi, Junxin; Shen, Jiabin; Caupp, Sarah; Wang, Angela; Nuss, Kathryn E; Kenney, Brian; Wheeler, Krista K; Lu, Bo; Xiang, Henry

2018-05-02

An accurate injury severity measurement is essential for the evaluation of pediatric trauma care and outcome research. The traditional Injury Severity Score (ISS) does not consider the differential risks of the Abbreviated Injury Scale (AIS) from different body regions nor is it pediatric specific. The objective of this study was to develop a weighted injury severity scoring (wISS) system for pediatric blunt trauma patients with better predictive power than ISS. Based on the association between mortality and AIS from each of the six ISS body regions, we generated different weights for the component AIS scores used in the calculation of ISS. The weights and wISS were generated using the National Trauma Data Bank (NTDB). The Nationwide Emergency Department Sample (NEDS) was used to validate our main results. Pediatric blunt trauma patients less than 16 years were included, and mortality was the outcome. Discrimination (areas under the receiver operating characteristic curve, sensitivity, specificity, positive predictive value, negative predictive value, concordance) and calibration (Hosmer-Lemeshow statistic) were compared between the wISS and ISS. The areas under the receiver operating characteristic curves from the wISS and ISS are 0.88 vs. 0.86 in ISS=1-74 and 0.77 vs. 0.64 in ISS=25-74 (p<0.0001). The wISS showed higher specificity, positive predictive value, negative predictive value, and concordance when they were compared at similar levels of sensitivity. The wISS had better calibration (smaller Hosmer-Lemeshow statistic) than the ISS (11.6 versus 19.7 for ISS=1-74 and 10.9 versus 12.6 for ISS= 25-74). The wISS showed even better discrimination with the NEDS. By weighting the AIS from different body regions, the wISS had significantly better predictive power for mortality than the ISS, especially in critically injured children.Level of Evidence and study typeLevel IV Prognostic/Epidemiological.

Microwave Driven Magnetic Plasma Accelerator Studies (CYCLOPS)

NASA Technical Reports Server (NTRS)

Crimi, G. F.; Eckert, A. C.; Miller, D. B.

1967-01-01

A microwave-driven cyclotron resonance plasma acceleration device was investigated using argon, krypton, xenon, and mercury as propellants. Limited ranges of propellant flow rate, input power, and magnetic field strength were used. Over-all efficiencies (including the 65% efficiency of the input polarizer) less than 10% were obtained for specific impulse values between 500 and 1500 sec. Power transfer efficiencies, however, approached 100% of the input power available in the right-hand component of the incident circularly polarized radiation. Beam diagnostics using Langmuir probes, cold gas mapping, r-f mapping and ion energy analyses were performed in conjunction with an engine operating in a pulsed mode. Measurements of transverse electron energies at the position of cyclotron resonant absorption yielded energy values more than an order of magnitude lower than anticipated. The measured electron energies were, however, consistent with the low values of average ion energy measured by retarding potential techniques. The low values of average ion energy were also consistent with the measured thrust values. It is hypothesized that ionization and radiation limit the electron kinetic energy to low-values thus limiting the energy which is finally transferred to the ion. Thermalization by electron-electron collision was also identified as an additional loss mechanism. The use of light alkali metals, which have relatively few low lying energy levels to excite, with the input power to mass ratio selected so as to limit the electron energies to less than the second ionization potential, is suggested. It is concluded, however, that the over-all efficiency for such propellants would be less than 40 per cent.

Gas phase recombination of hydrogen and deuterium atoms. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Trainor, D. W.; Ham, D. O.; Kaufman, F.

1973-01-01

Rate constants for the reaction H + H + M - H2 + M, with M = H2, He, and Ar were measured over the temperature range 77 to 298 K. Hydrogen atoms were produced by thermal dissociation and absolute atom concentrations were measured through use of self-balancing, isothermal catalytic probe detector. The specific rate constants were 8.1 + or - 0.4 x 10 to the minus 33rd power, 7.0 + or - 0.4 x 10 to the minus 33rd power, and 9.2 + or - 0.6 x at 298 K for M = H2, He, and Ar respectively; these values rising to 18.5 + or - 2.2 x 10 to the minus 33rd power, 12.0 + or - 1.5 x 10 to the minus 33rd power, and 27.4 + or - 4.6 x 10 to the minus 33rd power cm to the 6th power/molecules sq/sec at 77 K. for the equivalent deuterium atom process with D2 as the third body, the rate constants are 6.1 + or - 0.3 x 10 to the minus 33rd power cm to the 6th power/molecules sq/sec at 298 K and 15.1 + or - 1.0 x 10 to the minus 33rd power cm to the 6th power/molecules sq/sec at 77 K. These values are compared with previous experimental measurements and with recent theoretical calculations.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chinthavali, Madhu Sudhan; Wang, Zhiqiang

This paper presents a detailed parametric sensitivity analysis for a wireless power transfer (WPT) system in electric vehicle application. Specifically, several key parameters for sensitivity analysis of a series-parallel (SP) WPT system are derived first based on analytical modeling approach, which includes the equivalent input impedance, active / reactive power, and DC voltage gain. Based on the derivation, the impact of primary side compensation capacitance, coupling coefficient, transformer leakage inductance, and different load conditions on the DC voltage gain curve and power curve are studied and analyzed. It is shown that the desired power can be achieved by just changingmore » frequency or voltage depending on the design value of coupling coefficient. However, in some cases both have to be modified in order to achieve the required power transfer.« less

Nasal potential difference outcomes support diagnostic decisions in cystic fibrosis.

PubMed

Tridello, Gloria; Menin, Laura; Pintani, Emily; Bergamini, Gabriella; Assael, Baroukh Maurice; Melotti, Paola

2016-09-01

When cystic fibrosis (CF) is suspected Nasal Potential Difference (NPD) measurements are proposed to support controversial diagnosis: we investigated appropriate outcomes at the CF Centre of Verona. NPD were measured in 196 subjects: 50 non-CF, 65 classical CF (the reference group) and 81 with uncertain CF (case group). Discriminating power was determined by comparison between several outcomes from the CF reference group versus non-CF: basal, amiloride, 0Cl, isoproterenol, ATP, Delta-amiloride, Delta-0Cl, Delta-isoproterenol, Delta-ATP, Delta-isoproterenol+Delta-0Cl, Wilschanski Index (WI) and Sermet score (SS). The most appropriate cut-off values for variables with the best discriminating power were then applied to the case group. Descriptive statistics, logistic regression models and ROC curve analysis were applied. WI and SS were the most powerful in discriminating CF from non-CF subjects. In the reference group sensitivity of the 0.82 WI cut-off was 98%, specificity 96%; both sensitivity and specificity of the -0.44 SS cut-off value were 100%. For the case group, WI and SS were, respectively, consistent with CF diagnosis in 94% and 92% of the cases. Formulae have the highest discriminating power and can support the diagnosis in uncertain cases; they should be utilized for standardized interpretation of NPD for diagnosis and possibly for clinical research. Copyright © 2016. Published by Elsevier B.V.

Measurement of Glycosylated Alpha-Fetoprotein Improves Diagnostic Power over the Native Form in Hepatocellular Carcinoma

PubMed Central

Jin, Jonghwa; Park, Jiyoung; Yu, Su Jong; Yoon, Jung-Hwan; Kim, Youngsoo

2014-01-01

Serum alpha-fetoprotein (AFP) has long been used as a diagnostic marker for hepatocellular carcinoma (HCC), albeit controversially. Although it remains widely used in clinics, the value of AFP in HCC diagnosis has recently been challenged due to its significant rates of false positive and false negative findings. To improve the efficacy of AFP as HCC diagnostic marker, we developed a method of measuring total and glycosylated AFP by multiple reaction monitoring (MRM)-MS. In this study, we verified the total amount of AFP (nonglycopeptide levels) and the degree of glycosylated AFP (deglycopeptide levels) in 60 normal (41 men and 19 women; mean age 53 years; range 32–74 years), 35 LC (23 men and 12 women; mean age 56 years; range 43–78 years; HBV-related), and 60 HCC subjects (42 men and 18 women; mean age 58 years; range 38–76 years; HBV-related; 30 stage I, 15 stage II, and 10 stage III). By MRM-MS analysis, the nonglycopeptide had 56.7% sensitivity, 68.3% specificity, and an AUC of 0.687 [cutoff value: ≥0.02 (light/heavy ratio)], comparing the normal and HCC group, whereas the deglycopeptide had 93.3% sensitivity, 68.3% specificity, and an AUC of 0.859 [cutoff value: ≥0.02 (light/heavy ratio)]. In comparing the stage I HCC subgroup with the LC group, the nonglycopeptide had a sensitivity of 66.7%, specificity of 80.0%, and an AUC of 0.712 [cutoff value: ≥0.02 (light/heavy ratio)], whereas the deglycopeptide had a sensitivity of 96.7%, specificity of 80.0%, and an AUC of 0.918 [cutoff value: ≥0.02 (light/heavy ratio)]. These data demonstrate that the discriminatory power of the deglycopeptide is greater than that of the nonglycopeptide. We conclude that deglycopeptide can distinguish cancer status between normal subjects and HCC patients better than nonglycopeptide. PMID:25310463

High Voltage TAL Performance

NASA Technical Reports Server (NTRS)

Jacobson, David T.; Jankovsky, Robert S.; Rawlin, Vincent K.; Manzella, David H.

2001-01-01

The performance of a two-stage, anode layer Hall thruster was evaluated. Experiments were conducted in single and two-stage configurations. In single-stage configuration, the thruster was operated with discharge voltages ranging from 300 to 1700 V. Discharge specific impulses ranged from 1630 to 4140 sec. Thruster investigations were conducted with input power ranging from 1 to 8.7 kW, corresponding to power throttling of nearly 9: 1. An extensive two-stage performance map was generated. Data taken with total voltage (sum of discharge and accelerating voltage) constant revealed a decrease in thruster efficiency as the discharge voltage was increased. Anode specific impulse values were comparable in the single and two-stage configurations showing no strong advantage for two-stage operation.

System Statement of Tasks of Calculating and Providing the Reliability of Heating Cogeneration Plants in Power Systems

NASA Astrophysics Data System (ADS)

Biryuk, V. V.; Tsapkova, A. B.; Larin, E. A.; Livshiz, M. Y.; Sheludko, L. P.

2018-01-01

A set of mathematical models for calculating the reliability indexes of structurally complex multifunctional combined installations in heat and power supply systems was developed. Reliability of energy supply is considered as required condition for the creation and operation of heat and power supply systems. The optimal value of the power supply system coefficient F is based on an economic assessment of the consumers’ loss caused by the under-supply of electric power and additional system expences for the creation and operation of an emergency capacity reserve. Rationing of RI of the industrial heat supply is based on the use of concept of technological margin of safety of technological processes. The definition of rationed RI values of heat supply of communal consumers is based on the air temperature level iside the heated premises. The complex allows solving a number of practical tasks for providing reliability of heat supply for consumers. A probabilistic model is developed for calculating the reliability indexes of combined multipurpose heat and power plants in heat-and-power supply systems. The complex of models and calculation programs can be used to solve a wide range of specific tasks of optimization of schemes and parameters of combined heat and power plants and systems, as well as determining the efficiency of various redundance methods to ensure specified reliability of power supply.

Value Streams in Microgrids: A literature Review

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stadler, Michael; Center for Energy and Innovative Technologies; Cardoso, Gonçalo

2015-10-01

Microgrids are an increasingly common component of the evolving electricity grids with the potential to improve local reliability, reduce costs, and increase penetration rates for distributed renewable generation. The additional complexity of microgrids often leads to increased investment costs, creating a barrier for widespread adoption. These costs may result directly from specific needs for islanding detection, protection systems and power quality assurance that would otherwise be avoided in simpler system configurations. However, microgrids also facilitate additional value streams that may make up for their increased costs and improve the economic viability of microgrid deployment. This paper analyses the literature currentlymore » available on research relevant to value streams occurring in microgrids that may contribute to offset the increased investment costs. A review on research related to specific microgrid requirements is also presented.« less

The Political Economy of Education.

ERIC Educational Resources Information Center

Carnoy, Martin

1985-01-01

The political economy of education treats education as a factor shaped by the power relations between different economic, political, and social groups. Specific topics discussed include the economic value of education, education as an allocator of economic roles, education and social class, education and income distribution, and education and…

Do spectral bands of fetal heart rate variability associate with concomitant fetal scalp pH?

PubMed

Siira, Saila M; Ojala, Tiina H; Vahlberg, Tero J; Rosén, Karl G; Ekholm, Eeva M

2013-09-01

Objective information on specific fetal heart rate (FHR) parameters would be advantageous when assessing fetal responses to hypoxia. Small, visually undetectable changes in FHR variability can be quantified by power spectral analysis of FHR variability. To investigate the effect of intrapartum hypoxia and acidemia on spectral powers of FHR variability. This is a retrospective observational clinical study with data from an EU multicenter project. We had 462 fetuses with a normal pH-value (pH>7.20; controls) in fetal scalp blood sample (FBS) and 81 fetuses with a low scalp pH-value (≤ 7.20; low-FBS pH-fetuses). The low-FBS pH-fetuses were further divided into two subgroups according to the degree of acidemia: fetuses with FBS pH7.11-7.20 (n = 58) and fetuses with FBS pH ≤7.10 (n = 23). Spectral powers of FHR variability in relation to the concomitant FBS pH-value. Fetuses with FBS pH ≤7.20 had increased spectral powers of FHR variability compared with controls (2.49 AU vs. 2.23 AU; p = 0.038). However, the subgroup of most affected fetuses (those with FBS pH ≤7.10) had significantly lower FHR variability spectral powers when compared to fetuses with FBS pH7.11-7.20. This study shows that spectral powers of FHR variability change as a fetus becomes hypoxic, and that spectral powers decrease with deepening fetal acidemia. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Grunwald-Winstein Analysis - Isopropyl Chloroformate Solvolysis Revisited

PubMed Central

D’Souza, Malcolm J.; Reed, Darneisha N.; Erdman, Kevin J.; Kyong, Jin Burm; Kevill, Dennis N.

2009-01-01

Specific rates of solvolysis at 25 °C for isopropyl chloroformate (1) in 24 solvents of widely varying nucleophilicity and ionizing power, plus literature values for studies in water and formic acid, are reported. Previously published solvolytic rate constants at 40.0 °C are supplemented with two additional values in the highly ionizing fluoroalcohols. These rates are now are analyzed using the one and two-term Grunwald-Winstein Equations. In the more ionizing solvents including ten fluoroalcohols negligible sensitivities towards changes in solvent nucleophilicity (l) and very low sensitivities towards changes in solvent ionizing power (m) values are obtained, evocative to those previously observed for 1-adamantyl and 2-adamantyl chloroformates 2 and 3. These observations are rationalized in terms of a dominant solvolysis-decomposition with loss of the CO2 molecule. In nine of the more nucleophilic pure alchohols and aqueous solutions an association-dissociation mechanism is believed to be operative. Deficiencies in the acid production indicate 2-33% isopropyl chloride formation, with the higher values in less nucleophilic solvents. PMID:19399225

ANTHROPOMETRIC CHARACTERISTICS AND FUNCTIONAL CAPACITY OF ELITE ROWERS AND HANDBALL PLAYERS.

PubMed

Karaba Jakovljevic, Dea; Jovanovic, Gordana; Eric, Mirela; Klasnja, Aleksandar; Slavic, Danijel; Lukac, Damir

2016-09-01

Anthropometric and anaerobic profile of elite athletes are fundamental for the assessment of their respective performance. The present study was designed to evaluate the anthro- pornetric parameters, body composition and anaerobic characteristics of elite male handball players and rowers, and to compare them in relation to specific sport demands. The study group consisted of 41 elite national level athletes: 20 handball players (aged 23.7±3.72) and 21 rowers (aged 19.7±2.84). Anthropometric characteristics (body mass, body height, skinfold thickness, body circumferences), and body fat mass were evaluated, and Wingate anaerobic test for anaerobic power assessment Iwas applied. The significant differences were noted in chest-upper arm, waist and hip circumferences, and supraspinal and calf skinfolds between the two investigated groups. Rowers showed higher values of fat body mass (13.2±3.76 vs. 10.7±3.76%), but lower body mass index (22.0±1,92 vs. 25.7?2.31 kg/in12) compared to handball players. When analyzing the Wingate test parameters, significantly higher values of absolute anaerobic power (786±127 vs. 691±140 W), absolute explosive power in the handball players compared to the rowers were recorded ( 18±26.3 vs. 105±27.8 W/s), whi le rowers achieved higher relative anaerobic capacity (192±3 1.2 vs. 177±E20.8 J/ kg). Specific body composition and anthropometri- cal assessment as a part of morphological analysis should complement physiological profile of elite athletes. The analysis of the anaerobic performance shows that the handball players have greater alactic anaerobic and explosive power component, compared to the rowers in whom the anaerobic endurance and specific training have the greatest effect on the consumption of dominant metabolic substrate during the race.

Similarity principles for the biology of pelagic animals

PubMed Central

Barenblatt, G. I.; Monin, A. S.

1983-01-01

A similarity principle is formulated according to which the statistical pattern of the pelagic population is identical in all scales sufficiently large in comparison with the molecular one. From this principle, a power law is obtained analytically for the pelagic animal biomass distribution over the animal sizes. A hypothesis is presented according to which, under fixed external conditions, the oxygen exchange intensity of an animal is governed only by its mass and density and by the specific absorbing capacity of the animal's respiratory organ. From this hypothesis a power law is obtained by the method of dimensional analysis for the exchange intensity mass dependence. The known empirical values of the exponent of this power law are interpreted as an indication that the oxygen-absorbing organs of the animals can be represented as so-called fractal surfaces. In conclusion the biological principle of the decrease in specific exchange intensity with increase in animal mass is discussed. PMID:16593327

Directional power absorption in helicon plasma sources excited by a half-helix antenna

NASA Astrophysics Data System (ADS)

Afsharmanesh, Mohsen; Habibi, Morteza

2017-10-01

This paper deals with the investigation of the power absorption in helicon plasma excited through a half-helix antenna driven at 13.56 {{MHz}}. The simulations were carried out by means of a code, HELIC. They were carried out by taking into account different inhomogeneous radial density profiles and for a wide range of plasma densities, from {10}11 {{{cm}}}-3 to {10}13 {{{cm}}}-3. The magnetic field was 200, 400, 600 and 1000 {{G}}. A three-parameter function was used for generating various density profiles with different volume gradients, edge gradients and density widths. The density profile had a large effect on the efficient Trivelpiece-Gould (TG) and helicon mode excitation and antenna coupling to the plasma. The fraction of power deposition via the TG mode was extremely dependent on the plasma density near the plasma boundary. Interestingly, the obtained efficient parallel helicon wavelength was close to the anticipated value for Gaussian radial density profile. Power deposition was considerably asymmetric when the \\tfrac{n}{{B}0} ratio was more than a specific value for a determined density width. The longitudinal power absorption was symmetric at approximately {n}0={10}11 {{{cm}}}-3, irrespective of the magnetic field supposed. The asymmetry became more pronounced when the plasma density was {10}12 {{{cm}}}-3. The ratio of density width to the magnetic field was an important parameter in the power coupling. At high magnetic fields, the maximum of the power absorption was reached at higher plasma density widths. There was at least one combination of the plasma density, magnetic field and density width for which the RF power deposition at both side of the tube reached its maximum value.

Can Evolutionary Principles Explain Patterns of Family Violence?

ERIC Educational Resources Information Center

Archer, John

2013-01-01

The article's aim is to evaluate the application of the evolutionary principles of kin selection, reproductive value, and resource holding power to the understanding of family violence. The principles are described in relation to specific predictions and the mechanisms underlying these. Predictions are evaluated for physical violence perpetrated…

Videogames and Education

ERIC Educational Resources Information Center

Brown, Harry J.

2008-01-01

Videogames challenge our notions of identity, creativity, and moral value, and provide a powerful new avenue for teaching and learning. This book is a rich and provocative guide to the role of interactive media in cultural learning. It searches for specific ways to interpret videogames in the context of human experience and in the field of…

Effects of Temporal Wind Patterns on the Value of Wind-GeneratedElectricity at Different Sites in California and the Northwest

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fripp, Matthias; Wiser, Ryan

2006-08-04

Wind power production varies on a diurnal and seasonal basis. In this paper, we use wind speed data from three different sources to assess the effects of wind timing on the value of electric power from potential wind farm locations in California and the Northwestern United States. By ''value'', we refer to either the contribution of wind power to meeting the electric system's peak loads, or the financial value of wind power in electricity markets. Sites for wind power projects are often screened or compared based on the annual average power production that would be expected from wind turbines atmore » each site (Baban and Parry 2001; Brower et al. 2004; Jangamshetti and Rau 2001; Nielsen et al. 2002; Roy 2002; Schwartz 1999). However, at many locations, variations in wind speeds during the day and year are correlated with variations in the electric power system's load and wholesale market prices (Burton et al. 2001; Carlin 1983; Kennedy and Rogers 2003; Man Bae and Devine 1978; Sezgen et al. 1998); this correlation may raise or lower the value of wind power generated at each location. A number of previous reports address this issue somewhat indirectly by studying the contribution of individual wind power sites to the reliability or economic operation of the electric grid, using hourly wind speed data (Fleten et al.; Kahn 1991; Kirby et al. 2003; Milligan 2002; van Wijk et al. 1992). However, we have not identified any previous study that examines the effect of variations in wind timing across a broad geographical area on wholesale market value or capacity contribution of those different wind power sites. We have done so, to determine whether it is important to consider wind-timing when planning wind power development, and to try to identify locations where timing would have a more positive or negative effect. The research reported in this paper seeks to answer three specific questions: (1) How large of an effect can the temporal variation of wind power have on the value of wind in different wind resource areas? (2) Which locations are affected most positively or negatively by the seasonal and diurnal timing of wind speeds? (3) How compatible are wind resources in California and the Northwest (Washington, Oregon, Idaho, Montana and Wyoming) with wholesale power prices and loads in either region? The latter question is motivated by the fact that wind power projects in the Northwest could sell their output into California (and vice versa), and that California has an aggressive renewable energy policy that may ultimately yield such imports. We also assess whether modeled wind data from TrueWind Solutions, LLC, can help answer such questions, by comparing results found using the TrueWind data to those found using anemometers or wind farm power production data. This paper summarizes results that are presented in more detail in a recent report from Lawrence Berkeley National Laboratory (Fripp and Wiser 2006). The full report is available at http://eetd.lbl.gov/EA/EMP/re-pubs.html.« less

Battery Cell By-Pass Circuit

NASA Technical Reports Server (NTRS)

Mumaw, Susan J. (Inventor); Evers, Jeffrey (Inventor); Craig, Calvin L., Jr. (Inventor); Walker, Stuart D. (Inventor)

2001-01-01

The invention is a circuit and method of limiting the charging current voltage from a power supply net work applied to an individual cell of a plurality of cells making up a battery being charged in series. It is particularly designed for use with batteries that can be damaged by overcharging, such as Lithium-ion type batteries. In detail. the method includes the following steps: 1) sensing the actual voltage level of the individual cell; 2) comparing the actual voltage level of the individual cell with a reference value and providing an error signal representative thereof; and 3) by-passing the charging current around individual cell necessary to keep the individual cell voltage level generally equal a specific voltage level while continuing to charge the remaining cells. Preferably this is accomplished by by-passing the charging current around the individual cell if said actual voltage level is above the specific voltage level and allowing the charging current to the individual cell if the actual voltage level is equal or less than the specific voltage level. In the step of bypassing the charging current, the by-passed current is transferred at a proper voltage level to the power supply. The by-pass circuit a voltage comparison circuit is used to compare the actual voltage level of the individual cell with a reference value and to provide an error signal representative thereof. A third circuit, designed to be responsive to the error signal, is provided for maintaining the individual cell voltage level generally equal to the specific voltage level. Circuitry is provided in the third circuit for bypassing charging current around the individual cell if the actual voltage level is above the specific voltage level and transfers the excess charging current to the power supply net work. The circuitry also allows charging of the individual cell if the actual voltage level is equal or less than the specific voltage level.

Enhancing Specific Energy and Power in Asymmetric Supercapacitors - A Synergetic Strategy based on the Use of Redox Additive Electrolytes

PubMed Central

Singh, Arvinder; Chandra, Amreesh

2016-01-01

The strategy of using redox additive electrolyte in combination with multiwall carbon nanotubes/metal oxide composites leads to a substantial improvements in the specific energy and power of asymmetric supercapacitors (ASCs). When the pure electrolyte is optimally modified with a redox additive viz., KI, ~105% increase in the specific energy is obtained with good cyclic stability over 3,000 charge-discharge cycles and ~14.7% capacitance fade. This increase is a direct consequence of the iodine/iodide redox pairs that strongly modifies the faradaic and non-faradaic type reactions occurring on the surface of the electrodes. Contrary to what is shown in few earlier reports, it is established that indiscriminate increase in the concentration of redox additives will leads to performance loss. Suitable explanations are given based on theoretical laws. The specific energy or power values being reported in the fabricated ASCs are comparable or higher than those reported in ASCs based on toxic acetonitrile or expensive ionic liquids. The paper shows that the use of redox additive is economically favorable strategy for obtaining cost effective and environmentally friendly ASCs. PMID:27184260

Intracranial mapping of auditory perception: event-related responses and electrocortical stimulation.

PubMed

Sinai, A; Crone, N E; Wied, H M; Franaszczuk, P J; Miglioretti, D; Boatman-Reich, D

2009-01-01

We compared intracranial recordings of auditory event-related responses with electrocortical stimulation mapping (ESM) to determine their functional relationship. Intracranial recordings and ESM were performed, using speech and tones, in adult epilepsy patients with subdural electrodes implanted over lateral left cortex. Evoked N1 responses and induced spectral power changes were obtained by trial averaging and time-frequency analysis. ESM impaired perception and comprehension of speech, not tones, at electrode sites in the posterior temporal lobe. There was high spatial concordance between ESM sites critical for speech perception and the largest spectral power (100% concordance) and N1 (83%) responses to speech. N1 responses showed good sensitivity (0.75) and specificity (0.82), but poor positive predictive value (0.32). Conversely, increased high-frequency power (>60Hz) showed high specificity (0.98), but poorer sensitivity (0.67) and positive predictive value (0.67). Stimulus-related differences were observed in the spatial-temporal patterns of event-related responses. Intracranial auditory event-related responses to speech were associated with cortical sites critical for auditory perception and comprehension of speech. These results suggest that the distribution and magnitude of intracranial auditory event-related responses to speech reflect the functional significance of the underlying cortical regions and may be useful for pre-surgical functional mapping.

Intracranial mapping of auditory perception: Event-related responses and electrocortical stimulation

PubMed Central

Sinai, A.; Crone, N.E.; Wied, H.M.; Franaszczuk, P.J.; Miglioretti, D.; Boatman-Reich, D.

2010-01-01

Objective We compared intracranial recordings of auditory event-related responses with electrocortical stimulation mapping (ESM) to determine their functional relationship. Methods Intracranial recordings and ESM were performed, using speech and tones, in adult epilepsy patients with subdural electrodes implanted over lateral left cortex. Evoked N1 responses and induced spectral power changes were obtained by trial averaging and time-frequency analysis. Results ESM impaired perception and comprehension of speech, not tones, at electrode sites in the posterior temporal lobe. There was high spatial concordance between ESM sites critical for speech perception and the largest spectral power (100% concordance) and N1 (83%) responses to speech. N1 responses showed good sensitivity (0.75) and specificity (0.82), but poor positive predictive value (0.32). Conversely, increased high-frequency power (>60 Hz) showed high specificity (0.98), but poorer sensitivity (0.67) and positive predictive value (0.67). Stimulus-related differences were observed in the spatial-temporal patterns of event-related responses. Conclusions Intracranial auditory event-related responses to speech were associated with cortical sites critical for auditory perception and comprehension of speech. Significance These results suggest that the distribution and magnitude of intracranial auditory event-related responses to speech reflect the functional significance of the underlying cortical regions and may be useful for pre-surgical functional mapping. PMID:19070540

Spin properties of supermassive black holes with powerful outflows

NASA Astrophysics Data System (ADS)

Daly, Ruth. A.

2016-05-01

Relationships between beam power and accretion disc luminosity are studied for a sample of 55 high excitation radio galaxies (HERG), 13 low excitation radio galaxies (LERG), and 29 radio loud quasars (RLQ) with powerful outflows. The ratio of beam power to disc luminosity tends to be high for LERG, low for RLQ, and spans the full range of values for HERG. Writing general expressions for the disc luminosity and beam power and applying the empirically determined relationships allows a function that parametrizes the spins of the holes to be estimated. Interestingly, one of the solutions that is consistent with the data has a functional form that is remarkably similar to that expected in the generalized Blandford-Znajek model with a magnetic field that is similar in form to that expected in magnetically arrested disk (MAD) and advection-dominated accretion flow (ADAF) models. Values of the spin function, obtained independent of specific outflow models, suggest that spin and active galactic nucleus type are not related for these types of sources. The spin function can be used to solve for black hole spin in the context of particular outflow models, and one example is provided.

BWR station blackout: A RISMC analysis using RAVEN and RELAP5-3D

DOE PAGES

Mandelli, D.; Smith, C.; Riley, T.; ...

2016-01-01

The existing fleet of nuclear power plants is in the process of extending its lifetime and increasing the power generated from these plants via power uprates and improved operations. In order to evaluate the impact of these factors on the safety of the plant, the Risk-Informed Safety Margin Characterization (RISMC) project aims to provide insights to decision makers through a series of simulations of the plant dynamics for different initial conditions and accident scenarios. This paper presents a case study in order to show the capabilities of the RISMC methodology to assess impact of power uprate of a Boiling Watermore » Reactor system during a Station Black-Out accident scenario. We employ a system simulator code, RELAP5-3D, coupled with RAVEN which perform the stochastic analysis. Furthermore, our analysis is performed by: 1) sampling values from a set of parameters from the uncertainty space of interest, 2) simulating the system behavior for that specific set of parameter values and 3) analyzing the outcomes from the set of simulation runs.« less

Corneal Anterior Power Calculation for an IOL in Post-PRK Patients.

PubMed

De Bernardo, Maddalena; Iaccarino, Stefania; Cennamo, Michela; Caliendo, Luisa; Rosa, Nicola

2015-02-01

After corneal refractive surgery, there is an overestimation of the corneal power with the devices routinely used to measure it. Therefore, the objective of this study was to determine whether, in patients who underwent photorefractive keratectomy (PRK), it is possible to predict the earlier preoperative anterior corneal power from the postoperative (PO) posterior corneal power. A comparison is made using a formula published by Saiki for laser in situ keratomileusis patients and a new one calculated specifically from PRK patients. The Saiki formula was tested in 98 eyes of 98 patients (47 women) who underwent PRK for myopia or myopic astigmatism. Moreover, anterior and posterior mean keratometry (Km) values from a Scheimpflug camera were measured to obtain a specific regression formula. The mean (±SD) preoperative Km was 43.50 (±1.39) diopters (D) (range, 39.25 to 47.05 D). The mean (±SD) Km value calculated with the Saiki formula using the 6 months PO posterior Km was 42.94 (±1.19) D (range, 40.34 to 45.98 D) with a statistically significant difference (p < 0.001). Six months after PRK in our patients, the posterior Km was correlated with the anterior preoperative one by the following regression formula: y = -4.9707x + 12.457 (R² = 0.7656), where x is PO posterior Km and y is preoperative anterior Km, similar to the one calculated by Saiki. Care should be taken in using the Saiki formula to calculate the preoperative Km in patients who underwent PRK.

Using fleets of electric-drive vehicles for grid support

NASA Astrophysics Data System (ADS)

Tomić, Jasna; Kempton, Willett

Electric-drive vehicles can provide power to the electric grid when they are parked (vehicle-to-grid power). We evaluated the economic potential of two utility-owned fleets of battery-electric vehicles to provide power for a specific electricity market, regulation, in four US regional regulation services markets. The two battery-electric fleet cases are: (a) 100 Th!nk City vehicle and (b) 252 Toyota RAV4. Important variables are: (a) the market value of regulation services, (b) the power capacity (kW) of the electrical connections and wiring, and (c) the energy capacity (kWh) of the vehicle's battery. With a few exceptions when the annual market value of regulation was low, we find that vehicle-to-grid power for regulation services is profitable across all four markets analyzed. Assuming now more than current Level 2 charging infrastructure (6.6 kW) the annual net profit for the Th!nk City fleet is from US 7000 to 70,000 providing regulation down only. For the RAV4 fleet the annual net profit ranges from US 24,000 to 260,000 providing regulation down and up. Vehicle-to-grid power could provide a significant revenue stream that would improve the economics of grid-connected electric-drive vehicles and further encourage their adoption. It would also improve the stability of the electrical grid.

Positional Role Differences in the Aerobic and Anaerobic Power of Elite Basketball Players.

PubMed

Pojskić, Haris; Šeparović, Vlatko; Užičanin, Edin; Muratović, Melika; Mačković, Samir

2015-12-22

The aim of the present study was to compare the aerobic and anaerobic power and capacity of elite male basketball players who played multiple positions. Fifty-five healthy players were divided into the following three different subsamples according to their positional role: guards (n = 22), forwards (n = 19) and centers (n = 14). The following three tests were applied to estimate their aerobic and anaerobic power and capacities: the countermovement jump (CMJ), a multistage shuttle run test and the Running-based Anaerobic Sprint Test (RAST). The obtained data were used to calculate the players' aerobic and anaerobic power and capacities. To determine the possible differences between the subjects considering their different positions on the court, one-way analysis of variance (ANOVA) with the Bonferroni post-hoc test for multiple comparisons was used. The results showed that there was a significant difference between the different groups of players in eleven out of sixteen measured variables. Guards and forwards exhibited greater aerobic and relative values of anaerobic power, allowing shorter recovery times and the ability to repeat high intensity, basketball-specific activities. Centers presented greater values of absolute anaerobic power and capacities, permitting greater force production during discrete tasks. Coaches can use these data to create more individualized strength and conditioning programs for different positional roles.

Modeling the Value of Integrated Canadian and U.S. Power Sector Expansion

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cole, Wesley, Beiter, Philipp; Steinberg, Daniel

2016-09-08

The United States and Canada power systems are not isolated. Cross-border transmission and coordination of system operation create an interconnected power system, which results in combined imports and exports of electricity of greater than 70 TWh per year [1]. Currently, over 5 GW of new international transmission lines are in various stages of permitting and development. These lines may enable greater integration and coordination of the U.S. and Canada systems, which can in turn reduce challenges associated with integration of high penetrations of variable renewables. Furthermore, low-cost Canadian resources, such as wind and hydro, could contribute to compliance with themore » EPA's recently released Clean Power Plan. Improving integration and coordination internationally will reduce the costs of accessing these resources. This analysis work build on previous work by Ibanez and Zinaman [2]. In this work we seek to better understand the value of additional interconnection between the U.S. and Canadian power systems. Specifically, we quantify the value of additional interconnection and coordination within the Canadian-US integrated power system under scenarios in which large reductions (>80%) in power sector CO2 emissions are achieved. We explore how the ability to add additional cross-border transmission impacts capacity investment, the generation mix, system costs, and the ability of the system to integrate variable renewable energy into the power system. This analysis uses the Regional Energy Deployment System (ReEDS) capacity expansion model [3], [4] to quantify the value of the integrated power system expansion of the United States and Canada. ReEDS is an optimization model that assesses the deployment and operation (including transmission) of the electricity sector of the contiguous United States and Canadian provinces from 2016 through 2050. It has the ability to model the integration of renewable energy technologies into the grid. ReEDS captures renewable energy resources through the use of 356 individual resource regions and 134 balancing areas across the U.S. and is able to handle renewable energy issues such as variability in wind and solar output, transmission costs and constraints, and ancillary services requirements.« less

Novel Synthesis of 3D Graphene-CNF Electrode Architectures for Supercapacitor Applications

DTIC Science & Technology

2013-06-01

curves. Specifically, I would like to mention LCDR Chris Daskam, LT Russell Canty, LT Jamie Cook , LT Ashley Maxson, LT Samuel Fromille, and Edwin...systems to store energy for the amplifier to use on demand. Additionally, capacitors are used to supply large pulses of current for pulsed power...stark contrast to values quoted in recent studies: Zhu et al. [56] cite a specific capacitance of microwave exfoliated graphene electrodes of 200 F/g

Analysis of in situ electric field and specific absorption rate in human models for wireless power transfer system with induction coupling.

PubMed

Sunohara, Tetsu; Hirata, Akimasa; Laakso, Ilkka; Onishi, Teruo

2014-07-21

This study investigates the specific absorption rate (SAR) and the in situ electric field in anatomically based human models for the magnetic field from an inductive wireless power transfer system developed on the basis of the specifications of the wireless power consortium. The transfer system consists of two induction coils covered by magnetic sheets. Both the waiting and charging conditions are considered. The transfer frequency considered in this study is 140 kHz, which is within the range where the magneto-quasi-static approximation is valid. The SAR and in situ electric field in the chest and arm of the models are calculated by numerically solving the scalar potential finite difference equation. The electromagnetic modelling of the coils in the wireless power transfer system is verified by comparing the computed and measured magnetic field distributions. The results indicate that the peak value of the SAR averaged over a 10 g of tissue and that of the in situ electric field are 72 nW kg(-1) and 91 mV m(-1) for a transmitted power of 1 W, Consequently, the maximum allowable transmitted powers satisfying the exposure limits of the SAR (2 W kg(-1)) and the in situ electric field (18.9 V m(-1)) are found to be 28 MW and 43 kW. The computational results show that the in situ electric field in the chest is the most restrictive factor when compliance with the wireless power transfer system is evaluated according to international guidelines.

Changes in the Economic Value of Variable Generation at High Penetration Levels: A Pilot Case Study of California

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mills, Andrew; Wiser, Ryan

2012-05-18

We estimate the long-run economic value of variable renewable generation with increasing penetration using a unique investment and dispatch model that captures long-run investment decisions while also incorporating detailed operational constraints and hourly time resolution over a full year. High time resolution and the incorporation of operational constraints are important for estimating the economic value of variable generation, as is the use of a modeling framework that accommodates new investment decisions. The model is herein applied with a case study that is loosely based on California in 2030. Increasing amounts of wind, photovoltaics (PV), and concentrating solar power (CSP) with and without thermal energy storage (TES) are added one at a time. The marginal economic value of these renewable energy sources is estimated and then decomposed into capacity value, energy value, day-ahead forecast error cost, and ancillary services. The marginal economic value, as defined here, is primarily based on the combination of avoided capital investment cost and avoided variable fuel and operations and maintenance costs from other power plants in the power system. Though the model only captures a subset of the benefits and costs of renewable energy, it nonetheless provides unique insights into how the value of that subset changes with technology and penetration level. Specifically, in this case study implementation of the model, the marginal economic value of all three solar options is found to exceed the value of a flat-block of power (as well as wind energy) by \\more » $$20--30/MWh at low penetration levels, largely due to the high capacity value of solar at low penetration. Because the value of CSP per unit of energy is found to be high with or without thermal energy storage at low penetration, we find little apparent incremental value to thermal storage at low solar penetration in the present case study analysis. The marginal economic value of PV and CSP without thermal storage is found to drop considerably (by more than \\$$70/MWh) as the penetration of solar increases toward 30\\percent on an energy basis. This is due primarily to a steep drop in capacity value followed by a decrease in energy value. In contrast, the value of CSP with thermal storage drops much less dramatically as penetration increases. As a result, at solar penetration levels above 10\\percent, CSP with thermal storage is found to be considerably more valuable relative to PV and CSP without thermal storage. The marginal economic value of wind is found to be largely driven by energy value, and is lower than solar at low penetration. The marginal economic value of wind drops at a relatively slower rate with penetration, however. As a result, at high penetration, the value of wind can exceed the value of PV and CSP without thermal storage. Though some of these findings may be somewhat unique to the specific case study presented here, the results: (1) highlight the importance of an analysis framework that addresses long-term investment decisions as well as short-term dispatch and operational constraints, (2) can help inform long-term decisions about renewable energy procurement and supporting infrastructure, and (3) point to areas where further research is warranted.« less

Parasitism alters three power laws of scaling in a metazoan community: Taylor’s law, density-mass allometry, and variance-mass allometry

PubMed Central

Lagrue, Clément; Poulin, Robert; Cohen, Joel E.

2015-01-01

How do the lifestyles (free-living unparasitized, free-living parasitized, and parasitic) of animal species affect major ecological power-law relationships? We investigated this question in metazoan communities in lakes of Otago, New Zealand. In 13,752 samples comprising 1,037,058 organisms, we found that species of different lifestyles differed in taxonomic distribution and body mass and were well described by three power laws: a spatial Taylor’s law (the spatial variance in population density was a power-law function of the spatial mean population density); density-mass allometry (the spatial mean population density was a power-law function of mean body mass); and variance-mass allometry (the spatial variance in population density was a power-law function of mean body mass). To our knowledge, this constitutes the first empirical confirmation of variance-mass allometry for any animal community. We found that the parameter values of all three relationships differed for species with different lifestyles in the same communities. Taylor's law and density-mass allometry accurately predicted the form and parameter values of variance-mass allometry. We conclude that species of different lifestyles in these metazoan communities obeyed the same major ecological power-law relationships but did so with parameters specific to each lifestyle, probably reflecting differences among lifestyles in population dynamics and spatial distribution. PMID:25550506

Parasitism alters three power laws of scaling in a metazoan community: Taylor's law, density-mass allometry, and variance-mass allometry.

PubMed

Lagrue, Clément; Poulin, Robert; Cohen, Joel E

2015-02-10

How do the lifestyles (free-living unparasitized, free-living parasitized, and parasitic) of animal species affect major ecological power-law relationships? We investigated this question in metazoan communities in lakes of Otago, New Zealand. In 13,752 samples comprising 1,037,058 organisms, we found that species of different lifestyles differed in taxonomic distribution and body mass and were well described by three power laws: a spatial Taylor's law (the spatial variance in population density was a power-law function of the spatial mean population density); density-mass allometry (the spatial mean population density was a power-law function of mean body mass); and variance-mass allometry (the spatial variance in population density was a power-law function of mean body mass). To our knowledge, this constitutes the first empirical confirmation of variance-mass allometry for any animal community. We found that the parameter values of all three relationships differed for species with different lifestyles in the same communities. Taylor's law and density-mass allometry accurately predicted the form and parameter values of variance-mass allometry. We conclude that species of different lifestyles in these metazoan communities obeyed the same major ecological power-law relationships but did so with parameters specific to each lifestyle, probably reflecting differences among lifestyles in population dynamics and spatial distribution.

Cell design concepts for aqueous lithium-oxygen batteries: A model-based assessment

NASA Astrophysics Data System (ADS)

Grübl, Daniel; Bessler, Wolfgang G.

2015-11-01

Seven cell design concepts for aqueous (alkaline) lithium-oxygen batteries are investigated using a multi-physics continuum model for predicting cell behavior and performance in terms of the specific energy and specific power. Two different silver-based cathode designs (a gas diffusion electrode and a flooded cathode) and three different separator designs (a porous separator, a stirred separator chamber, and a redox-flow separator) are compared. Cathode and separator thicknesses are varied over a wide range (50 μm-20 mm) in order to identify optimum configurations. All designs show a considerable capacity-rate effect due to spatiotemporally inhomogeneous precipitation of solid discharge product LiOH·H2O. In addition, a cell design with flooded cathode and redox-flow separator including oxygen uptake within the external tank is suggested. For this design, the model predicts specific power up to 33 W/kg and specific energy up to 570 Wh/kg (gravimetric values of discharged cell including all cell components and catholyte except housing and piping).

Analysis of rock mass dynamic impact influence on the operation of a powered roof support control system

NASA Astrophysics Data System (ADS)

Szurgacz, Dawid; Brodny, Jaroław

2018-01-01

A powered roof support is a machine responsible for protection of an underground excavation against deformation generated by rock mass. In the case of dynamic impact of rock mass, the proper level of protection is hard to achieve. Therefore, the units of the roof support and its components are subject to detailed tests aimed at acquiring greater reliability, efficiency and efficacy. In the course of such test, however, it is not always possible to foresee values of load that may occur in actual conditions. The article presents a case of a dynamic load impacting the powered roof support during a high-energy tremor in an underground hard coal mine. The authors discuss the method for selecting powered roof support units proper for specific forecasted load conditions. The method takes into account the construction of the support and mining and geological conditions of an excavation. Moreover, the paper includes tests carried out on hydraulic legs and yield valves which were responsible for additional yielding of the support. Real loads impacting the support unit during tremors are analysed. The results indicated that the real registered values of the load were significantly greater than the forecasted values. The analysis results of roof support operation during dynamic impact generated by the rock mass (real life conditions) prompted the authors to develop a set of recommendations for manufacturers and users of powered roof supports. These include, inter alia, the need for innovative solutions for testing hydraulic section systems.

Intraocular lens design for treating high myopia based on individual eye model

NASA Astrophysics Data System (ADS)

Wang, Yang; Wang, Zhaoqi; Wang, Yan; Zuo, Tong

2007-02-01

In this research, we firstly design the phakic intraocular lens (PIOL) based on individual eye model with optical design software ZEMAX. The individual PIOL is designed to correct the defocus and astigmatism, and then we compare the PIOL power calculated from the individual eye model with that from the experiential formula. Close values of PIOL power are obtained between the individual eye model and the formula, but the suggested method has more accuracy with more functions. The impact of PIOL decentration on human eye is evaluated, including rotation decentration, flat axis decentration, steep axis decentration and axial movement of PIOL, which is impossible with traditional method. To control the PIOL decentration errors, we give the limit values of PIOL decentration for the specific eye in this study.

Predictive Value of Morphological Features in Patients with Autism versus Normal Controls

ERIC Educational Resources Information Center

Ozgen, H.; Hellemann, G. S.; de Jonge, M. V.; Beemer, F. A.; van Engeland, H.

2013-01-01

We investigated the predictive power of morphological features in 224 autistic patients and 224 matched-pairs controls. To assess the relationship between the morphological features and autism, we used the receiver operator curves (ROC). In addition, we used recursive partitioning (RP) to determine a specific pattern of abnormalities that is…

Interpreting Foucault: An Evaluation of a Foucauldian Critique of Education

ERIC Educational Resources Information Center

Woermann, Minka

2012-01-01

The potential strengths and weaknesses of a Foucauldian critique of education are discussed and evaluated. The article focuses specifically on the value of Foucault's work for critiquing social and political ideologies prevalent in education, which is understood as a societal institution, and hence, as a modern regime of institutional power. In…

Nonlinear Dynamics: Theoretical Perspectives and Application to Suicidology

ERIC Educational Resources Information Center

Schiepek, Gunter; Fartacek, Clemens; Sturm, Josef; Kralovec, Karl; Fartacek, Reinhold; Ploderl, Martin

2011-01-01

Despite decades of research, the prediction of suicidal behavior remains limited. As a result, searching for more specific risk factors and testing their predictive power are central in suicidology. This strategy may be of limited value because it assumes linearity to the suicidal process that is most likely nonlinear by nature and which can be…

Community Values as the Context for Interpreting Social Impacts.

ERIC Educational Resources Information Center

Canan, Penelope; Hennessy, Michael

A social impact assessment which focused on a Hawaiian community's evaluation of social change and development is reported. The research occurred on the island of Moloka'i, which depends largely on imports for its energy sources, although it has a number of natural sources (biomass, wind, solar, and water power). Specifically, the study identified…

In Situ Nanocalorimetric Investigations of Plasma Assisted Deposited Poly(ethylene oxide)-like Films by Specific Heat Spectroscopy.

PubMed

Madkou, Sherif; Melnichu, Iurii; Choukourov, Andrei; Krakovsky, Ivan; Biederman, Hynek; Schönhals, Andreas

2016-04-28

In recent years, highly cross-linked plasma polymers have started to unveil their potential in numerous biomedical applications in thin-film form. However, conventional diagnostic methods often fail due to their diverse molecular dynamics conformations. Here, glassy dynamics and the melting transition of thin PEO-like plasma assisted deposited (ppPEO) films (thickness 100 nm) were in situ studied by a combination of specific heat spectroscopy, utilizing a pJ/K sensitive ac-calorimeter chip, and composition analytical techniques. Different cross-linking densities were obtained by different plasma powers during the deposition of the films. Glassy dynamics were observed for all values of the plasma power. It was found that the glassy dynamics slows down with increasing the plasma power. Moreover, the underlying relaxation time spectra broaden indicating that the molecular motions become more heterogeneous with increasing plasma power. In a second set of the experiment, the melting behavior of the ppPEO films was studied. The melting temperature of ppPEO was found to decrease with increasing plasma power. This was explained by a decrease of the order in the crystals due to formation of chemical defects during the plasma process.

Recovery Act: Advanced Direct Methanol Fuel Cell for Mobile Computing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fletcher, James H.; Cox, Philip; Harrington, William J

2013-09-03

ABSTRACT Project Title: Recovery Act: Advanced Direct Methanol Fuel Cell for Mobile Computing PROJECT OBJECTIVE The objective of the project was to advance portable fuel cell system technology towards the commercial targets of power density, energy density and lifetime. These targets were laid out in the DOE’s R&D roadmap to develop an advanced direct methanol fuel cell power supply that meets commercial entry requirements. Such a power supply will enable mobile computers to operate non-stop, unplugged from the wall power outlet, by using the high energy density of methanol fuel contained in a replaceable fuel cartridge. Specifically this project focusedmore » on balance-of-plant component integration and miniaturization, as well as extensive component, subassembly and integrated system durability and validation testing. This design has resulted in a pre-production power supply design and a prototype that meet the rigorous demands of consumer electronic applications. PROJECT TASKS The proposed work plan was designed to meet the project objectives, which corresponded directly with the objectives outlined in the Funding Opportunity Announcement: To engineer the fuel cell balance-of-plant and packaging to meet the needs of consumer electronic systems, specifically at power levels required for mobile computing. UNF used existing balance-of-plant component technologies developed under its current US Army CERDEC project, as well as a previous DOE project completed by PolyFuel, to further refine them to both miniaturize and integrate their functionality to increase the system power density and energy density. Benefits of UNF’s novel passive water recycling MEA (membrane electrode assembly) and the simplified system architecture it enabled formed the foundation of the design approach. The package design was hardened to address orientation independence, shock, vibration, and environmental requirements. Fuel cartridge and fuel subsystems were improved to ensure effective fuel containment. PROJECT OVERVIEW The University of North Florida (UNF), with project partner the University of Florida, recently completed the Department of Energy (DOE) project entitled “Advanced Direct Methanol Fuel Cell for Mobile Computing”. The primary objective of the project was to advance portable fuel cell system technology towards the commercial targets as laid out in the DOE R&D roadmap by developing a 20-watt, direct methanol fuel cell (DMFC), portable power supply based on the UNF innovative “passive water recovery” MEA. Extensive component, sub-system, and system development and testing was undertaken to meet the rigorous demands of the consumer electronic application. Numerous brassboard (nonpackaged) systems were developed to optimize the integration process and facilitating control algorithm development. The culmination of the development effort was a fully-integrated, DMFC, power supply (referred to as DP4). The project goals were 40 W/kg for specific power, 55 W/l for power density, and 575 Whr/l for energy density. It should be noted that the specific power and power density were for the power section only, and did not include the hybrid battery. The energy density is based on three, 200 ml, fuel cartridges, and also did not include the hybrid battery. The results show that the DP4 system configured without the methanol concentration sensor exceeded all performance goals, achieving 41.5 W/kg for specific power, 55.3 W/l for power density, and 623 Whr/l for energy density. During the project, the DOE revised its technical targets, and the definition of many of these targets, for the portable power application. With this revision, specific power, power density, specific energy (Whr/kg), and energy density are based on the total system, including fuel tank, fuel, and hybridization battery. Fuel capacity is not defined, but the same value is required for all calculations. Test data showed that the DP4 exceeded all 2011 Technical Status values; for example, the DP4 energy density was 373 Whr/l versus the DOE 2011 status of 200 Whr/l. For the DOE 2013 Technical Goals, the operation time was increased from 10 hours to 14.3 hours. Under these conditions, the DP4 closely approached or surpassed the technical targets; for example, the DP4 achieved 468 Whr/l versus the goal of 500 Whr/l. Thus, UNF has successfully met the project goals. A fully-operational, 20-watt DMFC power supply was developed based on the UNF passive water recovery MEA. The power supply meets the project performance goals and advances portable power technology towards the commercialization targets set by the DOE.« less

Maximal oxygen uptake and cardiorespiratory response to maximal 400-m free swimming, running and cycling tests in competitive swimmers.

PubMed

Rodríguez, F A

2000-06-01

This study compared the cardiorespiratory response of trained swimmers to 400-m unimpeded front crawl swimming (SW), treadmill running (TR) and ergometer cycling (EC) maximal exercise tests, and evaluated the validity and specificity of a method to measure maximal aerobic power in swimming. Two series of experiments were conducted. In series A (n=15), comparisons were made between VO2peak and other cardiorespiratory variables in three maximal tests: after 400-m SW, and during incremental TR and EC. In series B, VO2 peak and related variables were measured after SW and during EC (n=33). No significant differences were observed between VO2peak and VE in the three modes of exercise, although SW values tended to be higher. After SW, maximal ventilatory response was characterized by higher tidal volumes (VT) and lower respiratory rates (fR) as compared with TR and EC. The highest heart rate values (fH) were also observed in TR, followed by EC and SW. In series B, no significant differences were observed either in peak VO2 or VE, but fH was also lower in SW. A maximal 400-m unimpeded freestyle SW test yields essentially equal or nonsignificantly higher peak VO2 and VE values than during maximal TR or EC tests in trained swimmers. The specific maximal cardiorespiratory response to the SW test is characterized by higher VT, lower fR, and lower fH. Breath-by-breath measurements during the immediate recovery after a 400-m voluntary maximal swim is proposed as a valid and specific test for directly measuring maximal metabolic parameters and evaluating specific maximal aerobic power in swimming.

Probabilistic Analysis Techniques Applied to Complex Spacecraft Power System Modeling

NASA Technical Reports Server (NTRS)

Hojnicki, Jeffrey S.; Rusick, Jeffrey J.

2005-01-01

Electric power system performance predictions are critical to spacecraft, such as the International Space Station (ISS), to ensure that sufficient power is available to support all the spacecraft s power needs. In the case of the ISS power system, analyses to date have been deterministic, meaning that each analysis produces a single-valued result for power capability because of the complexity and large size of the model. As a result, the deterministic ISS analyses did not account for the sensitivity of the power capability to uncertainties in model input variables. Over the last 10 years, the NASA Glenn Research Center has developed advanced, computationally fast, probabilistic analysis techniques and successfully applied them to large (thousands of nodes) complex structural analysis models. These same techniques were recently applied to large, complex ISS power system models. This new application enables probabilistic power analyses that account for input uncertainties and produce results that include variations caused by these uncertainties. Specifically, N&R Engineering, under contract to NASA, integrated these advanced probabilistic techniques with Glenn s internationally recognized ISS power system model, System Power Analysis for Capability Evaluation (SPACE).

Sex-specific predictive power of 6-minute walk test in chronic heart failure is not enhanced using percent achieved of published reference equations.

PubMed

Frankenstein, Lutz; Zugck, Christian; Nelles, Manfred; Schellberg, Dieter; Katus, Hugo; Remppis, Andrew

2008-04-01

The 6-minute walk test (6MWT) is an established prognostic tool in chronic heart failure. The strong influence of height, weight, age, and sex on 6MWT distance may be accounted for by using percentage achieved of predicted value rather than uncorrected 6MWT values. The study included 1069 patients (862 men) with a mean age 55.2 +/- 11.7 years and mean left ventricular ejection fraction of 29% +/- 10%, attending the heart failure clinic of the University of Heidelberg between 1995 and 2005. The predictive power and accuracy of 6MWT and achieved percentage values according to all available published equations for mortality and mortality or transplant combined were tested separately for each sex. The percentage values varied largely between equations. For all equations, women in New York Heart Association (NYHA) functional class I had higher values than men. Although the 6MWT significantly discriminated all NYHA classes for both sexes, only 1 equation discriminated all NYHA classes. No significant differences in the area under the receiver operating-characteristic curve were noted between achieved percentage values and 6MWT. Despite strong univariate significance, achieved percentage values did not retain multivariate significance. The 6MWT was independent from N-terminal brain natriuretic propeptide, NYHA, left ventricular ejection fraction, and peak oxygen uptake. We confirmed 6MWT to be a strong and independent risk predictor for both sexes. Because the prognostic power of 6MWT is not enhanced using percentage achieved of published reference equations, we suggest recalibration of these reference values rather than discarding this approach.

An Integrated Specification and Verification Environment for Component-Based Architectures of Large-Scale Distributed Systems

DTIC Science & Technology

2009-05-26

Interrupt HW Interrupt DFS Dynamic Frequency Selection TPC Transmit Power Control r- MPX Hub ! i j I Power Supply Init/Reset A/D...values of several variables: from IN_0_DAT when the Mailbox forwards data supplied by Client 0, from OUT1DAT when the conditions on the ready flags are...logically implies ip y 0, and also <j> logically implies ip y <p; (b) if for all i we have that cj>t+1 is of the form (p% y ip, then the chain

Diabetes and Impaired Fasting Glucose Prediction Using Anthropometric Indices in Adults from Maracaibo City, Venezuela.

PubMed

Bermúdez, Valmore; Salazar, Juan; Rojas, Joselyn; Calvo, María; Rojas, Milagros; Chávez-Castillo, Mervin; Añez, Roberto; Cabrera, Mayela

2016-12-01

To determine the predictive power of various anthropometric indices for the identification of dysglycemic states in Maracaibo, Venezuela. A cross-sectional study with randomized, multi-staged sampling was realized in 2230 adult subjects of both genders who had their body mass index (BMI), waist circumference (WC) and waist-height ratio (WHR) determined. Diagnoses of type 2 diabetes mellitus (DM2) and impaired fasting glucose (IFG) were made following ADA 2015 criteria. ROC curves were used to evaluate the predictive power of each anthropometric parameter. Area under the curve (AUC) values were compared through Delong's test. Of the total 2230 individuals (52.6 % females), 8.4 % were found to have DM2, and 19.5 % had IFG. Anthropometric parameters displayed greater predictive power regarding newly diagnosed diabetics, where WHR was the most important predictor in both females (AUC = 0.808; CI 95 % 0.715-0.900. Sensitivity: 82.8 %; specificity: 76.2 %) and males (AUC = 0.809; CI 95 % 0.736-0.882. Sensitivity: 78.6 %; specificity: 68.1 %), although all three parameters appeared to have comparable predictive power in this subset. In previously diagnosed diabetic subjects, WHR was superior to both WC and BMI in females, and WHR and WC were both superior to BMI in males. Lower predictive values were found for IFG in both genders. Accumulation of various altered anthropometric measurements was associated with increased odds ratios for both newly and previously diagnosed DM2. The predictive power of anthropometric measurements was greater for DM2 than IFG. We suggest assessment of as many available parameters as possible in the clinical setting.

Advancing solar energy forecasting through the underlying physics

NASA Astrophysics Data System (ADS)

Yang, H.; Ghonima, M. S.; Zhong, X.; Ozge, B.; Kurtz, B.; Wu, E.; Mejia, F. A.; Zamora, M.; Wang, G.; Clemesha, R.; Norris, J. R.; Heus, T.; Kleissl, J. P.

2017-12-01

As solar power comprises an increasingly large portion of the energy generation mix, the ability to accurately forecast solar photovoltaic generation becomes increasingly important. Due to the variability of solar power caused by cloud cover, knowledge of both the magnitude and timing of expected solar power production ahead of time facilitates the integration of solar power onto the electric grid by reducing electricity generation from traditional ancillary generators such as gas and oil power plants, as well as decreasing the ramping of all generators, reducing start and shutdown costs, and minimizing solar power curtailment, thereby providing annual economic value. The time scales involved in both the energy markets and solar variability range from intra-hour to several days ahead. This wide range of time horizons led to the development of a multitude of techniques, with each offering unique advantages in specific applications. For example, sky imagery provides site-specific forecasts on the minute-scale. Statistical techniques including machine learning algorithms are commonly used in the intra-day forecast horizon for regional applications, while numerical weather prediction models can provide mesoscale forecasts on both the intra-day and days-ahead time scale. This talk will provide an overview of the challenges unique to each technique and highlight the advances in their ongoing development which come alongside advances in the fundamental physics underneath.

Thermal analysis of large-capacity LiFePO4 power batteries for electric vehicles

NASA Astrophysics Data System (ADS)

Lin, Chunjing; Xu, Sichuan; Li, Zhao; Li, Bin; Chang, Guofeng; Liu, Jinling

2015-10-01

Excellent design of a thermal management system requires good understanding of the thermal behaviors of power batteries. In this study, the electrochemical and heat performances of a prismatic 40 Ah C/LiFePO4 battery are investigated with a focus on the influence of temperature on cell capacity in a mixed charge-discharge cycle. In addition, the heat generation and energy efficiency of a battery are determined during charge and discharge at different current rates. The experimental results indicate that in certain temperature ranges, both the charging and discharging capacities increase significantly as the temperature increases. In addition, the energy efficiency reaches more than 95% when the battery runs at a current rate of 0.33 C-2 C and temperature of 25-45 °C. A thermal mathematical model based on experimentally obtained internal resistances and entropy coefficients is developed. Using this model, the increase in the battery temperature is simulated based on specific heat values that are measured experimentally and calculated theoretically. The results from the simulation indicate that the temperature increase agrees well with the experimental values, the measured specific heat provides better results than the calculated specific heat and the heat generated decreases as the temperature increases.

Dynamics of in vivo power output and efficiency of Nasonia asynchronous flight muscle.

PubMed

Lehmann, Fritz-Olaf; Heymann, Nicole

2006-06-25

By simultaneously measuring aerodynamic performance, wing kinematics, and metabolic activity, we have estimated the in vivo limits of mechanical power production and efficiency of the asynchronous flight muscle (IFM) in three species of ectoparasitoid wasps genus Nasonia (N. giraulti, N. longicornis, and N. vitripennis). The 0.6 mg animals were flown under tethered flight conditions in a flight simulator that allowed modulation of power production by employing an open-loop visual stimulation technique. At maximum locomotor capacity, flight muscles of Nasonia are capable to sustain 72.2 +/- 18.3 W kg(-1) muscle mechanical power at a chemo-mechanical conversion efficiency of approximately 9.8 +/- 0.9%. Within the working range of the locomotor system, profile power requirement for flight dominates induced power requirement suggesting that the cost to overcome wing drag places the primary limit on overall flight performance. Since inertial power is only approximately 25% of the sum of induced and profile power requirements, Nasonia spp. may not benefit from elastic energy storage during wing deceleration phases. A comparison between wing size-polymorphic males revealed that wing size reduction is accompanied by a decrease in total flight muscle volume, muscle mass-specific mechanical power production, and total flight efficiency. In animals with small wings maximum total flight efficiency is below 0.5%. The aerodynamic and power estimates reported here for Nasonia are comparable to values reported previously for the fruit fly Drosophila flying under similar experimental conditions, while muscle efficiency of the tiny wasp is more at the lower end of values published for various other insects.

Estimating radiofrequency power deposition in body NMR imaging.

PubMed

Bottomley, P A; Redington, R W; Edelstein, W A; Schenck, J F

1985-08-01

Simple theoretical estimates of the average, maximum, and spatial variation of the radiofrequency power deposition (specific absorption rate) during hydrogen nuclear magnetic resonance imaging are deduced for homogeneous spheres and for cylinders of biological tissue with a uniformly penetrating linear rf field directed axially and transverse to the cylindrical axis. These are all simple scalar multiples of the expression for the cylinder in an axial field published earlier (Med. Phys. 8, 510 (1981]. Exact solutions for the power deposition in the cylinder with axial (Phys. Med. Biol. 23, 630 (1978] and transversely directed rf field are also presented, and the spatial variation of power deposition in head and body models is examined. In the exact models, the specific absorption rates decrease rapidly and monotonically with decreasing radius despite local increases in rf field amplitude. Conversion factors are provided for calculating the power deposited by Gaussian and sinc-modulated rf pulses used for slice selection in NMR imaging, relative to rectangular profiled pulses. Theoretical estimates are compared with direct measurements of the total power deposited in the bodies of nine adult males by a 63-MHz body-imaging system with transversely directed field, taking account of cable and NMR coil losses. The results for the average power deposition agree within about 20% for the exact model of the cylinder with axial field, when applied to the exposed torso volume enclosed by the rf coil. The average values predicted by the simple spherical and cylindrical models with axial fields, the exact cylindrical model with transverse field, and the simple truncated cylinder model with transverse field were about two to three times that measured, while the simple model consisting of an infinitely long cylinder with transverse field gave results about six times that measured. The surface power deposition measured by observing the incremental power as a function of external torso radius was comparable to the average value. This is consistent with the presence of a variable thickness peripheral adipose layer which does not substantially increase surface power deposition with increasing torso radius. The absence of highly localized intensity artifacts in 63-MHz body images does not suggest anomalously intense power deposition at localized internal sites, although peak power is difficult to measure.

The Study of Rain Specific Attenuation for the Prediction of Satellite Propagation in Malaysia

NASA Astrophysics Data System (ADS)

Mandeep, J. S.; Ng, Y. Y.; Abdullah, H.; Abdullah, M.

2010-06-01

Specific attenuation is the fundamental quantity in the calculation of rain attenuation for terrestrial path and slant paths representing as rain attenuation per unit distance (dB/km). Specific attenuation is an important element in developing the predicted rain attenuation model. This paper deals with the empirical determination of the power law coefficients which allow calculating the specific attenuation in dB/km from the knowledge of the rain rate in mm/h. The main purpose of the paper is to obtain the coefficients of k and α of power law relationship between specific attenuation. Three years (from 1st January 2006 until 31st December 2008) rain gauge and beacon data taken from USM, Nibong Tebal have been used to do the empirical procedure analysis of rain specific attenuation. The data presented are semi-empirical in nature. A year-to-year variation of the coefficients has been indicated and the empirical measured data was compared with ITU-R provided regression coefficient. The result indicated that the USM empirical measured data was significantly vary from ITU-R predicted value. Hence, ITU-R recommendation for regression coefficients of rain specific attenuation is not suitable for predicting rain attenuation at Malaysia.

Radiofrequency Exposures of Workers on Low-Power FM Radio Transmitters.

PubMed

Valic, Blaž; Kos, Bor; Gajšek, Peter

2017-05-01

Low-power radio transmitters are one of the most common radio frequency sources and the exposure limit values (ELVs) for occupational exposure may be exceeded close to them. Therefore, a detailed analysis and assessment of occupational exposure in their vicinity is presented in the paper. For 20 different exposure scenarios, electric field strength and specific absorption rate (SAR) values were computed to determine whether the action levels (ALs) and ELVs of the European directive 2013/35/EU are exceeded for different 500 W radio transmitters. The results show that the ALs are very conservative for such exposure situations. Even when the ALs are greatly exceeded, the SAR values are not necessarily above the limit. However, in some situations, the ELVs were also exceeded. The local 10 g averaged value of the SAR can be exceeded if the worker is grounded (in direct contact with the steel structure), while the whole body ELVs can be exceeded for exposures at distances of <1 m from the transmitting dipole array antennas. © The Author 2017. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Correlation of the Rates of Solvolysis of i-Butyl Fluoroformate and a Consideration of Leaving-Group Effects

PubMed Central

Lee, Yelin; Park, Kyoung-Ho; Seong, Mi Hye; Kyong, Jin Burm; Kevill, Dennis N.

2011-01-01

The specific rates of solvolysis of isobutyl fluoroformate (1) have been measured at 40.0 °C in 22 pure and binary solvents. These results correlated well with the extended Grunwald-Winstein (G-W) equation, which incorporated the NT solvent nucleophilicity scale and the YCl solvent ionizing power scale. The sensitivities (l and m-values) to changes in solvent nucleophilicity and solvent ionizing power, and the kF/kCl values are very similar to those observed previously for solvolyses of n-octyl fluoroformate, consistent with the additional step of an addition-elimination pathway being rate-determining. The solvent deuterium isotope effect value (kMeOH/kMeOD) for methanolysis of 1 was determined, and for solvolyses in ethanol, methanol, 80% ethanol, and 70% TFE, the values of the enthalpy and the entropy of activation for the solvolysis of 1 were also determined. The results are compared with those reported earlier for isobutyl chloroformate (2) and other alkyl haloformate esters and mechanistic conclusions are drawn. PMID:22174633

Determination of Strength Exercise Intensities Based on the Load-Power-Velocity Relationship

PubMed Central

Jandačka, Daniel; Beremlijski, Petr

2011-01-01

The velocity of movement and applied load affect the production of mechanical power output and subsequently the extent of the adaptation stimulus in strength exercises. We do not know of any known function describing the relationship of power and velocity and load in the bench press exercise. The objective of the study is to find a function modeling of the relationship of relative velocity, relative load and mechanical power output for the bench press exercise and to determine the intensity zones of the exercise for specifically focused strength training of soccer players. Fifteen highly trained soccer players at the start of a competition period were studied. The subjects of study performed bench presses with the load of 0, 10, 30, 50, 70 and 90% of the predetermined one repetition maximum with maximum possible speed of movement. The mean measured power and velocity for each load (kg) were used to develop a multiple linear regression function which describes the quadratic relationship between the ratio of power (W) to maximum power (W) and the ratios of the load (kg) to one repetition maximum (kg) and the velocity (m•s−1) to maximal velocity (m•s−1). The quadratic function of two variables that modeled the searched relationship explained 74% of measured values in the acceleration phase and 75% of measured values from the entire extent of the positive power movement in the lift. The optimal load for reaching maximum power output suitable for the dynamics effort strength training was 40% of one repetition maximum, while the optimal mean velocity would be 75% of maximal velocity. Moreover, four zones: maximum power, maximum velocity, velocity-power and strength-power were determined on the basis of the regression function. PMID:23486484

Determination of strength exercise intensities based on the load-power-velocity relationship.

PubMed

Jandačka, Daniel; Beremlijski, Petr

2011-06-01

The velocity of movement and applied load affect the production of mechanical power output and subsequently the extent of the adaptation stimulus in strength exercises. We do not know of any known function describing the relationship of power and velocity and load in the bench press exercise. The objective of the study is to find a function modeling of the relationship of relative velocity, relative load and mechanical power output for the bench press exercise and to determine the intensity zones of the exercise for specifically focused strength training of soccer players. Fifteen highly trained soccer players at the start of a competition period were studied. The subjects of study performed bench presses with the load of 0, 10, 30, 50, 70 and 90% of the predetermined one repetition maximum with maximum possible speed of movement. The mean measured power and velocity for each load (kg) were used to develop a multiple linear regression function which describes the quadratic relationship between the ratio of power (W) to maximum power (W) and the ratios of the load (kg) to one repetition maximum (kg) and the velocity (m•s(-1)) to maximal velocity (m•s(-1)). The quadratic function of two variables that modeled the searched relationship explained 74% of measured values in the acceleration phase and 75% of measured values from the entire extent of the positive power movement in the lift. The optimal load for reaching maximum power output suitable for the dynamics effort strength training was 40% of one repetition maximum, while the optimal mean velocity would be 75% of maximal velocity. Moreover, four zones: maximum power, maximum velocity, velocity-power and strength-power were determined on the basis of the regression function.

Kansas squat test: a reliable indicator of short-term anaerobic power.

PubMed

Fry, Andrew C; Kudrna, Rebecca A; Falvo, Michael J; Bloomer, Richard J; Moore, Christopher A; Schilling, Brian K; Weiss, Lawrence W

2014-03-01

The purposes of this study were to establish stability reliability of a measure of lower-body anaerobic power, the Kansas squat test (KST), and to compare the KST with the commonly used Wingate anaerobic test (WAnT) for lower-body power. Fourteen resistance-trained men (mean ± SD; age = 24.2 ± 3.6 years) performed both the KST and the WAnT twice on separate occasions. The KST consisted of using an external dynamometer to measure mean repetition power while performing 15 repetitions of speed squats using 70% of 1 repetition maximum system mass (barbell + body mass), initiating each repetition at 6-second intervals. Repetition power, mean power for all 15 repetitions, and % fatigue for the KST were all reliable (intraclass correlation coefficient = 0.754-0.937; p ≤ 0.05). There were no differences between tests for the mean power for all repetitions or relative fatigue (p ≤ 0.05) and no significant differences between tests for any individual repetition (test × repetition interaction, p < 0.05). Although absolute values were different (p > 0.05), significant correlations were found between the KST and WAnT for mean (r = 0.752) and maximum (r = 0.775) test powers but not for relative fatigue (r = 0.174). Lactate (HLa) responses were greater for the WAnT compared with the KST. These data indicate that the KST is reliable for resistance-trained men, and that measures of maximum and mean test powers for the KST are highly correlated to those values for the WAnT, but fatigue rates and HLa responses were not correlated. It appears that the KST is a lifting-specific anaerobic power and power endurance test that emphasizes phosphagen metabolism and may be used to assess training-induced changes in lower-body power.

How an antenna launches its input power into radiation: thepattern of the Poynting vector at and near an antenna

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jackson, J.D.

2005-05-18

In this paper I first address the question of whether theseat of the power radiated by an antenna made of conducting members isdistributed over the "arms" of the antenna according tomore » $$ - \\bf J \\cdotE$$, where $$\\bf J$$ is the specified current density and $$\\bf E$$ is theelectric field produced by that source. Poynting's theorem permits only aglobal identification of the total input power, usually from a localizedgenerator, with the total power radiated to infinity, not a localcorrespondence of $$- \\bf J \\cdot E\\ d^3x $$ with some specific radiatedpower, $$r^2 \\bf S \\cdot \\hat r\\ d\\Omega $$. I then describe a modelantenna consisting of two perfectly conducting hemispheres of radius\\emph a separated by a small equatorial gap across which occurs thedriving oscillatory electric field. The fields and surface current aredetermined by solution of the boundary value problem. In contrast to thefirst approach (not a boundary value problem), the tangential electricfield vanishes on the metallic surface. There is no radial Poyntingvector at the surface. Numerical examples are shown to illustrate how theenergy flows from the input region of the gap and is guided near theantenna by its "arms" until it is launched at larger \\emph r/a into theradiation pattern determined by the value of \\emph ka.« less

The environmental and public health benefits of achieving high penetrations of solar energy in the United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wiser, Ryan; Millstein, Dev; Mai, Trieu

We estimate the environmental and public health benefits that may be realized if solar energy cost reductions continue until solar power is competitive across the U.S. without subsidies. Specifically, we model, from 2015 to 2050, solar power-induced reductions to greenhouse gas (GHG) emissions, air pollutant emissions, and water usage. To find the incremental benefits of new solar deployment, we compare the difference between two scenarios, one where solar costs have fallen such that solar supplies 14% of the nation's electricity by 2030 and 27% by 2050, and a baseline scenario in which no solar is added after 2014. We monetizemore » benefits, where credible methods exist to do so. We find that under these scenarios, solar power reduces GHG and air pollutants by ~10%, from 2015 to 2050, providing a discounted present value of $56-$789 billion (central value of ~$250 billion, equivalent to ~2 cents/kWh-solar) in climate benefits and $77-$298 billion (central value of $167 billion, or ~1.4 cents/kWh-solar) in air quality and public health benefits. The ranges reflect uncertainty within the literature about the marginal impact of emissions of GHG and air pollutants. Solar power is also found to reduce water withdrawals and consumption by 4% and 9%, respectively, including in many drought-prone states.« less

Visual and Statistical Analysis of Digital Elevation Models Generated Using Idw Interpolator with Varying Powers

NASA Astrophysics Data System (ADS)

Asal, F. F.

2012-07-01

Digital elevation data obtained from different Engineering Surveying techniques is utilized in generating Digital Elevation Model (DEM), which is employed in many Engineering and Environmental applications. This data is usually in discrete point format making it necessary to utilize an interpolation approach for the creation of DEM. Quality assessment of the DEM is a vital issue controlling its use in different applications; however this assessment relies heavily on statistical methods with neglecting the visual methods. The research applies visual analysis investigation on DEMs generated using IDW interpolator of varying powers in order to examine their potential in the assessment of the effects of the variation of the IDW power on the quality of the DEMs. Real elevation data has been collected from field using total station instrument in a corrugated terrain. DEMs have been generated from the data at a unified cell size using IDW interpolator with power values ranging from one to ten. Visual analysis has been undertaken using 2D and 3D views of the DEM; in addition, statistical analysis has been performed for assessment of the validity of the visual techniques in doing such analysis. Visual analysis has shown that smoothing of the DEM decreases with the increase in the power value till the power of four; however, increasing the power more than four does not leave noticeable changes on 2D and 3D views of the DEM. The statistical analysis has supported these results where the value of the Standard Deviation (SD) of the DEM has increased with increasing the power. More specifically, changing the power from one to two has produced 36% of the total increase (the increase in SD due to changing the power from one to ten) in SD and changing to the powers of three and four has given 60% and 75% respectively. This refers to decrease in DEM smoothing with the increase in the power of the IDW. The study also has shown that applying visual methods supported by statistical analysis has proven good potential in the DEM quality assessment.

Ion optics for high power 50-cm-diam ion thrusters

NASA Technical Reports Server (NTRS)

Rawlin, Vincent K.; Millis, Marc G.

1989-01-01

The process used at the NASA-Lewis to fabricate 30 and 50-cm-diameter ion optics is described. The ion extraction capabilities of the 30 and 50-cm diameter ion optics were evaluated on divergent field and ring-cusp discharge chambers and compared. Perveance was found to be sensitive to the effects of the type and power of the discharge chamber and to the accelerator electrode hole diameter. Levels of up to 0.64 N and 20 kW for thrust and input power, respectively, were demonstrated with the divergent-field discharge chamber. Thruster efficiencies and specific impulse values up to 79 percent and 5000 sec., respectively, were achieved with the ring-cusp discharge chamber.

A methodology to identify stranded generation facilities and estimate stranded costs for Louisiana's electric utility industry

NASA Astrophysics Data System (ADS)

Cope, Robert Frank, III

1998-12-01

The electric utility industry in the United States is currently experiencing a new and different type of growing pain. It is the pain of having to restructure itself into a competitive business. Many industry experts are trying to explain how the nation as a whole, as well as individual states, will implement restructuring and handle its numerous "transition problems." One significant transition problem for federal and state regulators rests with determining a utility's stranded costs. Stranded generation facilities are assets which would be uneconomic in a competitive environment or costs for assets whose regulated book value is greater than market value. At issue is the methodology which will be used to estimate stranded costs. The two primary methods are known as "Top-Down" and "Bottom-Up." The "Top-Down" approach simply determines the present value of the losses in revenue as the market price for electricity changes over a period of time into the future. The problem with this approach is that it does not take into account technical issues associated with the generation and wheeling of electricity. The "Bottom-Up" approach computes the present value of specific strandable generation facilities and compares the resulting valuations with their historical costs. It is regarded as a detailed and difficult, but more precise, approach to identifying stranded assets and their associated costs. This dissertation develops a "Bottom-Up" quantitative, optimization-based approach to electric power wheeling within the state of Louisiana. It optimally evaluates all production capabilities and coordinates the movement of bulk power through transmission interconnections of competing companies in and around the state. Sensitivity analysis to this approach is performed by varying seasonal consumer demand, electric power imports, and transmission inter-connection cost parameters. Generation facility economic dispatch and transmission interconnection bulk power transfers, specific to each set of parameters, lead to the identification of stranded generation facilities. Stranded costs of non-dispatched and uneconomically dispatched generation facilities can then be estimated to indicate, arguably, the largest portion of restructuring transition costs as the industry is transformed from its present monopolistic structure to a competitive one.

Linking Supply Chain Governance and Biosecurity in the Context of HPAI Control in Western Java: A Value Chain Perspective

PubMed Central

Indrawan, Dikky; Rich, Karl M.; van Horne, Peter; Daryanto, Arief; Hogeveen, Henk

2018-01-01

Despite extensive efforts to control the highly pathogenic avian influenza (HPAI), it remains endemic in Western Java, Indonesia. To understand the limited effectiveness of HPAI control measures, it is important to map the complex structure of the poultry sector. The governance of the poultry value chain in particular, could play a pivotal role, yet there is limited information on the different chain governance structures and their impacts on HPAI control. This article uses value chain analysis (VCA), focusing on an in-depth assessment of governance structures as well as transaction cost economics and quantitative estimates of the market power of different chain actors, to establish a theoretical framework to examine biosecurity and HPAI control in the Western Java poultry chain. During the research, semi-structured interviews were conducted with key value-chain stakeholders, and the economic performance of identified actors was estimated. Results indicated the co-existence of four different poultry value chains in West Java: the integrator chain, the semi-automated slaughterhouse chain, the controlled slaughter-point chain, and the private slaughter-point chain. The integrator chain was characterized by the highest levels of coordination and a tight, hierarchical governance. In contrast, the other three types of value chains were less coordinated. The market power of the different actors within the four value chains also differed. In more integrated chains, slaughterhouses held considerable market power, while in more informal value chains, market power was in the hands of traders. The economic effects of HPAI and biosecurity measures also varied for the identified actors in the different value chains. Implementation of biosecurity and HPAI control measures was strongly related to the governance structure of the chain, with interactions between different chains and governance structures accentuating the risk of HPAI. Our findings highlight that a proper understanding of the chain governance structure is vital to improve the effectiveness of HPAI control measures, by making the interventions more specific and fit-for-purpose given the incentive structures present in different chains. PMID:29770325

Linking Supply Chain Governance and Biosecurity in the Context of HPAI Control in Western Java: A Value Chain Perspective.

PubMed

Indrawan, Dikky; Rich, Karl M; van Horne, Peter; Daryanto, Arief; Hogeveen, Henk

2018-01-01

Despite extensive efforts to control the highly pathogenic avian influenza (HPAI), it remains endemic in Western Java, Indonesia. To understand the limited effectiveness of HPAI control measures, it is important to map the complex structure of the poultry sector. The governance of the poultry value chain in particular, could play a pivotal role, yet there is limited information on the different chain governance structures and their impacts on HPAI control. This article uses value chain analysis (VCA), focusing on an in-depth assessment of governance structures as well as transaction cost economics and quantitative estimates of the market power of different chain actors, to establish a theoretical framework to examine biosecurity and HPAI control in the Western Java poultry chain. During the research, semi-structured interviews were conducted with key value-chain stakeholders, and the economic performance of identified actors was estimated. Results indicated the co-existence of four different poultry value chains in West Java: the integrator chain, the semi-automated slaughterhouse chain, the controlled slaughter-point chain, and the private slaughter-point chain. The integrator chain was characterized by the highest levels of coordination and a tight, hierarchical governance. In contrast, the other three types of value chains were less coordinated. The market power of the different actors within the four value chains also differed. In more integrated chains, slaughterhouses held considerable market power, while in more informal value chains, market power was in the hands of traders. The economic effects of HPAI and biosecurity measures also varied for the identified actors in the different value chains. Implementation of biosecurity and HPAI control measures was strongly related to the governance structure of the chain, with interactions between different chains and governance structures accentuating the risk of HPAI. Our findings highlight that a proper understanding of the chain governance structure is vital to improve the effectiveness of HPAI control measures, by making the interventions more specific and fit-for-purpose given the incentive structures present in different chains.

Biowaste-Derived Hierarchical Porous Carbon Nanosheets for Ultrahigh Power Density Supercapacitors.

PubMed

Yu, Dengfeng; Chen, Chong; Zhao, Gongyuan; Sun, Lei; Du, Baosheng; Zhang, Hong; Li, Zhuo; Sun, Ye; Besenbacher, Flemming; Yu, Miao

2018-03-05

Low-cost activated carbons with high capacitive properties remain desirable for supercapacitor applications. Herein, a three-dimensional scaffolding framework of porous carbon nanosheets (PCNSs) has been produced from a typical biowaste, namely, ground cherry calyces, the specific composition and natural structures of which have contributed to the PCNSs having a very large specific surface area of 1612 m 2  g -1 , a hierarchical pore size distribution, a turbostratic carbon structure with a high degree graphitization, and about 10 % oxygen and nitrogen heteroatoms. A high specific capacitance of 350 F g -1 at 0.1 A g -1 has been achieved in a two-electrode system with 6 m KOH; this value is among the highest specific capacitance of biomass-derived carbon materials. More inspiringly, a high energy density of 22.8 Wh kg -1 at a power density of 198.8 W kg -1 can be obtained with 1 m aqueous solution of Li 2 SO 4 , and an ultrahigh energy density of 81.4 Wh kg -1 at a power density of 446.3 W kg -1 is realized with 1-ethyl-3-methylimidazolium tetrafluoroborate electrolyte. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A matter of focus: Power-holders feel more responsible after adopting a cognitive other-focus, rather than a self-focus.

PubMed

Scholl, Annika; Sassenberg, Kai; Scheepers, Daan; Ellemers, Naomi; de Wit, Frank

2017-03-01

Social power implies responsibility. Yet, power-holders often follow only their own interests and overlook this responsibility. The present research illuminates how a previously adopted cognitive focus guides perceived responsibility when a person receives high (vs. low) power. In three experiments, adopting a cognitive focus on another person (vs. on the self or taking over another person's perspective) promoted perceived responsibility among individuals receiving high (but not low) power in a subsequent context. This effect was specific for perceived responsibility - a cognitive focus on another person did not change the perceived opportunity to pursue goals or the perceived relationship to an interaction partner (e.g., interpersonal closeness). While prior research examined how social values (i.e., chronically caring about others) guide responsibility among those holding power, the current findings highlight that mere cognitive processes (i.e., situationally focusing attention on others) alter perceived responsibility among those just about to receive power. © 2016 The British Psychological Society.

Prognostic value of biological markers in myocardial infarction patients.

PubMed

Berezin, Alexander E; Samura, Tatiana A

2013-04-01

The aim of this study was to compare the prognostic value of matrix metalloproteinase-3 and -9, and NT-pro-natriuretic peptide for fatal and nonfatal complications in Q-wave myocardial infarction patients in the acute and postinfarction periods. 85 men and women with documented Q-wave myocardial infarction were observed for 1 year after hospitalization. Clinical endpoints were identified through the hospital patient-tracking system, with a review of medical records for each recorded endpoint. Left ventricular ejection fraction and wall motion index were calculated. Measurements of matrix metalloproteinases and NT-pro-natriuretic peptide were performed by an enzyme-linked immunosorbent assay. A cutoff value of 9.7 ng·mL(-1) for matrix metalloproteinase-3 showed the best discriminatory power (sensitivity = 77.8%, specificity = 90.8%). The optimal cutoff value of matrix metalloproteinase-9 was 18.1 ng·mL(-1) (sensitivity, 70.5%; specificity, 75%), and the cutoff for NT-pro-natriuretic peptide was 885 pmol·L(-1) (sensitivity, 58%; specificity, 68.6%). Matrix metalloproteinase-3 and -9 were strongly related with a positive prognostic value of 70% (sensitivity and specificity, 84% and 82%, respectively). These data may be helpful for further stratification of patients into cardiovascular mortality risk groups.

Transcultural nursing care values, beliefs, and practices of American (USA) Gypsies.

PubMed

Bodner, A; Leininger, M

1992-01-01

This ethnonursing qualitative investigation was focused on the domain of culture care values, expression and meanings of selected American Gypsies. The purpose of the study was to explicate culture care American Gypsy lifeways in order to help nurses understand this largely unknown culture, and to offer guidelines for providing culturally congruent nursing care. Leininger's theory of Culture Care Diversity and Universality was the appropriate theory to use for this study, along with the ethnonursing research method to generate emic and etic grounded data. Findings substantiated that the world view, ethnohistory, religion (moral code), kinship and cultural values, and generic folk practices were powerful influences of Gypsy lifeways and supported culture congruent nursing care. Ethnohistorical facts strongly buttressed the cultural values, norms, and moral codes for culture specific care practices. Several Gypsy culture specific and dominant care meanings, expressions, and actions were confirmed and made credible from raw data and thematic analysis. They were: 1) protective in-group caring; 2) watching over and guarding against Gadje; 3) facilitating care rituals; 4) respecting Gypsy values; 5) alleviating Gadje harassment; 6) remaining suspicious of outsiders; and 7) dealing with purity and impurity moral codes and rules. Culture specific and congruent care generated from Leininger's theory with the three predicted modes were identified to guide nursing decisions and actions.

Modified Holographic Ricci Dark Energy in Chameleon Brans-Dicke Cosmology and Its Thermodynamic Consequence

NASA Astrophysics Data System (ADS)

Jawad, A.; Chattopadhyay, S.; Bhattacharya, S.; Pasqua, A.

2015-04-01

The objective of this paper is to discuss the Chameleon Brans-Dicke gravity with non-minimally matter coupling of scalar field. We take modified Holographic Ricci dark energy model in this gravity with its energy density in interaction with energy density of cold dark matter. We assume power-law ansatz for scale factor and scalar field to discuss potential as well as coupling functions in the evolving universe. These reconstructed functions are plotted versus scalar field and time for different values of power component of scale factor n. We observe that potential and coupling functions represent increasing behavior, in particular, consistent results for a specific value of n. Finally, we have examined validity of the generalized second law of thermodynamics and we have observed its validity for all values of n. The financial Supported from Department of Science and Technology, Govt. of India under Project Grant No. SR/FTP/PS-167/2011 is thankfully acknowledged by SC

Impact of the injection dose of exhaust gases, on work parameters of combustion engine

NASA Astrophysics Data System (ADS)

Marek, W.; Śliwiński, K.

2016-09-01

This article is another one from the series in which were presented research results indicated the possible areas of application of the pneumatic injection using hot combustion gases proposed by Professor Jarnuszkiewicz. This publication present the results of the control system of exhaust gas recirculation. The main aim of this research was to determine the effect of exhaust gas recirculation to the operating parameters of the internal combustion engine on the basis of laboratory measurements. All measurements were performed at a constant engine speed. These conditions correspond to the operation of the motor operating an electrical generator. The study was conducted on the four-stroke two-cylinder engine with spark ignition. The study were specifically tested on the air injection system and therefore the selection of the rotational speed was not bound, as in conventional versions of operating parameters of the electrical machine. During the measurement there were applied criterion which used power control corresponding to the requirements of load power, at minimal values of engine speed. Recirculation value determined by the following recurrent position control valve of the injection doses inflator gas for pneumatic injection system. They were studied and recorded, the impact of dose of gases recirculation to the operating and ecological engine parameters such as power, torque, specific fuel consumption, efficiency, air fuel ratio, exhaust gas temperature and nitrogen oxides and hydrocarbons.

Balance of excitation and inhibition determines 1/f power spectrum in neuronal networks.

PubMed

Lombardi, F; Herrmann, H J; de Arcangelis, L

2017-04-01

The 1/f-like decay observed in the power spectrum of electro-physiological signals, along with scale-free statistics of the so-called neuronal avalanches, constitutes evidence of criticality in neuronal systems. Recent in vitro studies have shown that avalanche dynamics at criticality corresponds to some specific balance of excitation and inhibition, thus suggesting that this is a basic feature of the critical state of neuronal networks. In particular, a lack of inhibition significantly alters the temporal structure of the spontaneous avalanche activity and leads to an anomalous abundance of large avalanches. Here, we study the relationship between network inhibition and the scaling exponent β of the power spectral density (PSD) of avalanche activity in a neuronal network model inspired in Self-Organized Criticality. We find that this scaling exponent depends on the percentage of inhibitory synapses and tends to the value β = 1 for a percentage of about 30%. More specifically, β is close to 2, namely, Brownian noise, for purely excitatory networks and decreases towards values in the interval [1, 1.4] as the percentage of inhibitory synapses ranges between 20% and 30%, in agreement with experimental findings. These results indicate that the level of inhibition affects the frequency spectrum of resting brain activity and suggest the analysis of the PSD scaling behavior as a possible tool to study pathological conditions.

Balance of excitation and inhibition determines 1/f power spectrum in neuronal networks

NASA Astrophysics Data System (ADS)

Lombardi, F.; Herrmann, H. J.; de Arcangelis, L.

2017-04-01

The 1/f-like decay observed in the power spectrum of electro-physiological signals, along with scale-free statistics of the so-called neuronal avalanches, constitutes evidence of criticality in neuronal systems. Recent in vitro studies have shown that avalanche dynamics at criticality corresponds to some specific balance of excitation and inhibition, thus suggesting that this is a basic feature of the critical state of neuronal networks. In particular, a lack of inhibition significantly alters the temporal structure of the spontaneous avalanche activity and leads to an anomalous abundance of large avalanches. Here, we study the relationship between network inhibition and the scaling exponent β of the power spectral density (PSD) of avalanche activity in a neuronal network model inspired in Self-Organized Criticality. We find that this scaling exponent depends on the percentage of inhibitory synapses and tends to the value β = 1 for a percentage of about 30%. More specifically, β is close to 2, namely, Brownian noise, for purely excitatory networks and decreases towards values in the interval [1, 1.4] as the percentage of inhibitory synapses ranges between 20% and 30%, in agreement with experimental findings. These results indicate that the level of inhibition affects the frequency spectrum of resting brain activity and suggest the analysis of the PSD scaling behavior as a possible tool to study pathological conditions.

Does Spontaneous Favorability to Power (vs. Universalism) Values Predict Spontaneous Prejudice and Discrimination?

PubMed

Souchon, Nicolas; Maio, Gregory R; Hanel, Paul H P; Bardin, Brigitte

2017-10-01

We conducted five studies testing whether an implicit measure of favorability toward power over universalism values predicts spontaneous prejudice and discrimination. Studies 1 (N = 192) and 2 (N = 86) examined correlations between spontaneous favorability toward power (vs. universalism) values, achievement (vs. benevolence) values, and a spontaneous measure of prejudice toward ethnic minorities. Study 3 (N = 159) tested whether conditioning participants to associate power values with positive adjectives and universalism values with negative adjectives (or inversely) affects spontaneous prejudice. Study 4 (N = 95) tested whether decision bias toward female handball players could be predicted by spontaneous attitude toward power (vs. universalism) values. Study 5 (N = 123) examined correlations between spontaneous attitude toward power (vs. universalism) values, spontaneous importance toward power (vs. universalism) values, and spontaneous prejudice toward Black African people. Spontaneous positivity toward power (vs. universalism) values was associated with spontaneous negativity toward minorities and predicted gender bias in a decision task, whereas the explicit measures did not. These results indicate that the implicit assessment of evaluative responses attached to human values helps to model value-attitude-behavior relations. © 2016 The Authors. Journal of Personality Published by Wiley Periodicals, Inc.

Cu(In,Ga)S2, Thin-Film Solar Cells Prepared by H2S Sulfurization of CuGa-In Precursor

NASA Technical Reports Server (NTRS)

Dhere, Neelkanth G.; Kulkarni, Shashank R.; Chavan, Sanjay S.; Ghongadi, Shantinath R.

2005-01-01

Thin-film CuInS2 solar cell is the leading candidate for space power because of bandgap near the optimum value for AM0 solar radiation outside the earth's atmosphere, excellent radiation hardness, and freedom from intrinsic degradation mechanisms unlike a-Si:H cells. Ultra-lightweight thin-film solar cells deposited on flexible polyimide plastic substrates such as Kapton(trademark), Upilex(trademark), and Apical(trademark) have a potential for achieving specific power of 1000 W/kg, while the state-of-art specific power of the present day solar cells is 66 W/kg. This paper describes the preparation of Cu-rich CuIn(sub 1-x)Ga(sub x)S(sub 2) (CIGS2) thin films and solar cells by a process of sulfurization of CuGa-In precursor similar to that being used for preparation of large-compact-grain CuIn(sub 1-x)Ga(sub x)Se2 thin films and efficient solar cells at FSEC PV Materials Lab.

Vertically Aligned Niobium Nanowire Arrays for Fast-Charging Micro-Supercapacitors.

PubMed

Mirvakili, Seyed M; Hunter, Ian W

2017-07-01

Planar micro-supercapacitors are attractive for system on chip technologies and surface mount devices due to their large areal capacitance and energy/power density compared to the traditional oxide-based capacitors. In the present work, a novel material, niobium nanowires, in form of vertically aligned electrodes for application in high performance planar micro-supercapacitors is introduced. Specific capacitance of up to 1 kF m -2 (100 mF cm -2 ) with peak energy and power density of 2 kJ m -2 (6.2 MJ m -3 or 1.7 mWh cm -3 ) and 150 kW m -2 (480 MW m -3 or 480 W cm -3 ), respectively, is achieved. This remarkable power density, originating from the extremely low equivalent series resistance value of 0.27 Ω (2.49 µΩ m 2 or 24.9 mΩ cm 2 ) and large specific capacitance, is among the highest for planar micro-supercapacitors electrodes made of nanomaterials. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Probabilistic Prognosis of Environmental Radioactivity Concentrations due to Radioisotopes Discharged to Water Bodies from Nuclear Power Plants.

PubMed

Tomás Zerquera, Juan; Mora, Juan C; Robles, Beatriz

2017-11-15

Due to their very low values, the complexity of comparing the contribution of nuclear power plants (NPPs) to environmental radioactivity with modeled values is recognized. In order to compare probabilistic prognosis of radioactivity concentrations with environmental measurement values, an exercise was performed using public data of radioactive routine discharges from three representative Spanish nuclear power plants. Specifically, data on liquid discharges from three Spanish NPPs: Almaraz, Vandellós II, and Ascó to three different aquatic bodies (river, lake, and coast) were used. Results modelled using generic conservative models together with Monte Carlo techniques used for uncertainties propagation were compared with values of radioactivity concentrations in the environment measured in the surroundings of these NPPs. Probability distribution functions were inferred for the source term, used as an input to the model to estimate the radioactivity concentrations in the environment due to discharges to the water bodies. Radioactivity concentrations measured in bottom sediments were used in the exercise due to their accumulation properties. Of all the radioisotopes measured in the environmental monitoring programs around the NPPs, only Cs-137, Sr-90, and Co-60 had positive values greater than their respective detection limits. Of those, Sr-90 and Cs-137 are easily measured in the environment, but significant contribution from the radioactive fall-out due to nuclear explosions in the atmosphere exists, and therefore their values cannot be attributed to the NPPs. On the contrary, Co-60 is especially useful as an indicator of the radioactive discharges from NPPs because its presence in the environment can solely be attributed to the impact of the closer nuclear facilities. All the modelled values for Co-60 showed a reasonable correspondence with measured environmental data in all cases, being conservative in two of them. The more conservative predictions obtained with the models were the activity concentrations in the sediments of a lake (Almaraz) where, on average, values two times higher were obtained. For the case of rivers (Ascó), calculated results were adequately conservative-up to 3.4 times on average. However, the results for coasts (Vandellos II) were in the same range as the environmental measurements, obtaining predictions that are only-at maximum-1.1 times higher than measured values. Only for this specific case of coasts could it be established that the models are not conservative enough, although the results, on average, are relatively close to the real values.

10 CFR 110.32 - Information required in an application for a specific license/NRC Form 7.

Code of Federal Regulations, 2011 CFR

2011-01-01

...) and its chemical and physical form. (2) For enriched uranium, the maximum weight percentage of... and its total dollar value. (4) For nuclear reactors, the name of the facility, its design power level..., physical and chemical characteristics, route of transit of shipment, classification (as defined in § 61.55...

Fluid property measurements study

NASA Technical Reports Server (NTRS)

Devaney, W. E.

1976-01-01

Fluid properties of refrigerant-21 were investigated at temperatures from the freezing point to 423 Kelvin and at pressures to 1.38 x 10 to the 8th power N/sq m (20,000 psia). The fluid properties included were: density, vapor pressure, viscosity, specific heat, thermal conductivity, thermal expansion coefficient, freezing point and bulk modulus. Tables of smooth values are reported.

Analysis of High-Power Diode Laser Heating Effects on HY-80 Steel for Laser Assisted Friction Stir Welding Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wiechec, Maxwell; Baker, Brad; McNelley, Terry

In this research, several conditions of high power diode laser heated HY-80 steel were characterized to determine the viability of using such lasers as a preheating source before friction stir welding in order to reduce frictional forces thereby reducing tool wear and increasing welding speeds. Differences in microstructures within heat affected zones were identified at specific laser powers and traverse speeds. Vickers hardness values were recorded and analyzed to validate the formation of additional martensite in diode laser heated regions of HY-80 steel. Conditions that produced little to no additional martensite were identified and relationships among high power diode lasermore » power, traverse speed, and martensite formation were determined. The development of heat affected zones, change in grain structure, and creation of additional martensite in HY-80 can be prevented through the optimization of laser amperage and transverse speed.« less

A low-power CMOS operational amplifier IC for a heterogeneous paper-based potentiostat

NASA Astrophysics Data System (ADS)

Bezuidenhout, P.; Land, K.; Joubert, T.-H.

2016-02-01

Electrochemical biosensing is used to detect specific analytes in fluids, such as bacterial and chemical contaminants. A common implementation of an electrochemical readout is a potentiostat, which usually includes potentiometric, amperometric, and impedimetric detection. Recently several researchers have developed small, low-cost, single-chip silicon-based potentiostats. With the advances in heterogeneous integration technology, low-power potentiostats can be implemented on paper and similar low cost substrates. This paper deals with the design of a low-power paper-based amperometric front-end for a low-cost and rapid detection environment. In amperometric detection a voltage signal is provided to a sensor system, while a small current value generated by an electrochemical redox reaction in the system is measured. In order to measure low current values, the noise of the circuit must be minimized, which is accomplished with a pre-amplification front-end stage, typically designed around an operational amplifier core. An appropriate circuit design for a low-power and low-cost amperometric front-end is identified, taking the heterogeneous integration of various components into account. The operational amplifier core is on a bare custom CMOS chip, which will be integrated onto the paper substrate alongside commercial off-the-shelf electronic components. A general-purpose low-power two-stage CMOS amplifier circuit is designed and simulated for the ams 350 nm 5 V process. After the layout design and verification, the IC was submitted for a multi-project wafer manufacturing run. The simulated results are a bandwidth of 2.4 MHz, a common-mode rejection ratio of 70.04 dB, and power dissipation of 0.154 mW, which are comparable with the analytical values.

Evaluation of puberty by verifying spontaneous and stimulated gonadotropin values in girls.

PubMed

Chin, Vivian L; Cai, Ziyong; Lam, Leslie; Shah, Bina; Zhou, Ping

2015-03-01

Changes in pharmacological agents and advancements in laboratory assays have changed the gonadotropin-releasing hormone analog stimulation test. To determine the best predictive model for detecting puberty in girls. Thirty-five girls, aged 2 years 7 months to 9 years 3 months, with central precocious puberty (CPP) (n=20) or premature thelarche/premature adrenarche (n=15). Diagnoses were based on clinical information, baseline hormones, bone age, and pelvic sonogram. Gonadotropins and E2 were analyzed using immunochemiluminometric assay. Logistic regression for CPP was performed. The best predictor of CPP is the E2-change model based on 3- to 24-h values, providing 80% sensitivity and 87% specificity. Three-hour luteinizing hormone (LH) provided 75% sensitivity and 87% specificity. Basal LH lowered sensitivity to 65% and specificity to 53%. The E2-change model provided the best predictive power; however, 3-h LH was more practical and convenient when evaluating puberty in girls.

Effect of polyaniline on MWCNTs supercapacitor properties prepared by electrophoretic deposition

NASA Astrophysics Data System (ADS)

Razak, Rozelia Azila Abd; Eleas, Nor Hamizah; Mohammad, Nurul Nazwa; Yusof, Azmi Mohamed; Zaine, Intan Syaffinazzilla

2017-08-01

Multi-walled carbon nanotubes (MWCNTs) is widely used as supercapacitor electrode material. However, the specific capacitance of MWCNTs cannot achieve optimum value to facilitate required demand. Conducting polymers have been introduced to achieve optimum energy density and power density of supercapacitor electrode material. Previous work had demonstrated the effects of adding conducting polymer into carbon base material to get pseudocapacitance effect. Nevertheless the effects specifically of polyaniline (PANi) to MWCNTs were significantly low. This work describes the effect of PANi adding on MWCNTs film prepared by electrophoretic deposition (EPD) technique in order to increase the specific capacitance of MWCNTs. The commercial MWCNTs is dispersed in deionized water by using crystal violet. The admixtures without PANi (sample A), 5wt.% of PANi (sample B) and 10wt.% of PANi (sample C) have been prepared by ex-situ polymerization. The voltage supplied for film deposition is 8 V for 5 minutes. The morphology, functional group and electrochemical properties of MWCNTs due to the presence of PANi had been studied. From FESEM analysis, the presence of PANi can be clearly observed for sample B and sample C while FTIR analysis, proves PANi structure on MWCNTs with its functional group presence in sample B and sample C through the absorbtion band which obviously shifted to higher value compare to sample A. Cyclic voltammogram (CV) analysis shown redox activity occurred in sample B and sample C with identical anodic and cathodic peaks. Sample B hold the higher specific capacitance and higher energy density compared than sample A and sample B. From galvanostatic charge-discharge (CD) measurement, the charge and discharge process for sample B is longer than sample A and sample C which consequently lower its power density. The presence of PANi at 5wt.% is able to increase specific capacitance as well as energy density to optimum value.

(14)C levels in the vicinity of the Fukushima Dai-ichi Nuclear Power Plant prior to the 2011 accident.

PubMed

Xu, Sheng; Cook, Gordon T; Cresswell, Alan J; Dunbar, Elaine; Freeman, Stewart P H T; Hastie, Helen; Hou, Xiaolin; Jacobsson, Piotr; Naysmith, Philip; Sanderson, David C W; Tripney, Brian G; Yamaguchi, Katsuhiko

2016-06-01

A 50-year-old Japanese cedar (Cryptomeria japonica) from Okuma, ∼1 km southwest of the Fukushima Dai-ichi Nuclear Power Plant, was cored and each annual ring was analysed for (14)C. The (14)C specific activity values varied from 330.4 Bq kg(-1) C in the tree ring formed in 1971 to 231.2 Bq kg(-1) C in the 2014 ring. During the periods 1971-1976 and 2011-2014, the (14)C specific activities are indistinguishable from the ambient background values. However, compared with the ambient atmospheric levels, the (14)C specific activities between 1977 and 2010 are significantly elevated, clearly indicating (14)C discharges from the reactors during their normal operations. In addition, the specific activities are positively correlated with the annual electricity generation values. The excess (14)C specific activities were <36 Bq kg(-1) C, corresponding to an additional annual effective dose of <2 μSv via the food ingestion pathway in the study location. The primary wind direction is east-southeast/southeast with a frequency of ∼30%, in comparison to ∼20% frequency for the direction of the site under study (north-northeast/northeast). This would tend to indicate a similar magnitude of additional effective dose and consequently no significant radiological impact of atmospheric (14)C discharges from the FDNPP during the entire period of normal operations. Additionally, no (14)C pulse in activity can be observed in the year 2011 ring. This might be caused by a limited (14)C release from the damaged reactors during the accident or that the prevailing wind during the short period of release (11th-25th March 2011) was not in the direction of Okuma. Copyright © 2016 Elsevier Ltd. All rights reserved.

[Comparison of application of Cochran-Armitage trend test and linear regression analysis for rate trend analysis in epidemiology study].

PubMed

Wang, D Z; Wang, C; Shen, C F; Zhang, Y; Zhang, H; Song, G D; Xue, X D; Xu, Z L; Zhang, S; Jiang, G H

2017-05-10

We described the time trend of acute myocardial infarction (AMI) from 1999 to 2013 in Tianjin incidence rate with Cochran-Armitage trend (CAT) test and linear regression analysis, and the results were compared. Based on actual population, CAT test had much stronger statistical power than linear regression analysis for both overall incidence trend and age specific incidence trend (Cochran-Armitage trend P value

Test results and description of a 1-kW free-piston Stirling engine with a dashpot load

NASA Technical Reports Server (NTRS)

Schreiber, J.

1983-01-01

A 1 kW (1.33 hp) single cylinder free piston Stirling engine was installed in the test facilities at the Lewis laboratory. The engine was designed specifically for research of the dynamics of its operation. A more complete description of the engine and its instrumentation is provided in a prior NASA paper TM-82999 by J. G. Schreiber. Initial tests at Lewis showed the power level and efficiency of the engine to be below design level. Tests were performed to help determine the specific problems in the engine causing the below design level performance. Modifications to engine hardware and to the facility where performed in an effort to bring the power output and efficiency to their design values. As finally configured the engine generated more than 1250 watts of output power at an engine efficiency greater than 32 percent. This report presents the tests performed to help determine the specific problems, the results if the problem was eliminated, the fix performed to the hardware, and the test results after the engine was tested. In cases where the fix did not cause the anticipated effects, a possible explanation is given.

Can 3-dimensional power Doppler indices improve the prenatal diagnosis of a potentially morbidly adherent placenta in patients with placenta previa?

PubMed

Haidar, Ziad A; Papanna, Ramesha; Sibai, Baha M; Tatevian, Nina; Viteri, Oscar A; Vowels, Patricia C; Blackwell, Sean C; Moise, Kenneth J

2017-08-01

Traditionally, 2-dimensional ultrasound parameters have been used for the diagnosis of a suspected morbidly adherent placenta previa. More objective techniques have not been well studied yet. The objective of the study was to determine the ability of prenatal 3-dimensional power Doppler analysis of flow and vascular indices to predict the morbidly adherent placenta objectively. A prospective cohort study was performed in women between 28 and 32 gestational weeks with known placenta previa. Patients underwent a two-dimensional gray-scale ultrasound that determined management decisions. 3-Dimensional power Doppler volumes were obtained during the same examination and vascular, flow, and vascular flow indices were calculated after manual tracing of the viewed placenta in the sweep; data were blinded to obstetricians. Morbidly adherent placenta was confirmed by histology. Severe morbidly adherent placenta was defined as increta/percreta on histology, blood loss >2000 mL, and >2 units of PRBC transfused. Sensitivities, specificities, predictive values, and likelihood ratios were calculated. Student t and χ 2 tests, logistic regression, receiver-operating characteristic curves, and intra- and interrater agreements using Kappa statistics were performed. The following results were found: (1) 50 women were studied: 23 had morbidly adherent placenta, of which 12 (52.2%) were severe morbidly adherent placenta; (2) 2-dimensional parameters diagnosed morbidly adherent placenta with a sensitivity of 82.6% (95% confidence interval, 60.4-94.2), a specificity of 88.9% (95% confidence interval, 69.7-97.1), a positive predictive value of 86.3% (95% confidence interval, 64.0-96.4), a negative predictive value of 85.7% (95% confidence interval, 66.4-95.3), a positive likelihood ratio of 7.4 (95% confidence interval, 2.5-21.9), and a negative likelihood ratio of 0.2 (95% confidence interval, 0.08-0.48); (3) mean values of the vascular index (32.8 ± 7.4) and the vascular flow index (14.2 ± 3.8) were higher in morbidly adherent placenta (P < .001); (4) area under the receiver-operating characteristic curve for the vascular and vascular flow indices were 0.99 and 0.97, respectively; (5) the vascular index ≥21 predicted morbidly adherent placenta with a sensitivity and a specificity of 95% (95% confidence interval, 88.2-96.9) and 91%, respectively (95% confidence interval, 87.5-92.4), 92% positive predictive value (95% confidence interval, 85.5-94.3), 90% negative predictive value (95% confidence interval, 79.9-95.3), positive likelihood ratio of 10.55 (95% confidence interval, 7.06-12.75), and negative likelihood ratio of 0.05 (95% confidence interval, 0.03-0.13); and (6) for the severe morbidly adherent placenta, 2-dimensional ultrasound had a sensitivity of 33.3% (95% confidence interval, 11.3-64.6), a specificity of 81.8% (95% confidence interval, 47.8-96.8), a positive predictive value of 66.7% (95% confidence interval, 24.1-94.1), a negative predictive value of 52.9% (95% confidence interval, 28.5-76.1), a positive likelihood ratio of 1.83 (95% confidence interval, 0.41-8.11), and a negative likelihood ratio of 0.81 (95% confidence interval, 0.52-1.26). A vascular index ≥31 predicted the diagnosis of a severe morbidly adherent placenta with a 100% sensitivity (95% confidence interval, 72-100), a 90% specificity (95% confidence interval, 81.7-93.8), an 88% positive predictive value (95% confidence interval, 55.0-91.3), a 100% negative predictive value (95% confidence interval, 90.9-100), a positive likelihood ratio of 10.0 (95% confidence interval, 3.93-16.13), and a negative likelihood ratio of 0 (95% confidence interval, 0-0.34). Intrarater and interrater agreements were 94% (P < .001) and 93% (P < .001), respectively. The vascular index accurately predicts the morbidly adherent placenta in patients with placenta previa. In addition, 3-dimensional power Doppler vascular and vascular flow indices were more predictive of severe cases of morbidly adherent placenta compared with 2-dimensional ultrasound. This objective technique may limit the variations in diagnosing morbidly adherent placenta because of the subjectivity of 2-dimensional ultrasound interpretations. Copyright © 2017 Elsevier Inc. All rights reserved.

The field theory of specific heat

NASA Astrophysics Data System (ADS)

Gusev, Yu. V.

2016-01-01

Finite temperature quantum field theory in the heat kernel method is used to study the heat capacity of condensed matter. The lattice heat is treated à la P. Debye as energy of the elastic (sound) waves. The dimensionless functional of free energy is re-derived with a cut-off parameter and used to obtain the specific heat of crystal lattices. The new dimensionless thermodynamical variable is formed as Planck's inverse temperature divided by the lattice constant. The dimensionless constant, universal for the class of crystal lattices, which determines the low temperature region of molar specific heat, is introduced and tested with the data for diamond lattice crystals. The low temperature asymptotics of specific heat is found to be the fourth power in temperature instead of the cubic power law of the Debye theory. Experimental data for the carbon group elements (silicon, germanium) and other materials decisively confirm the quartic law. The true low temperature regime of specific heat is defined by the surface heat, therefore, it depends on the geometrical characteristics of the body, while the absolute zero temperature limit is geometrically forbidden. The limit on the growth of specific heat at temperatures close to critical points, known as the Dulong-Petit law, appears from the lattice constant cut-off. Its value depends on the lattice type and it is the same for materials with the same crystal lattice. The Dulong-Petit values of compounds are equal to those of elements with the same crystal lattice type, if one mole of solid state matter were taken as the Avogadro number of the composing atoms. Thus, the Neumann-Kopp law is valid only in some special cases.

Automated respiratory cycles selection is highly specific and improves respiratory mechanics analysis.

PubMed

Rigo, Vincent; Graas, Estelle; Rigo, Jacques

2012-07-01

Selected optimal respiratory cycles should allow calculation of respiratory mechanic parameters focusing on patient-ventilator interaction. New computer software automatically selecting optimal breaths and respiratory mechanics derived from those cycles are evaluated. Retrospective study. University level III neonatal intensive care unit. Ten mins synchronized intermittent mandatory ventilation and assist/control ventilation recordings from ten newborns. The ventilator provided respiratory mechanic data (ventilator respiratory cycles) every 10 secs. Pressure, flow, and volume waves and pressure-volume, pressure-flow, and volume-flow loops were reconstructed from continuous pressure-volume recordings. Visual assessment determined assisted leak-free optimal respiratory cycles (selected respiratory cycles). New software graded the quality of cycles (automated respiratory cycles). Respiratory mechanic values were derived from both sets of optimal cycles. We evaluated quality selection and compared mean values and their variability according to ventilatory mode and respiratory mechanic provenance. To assess discriminating power, all 45 "t" values obtained from interpatient comparisons were compared for each respiratory mechanic parameter. A total of 11,724 breaths are evaluated. Automated respiratory cycle/selected respiratory cycle selections agreement is high: 88% of maximal κ with linear weighting. Specificity and positive predictive values are 0.98 and 0.96, respectively. Averaged values are similar between automated respiratory cycle and ventilator respiratory cycle. C20/C alone is markedly decreased in automated respiratory cycle (1.27 ± 0.37 vs. 1.81 ± 0.67). Tidal volume apparent similarity disappears in assist/control: automated respiratory cycle tidal volume (4.8 ± 1.0 mL/kg) is significantly lower than for ventilator respiratory cycle (5.6 ± 1.8 mL/kg). Coefficients of variation decrease for all automated respiratory cycle parameters in all infants. "t" values from ventilator respiratory cycle data are two to three times higher than ventilator respiratory cycles. Automated selection is highly specific. Automated respiratory cycle reflects most the interaction of both ventilator and patient. Improving discriminating power of ventilator monitoring will likely help in assessing disease status and following trends. Averaged parameters derived from automated respiratory cycles are more precise and could be displayed by ventilators to improve real-time fine tuning of ventilator settings.

Real options and asset valuation in competitive energy markets

NASA Astrophysics Data System (ADS)

Oduntan, Adekunle Richard

The focus of this work is to develop a robust valuation framework for physical power assets operating in competitive markets such as peaking or mid-merit thermal power plants and baseload power plants. The goal is to develop a modeling framework that can be adapted to different energy assets with different types of operating flexibilities and technical constraints and which can be employed for various purposes such as capital budgeting, business planning, risk management and strategic bidding planning among others. The valuation framework must also be able to capture the reality of power market rules and opportunities, as well as technical constraints of different assets. The modeling framework developed conceptualizes operating flexibilities of power assets as "switching options' whereby the asset operator decides at every decision point whether to switch from one operating mode to another mutually exclusive mode, within the limits of the equipment constraints of the asset. As a current decision to switch operating modes may affect future operating flexibilities of the asset and hence cash flows, a dynamic optimization framework is employed. The developed framework accounts for the uncertain nature of key value drivers by representing them with appropriate stochastic processes. Specifically, the framework developed conceptualizes the operation of a power asset as a multi-stage decision making problem where the operator has to make a decision at every stage to alter operating mode given currently available information about key value drivers. The problem is then solved dynamically by decomposing it into a series of two-stage sub-problems according to Bellman's optimality principle. The solution algorithm employed is the Least Squares Monte Carlo (LSM) method. The developed valuation framework was adapted for a gas-fired thermal power plant, a peaking hydroelectric power plant and a baseload power plant. This work built on previously published real options valuation methodologies for gas-fired thermal power plants by factoring in uncertainty from gas supply/consumption imbalance which is usually faced by gas-fired power generators. This source of uncertainty arises because of mismatch between natural gas and electricity wholesale markets. Natural gas markets in North America operate on a day-ahead basis while power plants are dispatched in real time. Inability of a power generator to match its gas supply and consumption in real time, leading to unauthorized gas over-run or under-run, attracts penalty charges from the gas supplier to the extent that the generator can not manage the imbalance through other means. By considering an illustrative power plant operating in Ontario, we show effects of gas-imbalance on dispatch strategies on a daily cycling operation basis and the resulting impact on net revenue. Similarly, we employ the developed valuation framework to value a peaking hydroelectric power plant. This application also builds on previous real options valuation work for peaking hydroelectric power plants by considering their operations in a joint energy and ancillary services market. Specifically, the valuation model is developed to capture the value of a peaking power plant whose owner has the flexibility to participate in a joint operating reserve market and an energy market, which is currently the case in the Ontario wholesale power market. The model factors in water inflow uncertainty into the reservoir forebay of a hydroelectric facility and also considers uncertain energy and operating reserve prices. The switching options considered include (i) a joint energy and operating reserve bid (ii) an energy only bid and (iii) a do nothing (idle) strategy. Being an energy limited power plant, by doing nothing at a decision interval, the power asset operator is able to timeshift scarce water for use at a future period when market situations are expected to be better. Finally, the developed valuation framework was employed to optimize life-cycle management decisions of a baseload power plant, such as a nuclear power plant. Given uncertainty of long-term value drivers, including power prices, equipment performance and the relationship between current life cycle spending and future equipment degradation, optimization is carried out with the objective of minimizing overall life-cycle related costs. These life-cycle costs include (i) lost revenue during planned and unplanned outages, (ii) potential costs of future equipment degradation due to inadequate preventative maintenance, and (iii) the direct costs of implementing the life-cycle projects. The switching options in this context include the option to shutdown the power plant in order to execute a given preventative maintenance and inspection project and the option to keep the option "alive" by choosing to delay a planned life-cycle activity.

Alignment and Initial Operation of an Advanced Solar Simulator

NASA Technical Reports Server (NTRS)

Jaworske, Donald A.; Jefferies, Kent S.; Mason, Lee S.

1996-01-01

A solar simulator utilizing nine 30-kW xenon arc lamps was built to provide radiant power for testing a solar dynamic space power system in a thermal vacuum environment. The advanced solar simulator achieved the following values specific to the solar dynamic system: (1) a subtense angle of 1 deg; (2) the ability to vary solar simulator intensity up to 1.7 kW/sq m; (3) a beam diameter of 4.8 m; and (4) uniformity of illumination on the order of +/-10%. The flexibility of the solar simulator design allows for other potential uses of the facility.

Impacts of Variable Renewable Energy on Bulk Power System Assets, Pricing, and Costs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wiser, Ryan H.; Mills, Andrew; Seel, Joachim

We synthesize available literature, data, and analysis on the degree to which growth in variable renewable energy (VRE) has impacted to date or might in the future impact bulk power system assets, pricing, and costs. We do not analyze impacts on specific power plants, instead focusing on national and regional system-level trends. The issues addressed are highly context dependent—affected by the underlying generation mix of the system, the amount of wind and solar penetration, and the design and structure of the bulk power system in each region. Moreover, analyzing the impacts of VRE on the bulk power system is amore » complex area of research and there is much more to be done to increase understanding of how VRE impacts the dynamics of current and future electricity markets. While more analysis is warranted, including additional location-specific assessments, several high-level findings emerge from this synthesis: -VRE Is Already Impacting the Bulk Power Market -VRE Impacts on Average Wholesale Prices Have Been Modest -VRE Impacts on Power Plant Retirements Have So Far Been Limited -VRE Impacts on the Bulk Power Market will Grow with Penetration -The ’System Value’ of VRE will Decline with Penetration -Power System Flexibility Can Reduce the Rate of VRE Value Decline All generation types are unique in some respect—bringing benefits and challenges to the power system—and wholesale markets, industry investments, and operational procedures have evolved over time to manage the characteristics of a changing generation fleet. With increased VRE penetrations, power system planners, operators, regulators, and policymakers will continue to be challenged to develop methods to smoothly and cost-effectively manage the reliable integration of these new and growing sources of electricity supply.« less

High Power MPD Thruster Development at the NASA Glenn Research Center

NASA Technical Reports Server (NTRS)

LaPointe, Michael R.; Mikellides, Pavlos G.; Reddy, Dhanireddy (Technical Monitor)

2001-01-01

Propulsion requirements for large platform orbit raising, cargo and piloted planetary missions, and robotic deep space exploration have rekindled interest in the development and deployment of high power electromagnetic thrusters. Magnetoplasmadynamic (MPD) thrusters can effectively process megawatts of power over a broad range of specific impulse values to meet these diverse in-space propulsion requirements. As NASA's lead center for electric propulsion, the Glenn Research Center has established an MW-class pulsed thruster test facility and is refurbishing a high-power steady-state facility to design, build, and test efficient gas-fed MPD thrusters. A complimentary numerical modeling effort based on the robust MACH2 code provides a well-balanced program of numerical analysis and experimental validation leading to improved high power MPD thruster performance. This paper reviews the current and planned experimental facilities and numerical modeling capabilities at the Glenn Research Center and outlines program plans for the development of new, efficient high power MPD thrusters.

Vaccine refrigeration

PubMed Central

McColloster, Patrick J; Martin-de-Nicolas, Andres

2014-01-01

This commentary reviews recent changes in Centers for Disease Control (CDC) vaccine storage guidelines that were developed in response to an investigative report by the Office of the Inspector General. The use of temperature data loggers with probes residing in glycol vials is advised along with storing vaccines in pharmaceutical refrigerators. These refrigerators provide good thermal distribution but can warm to 8 °C in less than one hour after the power is discontinued. Consequently, electric grid instability influences appropriate refrigerator selection and the need for power back-up. System Average Interruption Duration Index (SAIDI) values quantify this instability and can be used to formulate region-specific guidelines. A novel aftermarket refrigerator regulator with a battery back-up power supply and microprocessor control system is also described. PMID:24442209

Vaccine refrigeration: thinking outside of the box.

PubMed

McColloster, Patrick J; Martin-de-Nicolas, Andres

2014-01-01

This commentary reviews recent changes in Centers for Disease Control (CDC) vaccine storage guidelines that were developed in response to an investigative report by the Office of the Inspector General. The use of temperature data loggers with probes residing in glycol vials is advised along with storing vaccines in pharmaceutical refrigerators. These refrigerators provide good thermal distribution but can warm to 8 °C in less than one hour after the power is discontinued. Consequently, electric grid instability influences appropriate refrigerator selection and the need for power back-up. System Average Interruption Duration Index (SAIDI) values quantify this instability and can be used to formulate region-specific guidelines. A novel aftermarket refrigerator with a battery back-up power supply and microprocessor control system is also described.

Temperature Response of Emissivity in Intrinsic Silicon: A Selective Absorber for Solar Energy Harvesting

NASA Astrophysics Data System (ADS)

Heredia, Cristian Alonso

The National Academy of Engineers named affordable solar energy as one of the grand challenges for the twenty-first century. Even in sunniest U.S. locations, without subsidies, home generation is still cost prohibitive. To address the cost of solar energy, we investigated intrinsic silicon as a low emissivity selective absorber. We wanted to determine the emissivity of intrinsic silicon at elevated temperatures. At elevated temperatures, a selective absorber coupled to a heat engine could efficiently generate electrical power. Photothermal efficiency depends on the absorber's emissivity. I analyzed total hemispherical emissivity for graphite and intrinsic silicon using a thermal decay method inside a thermal isolation chamber. The results show low emissivity values for intrinsic silicon. Consequently, for temperatures less than 300 °C, intrinsic silicon has a small emissivity (0.16). This small value is in agreement with doped silicon experiments. However, unlike doped silicon, at elevated temperatures of 600 °C, intrinsic silicon emissivity values remain low (0.33). Our analysis suggests intrinsic silicon could convert more solar power into heat than an ideal blackbody. Specifically, the harvested heat could drive a heat engine for efficient power generation. Thus, a cost-effective electrical generating system can operate with a small land footprint using earth abundant silicon.

Wind Technology Modeling Within the System Advisor Model (SAM) (Poster)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Blair, N.; Dobos, A.; Ferguson, T.

This poster provides detail for implementation and the underlying methodology for modeling wind power generation performance in the National Renewable Energy Laboratory's (NREL's) System Advisor Model (SAM). SAM's wind power model allows users to assess projects involving one or more large or small wind turbines with any of the detailed options for residential, commercial, or utility financing. The model requires information about the wind resource, wind turbine specifications, wind farm layout (if applicable), and costs, and provides analysis to compare the absolute or relative impact of these inputs. SAM is a system performance and economic model designed to facilitate analysismore » and decision-making for project developers, financers, policymakers, and energy researchers. The user pairs a generation technology with a financing option (residential, commercial, or utility) to calculate the cost of energy over the multi-year project period. Specifically, SAM calculates the value of projects which buy and sell power at retail rates for residential and commercial systems, and also for larger-scale projects which operate through a power purchase agreement (PPA) with a utility. The financial model captures complex financing and rate structures, taxes, and incentives.« less

Positioning a University Outreach Center: Strategies for Support and Continuation.

ERIC Educational Resources Information Center

Skivington, Kristen D.

1998-01-01

Argues that a strong case can be made for supporting outreach as a value-added function in a university. Specific strategies for positioning outreach within the university by developing a power base are outlined. The case of the University of Michigan-Flint is offered as an example of this approach. Seven lessons learned in the process are noted.…

Temporal fluctuation scaling in populations and communities

Treesearch

Michael Kalyuzhny; Yishai Schreiber; Rachel Chocron; Curtis H. Flather; David A. Kessler; Nadav M. Shnerb

2014-01-01

Taylor's law, one of the most widely accepted generalizations in ecology, states that the variance of a population abundance time series scales as a power law of its mean. Here we reexamine this law and the empirical evidence presented in support of it. Specifically, we show that the exponent generally depends on the length of the time series, and its value...

Robust inference for responder analysis: Innovative clinical trial design using a minimum p-value approach.

PubMed

Lin, Yunzhi

2016-08-15

Responder analysis is in common use in clinical trials, and has been described and endorsed in regulatory guidance documents, especially in trials where "soft" clinical endpoints such as rating scales are used. The procedure is useful, because responder rates can be understood more intuitively than a difference in means of rating scales. However, two major issues arise: 1) such dichotomized outcomes are inefficient in terms of using the information available and can seriously reduce the power of the study; and 2) the results of clinical trials depend considerably on the response cutoff chosen, yet in many disease areas there is no consensus as to what is the most appropriate cutoff. This article addresses these two issues, offering a novel approach for responder analysis that could both improve the power of responder analysis and explore different responder cutoffs if an agreed-upon common cutoff is not present. Specifically, we propose a statistically rigorous clinical trial design that pre-specifies multiple tests of responder rates between treatment groups based on a range of pre-specified responder cutoffs, and uses the minimum of the p-values for formal inference. The critical value for hypothesis testing comes from permutation distributions. Simulation studies are carried out to examine the finite sample performance of the proposed method. We demonstrate that the new method substantially improves the power of responder analysis, and in certain cases, yields power that is approaching the analysis using the original continuous (or ordinal) measure.

QUALITY OF WOOD PELLETS PRODUCED IN BRITISH COLUMBIA FOR EXPORT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tumuluru, J.S.; Sokhansanj, Shahabaddine; Lim, C. Jim

2010-11-01

Wood pellet production and its use for heat and power production are increasing worldwide. The quality of export pellets has to consistently meet certain specifications as stipulated by the larger buyers, such as power utilities or as specified by the standards used for the non-industrial bag market. No specific data is available regarding the quality of export pellets to Europe. To develop a set of baseline data, wood pellets were sampled at an export terminal in Vancouver, British Columbia, Canada. The sampling period was 18 months in 2007-2008 when pellets were transferred from storage bins to the ocean vessels. Themore » sampling frequency was once every 1.5 to 2 months for a total of 9 loading/shipping events. The physical properties of the wood pellets measured were moisture content in the range of 3.5% to 6.5%, bulk density from 728 to 808 kg/m3, durability from 97% to 99%, fines content from 0.03% to 0.87%, calorific value as is from 17 to almost 18 MJ/kg, and ash content from 0.26% to 0.93%.The diameter and length were in the range of 6.4 to 6.5 mm and 14.0 to 19.0 mm, respectively. All of these values met the published non-industrial European grades (CEN) and the grades specified by the Pellet Fuel Institute for the United States for the bag market. The measured values for wood pellet properties were consistent except the ash content values decreased over the test period.« less

Quality of Wood Pellets Produced in British Columbia for Export

DOE Office of Scientific and Technical Information (OSTI.GOV)

J. S. Tumuluru; S. Sokhansanj; C. J. Lim

2010-11-01

Wood pellet production and its use for heat and power production are increasing worldwide. The quality of export pellets has to consistently meet certain specifications as stipulated by the larger buyers, such as power utilities or as specified by the standards used for the non-industrial bag market. No specific data is available regarding the quality of export pellets to Europe. To develop a set of baseline data, wood pellets were sampled at an export terminal in Vancouver, British Columbia, Canada. The sampling period was 18 months in 2007-2008 when pellets were transferred from storage bins to the ocean vessels. Themore » sampling frequency was once every 1.5 to 2 months for a total of 9 loading/shipping events. The physical properties of the wood pellets measured were moisture content in the range of 3.5% to 6.5%, bulk density from 728 to 808 kg/m3, durability from 97% to 99%, fines content from 0.03% to 0.87%, calorific value as is from 17 to almost 18 MJ/kg, and ash content from 0.26% to 0.93%.The diameter and length were in the range of 6.4 to 6.5 mm and 14.0 to 19.0 mm, respectively. All of these values met the published non-industrial European grades (CEN) and the grades specified by the Pellet Fuel Institute for the United States for the bag market. The measured values for wood pellet properties were consistent except the ash content values decreased over the test period.« less

The possibility of application of spiral brain computed tomography to traumatic brain injury.

PubMed

Lim, Daesung; Lee, Soo Hoon; Kim, Dong Hoon; Choi, Dae Seub; Hong, Hoon Pyo; Kang, Changwoo; Jeong, Jin Hee; Kim, Seong Chun; Kang, Tae-Sin

2014-09-01

The spiral computed tomography (CT) with the advantage of low radiation dose, shorter test time required, and its multidimensional reconstruction is accepted as an essential diagnostic method for evaluating the degree of injury in severe trauma patients and establishment of therapeutic plans. However, conventional sequential CT is preferred for the evaluation of traumatic brain injury (TBI) over spiral CT due to image noise and artifact. We aimed to compare the diagnostic power of spiral facial CT for TBI to that of conventional sequential brain CT. We evaluated retrospectively the images of 315 traumatized patients who underwent both brain CT and facial CT simultaneously. The hemorrhagic traumatic brain injuries such as epidural hemorrhage, subdural hemorrhage, subarachnoid hemorrhage, and contusional hemorrhage were evaluated in both images. Statistics were performed using Cohen's κ to compare the agreement between 2 imaging modalities and sensitivity, specificity, positive predictive value, and negative predictive value of spiral facial CT to conventional sequential brain CT. Almost perfect agreement was noted regarding hemorrhagic traumatic brain injuries between spiral facial CT and conventional sequential brain CT (Cohen's κ coefficient, 0.912). To conventional sequential brain CT, sensitivity, specificity, positive predictive value, and negative predictive value of spiral facial CT were 92.2%, 98.1%, 95.9%, and 96.3%, respectively. In TBI, the diagnostic power of spiral facial CT was equal to that of conventional sequential brain CT. Therefore, expanded spiral facial CT covering whole frontal lobe can be applied to evaluate TBI in the future. Copyright © 2014 Elsevier Inc. All rights reserved.

RF tissue-heating near metallic implants during magnetic resonance examinations: an approach in the ac limit.

PubMed

Ballweg, Verena; Eibofner, Frank; Graf, Hansjorg

2011-10-01

State of the art to access radiofrequency (RF) heating near implants is computer modeling of the devices and solving Maxwell's equations for the specific setup. For a set of input parameters, a fixed result is obtained. This work presents a theoretical approach in the alternating current (ac) limit, which can potentially render closed formulas for the basic behavior of tissue heating near metallic structures. Dedicated experiments were performed to support the theory. For the ac calculations, the implant was modeled as an RLC parallel circuit, with L being the secondary of a transformer and the RF transmission coil being its primary. Parameters influencing coupling, power matching, and specific absorption rate (SAR) were determined and formula relations were established. Experiments on a copper ring with a radial gap as capacitor for inductive coupling (at 1.5 T) and on needles for capacitive coupling (at 3 T) were carried out. The temperature rise in the embedding dielectric was observed as a function of its specific resistance using an infrared (IR) camera. Closed formulas containing the parameters of the setup were obtained for the frequency dependence of the transmitted power at fixed load resistance, for the calculation of the resistance for optimum power transfer, and for the calculation of the transmitted power in dependence of the load resistance. Good qualitative agreement was found between the course of the experimentally obtained heating curves and the theoretically determined power curves. Power matching revealed as critical parameter especially if the sample was resonant close to the Larmor frequency. The presented ac approach to RF heating near an implant, which mimics specific values for R, L, and C, allows for closed formulas to estimate the potential of RF energy transfer. A first reference point for worst-case determination in MR testing procedures can be obtained. Numerical approaches, necessary to determine spatially resolved heating maps, can be supported.

Aerobic power and peak power of elite America's Cup sailors.

PubMed

Neville, Vernon; Pain, Matthew T G; Folland, Jonathan P

2009-05-01

Big-boat yacht racing is one of the only able bodied sporting activities where standing arm-cranking ('grinding') is the primary physical activity. However, the physiological capabilities of elite sailors for standing arm-cranking have been largely unreported. The purpose of the study was to assess aerobic parameters, VO(2peak) and onset of blood lactate (OBLA), and anaerobic performance, torque-crank velocity and power-crank velocity relationships and therefore peak power (P (max)) and optimum crank-velocity (omega(opt)), of America's Cup sailors during standing arm-cranking. Thirty-three elite professional sailors performed a step test to exhaustion, and a subset of ten grinders performed maximal 7 s isokinetic sprints at different crank velocities, using a standing arm-crank ergometer. VO(2peak) was 4.7 +/- 0.5 L/min (range 3.6-5.5 L/min) at a power output of 332 +/- 44 W (range 235-425 W). OBLA occurred at a power output of 202 +/- 31 W (61% of W(max)) and VO(2) of 3.3 +/- 0.4 L/min (71% of VO(2peak)). The torque-crank velocity relationship was linear for all participants (r = 0.9 +/- 0.1). P (max) was 1,420 +/- 37 W (range 1,192-1,617 W), and omega(opt) was 125 +/- 6 rpm. These data are among the highest upper-body anaerobic and aerobic power values reported. The unique nature of these athletes, with their high fat-free mass and specific selection and training for standing arm cranking, likely accounts for the high values. The influence of crank velocity on peak power implies that power production during on-board 'grinding' may be optimised through the use of appropriate gear-ratios and the development of efficient gear change mechanisms.

The Use of Artificial Neural Networks for Forecasting the Electric Demand of Stand-Alone Consumers

NASA Astrophysics Data System (ADS)

Ivanin, O. A.; Direktor, L. B.

2018-05-01

The problem of short-term forecasting of electric power demand of stand-alone consumers (small inhabited localities) situated outside centralized power supply areas is considered. The basic approaches to modeling the electric power demand depending on the forecasting time frame and the problems set, as well as the specific features of such modeling, are described. The advantages and disadvantages of the methods used for the short-term forecast of the electric demand are indicated, and difficulties involved in the solution of the problem are outlined. The basic principles of arranging artificial neural networks are set forth; it is also shown that the proposed method is preferable when the input information necessary for prediction is lacking or incomplete. The selection of the parameters that should be included into the list of the input data for modeling the electric power demand of residential areas using artificial neural networks is validated. The structure of a neural network is proposed for solving the problem of modeling the electric power demand of residential areas. The specific features of generation of the training dataset are outlined. The results of test modeling of daily electric demand curves for some settlements of Kamchatka and Yakutia based on known actual electric demand curves are provided. The reliability of the test modeling has been validated. A high value of the deviation of the modeled curve from the reference curve obtained in one of the four reference calculations is explained. The input data and the predicted power demand curves for the rural settlement of Kuokuiskii Nasleg are provided. The power demand curves were modeled for four characteristic days of the year, and they can be used in the future for designing a power supply system for the settlement. To enhance the accuracy of the method, a series of measures based on specific features of a neural network's functioning are proposed.

Algebraic function operator expectation value based quantum eigenstate determination: A case of twisted or bent Hamiltonian, or, a spatially univariate quantum system on a curved space

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baykara, N. A.

Recent studies on quantum evolutionary problems in Demiralp’s group have arrived at a stage where the construction of an expectation value formula for a given algebraic function operator depending on only position operator becomes possible. It has also been shown that this formula turns into an algebraic recursion amongst some finite number of consecutive elements in a set of expectation values of an appropriately chosen basis set over the natural number powers of the position operator as long as the function under consideration and the system Hamiltonian are both autonomous. This recursion corresponds to a denumerable infinite number of algebraicmore » equations whose solutions can or can not be obtained analytically. This idea is not completely original. There are many recursive relations amongst the expectation values of the natural number powers of position operator. However, those recursions may not be always efficient to get the system energy values and especially the eigenstate wavefunctions. The present approach is somehow improved and generalized form of those expansions. We focus on this issue for a specific system where the Hamiltonian is defined on the coordinate of a curved space instead of the Cartesian one.« less

Use of the Sequential Organ Failure Assessment score for evaluating outcome among obstetric patients admitted to the intensive care unit.

PubMed

Jain, Shruti; Guleria, Kiran; Suneja, Amita; Vaid, Neelam B; Ahuja, Sharmila

2016-03-01

To evaluate the prognostic value of the Sequential Organ Failure Assessment (SOFA) score among obstetric patients admitted to the intensive care unit (ICU). A prospective study was conducted among 90 consecutive obstetric patients who were admitted to the ICU of Guru Teg Bahadur Hospital, Delhi, India, between October 6, 2010, and December 25, 2011. Maximum SOFA score was calculated for each of the six organ systems. Receiver operating characteristic curves were used to determine critical cutoff values for total, maximum total, and mean total SOFA scores at various time points. Total SOFA score at admission displayed an area under the curve (AUC) of 0.949, a cutoff value of at least 8.5, sensitivity of 86.7%, and specificity of 90.0%. Maximum total SOFA score had an AUC of 0.980, a cutoff value of at least 10.0, sensitivity of 96.7%, and specificity of 90.0%. Mean total SOFA score had an AUC of 0.997, a cutoff value of at least 9.0, sensitivity of 96.7%, and specificity of 96.7%. In terms of discriminatory power for predicting mortality among obstetric patients admitted to the ICU, total SOFA score at admission was the most relevant, simple, and accurate measure. Copyright © 2015 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

Simple, Defensible Sample Sizes Based on Cost Efficiency

PubMed Central

Bacchetti, Peter; McCulloch, Charles E.; Segal, Mark R.

2009-01-01

Summary The conventional approach of choosing sample size to provide 80% or greater power ignores the cost implications of different sample size choices. Costs, however, are often impossible for investigators and funders to ignore in actual practice. Here, we propose and justify a new approach for choosing sample size based on cost efficiency, the ratio of a study’s projected scientific and/or practical value to its total cost. By showing that a study’s projected value exhibits diminishing marginal returns as a function of increasing sample size for a wide variety of definitions of study value, we are able to develop two simple choices that can be defended as more cost efficient than any larger sample size. The first is to choose the sample size that minimizes the average cost per subject. The second is to choose sample size to minimize total cost divided by the square root of sample size. This latter method is theoretically more justifiable for innovative studies, but also performs reasonably well and has some justification in other cases. For example, if projected study value is assumed to be proportional to power at a specific alternative and total cost is a linear function of sample size, then this approach is guaranteed either to produce more than 90% power or to be more cost efficient than any sample size that does. These methods are easy to implement, based on reliable inputs, and well justified, so they should be regarded as acceptable alternatives to current conventional approaches. PMID:18482055

Lift and moment coefficients expanded to the seventh power of frequency for oscillating rectangular wings in supersonic flow and applied to a specific flutter problem

NASA Technical Reports Server (NTRS)

Nelson, Herbert C; Rainey, Ruby A; Watkins, Charles E

1954-01-01

Linearized theory for compressible unsteady flow is used to derive the velocity potential and lift and moment coefficients in the form of oscillating rectangular wing moving at a constant supersonic speed. Closed expressions for the velocity potential and lift and moment coefficients associated with pitching and translation are given to seventh power of the frequency. These expressions extend the range of usefulness of NACA report 1028 in which similar expressions were derived to the third power of the frequency of oscillation. For example, at a Mach number of 10/9 the expansion of the potential to the third power is an accurate representation of the potential for values of the reduced frequency only up to about 0.08; whereas the expansion of the potential to the seventh power is an accurate representation for values of the reduced frequency up to about 0.2. The section and total lift and moment coefficients are discussed with the aid of several figures. In addition, flutter speeds obtained in the Mach number range from 10/9 to 10/6 for a rectangular wing of aspect ratio 4.53 by using section coefficients derived on the basis of three-dimensional flow are compared with flutter speeds for this wing obtained by using coefficients derived on the basis of two-dimensional flow.

The value of identity: olfactory notes on orbitofrontal cortex function.

PubMed

Gottfried, Jay A; Zelano, Christina

2011-12-01

Neuroscientific research has emphatically promoted the idea that the key function of the orbitofrontal cortex (OFC) is to encode value. Associative learning studies indicate that OFC representations of stimulus cues reflect the predictive value of expected outcomes. Neuroeconomic studies suggest that the OFC distills abstract representations of value from discrete commodities to optimize choice. Although value-based models provide good explanatory power for many different findings, these models are typically disconnected from the very stimuli and commodities giving rise to those value representations. Little provision is made, either theoretically or empirically, for the necessary cooperative role of object identity, without which value becomes orphaned from its source. As a step toward remediating the value of identity, this review provides a focused olfactory survey of OFC research, including new work from our lab, to highlight the elemental involvement of this region in stimulus-specific predictive coding of both perceptual outcomes and expected values. © 2011 New York Academy of Sciences.

Diagnostic power of longitudinal strain at rest for the detection of obstructive coronary artery disease in patients with type 2 diabetes mellitus.

PubMed

Zuo, Houjuan; Yan, Jiangtao; Zeng, Hesong; Li, Wenyu; Li, Pengcheng; Liu, Zhengxiang; Cui, Guanglin; Lv, Jiagao; Wang, Daowen; Wang, Hong

2015-01-01

Global longitudinal strain (GLS) measured by 2-D speckle-tracking echocardiography (2-D STE) at rest has been recognized as a sensitive parameter in the detection of significant coronary artery disease (CAD). However, the diagnostic power of 2-D STE in the detection of significant CAD in patients with diabetes mellitus is unknown. Two-dimensional STE features were studied in total of 143 consecutive patients who underwent echocardiography and coronary angiography. Left ventricular global and segmental peak systolic longitudinal strains (PSLSs) were quantified by speckle-tracking imaging. In the presence of obstructive CAD (defined as stenosis ≥75%), global PSLS was significantly lower in patients with diabetes mellitus than in patients without (16.65 ± 2.29% vs. 17.32 ± 2.27%, p < 0.05). Receiver operating characteristic analysis revealed that global PSLS could effectively detect obstructive CAD in patients without diabetes mellitus (cutoff value: -18.35%, sensitivity: 78.8%, specificity: 77.5%). However, global PSLS could detect obstructive CAD in diabetic patients at a lower cutoff value with inadequate sensitivity and specificity (cutoff value: -17.15%; sensitivity: 61.1%, specificity: 52.9%). In addition, the results for segmental PSLS were similar to those for global PSLS. In conclusion, global and segmental PSLSs at rest were significantly lower in patients with both obstructive CAD and diabetes mellitus than in patients with obstructive CAD only; thus, PSLSs at rest might not be a useful parameter in the detection of obstructive CAD in patients with diabetes mellitus. Copyright © 2015 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Dosimetric characteristics of electron beams produced by a mobile accelerator for IORT.

PubMed

Pimpinella, M; Mihailescu, D; Guerra, A S; Laitano, R F

2007-10-21

Energy and angular distributions of electron beams with different energies were simulated by Monte Carlo calculations. These beams were generated by the NOVAC7 system (Hitesys, Italy), a mobile electron accelerator specifically dedicated to intra-operative radiation therapy (IORT). The electron beam simulations were verified by comparing the measured dose distributions with the corresponding calculated distributions. As expected, a considerable difference was observed in the energy and angular distributions between the IORT beams studied in the present work and the electron beams produced by conventional accelerators for non-IORT applications. It was also found that significant differences exist between the IORT beams used in this work and other IORT beams with different collimation systems. For example, the contribution from the scattered electrons to the total dose was found to be up to 15% higher in the NOVAC7 beams. The water-to-air stopping power ratios of the IORT beams used in this work were calculated on the basis of the beam energy distributions obtained by the Monte Carlo simulations. These calculated stopping power ratios, s(w,air), were compared with the corresponding s(w,air) values recommended by the TRS-381 and TRS-398 IAEA dosimetry protocols in order to estimate the deviations between a dosimetry based on generic parameters and a dosimetry based on parameters specifically obtained for the actual IORT beams. The deviations in the s(w,air) values were found to be as large as up to about 1%. Therefore, we recommend that a preliminary analysis should always be made when dealing with IORT beams in order to assess to what extent the possible differences in the s(w,air) values have to be accounted for or may be neglected on the basis of the specific accuracy needed in clinical dosimetry.

Ultrasonic power measurement system based on acousto-optic interaction.

PubMed

He, Liping; Zhu, Fulong; Chen, Yanming; Duan, Ke; Lin, Xinxin; Pan, Yongjun; Tao, Jiaquan

2016-05-01

Ultrasonic waves are widely used, with applications including the medical, military, and chemical fields. However, there are currently no effective methods for ultrasonic power measurement. Previously, ultrasonic power measurement has been reliant on mechanical methods such as hydrophones and radiation force balances. This paper deals with ultrasonic power measurement based on an unconventional method: acousto-optic interaction. Compared with mechanical methods, the optical method has a greater ability to resist interference and also has reduced environmental requirements. Therefore, this paper begins with an experimental determination of the acoustic power in water contained in a glass tank using a set of optical devices. Because the light intensity of the diffraction image generated by acousto-optic interaction contains the required ultrasonic power information, specific software was written to extract the light intensity information from the image through a combination of filtering, binarization, contour extraction, and other image processing operations. The power value can then be obtained rapidly by processing the diffraction image using a computer. The results of this work show that the optical method offers advantages that include accuracy, speed, and a noncontact measurement method.

Nuclear powered Mars cargo transport mission utilizing advanced ion propulsion

NASA Technical Reports Server (NTRS)

Galecki, Diane L.; Patterson, Michael J.

1987-01-01

Nuclear-powered ion propulsion technology was combined with detailed trajectory analysis to determine propulsion system and trajectory options for an unmanned cargo mission to Mars in support of manned Mars missions. A total of 96 mission scenarios were identified by combining two power levels, two propellants, four values of specific impulse per propellant, three starting altitudes, and two starting velocities. Sixty of these scenarios were selected for a detailed trajectory analysis; a complete propulsion system study was then conducted for 20 of these trajectories. Trip times ranged from 344 days for a xenon propulsion system operating at 300 kW total power and starting from lunar orbit with escape velocity, to 770 days for an argon propulsion system operating at 300 kW total power and starting from nuclear start orbit with circular velocity. Trip times for the 3 MW cases studied ranged from 356 to 413 days. Payload masses ranged from 5700 to 12,300 kg for the 300 kW power level, and from 72,200 to 81,500 kg for the 3 MW power level.

System-state and operating condition sensitive control method and apparatus for electric power delivery systems

NASA Technical Reports Server (NTRS)

Burns, III, William Wesley (Inventor); Wilson, Thomas George (Inventor)

1978-01-01

This invention provides a method and apparatus for determining a precise switching sequence for the power switching elements of electric power delivery systems of the on-off switching type and which enables extremely fast transient response, precise regulation and highly stable operation. The control utilizes the values of the power delivery system power handling network components, a desired output characteristic, a system timing parameter, and the externally imposed operating conditions to determine where steady state operations should be in order to yield desired output characteristics for the given system specifications. The actual state of the power delivery system is continuously monitored and compared to a state-space boundary which is derived from the desired equilibrium condition, and from the information obtained from this comparison, the system is moved to the desired equilibrium condition in one cycle of switching control. Since the controller continuously monitors the power delivery system's externally imposed operating conditions, a change in the conditions is immediately sensed and a new equilibrium condition is determined and achieved, again in a single cycle of switching control.

Ultrasonic power measurement system based on acousto-optic interaction

NASA Astrophysics Data System (ADS)

He, Liping; Zhu, Fulong; Chen, Yanming; Duan, Ke; Lin, Xinxin; Pan, Yongjun; Tao, Jiaquan

2016-05-01

Ultrasonic waves are widely used, with applications including the medical, military, and chemical fields. However, there are currently no effective methods for ultrasonic power measurement. Previously, ultrasonic power measurement has been reliant on mechanical methods such as hydrophones and radiation force balances. This paper deals with ultrasonic power measurement based on an unconventional method: acousto-optic interaction. Compared with mechanical methods, the optical method has a greater ability to resist interference and also has reduced environmental requirements. Therefore, this paper begins with an experimental determination of the acoustic power in water contained in a glass tank using a set of optical devices. Because the light intensity of the diffraction image generated by acousto-optic interaction contains the required ultrasonic power information, specific software was written to extract the light intensity information from the image through a combination of filtering, binarization, contour extraction, and other image processing operations. The power value can then be obtained rapidly by processing the diffraction image using a computer. The results of this work show that the optical method offers advantages that include accuracy, speed, and a noncontact measurement method.

Accuracy of three-dimensional multislice view Doppler in diagnosis of morbid adherent placenta

PubMed Central

Abdel Moniem, Alaa M.; Ibrahim, Ahmed; Akl, Sherif A.; Aboul-Enen, Loay; Abdelazim, Ibrahim A.

2015-01-01

Objective To detect the accuracy of the three-dimensional multislice view (3D MSV) Doppler in the diagnosis of morbid adherent placenta (MAP). Material and Methods Fifty pregnant women at ≥28 weeks gestation with suspected MAP were included in this prospective study. Two dimensional (2D) trans-abdominal gray-scale ultrasound scan was performed for the subjects to confirm the gestational age, placental location, and findings suggestive of MAP, followed by the 3D power Doppler and then the 3D MSV Doppler to confirm the diagnosis of MAP. Intraoperative findings and histopathology results of removed uteri in cases managed by emergency hysterectomy were compared with preoperative sonographic findings to detect the accuracy of the 3D MSV Doppler in the diagnosis of MAP. Results The 3D MSV Doppler increased the accuracy and predictive values of the diagnostic criteria of MAP compared with the 3D power Doppler. The sensitivity and negative predictive value (NPV) (79.6% and 82.2%, respectively) of crowded vessels over the peripheral sub-placental zone to detect difficult placental separation and considerable intraoperative blood loss in cases of MAP using the 3D power Doppler was increased to 82.6% and 84%, respectively, using the 3D MSV Doppler. In addition, the sensitivity, specificity, and positive predictive value (PPV) (90.9%, 68.8%, and 47%, respectively) of the disruption of the uterine serosa-bladder interface for the detection of emergency hysterectomy in cases of MAP using the 3D power Doppler was increased to 100%, 71.8%, and 50%, respectively, using the 3D MSV Doppler. Conclusion The 3D MSV Doppler is a useful adjunctive tool to the 3D power Doppler or color Doppler to refine the diagnosis of MAP. PMID:26401104

β-Cobalt sulfide nanoparticles decorated graphene composite electrodes for high capacity and power supercapacitors

NASA Astrophysics Data System (ADS)

Qu, Baihua; Chen, Yuejiao; Zhang, Ming; Hu, Lingling; Lei, Danni; Lu, Bingan; Li, Qiuhong; Wang, Yanguo; Chen, Libao; Wang, Taihong

2012-11-01

Electrochemical supercapacitors have drawn much attention because of their high power and reasonably high energy densities. However, their performances still do not reach the demand of energy storage. In this paper β-cobalt sulfide nanoparticles were homogeneously distributed on a highly conductive graphene (CS-G) nanocomposite, which was confirmed by transmission electron microscopy analysis, and exhibit excellent electrochemical performances including extremely high values of specific capacitance (~1535 F g-1) at a current density of 2 A g-1, high-power density (11.98 kW kg-1) at a discharge current density of 40 A g-1 and excellent cyclic stability. The excellent electrochemical performances could be attributed to the graphene nanosheets (GNSs) which could maintain the mechanical integrity. Also the CS-G nanocomposite electrodes have high electrical conductivity. These results indicate that high electronic conductivity of graphene nanocomposite materials is crucial to achieving high power and energy density for supercapacitors.

β-Cobalt sulfide nanoparticles decorated graphene composite electrodes for high capacity and power supercapacitors.

PubMed

Qu, Baihua; Chen, Yuejiao; Zhang, Ming; Hu, Lingling; Lei, Danni; Lu, Bingan; Li, Qiuhong; Wang, Yanguo; Chen, Libao; Wang, Taihong

2012-12-21

Electrochemical supercapacitors have drawn much attention because of their high power and reasonably high energy densities. However, their performances still do not reach the demand of energy storage. In this paper β-cobalt sulfide nanoparticles were homogeneously distributed on a highly conductive graphene (CS-G) nanocomposite, which was confirmed by transmission electron microscopy analysis, and exhibit excellent electrochemical performances including extremely high values of specific capacitance (~1535 F g(-1)) at a current density of 2 A g(-1), high-power density (11.98 kW kg(-1)) at a discharge current density of 40 A g(-1) and excellent cyclic stability. The excellent electrochemical performances could be attributed to the graphene nanosheets (GNSs) which could maintain the mechanical integrity. Also the CS-G nanocomposite electrodes have high electrical conductivity. These results indicate that high electronic conductivity of graphene nanocomposite materials is crucial to achieving high power and energy density for supercapacitors.

Thunderstorms and ground-based radio noise as observed by radio astronomy Explorer 1

NASA Technical Reports Server (NTRS)

Caruso, J. A.; Herman, J. R.

1973-01-01

Radio Astronomy Explorer (RAE) data were analyzed to determine the frequency dependence of HF terrestrial radio noise power. RAE observations of individual thunderstorms, mid-ocean areas, and specific geographic regions for which concommitant ground based measurements are available indicate that noise power is a monotonically decreasing function of frequency which conforms to expectations over the geographic locations and time periods investigated. In all cases investigated, active thunderstorm regions emit slightly higher power as contrasted to RAE observations of the region during meteorologically quiet periods. Noise levels are some 15 db higher than predicted values over mid-ocean, while in locations where ground based measurements are available a maximum deviation of 5 db occurs. Worldwide contour mapping of the noise power at 6000 km for five individual months and four observing frequencies, examples of which are given, indicate high noise levels over continental land masses with corresponding lower levels over ocean regions.

90Sr specific activity of teeth of abandoned cattle after the Fukushima accident - teeth as an indicator of environmental pollution.

PubMed

Koarai, Kazuma; Kino, Yasushi; Takahashi, Atsushi; Suzuki, Toshihiko; Shimizu, Yoshinaka; Chiba, Mirei; Osaka, Ken; Sasaki, Keiichi; Urushihara, Yusuke; Fukuda, Tomokazu; Isogai, Emiko; Yamashiro, Hideaki; Oka, Toshitaka; Sekine, Tsutomu; Fukumoto, Manabu; Shinoda, Hisashi

2018-03-01

90 Sr specific activity in the teeth of young cattle that were abandoned in Kawauchi village and Okuma town located in the former evacuation areas of the Fukushima-Daiichi Nuclear Power Plant (FNPP) accident were measured. Additionally, specific activity in contaminated surface soils sampled from the same area was measured. (1) All cattle teeth examined were contaminated with 90 Sr. The specific activity, however, varied depending on the developmental stage of the teeth during the FNPP accident; teeth that had started development before the accident exhibited comparatively lower values, while teeth developed mainly after the accident showed higher values. (2) Values of 90 Sr-specific activity in teeth formed after the FNPP accident were higher than those of the bulk soil but similar to those in the exchangeable fraction (water and CH 3 COONH 4 soluble fractions) of the soil. The findings suggest that 90 Sr was incorporated into the teeth during the process of development, and that 90 Sr in the soluble and/or leachable fractions of the soil might migrate into teeth and contribute to the amount of 90 Sr in the teeth. Thus, the concentration of 90 Sr in teeth formed after the FNPP accident might reflect the extent of 90 Sr pollution in the environment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Results of an Analysis of Field Studies of the Intrinsic Dynamic Characteristics Important for the Safety of Nuclear Power Plant Equipment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaznovsky, A. P., E-mail: kaznovskyap@atech.ru; Kasiyanov, K. G.; Ryasnyj, S. I.

2015-01-15

A classification of the equipment important for the safety of nuclear power plants is proposed in terms of its dynamic behavior under seismic loading. An extended bank of data from dynamic tests over the entire range of thermal and mechanical equipment in generating units with VVER-1000 and RBMK-1000 reactors is analyzed. Results are presented from a study of the statistical behavior of the distribution of vibrational frequencies and damping decrements with the “small perturbation” factor that affects the measured damping decrements taken into account. A need to adjust the regulatory specifications for choosing the values of the damping decrements withmore » specified inertial loads on equipment owing to seismic effects during design calculations is identified. Minimum values of the decrements are determined and proposed for all types of equipment as functions of the directions and natural vibration frequencies of the dynamic interactions to be adopted as conservative standard values in the absence of actual experimental data in the course of design studies of seismic resistance.« less

Correlation of the rates of solvolysis of α-bromoisobutyrophenone using both simple and extended forms of the Grunwald-Winstein equation and the application of correlation analysis to related studies.

PubMed

Kevill, Dennis Neil; Kim, Chang-Bae; D'Souza, Malcolm John

2018-03-01

A Grunwald-Winstein treatment of the specific rates of solvolysis of α-bromoisobutyrophenone in 100% methanol and in several aqueous ethanol, methanol, acetone, 2,2,2-trifluoroethanol (TFE), and 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP) mixtures gives a good logarithmic correlation against a linear combination of N T (solvent nucleophilicity) and Y Br (solvent ionizing power) values. The l and m sensitivity values are compared to those previously reported for α-bromoacetophenone and to those obtained from parallel treatments of literature specific rate values for the solvolyses of several tertiary mesylates containing a C(=O)R group attached at the α-carbon. Kinetic data obtained earlier by Pasto and Sevenair for the solvolyses of the same substrate in 75% aqueous ethanol (by weight) in the presence of silver perchlorate and perchloric acid are analyzed using multiple regression analysis.

Experience-based consulting: the value proposition.

PubMed

Pliner, Nicole; Thrall, James; Boland, Giles; Palumbo, Denise

2004-11-01

Consulting is a profession universally accepted and well entrenched throughout the business world. Whether it is providing objective analysis, supplying a specific expertise, managing a project, or simply adding extra manpower, consultants can add value. However, what are the attributes of a good consultant? In health care, with the rapid pace of emerging technologies, economic intricacies, and the complexities of clinical care, hands-on experience is the key. Recognizing the power of consultants with hands-on experience, the Department of Radiology at Massachusetts General Hospital launched the Radiology Consulting Group, an "experience-based" model for consulting that may potentially shift the profession's paradigm.

Periprosthetic infection: where do we stand with regard to Gram stain?

PubMed

Ghanem, Elie; Ketonis, Constantinos; Restrepo, Camilo; Joshi, Ashish; Barrack, Robert; Parvizi, Javad

2009-02-01

One of the routinely used intraoperative tests for diagnosis of periprosthetic infection (PPI) is the Gram stain. It is not known if the result of this test can vary according to the type of joint affected or the number of specimen samples collected. We examined the role of this diagnostic test in a large cohort of patients from a single institution. A positive gram stain was defined as the visualization of bacterial cells or "many neutrophils" (> 5 per high-power field) in the smear. The sensitivity, specificity, and predictive values of each individual diagnostic arm of Gram stain were determined. Combinations were performed in series, which required both tests to be positive to confirm infection, and also in parallel, which necessitated both tests to be negative to rule out infection. The presence of organisms and "many" neutrophils on a Gram smear had high specificity (98-100%) and positive predictive value (89-100%) in both THA and TKA. The sensitivities (30-50%) and negative predictive values (70-79%) of the 2 tests were low for both joint types. When the 2 tests were combined in series, the specificity and positive predictive value were absolute (100%). The sensitivity and the negative predictive value improved for both THA and TKA (43-64% and 82%, respectively). Although the 2 diagnostic arms of Gram staining can be combined to achieve improved negative predictive value (82%), Gram stain continues to have little value in ruling out PPI. With the advances in the field of molecular biology, novel diagnostic modalities need to be designed that can replace these traditional and poor tests.

Conformal Galilei algebras, symmetric polynomials and singular vectors

NASA Astrophysics Data System (ADS)

Křižka, Libor; Somberg, Petr

2018-01-01

We classify and explicitly describe homomorphisms of Verma modules for conformal Galilei algebras cga_ℓ (d,C) with d=1 for any integer value ℓ \\in N. The homomorphisms are uniquely determined by singular vectors as solutions of certain differential operators of flag type and identified with specific polynomials arising as coefficients in the expansion of a parametric family of symmetric polynomials into power sum symmetric polynomials.

Power Analysis of Artificial Selection Experiments Using Efficient Whole Genome Simulation of Quantitative Traits

PubMed Central

Kessner, Darren; Novembre, John

2015-01-01

Evolve and resequence studies combine artificial selection experiments with massively parallel sequencing technology to study the genetic basis for complex traits. In these experiments, individuals are selected for extreme values of a trait, causing alleles at quantitative trait loci (QTL) to increase or decrease in frequency in the experimental population. We present a new analysis of the power of artificial selection experiments to detect and localize quantitative trait loci. This analysis uses a simulation framework that explicitly models whole genomes of individuals, quantitative traits, and selection based on individual trait values. We find that explicitly modeling QTL provides qualitatively different insights than considering independent loci with constant selection coefficients. Specifically, we observe how interference between QTL under selection affects the trajectories and lengthens the fixation times of selected alleles. We also show that a substantial portion of the genetic variance of the trait (50–100%) can be explained by detected QTL in as little as 20 generations of selection, depending on the trait architecture and experimental design. Furthermore, we show that power depends crucially on the opportunity for recombination during the experiment. Finally, we show that an increase in power is obtained by leveraging founder haplotype information to obtain allele frequency estimates. PMID:25672748

Toward reconciling instantaneous roadside measurements of light duty vehicle exhaust emissions with type approval driving cycles.

PubMed

Rhys-Tyler, Glyn A; Bell, Margaret C

2012-10-02

A method is proposed to relate essentially instantaneous roadside measurements of vehicle exhaust emissions, with emission results generated over a type approval driving cycle. An urban remote sensing data set collected in 2008 is used to define the dynamic relationship between vehicle specific power and exhaust emissions, across a range of vehicle ages, engine capacities, and fuel types. The New European Driving Cycle is synthesized from the remote sensing data using vehicle specific power to characterize engine load, and the results compared with official published emissions data from vehicle type approval tests over the same driving cycle. Mean carbon monoxide emissions from gasoline-powered cars ≤ 3 years old measured using remote sensing are found to be 1.3 times higher than published original type approval test values; this factor increases to 2.2 for cars 4-8 years old, and 6.4 for cars 9-12 years old. The corresponding factors for diesel cars are 1.1, 1.4, and 1.2, respectively. Results for nitric oxide, hydrocarbons, and particulate matter are also reported. The findings have potential implications for the design of traffic management interventions aimed at reducing emissions, fleet inspection and maintenance programs, and the specification of vehicle emission models.

Novel pulsed switched power supply for a fast field cycling NMR spectrometer.

PubMed

Sousa, D M; Fernandes, P A L; Marques, G D; Ribeiro, A C; Sebastião, P J

2004-01-01

In this paper, we outline the operating principles of a pulsed switched power supply for a fast field-cycling nuclear magnetic resonance spectrometer. The power supply uses a variant of a four-quadrant chopper with a duty cycle that defines the average output current. With this topology only two semiconductors are necessary to drive hundreds of amperes with an output power of several kilowatts. The output current ripple has a well-defined shape that can be reduced to acceptable values by a careful design of the semiconductors' controlling circuits and drivers. A power supply prototype was tested with a home build air-core magnet operating with fields between 0 and 0.21 T. The system is computer controlled using pulse generator and data acquisition PC cards, and specific user-friendly home-developed software. A comparative proton relaxometry study in two well-known liquid crystal compounds 5CB and MBBA was performed to check the reproducibility of the T1 measurements.

Prediction of anaerobic power values from an abbreviated WAnT protocol.

PubMed

Stickley, Christopher D; Hetzler, Ronald K; Kimura, Iris F

2008-05-01

The traditional 30-second Wingate anaerobic test (WAnT) is a widely used anaerobic power assessment protocol. An abbreviated protocol has been shown to decrease the mild to severe physical discomfort often associated with the WAnT. Therefore, the purpose of this study was to determine whether a 20-second WAnT protocol could be used to accurately predict power values of a standard 30-second WAnT. In 96 college females, anaerobic power variables were assessed using a standard 30-second WAnT protocol. Maximum power values as well as instantaneous power at 10, 15, and 20 seconds were recorded. Based on these results, stepwise regression analysis was performed to determine the accuracy with which mean power, minimum power, 30-second power, and percentage of fatigue for a standard 30-second WAnT could be predicted from values obtained during the first 20 seconds of testing. Mean power values showed the highest level of predictability (R2 = 0.99) from the 20-second values. Minimum power, 30-second power, and percentage of fatigue also showed high levels of predictability (R2 = 0.91, 0.84, and 0.84, respectively) using only values obtained during the first 20 seconds of the protocol. An abbreviated (20-second) WAnT protocol appears to effectively predict results of a standard 30-second WAnT in college-age females, allowing for comparison of data to published norms. A shortened test may allow for a decrease in unwanted side effects associated with the traditional WAnT protocol.

Real-Time Load-Side Control of Electric Power Systems

NASA Astrophysics Data System (ADS)

Zhao, Changhong

Two trends are emerging from modern electric power systems: the growth of renewable (e.g., solar and wind) generation, and the integration of information technologies and advanced power electronics. The former introduces large, rapid, and random fluctuations in power supply, demand, frequency, and voltage, which become a major challenge for real-time operation of power systems. The latter creates a tremendous number of controllable intelligent endpoints such as smart buildings and appliances, electric vehicles, energy storage devices, and power electronic devices that can sense, compute, communicate, and actuate. Most of these endpoints are distributed on the load side of power systems, in contrast to traditional control resources such as centralized bulk generators. This thesis focuses on controlling power systems in real time, using these load side resources. Specifically, it studies two problems. (1) Distributed load-side frequency control: We establish a mathematical framework to design distributed frequency control algorithms for flexible electric loads. In this framework, we formulate a category of optimization problems, called optimal load control (OLC), to incorporate the goals of frequency control, such as balancing power supply and demand, restoring frequency to its nominal value, restoring inter-area power flows, etc., in a way that minimizes total disutility for the loads to participate in frequency control by deviating from their nominal power usage. By exploiting distributed algorithms to solve OLC and analyzing convergence of these algorithms, we design distributed load-side controllers and prove stability of closed-loop power systems governed by these controllers. This general framework is adapted and applied to different types of power systems described by different models, or to achieve different levels of control goals under different operation scenarios. We first consider a dynamically coherent power system which can be equivalently modeled with a single synchronous machine. We then extend our framework to a multi-machine power network, where we consider primary and secondary frequency controls, linear and nonlinear power flow models, and the interactions between generator dynamics and load control. (2) Two-timescale voltage control: The voltage of a power distribution system must be maintained closely around its nominal value in real time, even in the presence of highly volatile power supply or demand. For this purpose, we jointly control two types of reactive power sources: a capacitor operating at a slow timescale, and a power electronic device, such as a smart inverter or a D-STATCOM, operating at a fast timescale. Their control actions are solved from optimal power flow problems at two timescales. Specifically, the slow-timescale problem is a chance-constrained optimization, which minimizes power loss and regulates the voltage at the current time instant while limiting the probability of future voltage violations due to stochastic changes in power supply or demand. This control framework forms the basis of an optimal sizing problem, which determines the installation capacities of the control devices by minimizing the sum of power loss and capital cost. We develop computationally efficient heuristics to solve the optimal sizing problem and implement real-time control. Numerical experiments show that the proposed sizing and control schemes significantly improve the reliability of voltage control with a moderate increase in cost.

[Predictors and longitudinal changes of depression and anxiety among medical college students].

PubMed

Lee, Hyun-Ji; Jang, Eun-Young; Park, Yong-Chon; Kim, Daeho

2013-06-01

This longitudinal study was designed to examine the change in depression and anxiety and their predictors over 1 year among premedical and medical students. We compared depression and anxiety from 2 waves and determined the predictive power of personality, narcissism, social comparison, and social reward value on them. Two hundred twenty-six students at a medical school in Seoul were divided into 4 groups according to academic year and completed a questionnaire at the end of 2010 and 2011. The questionnaire included the Zung Depression Scale; Zung Anxiety Scale; scales for social comparison, narcissism, and social reward value; and Neuroticism-Extraversion-Openness Personality Inventory. Among first- and second-year medical students, depression and anxiety increased significantly over the previous year. However, irrespective of academic year, depression increased significantly after 1 year. Also, social reward value had a moderating effect. Specifically, among students with low social reward value who entered their first year of medical school, the negative impact of the tendency toward depression and anxiety was amplified compared with older students. Because the predictors of mental health differ between groups, each group must receive specific, appropriate education. Also, because social reward value is important moderating factor of mental health, education and intervention programs that focus on social reward value are needed.

Standardization of the water heat carrier quality at Russian thermal power plants

NASA Astrophysics Data System (ADS)

Larin, B. M.; Larin, A. B.; Suslov, S. Yu.; Kirilina, A. V.

2017-04-01

The necessity of developing a new industry-specific standard of the heat carrier quality for the operating, newly commissioned, and prospective power-generating units of the thermal power plants is substantiated. The need of extending the scope of the automatic chemical monitoring and the possibility of indirect measurements of some basic standardized and diagnostic indices of the water chemistry using the specific conductance are shown. Investigations proved the possibility of automatic chemical monitoring of the phosphating of the drum boilers and quantitative control of potentially acidic impurities in the feed water in oncethrough boilers. The normative STO NP INVEL document developed at OAO VTI in 2009 is proposed as the basis for alterations and amendments. A new index, the total organic carbon, is introduced into this document. The standardized value of this index in the drum boiler feed water and steam is 100 μg/dm3. According to the above normative document, the scope of the chemical monitoring should be extended by measurements of the specific conductance of the direct and H-cation samples of both the feed and the boiler water. The content of chlorides should also be standardized. For the first time, normative restrictions are suggested on amine-containing water chemistry of the power-generating units with the combined cycle gas turbines. Flowcharts are proposed for pretreatment of the make-up water on the basis of low-mineralized natural waters with high organic substance contents, which reduces the oxidizability by 70-80%.

Some lemma on spectrum of eigen value regarding power method

NASA Astrophysics Data System (ADS)

Jamali, A. R. M. Jalal Uddin; Alam, Md. Sah

2017-04-01

Eigen value problems arise in almost all science and engineering fields. There exist some smart methods in literature in which most of them are able to find only Eigen values but could not find corresponding Eigen vectors. There exist many engineering as well as scientific fields in which both largest as well as smallest Eigen pairs are required. Power method is very simple but a powerful tool for finding largest Eigen value and corresponding Eigen vector (Eigen-pair). Again Inverse Power method is applied to find out smallest Eigen-pair and/or desire Eigen-pairs. But it is known that Inverse Power method is computationally very costly. On the other hand by using shifting property, Power method can find further Eigen-pairs. But the position of this Eigen value in the set of spectrum of the Eigen values is not identified. In this regard we proposed four lemma associate with Modified Power method. Each Lemma is proved ornately. The Modified Power method is implemented and illustrates an example for the verification of the Lemma. By using lemma the modified power algorithm is able to find out both largest and smallest Eigen-pairs successfully and efficiently in some cases. Moreover by the help of the Lemma, algorithm is able to detect the nature (positive and negative) of the Eigen values.

Hydrogen in thin Pd-based layers deposited on reticulated vitreous carbon-A new system for electrochemical capacitors

NASA Astrophysics Data System (ADS)

Łukaszewski, M.; Żurowski, A.; Czerwiński, A.

Reticulated vitreous carbon (RVC) has been used as a matrix for electrodeposition of thin layers of Pd and Pd-rich Pd-Rh alloys. It was found that RVC substrate does not affect qualitatively hydrogen absorption behavior of Pd-based deposits. Similarly to thin Pd or Pd alloy layers deposited on Au wires, the α-β phase transition controls the overall rate of hydrogen absorption and desorption into/from Pd-based/RVC electrodes. The possibility of the application of these materials as phase charging-discharging systems was investigated. The values of specific pseudocapacitance, specific power and specific energy were comparable with those for supercapacitors utilizing various redox reactions.

The power and robustness of maximum LOD score statistics.

PubMed

Yoo, Y J; Mendell, N R

2008-07-01

The maximum LOD score statistic is extremely powerful for gene mapping when calculated using the correct genetic parameter value. When the mode of genetic transmission is unknown, the maximum of the LOD scores obtained using several genetic parameter values is reported. This latter statistic requires higher critical value than the maximum LOD score statistic calculated from a single genetic parameter value. In this paper, we compare the power of maximum LOD scores based on three fixed sets of genetic parameter values with the power of the LOD score obtained after maximizing over the entire range of genetic parameter values. We simulate family data under nine generating models. For generating models with non-zero phenocopy rates, LOD scores maximized over the entire range of genetic parameters yielded greater power than maximum LOD scores for fixed sets of parameter values with zero phenocopy rates. No maximum LOD score was consistently more powerful than the others for generating models with a zero phenocopy rate. The power loss of the LOD score maximized over the entire range of genetic parameters, relative to the maximum LOD score calculated using the correct genetic parameter value, appeared to be robust to the generating models.

DOE Office of Scientific and Technical Information (OSTI.GOV)

He, Liping; Zhu, Fulong, E-mail: zhufulong@hust.edu.cn; Duan, Ke

Ultrasonic waves are widely used, with applications including the medical, military, and chemical fields. However, there are currently no effective methods for ultrasonic power measurement. Previously, ultrasonic power measurement has been reliant on mechanical methods such as hydrophones and radiation force balances. This paper deals with ultrasonic power measurement based on an unconventional method: acousto-optic interaction. Compared with mechanical methods, the optical method has a greater ability to resist interference and also has reduced environmental requirements. Therefore, this paper begins with an experimental determination of the acoustic power in water contained in a glass tank using a set of opticalmore » devices. Because the light intensity of the diffraction image generated by acousto-optic interaction contains the required ultrasonic power information, specific software was written to extract the light intensity information from the image through a combination of filtering, binarization, contour extraction, and other image processing operations. The power value can then be obtained rapidly by processing the diffraction image using a computer. The results of this work show that the optical method offers advantages that include accuracy, speed, and a noncontact measurement method.« less

An accelerated calendar and cycle life study of Li-ion cells.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bloom, I.; Cole, B. W.; Sohn, J. J.

2001-10-15

The accelerated calendar and cycle life of lithium-ion cells was studied. Useful cell life was strongly affected by temperature, time, state-of-charge (SOC) and change in state-of-charge ({Delta}SOC). In calendar life experiments, useful cell life was strongly affected by temperature and time. Temperature accelerated cell performance degradation. The rates of area specific impedance (ASI) increase and power fade followed simple laws based on a power of time and Arrhenius kinetics. The data have been modeled using these two concepts and the calculated data agree well with the experimental values. The calendar life ASI increase and power fade data follow (time){sup 1/2}more » kinetics. This behavior may be due to solid electrolyte interface layer growth. From the cycle life experiments, the ASI increase data follow (time){sup 1/2} kinetics also, but there is an apparent change in overall power fade mechanism when going from 3 to 6% {Delta}SOC. Here, the power of time drops to below 1/2, which indicates that the power fade mechanism is more complex than layer growth.« less

A location selection policy of live virtual machine migration for power saving and load balancing.

PubMed

Zhao, Jia; Ding, Yan; Xu, Gaochao; Hu, Liang; Dong, Yushuang; Fu, Xiaodong

2013-01-01

Green cloud data center has become a research hotspot of virtualized cloud computing architecture. And load balancing has also been one of the most important goals in cloud data centers. Since live virtual machine (VM) migration technology is widely used and studied in cloud computing, we have focused on location selection (migration policy) of live VM migration for power saving and load balancing. We propose a novel approach MOGA-LS, which is a heuristic and self-adaptive multiobjective optimization algorithm based on the improved genetic algorithm (GA). This paper has presented the specific design and implementation of MOGA-LS such as the design of the genetic operators, fitness values, and elitism. We have introduced the Pareto dominance theory and the simulated annealing (SA) idea into MOGA-LS and have presented the specific process to get the final solution, and thus, the whole approach achieves a long-term efficient optimization for power saving and load balancing. The experimental results demonstrate that MOGA-LS evidently reduces the total incremental power consumption and better protects the performance of VM migration and achieves the balancing of system load compared with the existing research. It makes the result of live VM migration more high-effective and meaningful.

A Location Selection Policy of Live Virtual Machine Migration for Power Saving and Load Balancing

PubMed Central

Xu, Gaochao; Hu, Liang; Dong, Yushuang; Fu, Xiaodong

2013-01-01

Green cloud data center has become a research hotspot of virtualized cloud computing architecture. And load balancing has also been one of the most important goals in cloud data centers. Since live virtual machine (VM) migration technology is widely used and studied in cloud computing, we have focused on location selection (migration policy) of live VM migration for power saving and load balancing. We propose a novel approach MOGA-LS, which is a heuristic and self-adaptive multiobjective optimization algorithm based on the improved genetic algorithm (GA). This paper has presented the specific design and implementation of MOGA-LS such as the design of the genetic operators, fitness values, and elitism. We have introduced the Pareto dominance theory and the simulated annealing (SA) idea into MOGA-LS and have presented the specific process to get the final solution, and thus, the whole approach achieves a long-term efficient optimization for power saving and load balancing. The experimental results demonstrate that MOGA-LS evidently reduces the total incremental power consumption and better protects the performance of VM migration and achieves the balancing of system load compared with the existing research. It makes the result of live VM migration more high-effective and meaningful. PMID:24348165

Performance Evaluation on Otto Engine Generator Using Gasoline and Biogas from Palm Oil Mill Effluent

NASA Astrophysics Data System (ADS)

Irvan; Trisakti, B.; Husaini, T.; Sitio, A.; Sitorus, TB

2017-06-01

Biogas is a flammable gas produced from the fermentation of organic materials by anaerobic bacteria originating from household waste manure and organic waste including palm oil mill effluent (POME). POME is mainly discharged from the sterilization unit of palm oil processing into crude palm oil. This study utilized biogas produced from liquid waste palm oil for use as fuel in the Otto engine generator 4 - stroke, type STARKE GFH1900LX with a peak power of 1.3 kW, 1.0 kW average power, bore 55 mm, stroke 40 mm, Vd 95 × 10-6 m3, Vc 10 × 10-6 m3, compression ratio of 10.5 : 1, and the number of cylinders = 1. The objective of this study is to evaluate the performance of Otto engine generator fueled with biogas that generated from POME, then comparing its performance fueled by gasoline. The performance included power, torque, specific fuel consumption, thermal efficiency, and the air-fuel ratio. Experiment was conducted by using a variation of the lamp load of 100, 200, 300, 400, and 500 W. The results revealed that the use of biogas as fuel decreased in power, torque, brake thermal efficiency, and air fuel ratio (AFR), while there is an increasing of value specific fuel consumption (SFC).

Nickel-hydrogen batteries from Intelsat 5 to space station

NASA Technical Reports Server (NTRS)

Vanommering, G.; Applewhite, A. Z.

1986-01-01

The heritage of the Ni-H2 technology that makes the space station application feasible is discussed. It also describes a design for a potential space station Ni-H2 battery system. Specific design values presented here were developed by Ford Aerospace as part of the Rocketdyne team effort on the Phase B Definition and Preliminary Design of the Space Station Power System in support of NASA Lewis Research Center.

Variable frequency iteration MPPT for resonant power converters

DOEpatents

Zhang, Qian; Bataresh, Issa; Chen, Lin

2015-06-30

A method of maximum power point tracking (MPPT) uses an MPPT algorithm to determine a switching frequency for a resonant power converter, including initializing by setting an initial boundary frequency range that is divided into initial frequency sub-ranges bounded by initial frequencies including an initial center frequency and first and second initial bounding frequencies. A first iteration includes measuring initial powers at the initial frequencies to determine a maximum power initial frequency that is used to set a first reduced frequency search range centered or bounded by the maximum power initial frequency including at least a first additional bounding frequency. A second iteration includes calculating first and second center frequencies by averaging adjacent frequent values in the first reduced frequency search range and measuring second power values at the first and second center frequencies. The switching frequency is determined from measured power values including the second power values.

Supercapacitors based on self-assembled graphene organogel.

PubMed

Sun, Yiqing; Wu, Qiong; Shi, Gaoquan

2011-10-14

Self-assembled graphene organogel (SGO) with 3-dimensional (3D) macrostructure was prepared by solvothermal reduction of a graphene oxide (GO) dispersion in propylene carbonate (PC). This SGO was used as an electrode material for fabricating supercapacitors with a PC electrolyte. The supercapacitor can be operated in a wide voltage range of 0-3 V and exhibits a high specific capacitance of 140 F g(-1) at a discharge current density of 1 A g(-1). Furthermore, it can still keep a specific capacitance of 90 F g(-1) at a high current density of 30 A g(-1). The maximum energy density of the SGO based supercapacitor was tested to be 43.5 Wh kg(-1), and this value is higher than those of the graphene based supercapacitors with aqueous or PC electrolytes reported previously. Furthermore, at a high discharge current density of 30 A g(-1), the energy and power densities of the supercapacitor were measured to be 15.4 Wh kg(-1) and 16,300 W kg(-1), respectively. These results indicate that the supercapacitor has a high specific capacitance and power density, and excellent rate capability.

Reduced graphene oxide and vertically aligned carbon nanotubes superhydrophilic films for supercapacitors devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zanin, H., E-mail: hudsonzanin@gmail.com; Departamento de Semicondutores, Instrumentos e Fotônica, Faculdade de Engenharia Elétrica e Computação, Universidade Estadual de Campinas, UNICAMP, Campinas 13083-970; Saito, E., E-mail: esaito135@gmail.com

2014-01-01

Graphical abstract: - Highlights: • Graphene nanosheets were produced onto wire rods. • RGO and VACNT-O were evaluated and compared as supercapacitor electrode. • RGO and VACNT-O have structural and electrochemical properties quite similars. • The materials present good specific capacitance, energy storage and power delivery. - Abstract: Reduced graphene oxide (RGO) and vertically aligned carbon nanotubes (VACNT) superhydrophilic films were prepared by chemical vapor deposition techniques for electrical energy storage investigations. These electrodes were characterized in terms of their material and electrochemical properties by scanning electron microscopy (SEM), surface wettability, Fourier transform infrared spectroscopy (FTIR), energy dispersive and Ramanmore » spectroscopies, cyclic voltammetry (CV) and galvanostatic charge–discharge. We observed several physical structural and electrochemical similarities between these carbon-based materials with particular attention to very good specific capacitance, ultra-high energy storage and fast power delivery. Our results showed that the main difference between specific capacitance values is attributed to pseudocapacitive contribution and high density of multiwall nanotubes tips. In this work we have tested a supercapacitor device using the VACNT electrodes.« less

Power Doppler flow mapping and four-dimensional ultrasound for evaluating tubal patency compared with laparoscopy.

PubMed

Soliman, Amr A; Shaalan, Waleed; Abdel-Dayem, Tamer; Awad, Elsayed Elbadawy; Elkassar, Yasser; Lüdders, Dörte; Malik, Eduard; Sallam, Hassan N

2015-12-01

To study the accuracy of four-dimensional (4D) ultrasound and power Doppler flow mapping in detecting tubal patency in women with sub-/infertility, and compare it with laparoscopy and chromopertubation. A prospective study. The study was performed in the outpatient clinic and infertility unit of a university hospital. The sonographic team and laparoscopic team were blinded to the results of each other. Women aged younger than 43 years seeking medical advice due to primary or secondary infertility and who planned to have a diagnostic laparoscopy performed, were recruited to the study after signing an informed consent. All of the recruited patients had power Doppler flow mapping and 4D hysterosalpingo-sonography by injecting sterile saline into the fallopian tubes 1 day before surgery. Registering Doppler signals, while using power Doppler, both at the tubal ostia and fimbrial end and the ability to demonstrate the course of the tube especially the isthmus and fimbrial end, while using 4D mode, was considered a patent tube. Out of 50 recruited patients, 33 women had bilateral patent tubes and five had unilateral patent tubes as shown by chromopertubation during diagnostic laparoscopy. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy for two-dimensional power Doppler hysterosalpingography were 94.4%, 100%, 100%, 89.2%, and 96.2%, respectively and for 4D ultrasound were 70.4%, 100%, 100%, 70.4%, and 82.6%, respectively. Four-dimensional saline hysterosalpingography has acceptable accuracy in detecting tubal patency, but is surpassed by power Doppler saline hysterosalpingography. Power Doppler saline hysterosalpingography could be incorporated into the routine sub-/infertility workup. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Design of the value of imaging in enhancing the wellness of your heart (VIEW) trial and the impact of uncertainty on power.

PubMed

Ambrosius, Walter T; Polonsky, Tamar S; Greenland, Philip; Goff, David C; Perdue, Letitia H; Fortmann, Stephen P; Margolis, Karen L; Pajewski, Nicholas M

2012-04-01

Although observational evidence has suggested that the measurement of coronary artery calcium (CAC) may improve risk stratification for cardiovascular events and thus help guide the use of lipid-lowering therapy, this contention has not been evaluated within the context of a randomized trial. The Value of Imaging in Enhancing the Wellness of Your Heart (VIEW) trial is proposed as a randomized study in participants at low intermediate risk of future coronary heart disease (CHD) events to evaluate whether CAC testing leads to improved patient outcomes. To describe the challenges encountered in designing a prototypical screening trial and to examine the impact of uncertainty on power. The VIEW trial was designed as an effectiveness clinical trial to examine the benefit of CAC testing to guide therapy on a primary outcome consisting of a composite of nonfatal myocardial infarction, probable or definite angina with revascularization, resuscitated cardiac arrest, nonfatal stroke (not transient ischemic attack (TIA)), CHD death, stroke death, other atherosclerotic death, or other cardiovascular disease (CVD) death. Many critical choices were faced in designing the trial, including (1) the choice of primary outcome, (2) the choice of therapy, (3) the target population with corresponding ethical issues, (4) specifications of assumptions for sample size calculations, and (5) impact of uncertainty in these assumptions on power/sample size determination. We have proposed a sample size of 30,000 (800 events), which provides 92.7% power. Alternatively, sample sizes of 20,228 (539 events), 23,138 (617 events), and 27,078 (722 events) provide 80%, 85%, and 90% power. We have also allowed for uncertainty in our assumptions by computing average power integrated over specified prior distributions. This relaxation of specificity indicates a reduction in power, dropping to 89.9% (95% confidence interval (CI): 89.8-89.9) for a sample size of 30,000. Samples sizes of 20,228, 23,138, and 27,078 provide power of 78.0% (77.9-78.0), 82.5% (82.5-82.6), and 87.2% (87.2-87.3), respectively. These power estimates are dependent on form and parameters of the prior distributions. Despite the pressing need for a randomized trial to evaluate the utility of CAC testing, conduct of such a trial requires recruiting a large patient population, making efficiency of critical importance. The large sample size is primarily due to targeting a study population at relatively low risk of a CVD event. Our calculations also illustrate the importance of formally considering uncertainty in power calculations of large trials as standard power calculations may tend to overestimate power.

Design of the Value of Imaging in Enhancing the Wellness of Your Heart (VIEW) Trial and the Impact of Uncertainty on Power

PubMed Central

Ambrosius, Walter T.; Polonsky, Tamar S.; Greenland, Philip; Goff, David C.; Perdue, Letitia H.; Fortmann, Stephen P.; Margolis, Karen L.; Pajewski, Nicholas M.

2014-01-01

Background Although observational evidence has suggested that the measurement of CAC may improve risk stratification for cardiovascular events and thus help guide the use of lipid-lowering therapy, this contention has not been evaluated within the context of a randomized trial. The Value of Imaging in Enhancing the Wellness of Your Heart (VIEW) trial is proposed as a randomized study in participants at low intermediate risk of future coronary heart disease (CHD) events to evaluate whether coronary artery calcium (CAC) testing leads to improved patient outcomes. Purpose To describe the challenges encountered in designing a prototypical screening trial and to examine the impact of uncertainty on power. Methods The VIEW trial was designed as an effectiveness clinical trial to examine the benefit of CAC testing to guide therapy on a primary outcome consisting of a composite of non-fatal myocardial infarction, probable or definite angina with revascularization, resuscitated cardiac arrest, non-fatal stroke (not transient ischemic attack (TIA)), CHD death, stroke death, other atherosclerotic death, or other cardiovascular disease (CVD) death. Many critical choices were faced in designing the trial, including: (1) the choice of primary outcome, (2) the choice of therapy, (3) the target population with corresponding ethical issues, (4) specifications of assumptions for sample size calculations, and (5) impact of uncertainty in these assumptions on power/sample size determination. Results We have proposed a sample size of 30,000 (800 events) which provides 92.7% power. Alternatively, sample sizes of 20,228 (539 events), 23,138 (617 events) and 27,078 (722 events) provide 80, 85, and 90% power. We have also allowed for uncertainty in our assumptions by computing average power integrated over specified prior distributions. This relaxation of specificity indicates a reduction in power, dropping to 89.9% (95% confidence interval (CI): 89.8 to 89.9) for a sample size of 30,000. Samples sizes of 20,228, 23,138, and 27,078 provide power of 78.0% (77.9 to 78.0), 82.5% (82.5 to 82.6), and 87.2% (87.2 to 87.3), respectively. Limitations These power estimates are dependent on form and parameters of the prior distributions. Conclusions Despite the pressing need for a randomized trial to evaluate the utility of CAC testing, conduct of such a trial requires recruiting a large patient population, making efficiency of critical importance. The large sample size is primarily due to targeting a study population at relatively low risk of a CVD event. Our calculations also illustrate the importance of formally considering uncertainty in power calculations of large trials as standard power calculations may tend to overestimate power. PMID:22333998

Action of an antioxidant complex on the antioxidant power of saliva.

PubMed

Cornelli, U; Belcaro, G; Nardi, G M; Cesarone, M R; Dugall, M; Hosoi, M; Grossi, M G; Ippolito, E; Ledda, A; Ruffini, I

2010-06-01

Based on the results of the soluble antioxidants test (SAT), we have produced a combination of oral antioxidants aimed at increasing the antioxidant power of saliva. Several antioxidants are included in this product (Vit E, beta-carotene, Vit A, Vit C, polyphenols, cathechins, ellagic acid, anthocyanins, coenzyme Q10 and pyridoxine in association with Se, Zn, L-cysteine). The aim of this registry study was to evaluate the efficacy of these antioxidants in saliva, plasma and urines. MF Odontovis, an antioxidant complex, was administered to healthy subjects in the evening for one week with a final administration in the morning. Plasma, urine and saliva showed an increase in antioxidant power following both the evening administration and the final morning administration. The antioxidant action appeared to be present even at night when salival secretion is lower. Plasma SAT levels (SATs) in the morning following evening treatment were increased by 21% in comparison with controls. Morning administration increased levels up to 34% when measured 4 hours after treatment. Comparable increases were observed in saliva (SATs and morning values were +44 %; +58% two hours after morning administration and +28 % after 4 hours). In urine the evening administration caused an increase in antioxidant power (+6%). This study indicated that antioxidant levels can be increased with specific nutritional supplement. The clinical value of an increased antioxidant power in biological fluids, particularly in saliva, may be relevant for future trials of prevention and treatment.

A maximum entropy principle for inferring the distribution of 3D plasmoids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lingam, Manasvi; Comisso, Luca

The principle of maximum entropy, a powerful and general method for inferring the distribution function given a set of constraints, is applied to deduce the overall distribution of 3D plasmoids (flux ropes/tubes) for systems where resistive MHD is applicable and large numbers of plasmoids are produced. The analysis is undertaken for the 3D case, with mass, total flux, and velocity serving as the variables of interest, on account of their physical and observational relevance. The distribution functions for the mass, width, total flux, and helicity exhibit a power-law behavior with exponents of -4/3, -2, -3, and -2, respectively, for smallmore » values, whilst all of them display an exponential falloff for large values. In contrast, the velocity distribution, as a function of v=|v|, is shown to be flat for v→0, and becomes a power law with an exponent of -7/3 for v→∞. Most of these results are nearly independent of the free parameters involved in this specific problem. In conclusion, a preliminary comparison of our results with the observational evidence is presented, and some of the ensuing space and astrophysical implications are briefly discussed.« less

A maximum entropy principle for inferring the distribution of 3D plasmoids

DOE PAGES

Lingam, Manasvi; Comisso, Luca

2018-01-18

The principle of maximum entropy, a powerful and general method for inferring the distribution function given a set of constraints, is applied to deduce the overall distribution of 3D plasmoids (flux ropes/tubes) for systems where resistive MHD is applicable and large numbers of plasmoids are produced. The analysis is undertaken for the 3D case, with mass, total flux, and velocity serving as the variables of interest, on account of their physical and observational relevance. The distribution functions for the mass, width, total flux, and helicity exhibit a power-law behavior with exponents of -4/3, -2, -3, and -2, respectively, for smallmore » values, whilst all of them display an exponential falloff for large values. In contrast, the velocity distribution, as a function of v=|v|, is shown to be flat for v→0, and becomes a power law with an exponent of -7/3 for v→∞. Most of these results are nearly independent of the free parameters involved in this specific problem. In conclusion, a preliminary comparison of our results with the observational evidence is presented, and some of the ensuing space and astrophysical implications are briefly discussed.« less

Protective effects of buckwheat honey on DNA damage induced by hydroxyl radicals.

PubMed

Zhou, Juan; Li, Peng; Cheng, Ni; Gao, Hui; Wang, Bini; Wei, Yahui; Cao, Wei

2012-08-01

To understand the antioxidant properties of buckwheat honeys, we investigated their antioxidant effects on hydroxyl radical-induced DNA breaks in the non-site-specific and site-specific systems, the physicochemical properties, antioxidant activities (1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical scavenging activity, chelating, and reducing power assays), total phenolic content and individual phenolic acids were also determined. Total phenolic content of buckwheat honeys ranged from 774 to 1694 mg PA/kg, and p-hydroxybenzoic and p-coumaric acids proved to be the main components in buckwheat honeys. All the buckwheat honey samples possess stronger capability to protect DNA in the non-site-specific systems than in the site-specific systems from being damaged by hydroxyl radicals. In the non-site-specific and site-specific system, buckwheat honeys samples prevented ()OH-induced DNA breaks by 21-78% and 5-31% over control value, respectively. Copyright © 2012 Elsevier Ltd. All rights reserved.

Bayes factors based on robust TDT-type tests for family trio design.

PubMed

Yuan, Min; Pan, Xiaoqing; Yang, Yaning

2015-06-01

Adaptive transmission disequilibrium test (aTDT) and MAX3 test are two robust-efficient association tests for case-parent family trio data. Both tests incorporate information of common genetic models including recessive, additive and dominant models and are efficient in power and robust to genetic model specifications. The aTDT uses information of departure from Hardy-Weinberg disequilibrium to identify the potential genetic model underlying the data and then applies the corresponding TDT-type test, and the MAX3 test is defined as the maximum of the absolute value of three TDT-type tests under the three common genetic models. In this article, we propose three robust Bayes procedures, the aTDT based Bayes factor, MAX3 based Bayes factor and Bayes model averaging (BMA), for association analysis with case-parent trio design. The asymptotic distributions of aTDT under the null and alternative hypothesis are derived in order to calculate its Bayes factor. Extensive simulations show that the Bayes factors and the p-values of the corresponding tests are generally consistent and these Bayes factors are robust to genetic model specifications, especially so when the priors on the genetic models are equal. When equal priors are used for the underlying genetic models, the Bayes factor method based on aTDT is more powerful than those based on MAX3 and Bayes model averaging. When the prior placed a small (large) probability on the true model, the Bayes factor based on aTDT (BMA) is more powerful. Analysis of a simulation data about RA from GAW15 is presented to illustrate applications of the proposed methods.

Radial turbine cooling

NASA Technical Reports Server (NTRS)

Roelke, Richard J.

1992-01-01

Radial turbines have been used extensively in many applications including small ground based electrical power generators, automotive engine turbochargers and aircraft auxiliary power units. In all of these applications the turbine inlet temperature is limited to a value commensurate with the material strength limitations and life requirements of uncooled metal rotors. To take advantage of all the benefits that higher temperatures offer, such as increased turbine specific power output or higher cycle thermal efficiency, requires improved high temperature materials and/or blade cooling. Extensive research is on-going to advance the material properties of high temperature superalloys as well as composite materials including ceramics. The use of ceramics with their high temperature potential and low cost is particularly appealing for radial turbines. However until these programs reach fruition the only way to make significant step increases beyond the present material temperature barriers is to cool the radial blading.

Occipital Alpha and Gamma Oscillations Support Complementary Mechanisms for Processing Stimulus Value Associations.

PubMed

Marshall, Tom R; den Boer, Sebastiaan; Cools, Roshan; Jensen, Ole; Fallon, Sean James; Zumer, Johanna M

2018-01-01

Selective attention is reflected neurally in changes in the power of posterior neural oscillations in the alpha (8-12 Hz) and gamma (40-100 Hz) bands. Although a neural mechanism that allows relevant information to be selectively processed has its advantages, it may lead to lucrative or dangerous information going unnoticed. Neural systems are also in place for processing rewarding and punishing information. Here, we examine the interaction between selective attention (left vs. right) and stimulus's learned value associations (neutral, punished, or rewarded) and how they compete for control of posterior neural oscillations. We found that both attention and stimulus-value associations influenced neural oscillations. Whereas selective attention had comparable effects on alpha and gamma oscillations, value associations had dissociable effects on these neural markers of attention. Salient targets (associated with positive and negative outcomes) hijacked changes in alpha power-increasing hemispheric alpha lateralization when salient targets were attended, decreasing it when they were being ignored. In contrast, hemispheric gamma-band lateralization was specifically abolished by negative distractors. Source analysis indicated occipital generators of both attentional and value effects. Thus, posterior cortical oscillations support both the ability to selectively attend while at the same time retaining the ability to remain sensitive to valuable features in the environment. Moreover, the versatility of our attentional system to respond separately to salient from merely positively valued stimuli appears to be carried out by separate neural processes reflected in different frequency bands.

Periprosthetic infection: where do we stand with regard to Gram stain?

PubMed Central

Ghanem, Elie; Ketonis, Constantinos; Restrepo, Camilo; Joshi, Ashish; Barrack, Robert

2009-01-01

Background and purpose One of the routinely used intraoperative tests for diagnosis of periprosthetic infection (PPI) is the Gram stain. It is not known if the result of this test can vary according to the type of joint affected or the number of specimen samples collected. We examined the role of this diagnostic test in a large cohort of patients from a single institution. Materials and methods A positive gram stain was defined as the visualization of bacterial cells or “many neutrophils” (> 5 per high-power field) in the smear. The sensitivity, specificity, and predictive values of each individual diagnostic arm of Gram stain were determined. Combinations were performed in series, which required both tests to be positive to confirm infection, and also in parallel, which necessitated both tests to be negative to rule out infection. Results The presence of organisms and “many” neutrophils on a Gram smear had high specificity (98–100%) and positive predictive value (89–100%) in both THA and TKA. The sensitivities (30–50%) and negative predictive values (70–79%) of the 2 tests were low for both joint types. When the 2 tests were combined in series, the specificity and positive predictive value were absolute (100%). The sensitivity and the negative predictive value improved for both THA and TKA (43–64% and 82%, respectively). Interpretation Although the 2 diagnostic arms of Gram staining can be combined to achieve improved negative predictive value (82%), Gram stain continues to have little value in ruling out PPI. With the advances in the field of molecular biology, novel diagnostic modalities need to be designed that can replace these traditional and poor tests. PMID:19297787

Power reflectance testing in newborns and infants.

PubMed

Lima, Ticianna Garambone de Cerqueira; Becker, Helena Maria Gonçalves; Becker, Celso Gonçalves; Ferreira, Daniele Barreto da Cunha; Resende, Camilo Brandão de; Guimarães, Roberto Eustáquio Santos

2015-01-01

Auditory screening in newborns allows for detection of hearing problems early in life. However, middle ear diseases can make the diagnosis more difficult. To evaluate the power reflectance test as an indicator of the middle ear disease and to compare it to tympanometry. Case study evaluating 105 newborns and infants who participated in the audiology screening in 2013. The following exams were performed: transient otoacoustic emissions, power reflectance, and tympanometry. In the optoacoustic emission evaluation, approximately 95% of the subjects passed the test. The specificity of power reflectance in all frequencies studied ranged from 75.3% to 95.9%, and that of tympanometry at 1000Hz ranged from 83% to 87.2%; there was agreement among these exams. The outcome of power reflectance tests at 2000Hz and 3000Hz showed a correlation with tympanometry and otoacoustic emissions, and these were the most appropriate frequencies to determine middle ear disease through power reflectance measurement. It was also observed that values of power reflectance above reference levels suggested the presence of fluid in the middle ear, and thus a conductive hearing loss. Copyright © 2015 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

Demonstration of Active Power Controls by Utility-Scale PV Power Plant in an Island Grid: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gevorgian, Vahan; O'Neill, Barbara

The National Renewable Energy Laboratory (NREL), AES, and the Puerto Rico Electric Power Authority conducted a demonstration project on a utility-scale photovoltaic (PV) plant to test the viability of providing important ancillary services from this facility. As solar generation increases globally, there is a need for innovation and increased operational flexibility. A typical PV power plant consists of multiple power electronic inverters and can contribute to grid stability and reliability through sophisticated 'grid-friendly' controls. In this way, it may mitigate the impact of its variability on the grid and contribute to important system requirements more like traditional generators. In 2015,more » testing was completed on a 20-MW AES plant in Puerto Rico, and a large amount of test data was produced and analyzed that demonstrates the ability of PV power plants to provide various types of new grid-friendly controls. This data showed how active power controls can leverage PV's value from being simply an intermittent energy resource to providing additional ancillary services for an isolated island grid. Specifically, the tests conducted included PV plant participation in automatic generation control, provision of droop response, and fast frequency response.« less

Power Enhancement in High Dimensional Cross-Sectional Tests

PubMed Central

Fan, Jianqing; Liao, Yuan; Yao, Jiawei

2016-01-01

We propose a novel technique to boost the power of testing a high-dimensional vector H : θ = 0 against sparse alternatives where the null hypothesis is violated only by a couple of components. Existing tests based on quadratic forms such as the Wald statistic often suffer from low powers due to the accumulation of errors in estimating high-dimensional parameters. More powerful tests for sparse alternatives such as thresholding and extreme-value tests, on the other hand, require either stringent conditions or bootstrap to derive the null distribution and often suffer from size distortions due to the slow convergence. Based on a screening technique, we introduce a “power enhancement component”, which is zero under the null hypothesis with high probability, but diverges quickly under sparse alternatives. The proposed test statistic combines the power enhancement component with an asymptotically pivotal statistic, and strengthens the power under sparse alternatives. The null distribution does not require stringent regularity conditions, and is completely determined by that of the pivotal statistic. As specific applications, the proposed methods are applied to testing the factor pricing models and validating the cross-sectional independence in panel data models. PMID:26778846

Improving a complex finite-difference ground water flow model through the use of an analytic element screening model

USGS Publications Warehouse

Hunt, R.J.; Anderson, M.P.; Kelson, V.A.

1998-01-01

This paper demonstrates that analytic element models have potential as powerful screening tools that can facilitate or improve calibration of more complicated finite-difference and finite-element models. We demonstrate how a two-dimensional analytic element model was used to identify errors in a complex three-dimensional finite-difference model caused by incorrect specification of boundary conditions. An improved finite-difference model was developed using boundary conditions developed from a far-field analytic element model. Calibration of a revised finite-difference model was achieved using fewer zones of hydraulic conductivity and lake bed conductance than the original finite-difference model. Calibration statistics were also improved in that simulated base-flows were much closer to measured values. The improved calibration is due mainly to improved specification of the boundary conditions made possible by first solving the far-field problem with an analytic element model.This paper demonstrates that analytic element models have potential as powerful screening tools that can facilitate or improve calibration of more complicated finite-difference and finite-element models. We demonstrate how a two-dimensional analytic element model was used to identify errors in a complex three-dimensional finite-difference model caused by incorrect specification of boundary conditions. An improved finite-difference model was developed using boundary conditions developed from a far-field analytic element model. Calibration of a revised finite-difference model was achieved using fewer zones of hydraulic conductivity and lake bed conductance than the original finite-difference model. Calibration statistics were also improved in that simulated base-flows were much closer to measured values. The improved calibration is due mainly to improved specification of the boundary conditions made possible by first solving the far-field problem with an analytic element model.

Discriminating crop and other canopies by overlapping binary image layers

NASA Astrophysics Data System (ADS)

Doi, Ryoichi

2013-02-01

For optimal management of agricultural fields by remote sensing, discrimination of the crop canopy from weeds and other objects is essential. In a digital photograph, a rice canopy was discriminated from a variety of weed and tree canopies and other objects by overlapping binary image layers of red-green-blue and other color components indicating the pixels with target canopy-specific (intensity) values based on the ranges of means ±(3×) standard deviations. By overlapping and merging the binary image layers, the target canopy specificity improved to 0.0015 from 0.027 for the yellow 1× standard deviation binary image layer, which was the best among all combinations of color components and means ±(3×) standard deviations. The most target rice canopy-likely pixels were further identified by limiting the pixels at different luminosity values. The discriminatory power was also visually demonstrated in this manner.

ALARA database value in future outage work planning and dose management

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, D.W.; Green, W.H.

1995-03-01

ALARA database encompassing job-specific duration and man-rem plant specific information over three refueling outages represents an invaluable tool for the outage work planner and ALARA engineer. This paper describes dose-management trends emerging based on analysis of three refueling outages at Clinton Power Station. Conclusions reached based on hard data available from a relational database dose-tracking system is a valuable tool for planning of future outage work. The system`s ability to identify key problem areas during a refueling outage is improving as more outage comparative data becomes available. Trends over a three outage period are identified in this paper in themore » categories of number and type of radiation work permits implemented, duration of jobs, projected vs. actual dose rates in work areas, and accuracy of outage person-rem projection. The value of the database in projecting 1 and 5 year station person-rem estimates is discussed.« less

Retributive and restorative justice.

PubMed

Wenzel, Michael; Okimoto, Tyler G; Feather, Norman T; Platow, Michael J

2008-10-01

The emergence of restorative justice as an alternative model to Western, court-based criminal justice may have important implications for the psychology of justice. It is proposed that two different notions of justice affect responses to rule-breaking: restorative and retributive justice. Retributive justice essentially refers to the repair of justice through unilateral imposition of punishment, whereas restorative justice means the repair of justice through reaffirming a shared value-consensus in a bilateral process. Among the symbolic implications of transgressions, concerns about status and power are primarily related to retributive justice and concerns about shared values are primarily related to restorative justice. At the core of these processes, however, lies the parties' construal of their identity relation, specifically whether or not respondents perceive to share an identity with the offender. The specific case of intergroup transgressions is discussed, as are implications for future research on restoring a sense of justice after rule-breaking.

Control of Solar Power Plants Connected Grid with Simple Calculation Method on Residential Homes

NASA Astrophysics Data System (ADS)

Kananda, Kiki; Nazir, Refdinal

2017-12-01

One of the most compatible renewable energy in all regions to apply is solar energy. Solar power plants can be built connected to existing or stand-alone power grids. In assisting the residential electricity in which there is a power grid, then a small scale solar energy power plants is very appropriate. However, the general constraint of solar energy power plants is still low in terms of efficiency. Therefore, this study will explain how to control the power of solar power plants more optimally, which is expected to reactive power to zero to raise efficiency. This is a continuation of previous research using Newton Rapshon control method. In this study we introduce a simple method by using ordinary mathematical calculations of solar-related equations. In this model, 10 PV modules type of ND T060M1 with a 60 Wp capacity are used. The calculations performed using MATLAB Simulink provide excellent value. For PCC voltage values obtained a stable quantity of approximately 220 V. At a maximum irradiation condition of 1000 W / m2, the reactive power value of Q solar generating system maximum 20.48 Var and maximum active power of 417.5 W. In the condition of lower irradiation, value of reactive power Q almost close to zero 0.77Var. This simple mathematical method can provide excellent quality control power values.

Synthesis and characterization of RuO(2)/poly(3,4-ethylenedioxythiophene) composite nanotubes for supercapacitors.

PubMed

Liu, Ran; Duay, Jonathon; Lane, Timothy; Bok Lee, Sang

2010-05-07

We report the synthesis of composite RuO(2)/poly(3,4-ethylenedioxythiophene) (PEDOT) nanotubes with high specific capacitance and fast charging/discharging capability as well as their potential application as electrode materials for a high-energy and high-power supercapacitor. RuO(2)/PEDOT nanotubes were synthesized in a porous alumina membrane by a step-wise electrochemical deposition method, and their structures were characterized using electron microscopy. Cyclic voltammetry was used to qualitatively characterize the capacitive properties of the composite RuO(2)/PEDOT nanotubes. Their specific capacitance, energy density and power density were evaluated by galvanostatic charge/discharge cycles at various current densities. The pseudocapacitance behavior of these composite nanotubes originates from ion diffusion during the simultaneous and parallel redox processes of RuO(2) and PEDOT. We show that the energy density (specific capacitance) of PEDOT nanotubes can be remarkably enhanced by electrodepositing RuO(2) into their porous walls and onto their rough internal surfaces. The flexible PEDOT prevents the RuO(2) from breaking and detaching from the current collector while the rigid RuO(2) keeps the PEDOT nanotubes from collapsing and aggregating. The composite RuO(2)/PEDOT nanotube can reach a high power density of 20 kW kg(-1) while maintaining 80% energy density (28 Wh kg(-1)) of its maximum value. This high power capability is attributed to the fast charge/discharge of nanotubular structures: hollow nanotubes allow counter-ions to readily penetrate into the composite material and access their internal surfaces, while a thin wall provides a short diffusion distance to facilitate ion transport. The high energy density originates from the RuO(2), which can store high electrical/electrochemical energy intrinsically. The high specific capacitance (1217 F g(-1)) which is contributed by the RuO(2) in the composite RuO(2)/PEDOT nanotube is realized because of the high specific surface area of the nanotubular structures. Such PEDOT/RuO(2) composite nanotube materials are an ideal candidate for the development of high-energy and high-power supercapacitors.

Extended space expectation values of position related operators for hydrogen-like quantum system evolutions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kalay, Berfin; Demiralp, Metin

2014-10-06

The expectation value definitions over an extended space from the considered Hilbert space of the system under consideration is given in another paper of the second author in this symposium. There, in that paper, the conceptuality rather than specification is emphasized on. This work uses that conceptuality to investigate the time evolutions of the position related operators' expectation values not in its standard meaning but rather in a new version of the definition over not the original Hilbert space but in the space obtained by extensions via introducing the images of the given initial wave packet under the positive integermore » powers of the system Hamiltonian. These images may not be residing in the same space of the initial wave packet when certain singularities appear in the structure of the system Hamiltonian. This may break down the existence of the integrals in the definitions of the expectation values. The cure is the use of basis functions in the abovementioned extended space and the sandwiching of the target operator whose expectation value is under questioning by an appropriately chosen operator guaranteeing the existence of the relevant integrals. Work specifically focuses on the hydrogen-like quantum systems whose Hamiltonians contain a polar singularity at the origin.« less

Statistical guidelines for assessing marine avian hotspots and coldspots: A case study on wind energy development in the U.S. Atlantic Ocean

USGS Publications Warehouse

Zipkin, Elise F.; Kinlan, Brian P.; Sussman, Allison; Rypkema, Diana; Wimer, Mark; O'Connell, Allan F.

2015-01-01

Estimating patterns of habitat use is challenging for marine avian species because seabirds tend to aggregate in large groups and it can be difficult to locate both individuals and groups in vast marine environments. We developed an approach to estimate the statistical power of discrete survey events to identify species-specific hotspots and coldspots of long-term seabird abundance in marine environments. We illustrate our approach using historical seabird data from survey transects in the U.S. Atlantic Ocean Outer Continental Shelf (OCS), an area that has been divided into “lease blocks” for proposed offshore wind energy development. For our power analysis, we examined whether discrete lease blocks within the region could be defined as hotspots (3 × mean abundance in the OCS) or coldspots (1/3 ×) for individual species within a given season. For each of 74 species/season combinations, we determined which of eight candidate statistical distributions (ranging in their degree of skewedness) best fit the count data. We then used the selected distribution and estimates of regional prevalence to calculate and map statistical power to detect hotspots and coldspots, and estimate the p-value from Monte Carlo significance tests that specific lease blocks are in fact hotspots or coldspots relative to regional average abundance. The power to detect species-specific hotspots was higher than that of coldspots for most species because species-specific prevalence was relatively low (mean: 0.111; SD: 0.110). The number of surveys required for adequate power (> 0.6) was large for most species (tens to hundreds) using this hotspot definition. Regulators may need to accept higher proportional effect sizes, combine species into groups, and/or broaden the spatial scale by combining lease blocks in order to determine optimal placement of wind farms. Our power analysis approach provides a general framework for both retrospective analyses and future avian survey design and is applicable to a broad range of research and conservation problems.

Nonparametric evaluation of quantitative traits in population-based association studies when the genetic model is unknown.

PubMed

Konietschke, Frank; Libiger, Ondrej; Hothorn, Ludwig A

2012-01-01

Statistical association between a single nucleotide polymorphism (SNP) genotype and a quantitative trait in genome-wide association studies is usually assessed using a linear regression model, or, in the case of non-normally distributed trait values, using the Kruskal-Wallis test. While linear regression models assume an additive mode of inheritance via equi-distant genotype scores, Kruskal-Wallis test merely tests global differences in trait values associated with the three genotype groups. Both approaches thus exhibit suboptimal power when the underlying inheritance mode is dominant or recessive. Furthermore, these tests do not perform well in the common situations when only a few trait values are available in a rare genotype category (disbalance), or when the values associated with the three genotype categories exhibit unequal variance (variance heterogeneity). We propose a maximum test based on Marcus-type multiple contrast test for relative effect sizes. This test allows model-specific testing of either dominant, additive or recessive mode of inheritance, and it is robust against variance heterogeneity. We show how to obtain mode-specific simultaneous confidence intervals for the relative effect sizes to aid in interpreting the biological relevance of the results. Further, we discuss the use of a related all-pairwise comparisons contrast test with range preserving confidence intervals as an alternative to Kruskal-Wallis heterogeneity test. We applied the proposed maximum test to the Bogalusa Heart Study dataset, and gained a remarkable increase in the power to detect association, particularly for rare genotypes. Our simulation study also demonstrated that the proposed non-parametric tests control family-wise error rate in the presence of non-normality and variance heterogeneity contrary to the standard parametric approaches. We provide a publicly available R library nparcomp that can be used to estimate simultaneous confidence intervals or compatible multiplicity-adjusted p-values associated with the proposed maximum test.

A Simple, Efficient and Effective Modeling Approach to Determine Baseflow Based on Concentration-Discharge Relationships

NASA Astrophysics Data System (ADS)

Liu, F.; Miller, M. P.; Conklin, M. H.

2017-12-01

Concentration-discharge relationships in streamflow are a precursor for diagnosing endmember mixing. With a strong power-law relationship between concentration and discharge, previous studies have shown that conservative solute concentrations in streamflow can be explained by mixing of two endmembers, i.e., quick runoff (QR) and baseflow (BF). This current study showed that the unique concentration-discharge power-law curve provides two characteristic values of solute concentrations at extremely high and low flows and these envelope values can be used to aid two-endmember mixing models. In an example conducted in the Upper Colorado River Basin (UCRB), daily specific conductance (SC) and discharge were strongly correlated by a power-law function on both rising and falling limbs from 1983 to 2015 (R2 > 0.9 for all years). The high envelope SC value in each year was directly used to characterize baseflow for that year, while the low envelope SC value was adjusted to represent quick runoff, a collective term for surface runoff and responsive shallow subsurface runoff. The peak flow was considered to be dominated by QR with only a small portion of BF. The ratio of minimum to maximum flows was used to calibrate the low envelope SC value. This ratio represents the least fraction of baseflow to total flow at the peak flow, as baseflow increases with total flow based on published studies. The SC value at the peak flow was considered to be a mixture of QR and BF with the minimum/maximum flow ratio as baseflow fraction and thus SC value in QR was determined with a mass balance equation. The baseflow fractions determined in two-endmember mixing models by this characterization of QR from 1983 to 2011 match those by Miller et al. [2014] very well (R2 = 0.96, slope = 1.07, intercept = -0.13). Baseflow fractions were slightly under-estimated by this approach mainly due to the fact that responsive shallow subsurface runoff was considered to be part of quick flow in this study rather than part of baseflow. This approach provides a simple, efficient and effective modeling tool for estimating baseflow without requiring any samples from endmembers in catchments with a strong power-law relation.

Enhanced thermoelectric properties of n-type NbCoSn half-Heusler by improving phase purity

DOE PAGES

He, Ran; Huang, Lihong; Wang, Yumei; ...

2016-06-01

In this paper, we report the thermoelectric properties of NbCoSn-based n-type half-Heuslers (HHs) that were obtained through arc melting, ball milling, and hot pressing process. With 10% Sb substitution at the Sn site, we obtained enhanced n-type properties with a maximum power factor reaching ~35 μW cm -1 K -2 and figure of merit (ZT) value ~0.6 in NbCoSn 0.9Sb 0.1. The ZT is doubled compared to the previous report. In addition, the specific power cost ($ W -1) is decreased by ~68% comparing to HfNiSn-based n-type HH because of the elimination of Hf.

Performance optimization of the power user electric energy data acquire system based on MOEA/D evolutionary algorithm

NASA Astrophysics Data System (ADS)

Ding, Zhongan; Gao, Chen; Yan, Shengteng; Yang, Canrong

2017-10-01

The power user electric energy data acquire system (PUEEDAS) is an important part of smart grid. This paper builds a multi-objective optimization model for the performance of the PUEEADS from the point of view of the combination of the comprehensive benefits and cost. Meanwhile, the Chebyshev decomposition approach is used to decompose the multi-objective optimization problem. We design a MOEA/D evolutionary algorithm to solve the problem. By analyzing the Pareto optimal solution set of multi-objective optimization problem and comparing it with the monitoring value to grasp the direction of optimizing the performance of the PUEEDAS. Finally, an example is designed for specific analysis.

Radiation tolerant 1 micron CMOS technology

NASA Astrophysics Data System (ADS)

Crevel, P.; Rodde, K.

1991-03-01

Starting from a standard one micron Complementary Metal Oxide Semiconductor (CMOS) for high density, low power memory applications, the degree of radiation tolerance of the baseline process is evaluated. Implemented process modifications to improve latchup sensitivity under heavy ion irradiation as well as total dose effects without changing layout rules are described. By changing doping profiles in Metal Nitride Oxide Semiconductors (MNOS) and P-channel MOS (PMOS) device regions, it is possible to guarantee data sheet specification of a 64 K low power static RAM for total gamma dose up to 35 krad (Si) (and even higher values for the gate array family) without latch up for Linear Energy Transfer LET up to 115 MeV/(mg/cm squared).

Development of Species-Specific SCAR Markers, Based on a SCoT Analysis, to Authenticate Physalis (Solanaceae) Species

PubMed Central

Feng, Shangguo; Zhu, Yujia; Yu, Chenliang; Jiao, Kaili; Jiang, Mengying; Lu, Jiangjie; Shen, Chenjia; Ying, Qicai; Wang, Huizhong

2018-01-01

Physalis is an important genus in the Solanaceae family. It includes many species of significant medicinal value, edible value, and ornamental value. However, many Physalis species are easily confused because of their similar morphological traits, which hinder the utilization and protection of Physalis resources. Therefore, it is necessary to create fast, sensitive, and reliable methods for the Physalis species authentication. Intended for that, in this study, species-specific sequence-characterized amplified region (SCAR) markers were developed for accurate identification of the closely related Physalis species P. angulata, P. minima, P. pubescens, and P. alkekengi var. franchetii, based on a simple and novel marker system, start codon targeted (SCoT) marker. A total of 34 selected SCoT primers yielded 289 reliable SCoT loci, of which 265 were polymorphic. Four species-specific SCoT fragments (SCoT3-1404, SCoT3-1589, SCoT5-550, and SCoT36-520) from Physalis species were successfully identified, cloned, and sequenced. Based on these selected specific DNA fragments, four SCAR primers pairs were developed and named ST3KZ, ST3MSJ, ST5SJ, and ST36XSJ. PCR analysis of each of these primer pairs clearly demonstrated a specific amplified band in all samples of the target Physalis species, but no amplification was observed in other Physalis species. Therefore, the species-specific SCAR primer pairs developed in this study could be used as powerful tools that can rapidly, effectively, and reliably identify and differentiate Physalis species.

Study of permeability characteristics of membranes

NASA Technical Reports Server (NTRS)

Spiegler, K. S.; Messalem, R. M.; Moore, R. J.; Leibovitz, J.

1971-01-01

Pressure-permeation experiments were performed with the concentration-clamp cell. Streaming potentials and hydraulic permeabilities were measured for an AMF C-103 cation-exchange membrane bounded by 0.1 N NaCl solutions. The streaming potential calculated from the slope of the recorded potential differences versus the applied pressure, yields a value of 1.895 millivolt/dekabar. When comparison with other membranes of similar characteristics could be made, good agreement was found. The values of the hydraulic permeability varied somewhat with the applied pressure difference and are between 1.3 x 10 to the minus 8th power and 3.9 x 10 to the minus 8th power sq cm/dekabar-sec. The specific hydraulic permeabilities were also calculated and compared with data from the literature. Fair agreement was found. The diffusion coefficient of the chloride ion in the AMF C-103 membrane was calculated, using Fick's first law of diffusion based on ion concentrations calculated from the Donnan equilibrium concentration of Cl(-).

Monte Carlo calculation of proton stopping power and ranges in water for therapeutic energies

NASA Astrophysics Data System (ADS)

Bozkurt, Ahmet

2017-09-01

Monte Carlo is a statistical technique for obtaining numerical solutions to physical or mathematical problems that are analytically impractical, if not impossible, to solve. For charged particle transport problems, it presents many advantages over deterministic methods since such problems require a realistic description of the problem geometry, as well as detailed tracking of every source particle. Thus, MC can be considered as a powerful alternative to the well-known Bethe-Bloche equation where an equation with various corrections is used to obtain stopping power and ranges of electrons, positrons, protons, alphas, etc. This study presents how a stochastic method such as MC can be utilized to obtain certain quantities of practical importance related to charged particle transport. Sample simulation geometries were formed for water medium where disk shaped thin detectors were employed to compute average values of absorbed dose and flux at specific distances. For each detector cell, these quantities were utilized to evaluate the values of the range and the stopping power, as well as the shape of Bragg curve, for mono-energetic point source pencil beams of protons. The results were found to be ±2% compared to the data from the NIST compilation. It is safe to conclude that this approach can be extended to determine dosimetric quantities for other media, energies and charged particle types.

Pain in fibromyalgia and discrimination power of the instruments: Visual Analog Scale, Dolorimetry and the McGill Pain Questionnaire.

PubMed

Marques, Amélia Pasqual; Assumpção, Ana; Matsutani, Luciana A; Pereira, Carlos A Bragança; Lage, Lais

2008-01-01

The aim of this study was to verify the discriminative power of the most widely used pain assessment instruments. The sample consisted of 279 subjects divided into Fibromyalgia Group FM- 205 patients with fibromyalgia and Control Group CG-74 healthy subjects), mean age 49.29 +/- 10.76 years. Only 9 subjects were male, 6 in FM and 3 in CG. FM were outpatients from the Rheumatology Clinic of the University of São Paulo--Hospital das Clínicas (HCFMUSP); the CG included people accompanying patients and hospital staff with similar socio-demographic characteristics. Three instruments were used to assess pain: the McGill Pain Questionnaire MPQ, the Visual Analog Scale (VAS), and the Dolorimetry, to measure pain threshold on tender points (generating the TP index). In order to assess the discriminative power of the instruments the measurements obtained were submitted to descriptive analysis and inferential analysis using ROC Curve-sensibility (S), specificity (S1) and area under the curve (AUC)--and Contingence tables with Chi-square Test and odds ratio. Significance level was 0.05. Higher sensibility specificity and area under the curve was obtained by VAS (80% 80% and 0.864, respectively), followed by Dolorimetry (S 77% S177% and AUC 0.851), McGill Sensory (S 72% S167% and AUC 0.765) and McGill Affective (S 69% S1 67% and AUC 0.753). VAS presented the higher sensibility, specificity and AUC, showing the greatest discriminative power among the instruments. However, these values are considerably similar to those of Dolorimetry.

Fuel system design concepts for broad property fuels

NASA Technical Reports Server (NTRS)

Versaw, E. F.

1984-01-01

The results of a study assessing the impact of using jet fuel with relaxed specification properties on an aircraft fuel system are given. The study objectives were to identify credible values for specific fuel properties which might be relaxed, to evolve advanced fuel system designs for airframe and engines which would permit use of the specified relaxed properties fuels, and to evaluate performance of the candidate advanced fuel systems and the relaxed property fuels in a typical transport aircraft. The study used, as a baseline, the fuel system incorporated in the Lockheed Tristar. This aircraft is powered by three RB.211-524 Rolls-Royce engines and incorporates a Pratt and Whitney ST6C-421 auxiliary power unit for engine starting and inflight emergency electrical power. The fuel property limits examined are compared with commercial Jet A kerosene and the NASA RFP fuel properties. A screening of these properties established that a higher freezing point and a lower thermal stability would impact fuel system design more significantly than any of the other property changes. Three candidate fuel systems which combine the ability to operate with fuels having both a high freeze point and a low thermal stability are described. All candidates employ bleed air to melt fuel freeze-out prior to starting the APU or an inoperable engine. The effects of incorporating these systems on aircraft weight and engine specific fuel consumption are given.

A MEMS and agile optics-based dual-mode variable optical power splitter with no moving parts

NASA Astrophysics Data System (ADS)

Khwaja, Tariq S.; Suleman, Hamid; Reza, Syed Azer

2017-06-01

In this paper, we present a novel design of an optical power splitter. Owing to the inherent variable power split ratios that the proposed design delivers, it is ideal for use in communications, sensing and signal processing applications where variable power splitting is often quintessential. The proposed power splitter module is dual mode as it combines the use of a Micro-Electro-Mechanical Systems (MEMS) based Digital Micro-mirror Device (DMD) and an Electronically Controlled Tunable Lens (ECTL) to split the power of an input optical signal between two output ports - the designated port and the surplus port. The use of a reflective Digital Spatial Light Modulator (DSLM) such as the DMD provides a motion-free digital control of the split ratio between the two output ports. Although the digital step between two possible successive split ratios can be fairly minimal with the use of a high resolution DMD but it is a challenge to correctly ascertain the exact image pattern on the DMD to obtain any desired specific split ratio. To counter this challenge, we propose the synchronized use of a circular pattern on the DMD, which serves as a circular clear aperture with a tunable radius, and an ECTL. The radius of the circular pattern on the DMD provides a digital control of the split ratio between the two ports whereas the ECTL, depending on its controller, can provide either an analog or a digital control by altering the beam radius which is incident at the DMD circular pattern. The radius of the circular pattern on the DMD can be minimally changed by one micro-pixel thickness. Setting the radius of the circular pattern on the DMD to an appropriate value provides the closest "ball-park" split ratio whereas further tuning the ECTL aids in slightly altering from this digitally set value to obtain the exact desired split ratio in-between any two digitally-set successive split ratios that correspond to any clear aperture radius of the DMD pattern and its incremental minimal allowable change of one micropixel. We provide a detailed scheme to calculate the desired DMD aperture radius as well as the focal length setting of the ECTL to obtain any given split ratio. By setting tolerance limits on the split ratio, we also show that our method affords diversity by providing multiple possible solutions to achieve a desired optical power split ratio within the specified tolerances. We also demonstrate the validation of the proposed concept with initial experimental results and discussions. These experimental results show a repeatable splitter operation and the resulting power split ratios according to the theoretical predictions. With the experimental data, we also demonstrate the effectiveness of the method in obtaining any particular split ratio through different DMD and ECTL configurations with specific split ratio tolerance values.

User's design handbook for a Standardized Control Module (SCM) for DC to DC Converters, volume 2

NASA Technical Reports Server (NTRS)

Lee, F. C.

1980-01-01

A unified design procedure is presented for selecting the key SCM control parameters for an arbitrarily given power stage configuration and parameter values, such that all regulator performance specifications can be met and optimized concurrently in a single design attempt. All key results and performance indices, for buck, boost, and buck/boost switching regulators which are relevant to SCM design considerations are included to facilitate frequent references.

An expert system for natural language processing

NASA Technical Reports Server (NTRS)

Hennessy, John F.

1988-01-01

A solution to the natural language processing problem that uses a rule based system, written in OPS5, to replace the traditional parsing method is proposed. The advantage to using a rule based system are explored. Specifically, the extensibility of a rule based solution is discussed as well as the value of maintaining rules that function independently. Finally, the power of using semantics to supplement the syntactic analysis of a sentence is considered.

Electrochemically synthesized nanocrystalline spinel thin film for high performance supercapacitor

NASA Astrophysics Data System (ADS)

Gupta, Vinay; Gupta, Shubhra; Miura, Norio

Spinels are not known for their supercapacitive nature. Here, we have explored electrochemically synthesized nanostructured NiCo 2O 4 spinel thin-film electrode for electrochemical supercapacitors. The nanostructured NiCo 2O 4 spinel thin film exhibited a high specific capacitance value of 580 F g -1 and an energy density of 32 Wh kg -1 at the power density of 4 kW kg -1, accompanying with good cyclic stability.

Active Learning Using Arbitrary Binary Valued Queries

DTIC Science & Technology

1990-10-01

active learning in the sense that the learner has complete choice in the information received. Specifically, we allow the learner to ask arbitrary yes...no questions. We consider both active learning under a fixed distribution and distribution-free active learning . In the case of active learning , the...a concept class is actively learnable iff it is finite, so that active learning is in fact less powerful than the usual passive learning model. We

Nanoporous metal/oxide hybrid electrodes for electrochemical supercapacitors

NASA Astrophysics Data System (ADS)

Lang, Xingyou; Hirata, Akihiko; Fujita, Takeshi; Chen, Mingwei

2011-04-01

Electrochemical supercapacitors can deliver high levels of electrical power and offer long operating lifetimes, but their energy storage density is too low for many important applications. Pseudocapacitive transition-metal oxides such as MnO2 could be used to make electrodes in such supercapacitors, because they are predicted to have a high capacitance for storing electrical charge while also being inexpensive and not harmful to the environment. However, the poor conductivity of MnO2 (10-5-10-6 S cm-1) limits the charge/discharge rate for high-power applications. Here, we show that hybrid structures made of nanoporous gold and nanocrystalline MnO2 have enhanced conductivity, resulting in a specific capacitance of the constituent MnO2 (~1,145 F g-1) that is close to the theoretical value. The nanoporous gold allows electron transport through the MnO2, and facilitates fast ion diffusion between the MnO2 and the electrolytes while also acting as a double-layer capacitor. The high specific capacitances and charge/discharge rates offered by such hybrid structures make them promising candidates as electrodes in supercapacitors, combining high-energy storage densities with high levels of power delivery.

Nanoporous metal/oxide hybrid electrodes for electrochemical supercapacitors.

PubMed

Lang, Xingyou; Hirata, Akihiko; Fujita, Takeshi; Chen, Mingwei

2011-04-01

Electrochemical supercapacitors can deliver high levels of electrical power and offer long operating lifetimes, but their energy storage density is too low for many important applications. Pseudocapacitive transition-metal oxides such as MnO(2) could be used to make electrodes in such supercapacitors, because they are predicted to have a high capacitance for storing electrical charge while also being inexpensive and not harmful to the environment. However, the poor conductivity of MnO(2) (10(-5)-10(-6) S cm(-1)) limits the charge/discharge rate for high-power applications. Here, we show that hybrid structures made of nanoporous gold and nanocrystalline MnO(2) have enhanced conductivity, resulting in a specific capacitance of the constituent MnO(2) (~1,145 F g(-1)) that is close to the theoretical value. The nanoporous gold allows electron transport through the MnO(2), and facilitates fast ion diffusion between the MnO(2) and the electrolytes while also acting as a double-layer capacitor. The high specific capacitances and charge/discharge rates offered by such hybrid structures make them promising candidates as electrodes in supercapacitors, combining high-energy storage densities with high levels of power delivery.

Microwave influence on the isolated heart function. 1: Effect of modulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pakhomov, A.G.; Dubovick, B.V.; Degtyariov, I.G.

1995-09-01

Dependence of the microwave effect on modulation parameters (pulse width, duty ratio, and peak intensity) was studied in an isolated frog auricle preparation. The rate and amplitude of spontaneous auricle twitches were measured during and after a 2 min exposure to 915 or 885 MHz microwaves and were compared to preexposure values. The studied ranges of modulation parameters were: pulse width, 10{sup {minus}6}--10{sup {minus}2} s; duty ratio, 7:100000, and peak specific absorption rate, 100--3,000 W/kg. Combinations of the parameters were chosen by chance, and about 400 various exposure regimes were tested. The experiments established that no regime was effective unlessmore » the average microwave power was high enough to induce preparation heating (0.1--0.4 C). The twitch rate instantly increased, and the amplitude decreased, as the temperature rose; similar changes could be induced by equivalent conventional heating. the data provide evidence that the effect of short-term microwave exposure on the isolated heart pacemaker and contractile functions depends on pulse modulation just as much as modulation determines the average absorbed power. These functions demonstrated no specific dependence on exposure parameters such as frequency or power windows.« less

Channel correlation of free space optical communication systems with receiver diversity in non-Kolmogorov atmospheric turbulence

NASA Astrophysics Data System (ADS)

Ma, Jing; Fu, Yulong; Tan, Liying; Yu, Siyuan; Xie, Xiaolong

2018-05-01

Spatial diversity as an effective technique to mitigate the turbulence fading has been widely utilized in free space optical (FSO) communication systems. The received signals, however, will suffer from channel correlation due to insufficient spacing between component antennas. In this paper, the new expressions of the channel correlation coefficient and specifically its components (the large- and small-scale channel correlation coefficients) for a plane wave with aperture effects are derived for horizontal link in moderate-to-strong turbulence, using a non-Kolmogorov spectrum that has a generalized power law in the range of 3-4 instead of the fixed classical Kolmogorov power law of 11/3. And then the influence of power law variations on the channel correlation coefficient and its components are analysed. The numerical results indicated that various value of the power law lead to varying effects on the channel correlation coefficient and its components. This work will help with the further investigation on the fading correlation in spatial diversity systems.

Highly porous activated carbon based adsorption cooling system employing difluoromethane and a mixture of pentafluoroethane and difluoromethane

NASA Astrophysics Data System (ADS)

Askalany, Ahmed A.; Saha, Bidyut B.

2017-01-01

This paper presents a simulation for a low-grade thermally powered two-beds adsorption cooling system employing HFC-32 and a mixture of HFC-32 and HFC-125 (HFC-410a) with activated carbon of type Maxsorb III. The present simulation model adopts experimentally measured adsorption isotherms, adsorption kinetics and isosteric heat of adsorption data. Effect of operating conditions (mass flow rate of hot water, driving heat source temperature and evaporator temperature) on the system performance has been studied in detail. The simulation results showed that the system could be powered by low-grade heat source temperature (below 85 °C). AC/HFC-32 and AC/HFC-410a adsorption cooling cycles achieved close specific cooling power and coefficient of performance values of 0.15 kW/kg and 0.3, respectively at a regeneration temperature of 90 °C along with evaporator temperature of 10 °C. The investigated semi continuous adsorption cooling system could produce a cooling power of 9 kW.

Aortic Wave Dynamics and Its Influence on Left Ventricular Workload

PubMed Central

Pahlevan, Niema M.; Gharib, Morteza

2011-01-01

The pumping mechanism of the heart is pulsatile, so the heart generates pulsatile flow that enters into the compliant aorta in the form of pressure and flow waves. We hypothesized that there exists a specific heart rate at which the external left ventricular (LV) power is minimized. To test this hypothesis, we used a computational model to explore the effects of heart rate (HR) and aortic rigidity on left ventricular (LV) power requirement. While both mean and pulsatile parts of the pressure play an important role in LV power requirement elevation, at higher rigidities the effect of pulsatility becomes more dominant. For any given aortic rigidity, there exists an optimum HR that minimizes the LV power requirement at a given cardiac output. The optimum HR shifts to higher values as the aorta becomes more rigid. To conclude, there is an optimum condition for aortic waves that minimizes the LV pulsatile load and consequently the total LV workload. PMID:21853075

ASSESSMENT OF PUBLIC EXPOSURE FORM WLANS IN THE WEST BANK-PALESTINE.

PubMed

Lahham, Adnan; Sharabati, Afifeh; ALMasri, Hussein

2017-11-01

A total of 271 measurements were conducted at 69 different sites including homes, hospitals, educational institutions and other public places to assess the exposure to radiofrequency emission from wireless local area networks (WLANs). Measurements were conducted at different distances from 40 to 10 m from the access points (APs) in real life conditions using Narda SRM-3000 selective radiation meter. Three measurements modes were considered at 1 m distance from the AP which are transmit mode, idle mode, and from the client card (laptop computer). All measurements were conducted indoor in the West Bank environment. Power density levels from WLAN systems were found to vary from 0.001 to ~1.9 μW cm-2 with an average of 0.12 μW cm-2. Maximum value found was in university environment, while the minimum was found in schools. For one measurement case where the AP was 20 cm far while transmitting large files, the measured power density reached a value of ~4.5 μW cm-2. This value is however 221 times below the general public exposure limit recommended by the International Commission on Non-Ionizing Radiation Protection, which was not exceeded in any case. Measurements of power density at 1 m around the laptop resulted in less exposure than the AP in both transmit and idle modes as well. Specific absorption rate for the head of the laptop user was estimated and found to vary from 0.1 to 2 mW/kg. The frequency distribution of measured power densities follows a log-normal distribution which is generally typical in the assessment of exposure resulting from sources of radiofrequency emissions. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

The G8 screening tool detects relevant geriatric impairments and predicts survival in elderly patients with a haematological malignancy.

PubMed

Hamaker, Marije E; Mitrovic, M; Stauder, R

2014-06-01

The G8 screening tool was developed to separate fit older cancer patients who were able to receive standard treatment from those that should undergo a geriatric assessment to guide tailoring of therapy. We set out to determine the discriminative power and prognostic value of the G8 in older patients with a haematological malignancy. Between September 2009 and May 2013, a multi-dimensional geriatric assessment was performed in consecutive patients aged ≥67 years diagnosed with blood cancer at the Innsbruck University Hospital. The assessment included (instrumental) activities of daily living, cognition, mood, nutritional status, mobility, polypharmacy and social support. In parallel, the G8 was also administered (cut-off ≤ 14). Using a cut-off of ≥2 impaired domains, 70 % of the 108 included patients were considered as having an impaired geriatric assessment while 61 % had an impaired G8. The G8 lacked discriminative power for impairments on full geriatric assessment: sensitivity 69, specificity 79, positive predictive value 89 and negative predictive value 50 %. However, G8 was an independent predictor of mortality within the first year after inclusion (hazard ratio 3.93; 95 % confidence interval 1.67-9.22, p < 0.001). Remarkably, patients with impaired G8 fared poorly, irrespective of treatment choices (p < 0.001). This is the first report on the clinical and prognostic relevance of G8 in elderly patients with haematological malignancies. Although the G8 lacked discriminative power for outcome of multi-dimensional geriatric assessment, this score appears to be a powerful prognosticator and could potentially represent a useful tool in treatment decisions. This novel finding certainly deserves further exploration.

LED power efficiency of biomass, fatty acid, and carotenoid production in Nannochloropsis microalgae.

PubMed

Ma, Ruijuan; Thomas-Hall, Skye R; Chua, Elvis T; Eltanahy, Eladl; Netzel, Michael E; Netzel, Gabriele; Lu, Yinghua; Schenk, Peer M

2018-03-01

The microalga Nannochloropsis produces high-value omega-3-rich fatty acids and carotenoids. In this study the effects of light intensity and wavelength on biomass, fatty acid, and carotenoid production with respect to light output efficiency were investigated. Similar biomass and fatty acid yields were obtained at high light intensity (150 μmol m -2  s -1 ) LEDs on day 7 and low light intensity (50 μmol m -2  s -1 ) LEDs on day 11 during cultivation, but the power efficiencies of biomass and fatty acid (specifically eicosapentaenoic acid) production were higher for low light intensity. Interestingly, low light intensity enhanced both, carotenoid power efficiency of carotenoid biosynthesis and yield. White LEDs were neither advantageous for biomass and fatty acid yields, nor the power efficiency of biomass, fatty acid, and carotenoid production. Noticeably, red LED resulted in the highest biomass and fatty acid power efficiency, suggesting that LEDs can be fine-tuned to grow Nannochloropsis algae more energy-efficiently. Copyright © 2017 Elsevier Ltd. All rights reserved.

Design of DSP-based high-power digital solar array simulator

NASA Astrophysics Data System (ADS)

Zhang, Yang; Liu, Zhilong; Tong, Weichao; Feng, Jian; Ji, Yibo

2013-12-01

To satisfy rigid performance specifications, a feedback control was presented for zoom optical lens plants. With the increasing of global energy consumption, research of the photovoltaic(PV) systems get more and more attention. Research of the digital high-power solar array simulator provides technical support for high-power grid-connected PV systems research.This paper introduces a design scheme of the high-power digital solar array simulator based on TMS320F28335. A DC-DC full-bridge topology was used in the system's main circuit. The switching frequency of IGBT is 25kHz.Maximum output voltage is 900V. Maximum output current is 20A. Simulator can be pre-stored solar panel IV curves.The curve is composed of 128 discrete points .When the system was running, the main circuit voltage and current values was feedback to the DSP by the voltage and current sensors in real-time. Through incremental PI,DSP control the simulator in the closed-loop control system. Experimental data show that Simulator output voltage and current follow a preset solar panels IV curve. In connection with the formation of high-power inverter, the system becomes gridconnected PV system. The inverter can find the simulator's maximum power point and the output power can be stabilized at the maximum power point (MPP).

Urinary metallomics as a novel biomarker discovery platform: Breast cancer as a case study.

PubMed

Burton, Casey; Dan, Yongbo; Donovan, Ariel; Liu, Kun; Shi, Honglan; Ma, Yinfa; Bosnak, Cynthia P

2016-01-15

Urinary metallomics is presented here as a new "omics" approach that aims to facilitate personalized cancer screening and prevention by improving our understanding of urinary metals in disease. Twenty-two urinary metals were examined with inductively-coupled plasma-mass spectrometry in 138 women newly diagnosed with breast cancer and benign conditions. Urinary metals from spot urine samples were adjusted to renal dilution using urine specific gravity. Two urinary metals, copper (P-value=0.036) and lead (P-value=0.003), were significantly increased in the urine of breast cancer patients. A multivariate model that comprised copper, lead, and patient age afforded encouraging discriminatory power (AUC: 0.728, P-value<0.0005), while univariate models of copper (61.7% sensitivity, 50.0% specificity) and lead (76.6% sensitivity, 51.2% specificity) at optimized cutoff thresholds compared favorably with other breast cancer diagnostic modalities such as mammography. Correlations found among various metals suggested potential geographic and dietary influences on the urine metallome that warrant further investigation. This proof-of-concept work introduces urinary metallomics as a noninvasive, potentially transformative "omics" approach to early cancer detection. Urinary copper and lead have also been preliminarily identified as potential breast cancer biomarkers. Copyright © 2015 Elsevier B.V. All rights reserved.

Performance characteristics of quasi-steady MPD discharges. [spacecraft plasma propulsion thrust efficiency and specific impulse

NASA Technical Reports Server (NTRS)

Rudolph, L. K.; Jahn, R. G.; Clark, K. E.; Von Jaskowsky, W. F.

1976-01-01

The onset of voltage fluctuations in a multi-megawatt quasi-steady MPD accelerator, indicative of increased cathode ablation and a consequent degradation of performance, is found to be a function of cathode size. With longer cathodes, this onset shifts to substantially higher powers per unit mass flow and the plasma exhaust velocity can be increased to values previously thought inaccessible to accelerators of this class. Centerline velocities up to 30 km/sec have been measured in argon, which for the observed exhaust profiles translate into specific impulses up to 2400 sec and corresponding thrust efficiencies above 30%.

50 KW Class Krypton Hall Thruster Performance

NASA Technical Reports Server (NTRS)

Jacobson, David T.; Manzella, David H.

2003-01-01

The performance of a 50-kilowatt-class Hall thruster designed for operation on xenon propellant was measured using kryton propellant. The thruster was operated at discharge power levels ranging from 6.4 to 72.5 kilowatts. The device produced thrust ranging from 0.3 to 2.5 newtons. The thruster was operated at discharge voltages between 250 and 1000 volts. At the highest anode mass flow rate and discharge voltage and assuming a 100 percent singly charged condition, the discharge specific impulse approached the theoretical value. Discharge specific impulse of 4500 seconds was demonstrated at a discharge voltage of 1000 volts. The peak discharge efficiency was 64 percent at 650 volts.

Power API Prototype

DOE Office of Scientific and Technical Information (OSTI.GOV)

2014-12-04

The software serves two purposes. The first purpose of the software is to prototype the Sandia High Performance Computing Power Application Programming Interface Specification effort. The specification can be found at http://powerapi.sandia.gov . Prototypes of the specification were developed in parallel with the development of the specification. Release of the prototype will be instructive to anyone who intends to implement the specification. More specifically, our vendor collaborators will benefit from the availability of the prototype. The second is in direct support of the PowerInsight power measurement device, which was co-developed with Penguin Computing. The software provides a cluster wide measurementmore » capability enabled by the PowerInsight device. The software can be used by anyone who purchases a PowerInsight device. The software will allow the user to easily collect power and energy information of a node that is instrumented with PowerInsight. The software can also be used as an example prototype implementation of the High Performance Computing Power Application Programming Interface Specification.« less

A Study of Carbon Nanofibers and Active Carbon as Symmetric Supercapacitor in Aqueous Electrolyte: A Comparative Study

NASA Astrophysics Data System (ADS)

Daraghmeh, Allan; Hussain, Shahzad; Saadeddin, Iyad; Servera, Llorenç; Xuriguera, Elena; Cornet, Albert; Cirera, Albert

2017-12-01

Symmetric supercapacitors are fabricated by carbon nanofibers (CNF) and activated carbon (AC) using similar proportions of 7 wt% polyvinylidene fluoride (PVDF) polymer binder in an aqueous electrolyte. In this study, a comparison of porous texture and electrochemical performances between CNFs and AC based supercapacitors was carried out. Electrodes were assembled in the cell without a current collector. The prepared electrodes of CNFs and AC present Brunauer-Emmett-Teller (BET) surface area of 83 and 1042 m2/g, respectively. The dominant pore structure for CNFs is mesoporous while for AC is micropore. The results showed that AC provided higher specific capacitance retention up to very fast scan rate of 500 mV/s. AC carbon had a specific capacitance of 334 F/g, and CNFs had 52 F/g at scan rate 5 mV/s in aqueous solution. Also, the results indicate the superior conductivity of CNFs in contrast to AC counterparts. The measured equivalent series resistance (ESR) showed a very small value for CNFs (0.28 Ω) in comparison to AC that has an ESR resistance of (3.72 Ω). Moreover, CNF delivered higher specific power (1860 W/kg) than that for AC (450 W/kg). On the other hand, AC gave higher specific energy (18.1 Wh/kg) than that for CNFs (2 Wh/kg).This indicates that the AC is good for energy applications. Whereas, CNF is good for power application. Indeed, the higher surface area will lead to higher specific capacitance and hence higher energy density for AC. For CNF, lower ESR is responsible for having higher power density. Both CNF and AC supercapacitor exhibit an excellent charge-discharge stability up to 2500 cycles.

Strategy of investment in electricity sources--Market value of a power plant and the electricity market

NASA Astrophysics Data System (ADS)

Bartnik, R.; Hnydiuk-Stefan, A.; Buryn, Z.

2017-11-01

This paper reports the results of the investment strategy analysis in different electricity sources. New methodology and theory of calculating the market value of the power plant and value of the electricity market supplied by it are presented. The financial gain forms the most important criteria in the assessment of an investment by an investor. An investment strategy has to involve a careful analysis of each considered project in order that the right decision and selection will be made while various components of the projects will be considered. The latter primarily includes the aspects of risk and uncertainty. Profitability of an investment in the electricity sources (as well as others) is offered by the measures applicable for the assessment of the economic effectiveness of an investment based on calculations e.g. power plant market value and the value of the electricity that is supplied by a power plant. The values of such measures decide on an investment strategy in the energy sources. This paper contains analysis of exemplary calculations results of power plant market value and the electricity market value supplied by it.

Computer simulation of fat and muscle burn in long-distance bird migration

PubMed

Pennycuick

1998-03-07

The mechanical power required from a bird's flight muscles was recalculated at regular intervals (default 6 min), and the energy consumed in the interval was accounted for by reducing fuel reserves, which also reduced the all-up mass and the body cross-sectional area. Part of the energy requirement was met by consuming flight muscle tissue, according to one of three alternative "muscle burn criteria". These were (1) specific work held constant, (2) power density held constant and (3) muscle mass held constant, i.e. no muscle consumed. Holding the specific work constant produced results in the best agreement with the results of other studies. This criterion was therefore selected to compare simulated flights of three very different species whose flight and migrations have been extensively studied, (1) Thrush Nightingale (Luscinia luscinia), (2) Knot (Calidris canutus) and (3) Whooper Swan (Cygnus cygnus). The ratio of protein to fat consumed ranged from 0.19 to 0.36, depending mainly on the starting value assumed for the muscle fraction. Specific work and starting power density were much higher for the Whooper Swan than for the two smaller species, suggesting that the latter have power to spare for climbing to high cruising altitudes, whereas the swan has not. If all three species were able to reach high cruising altitudes, the result would be a large reduction in journey time, which in turn would result in a small increase in range, due to a saving of energy required for basal metabolism. On current assumptions, the proportion of the fuel energy spent on basal metabolism would be eight times higher in the Thrush Nightingale than in the Whooper Swan, consequently the gain in range due to flying high would be greater in the smaller bird. In order to run the simulation, assumptions have been made at the primary physical level, to calculate the mechanical power required, and also at the secondary physiological level, to convert this into fuel consumption. The physical assumptions mostly take the form of variables whose existence is not in doubt, but whose values are poorly known, whereas in the case of some of the most important physiological variables, even the principles are unknown. Attention is drawn to a number of problems in need of attention, including (1) the mass and energy requirements of respiratory and circulatory organs required to sustain aerobically a given level of mechanical power; (2) the capabilities of bird lungs at high altitudes; (3) the possibility that heart muscle and lung tissue may be consumed in flight; (4) the two "biological constants", isometric force per myosin fibril and inverse power density of mitochondria; (5) the energy density of different fuels, and the conversion efficiency of the flight muscles; and (6) the manner in which basal metabolism combines with other demands for power in an exercising animal. Copyright 1998 Academic Press Limited

Ridge Waveguide Structures in Magnesium-Doped Lithium Niobate

NASA Technical Reports Server (NTRS)

Himmer, Phillip; Battle, Philip; Suckow, William; Switzer, Greg

2011-01-01

This work proposes to establish the feasibility of fabricating isolated ridge waveguides in 5% MgO:LN. Ridge waveguides in MgO:LN will significantly improve power handling and conversion efficiency, increase photonic component integration, and be well suited to spacebased applications. The key innovation in this effort is to combine recently available large, high-photorefractive-damage-threshold, z-cut 5% MgO:LN with novel ridge fabrication techniques to achieve high-optical power, low-cost, high-volume manufacturing of frequency conversion structures. The proposed ridge waveguide structure should maintain the characteristics of the periodically poled bulk substrate, allowing for the efficient frequency conversion typical of waveguides and the high optical damage threshold and long lifetimes typical of the 5% doped bulk substrate. The low cost and large area of 5% MgO:LN wafers, and the improved performance of the proposed ridge waveguide structure, will enhance existing measurement capabilities as well as reduce the resources required to achieve high-performance specifications. The purpose of the ridge waveguides in MgO:LN is to provide platform technology that will improve optical power handling and conversion efficiency compared to existing waveguide technology. The proposed ridge waveguide is produced using standard microfabrication techniques. The approach is enabled by recent advances in inductively coupled plasma etchers and chemical mechanical planarization techniques. In conjunction with wafer bonding, this fabrication methodology can be used to create arbitrarily shaped waveguides allowing complex optical circuits to be engineered in nonlinear optical materials such as magnesium doped lithium niobate. Researchers here have identified NLO (nonlinear optical) ridge waveguide structures as having suitable value to be the leading frequency conversion structures. Its value is based on having the low-cost fabrication necessary to satisfy the challenging pricing requirements as well as achieve the power handling and other specifications in a suitably compact package.

Human Exposure to Electromagnetic Fields from Parallel Wireless Power Transfer Systems.

PubMed

Wen, Feng; Huang, Xueliang

2017-02-08

The scenario of multiple wireless power transfer (WPT) systems working closely, synchronously or asynchronously with phase difference often occurs in power supply for household appliances and electric vehicles in parking lots. Magnetic field leakage from the WPT systems is also varied due to unpredictable asynchronous working conditions. In this study, the magnetic field leakage from parallel WPT systems working with phase difference is predicted, and the induced electric field and specific absorption rate (SAR) in a human body standing in the vicinity are also evaluated. Computational results are compared with the restrictions prescribed in the regulations established to limit human exposure to time-varying electromagnetic fields (EMFs). The results show that the middle region between the two WPT coils is safer for the two WPT systems working in-phase, and the peripheral regions are safer around the WPT systems working anti-phase. Thin metallic plates larger than the WPT coils can shield the magnetic field leakage well, while smaller ones may worsen the situation. The orientation of the human body will influence the maximum magnitude of induced electric field and its distribution within the human body. The induced electric field centralizes in the trunk, groin, and genitals with only one exception: when the human body is standing right at the middle of the two WPT coils working in-phase, the induced electric field focuses on lower limbs. The SAR value in the lungs always seems to be greater than in other organs, while the value in the liver is minimal. Human exposure to EMFs meets the guidelines of the International Committee on Non-Ionizing Radiation Protection (ICNIRP), specifically reference levels with respect to magnetic field and basic restrictions on induced electric fields and SAR, as the charging power is lower than 3.1 kW and 55.5 kW, respectively. These results are positive with respect to the safe applications of parallel WPT systems working simultaneously.

Severe accidents in the energy sector: comparative perspective.

PubMed

Hirschberg, Stefan; Burgherr, Peter; Spiekerman, Gerard; Dones, Roberto

2004-07-26

This paper addresses one of the controversial issues in the current comparative studies of the environmental and health impacts of energy systems, i.e. the treatment of severe accidents. The work covers technical aspects of severe accidents and thus primarily reflects an engineering perspective on the energy-related risk issues, though some social implications are also touched upon. The assessment concerns fossil energy sources (coal, oil and gas), nuclear power and hydro power. The scope is not limited to the power production (conversion) step of these energy chains but, whenever applicable, also includes exploration, extraction, transports, processing, storage and waste disposal. With the exception of the nuclear chain the focus of the work has been on the evaluation of the historical experience of accidents. The basis used for this evaluation is a comprehensive database ENSAD (Energy-related Severe Accident Database), established by the Paul Scherrer Institut (PSI). For hypothetical nuclear accidents the probabilistic technique has also been employed and extended to cover the assessment of economic consequences of such accidents. The broader picture obtained by coverage of full energy chains leads on the world-wide basis to aggregated immediate fatality rates being much higher for the fossil chains than what one would expect if only power plants were considered. Generally, the immediate fatality rates are for all considered energy carriers significantly higher for the non-OECD countries than for OECD countries. In the case of hydro and nuclear the difference is in fact dramatic. The presentation of results is not limited to the aggregated values specific for each energy chain. Also frequency-consequence curves are provided. They reflect implicitly the ranking based on the aggregated values but include also such information as the observed or predicted chain-specific maximum extents of damages. This perspective on severe accidents may lead to different system rankings, depending on the individual risk aversion.

Human Exposure to Electromagnetic Fields from Parallel Wireless Power Transfer Systems

PubMed Central

Wen, Feng; Huang, Xueliang

2017-01-01

The scenario of multiple wireless power transfer (WPT) systems working closely, synchronously or asynchronously with phase difference often occurs in power supply for household appliances and electric vehicles in parking lots. Magnetic field leakage from the WPT systems is also varied due to unpredictable asynchronous working conditions. In this study, the magnetic field leakage from parallel WPT systems working with phase difference is predicted, and the induced electric field and specific absorption rate (SAR) in a human body standing in the vicinity are also evaluated. Computational results are compared with the restrictions prescribed in the regulations established to limit human exposure to time-varying electromagnetic fields (EMFs). The results show that the middle region between the two WPT coils is safer for the two WPT systems working in-phase, and the peripheral regions are safer around the WPT systems working anti-phase. Thin metallic plates larger than the WPT coils can shield the magnetic field leakage well, while smaller ones may worsen the situation. The orientation of the human body will influence the maximum magnitude of induced electric field and its distribution within the human body. The induced electric field centralizes in the trunk, groin, and genitals with only one exception: when the human body is standing right at the middle of the two WPT coils working in-phase, the induced electric field focuses on lower limbs. The SAR value in the lungs always seems to be greater than in other organs, while the value in the liver is minimal. Human exposure to EMFs meets the guidelines of the International Committee on Non-Ionizing Radiation Protection (ICNIRP), specifically reference levels with respect to magnetic field and basic restrictions on induced electric fields and SAR, as the charging power is lower than 3.1 kW and 55.5 kW, respectively. These results are positive with respect to the safe applications of parallel WPT systems working simultaneously. PMID:28208709

Cardiovascular performance of adult breeding sows fails to obey allometric scaling laws.

PubMed

van Essen, G J; Vernooij, J C M; Heesterbeek, J A P; Anjema, D; Merkus, D; Duncker, D J

2011-02-01

In view of the remarkable decrease of the relative heart weight (HW) and the relative blood volume in growing pigs, we investigated whether HW, cardiac output (CO), and stroke volume (SV) of modern growing pigs are proportional to BW, as predicted by allometric scaling laws: HW (or CO or SV) = a·BW(b), in which a and b are constants, and constant b is a multiple of 0.25 (quarter-power scaling law). Specifically, we tested the hypothesis that both HW and CO scale with BW to the power of 0.75 (HW or CO = a·BW(0.75)) and SV scales with BW to the power of 1.00 (SV = a·BW(1.0)). For this purpose, 2 groups of pigs (group 1, consisting of 157 pigs of 50 ± 1 kg; group 2, consisting of 45 pigs of 268 ± 18 kg) were surgically instrumented with a flow probe or a thermodilution dilution catheter, under open-chest anesthetized conditions to measure CO and SV, after which HW was determined. The 95% confidence intervals of power-coefficient b for HW were 0.74 to 0.80, encompassing the predicted value of 0.75, suggesting that HW increased proportionally with BW, as predicted by the allometric scaling laws. In contrast, the 95% confidence intervals of power-coefficient b for CO and SV as measured with flow probes were 0.40 to 0.56 and 0.39 to 0.61, respectively, and values obtained with the thermodilution technique were 0.34 to 0.53 and 0.40 to 0.62, respectively. Thus, the 95% confidence limits failed to encompass the predicted values of b for CO and SV of 0.75 and 1.0, respectively. In conclusion, although adult breeding sows display normal heart growth, cardiac performance appears to be disproportionately low for BW. This raises concern regarding the health status of adult breeding sows.

The utility of ultrasound superb microvascular imaging for evaluation of breast tumour vascularity: comparison with colour and power Doppler imaging regarding diagnostic performance.

PubMed

Park, A Y; Seo, B K; Woo, O H; Jung, K S; Cho, K R; Park, E K; Cha, S H; Cha, J

2018-03-01

To investigate the utility of superb microvascular imaging (SMI) for evaluating the vascularity of breast masses in comparison with colour or power Doppler ultrasound (US) and the effect on diagnostic performance. A total of 191 biopsy-proven masses (99 benign and 92 malignant) in 166 women with greyscale, colour Doppler, power Doppler, and SMI images were enrolled in this retrospective study. Three radiologists analysed the vascular images using a three-factor scoring system to evaluate the number, morphology, and distribution of tumour vessels. They assessed the Breast Imaging-Reporting and Data System categories for greyscale US alone and combinations of greyscale US and each type of vascular US. The Kruskal-Wallis test was performed and the area under the receiver-operating characteristic curve (AUC) measured. On SMI, vascular scores were compared between benign and malignant masses and the optimal cut-off value for the overall score was determined. SMI showed higher vascular scores than colour or power Doppler US and malignant masses had higher scores than benign masses (p<0.001). The diagnostic performance of the combination of greyscale US and SMI was higher than those of greyscale US alone and greyscale and colour or power Doppler US (AUC, 0.815 versus 0.774, 0.789, 0.791; p<0.001). The optimal cut-off value of the overall vascular score was 5 with a sensitivity of 82.3% and a specificity of 65.3% (AUC, 0.808). SMI is superior to colour or power Doppler US for characterising the vascularity in breast masses and improving diagnostic performance. Copyright © 2017 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

TATES: Efficient Multivariate Genotype-Phenotype Analysis for Genome-Wide Association Studies

PubMed Central

van der Sluis, Sophie; Posthuma, Danielle; Dolan, Conor V.

2013-01-01

To date, the genome-wide association study (GWAS) is the primary tool to identify genetic variants that cause phenotypic variation. As GWAS analyses are generally univariate in nature, multivariate phenotypic information is usually reduced to a single composite score. This practice often results in loss of statistical power to detect causal variants. Multivariate genotype–phenotype methods do exist but attain maximal power only in special circumstances. Here, we present a new multivariate method that we refer to as TATES (Trait-based Association Test that uses Extended Simes procedure), inspired by the GATES procedure proposed by Li et al (2011). For each component of a multivariate trait, TATES combines p-values obtained in standard univariate GWAS to acquire one trait-based p-value, while correcting for correlations between components. Extensive simulations, probing a wide variety of genotype–phenotype models, show that TATES's false positive rate is correct, and that TATES's statistical power to detect causal variants explaining 0.5% of the variance can be 2.5–9 times higher than the power of univariate tests based on composite scores and 1.5–2 times higher than the power of the standard MANOVA. Unlike other multivariate methods, TATES detects both genetic variants that are common to multiple phenotypes and genetic variants that are specific to a single phenotype, i.e. TATES provides a more complete view of the genetic architecture of complex traits. As the actual causal genotype–phenotype model is usually unknown and probably phenotypically and genetically complex, TATES, available as an open source program, constitutes a powerful new multivariate strategy that allows researchers to identify novel causal variants, while the complexity of traits is no longer a limiting factor. PMID:23359524

Optimization of hydrostatic pressure at varied sonication conditions--power density, intensity, very low frequency--for isothermal ultrasonic sludge treatment.

PubMed

Delmas, Henri; Le, Ngoc Tuan; Barthe, Laurie; Julcour-Lebigue, Carine

2015-07-01

This work aims at investigating for the first time the key sonication (US) parameters: power density (DUS), intensity (IUS), and frequency (FS) - down to audible range, under varied hydrostatic pressure (Ph) and low temperature isothermal conditions (to avoid any thermal effect). The selected application was activated sludge disintegration, a major industrial US process. For a rational approach all comparisons were made at same specific energy input (ES, US energy per solid weight) which is also the relevant economic criterion. The decoupling of power density and intensity was obtained by either changing the sludge volume or most often by changing probe diameter, all other characteristics being unchanged. Comprehensive results were obtained by varying the hydrostatic pressure at given power density and intensity. In all cases marked maxima of sludge disintegration appeared at optimum pressures, which values increased at increasing power intensity and density. Such optimum was expected due to opposite effects of increasing hydrostatic pressure: higher cavitation threshold then smaller and fewer bubbles, but higher temperature and pressure at the end of collapse. In addition the first attempt to lower US frequency down to audible range was very successful: at any operation condition (DUS, IUS, Ph, sludge concentration and type) higher sludge disintegration was obtained at 12 kHz than at 20 kHz. The same values of optimum pressure were observed at 12 and 20 kHz. At same energy consumption the best conditions - obtained at 12 kHz, maximum power density 720 W/L and 3.25 bar - provided about 100% improvement with respect to usual conditions (1 bar, 20 kHz). Important energy savings and equipment size reduction may then be expected. Copyright © 2014 Elsevier B.V. All rights reserved.

Analyzing Small Signal Stability of Power System based on Online Data by Use of SMES

NASA Astrophysics Data System (ADS)

Ishikawa, Hiroyuki; Shirai, Yasuyuki; Nitta, Tanzo; Shibata, Katsuhiko

The purpose of this study is to estimate eigen-values and eigen-vectors of a power system from on-line data to evaluate the power system stability. Power system responses due to the small power modulation of known pattern from SMES (Superconducting Magnetic Energy Storage) were analyzed, and the transfer functions between the power modulation and power oscillations of generators were obtained. Eigen-values and eigen-vectors were estimated from the transfer functions. Experiments were carried out by use of a model SMES and Advanced Power System Analyzer (APSA), which is an analogue type power system simulator of Kansai Electric Power Company Inc., Japan. Changes in system condition were observed by the estimated eigen-values and eigen-vectors. Result agreed well with the resent report and digital simulation. This method gives a new application for SMES, which will be installed for improving electric power quality.

Effect of postural changes on aldosterone to plasma renin ratio in patients with suspected secondary hypertension.

PubMed

Barigou, M; Ah-Kang, F; Orloff, E; Amar, J; Chamontin, B; Bouhanick, B

2015-06-01

To study the influence of postural changes on aldosterone to renin ratio (ARR) in patients with suspected secondary hypertension and to evaluate the sensitivity and specificity of the recommended seated ARR compared to supine and upright ARR for primary aldosteronism screening. Fifty-three hypertensive patients were prospectively hospitalized for secondary hypertension exploration (age: 51 ± 12, 66% males). After withdrawal of drugs interfering with renin angiotensin system, plasma aldosterone and direct renin concentration were measured in the morning, at bed after an overnight supine position, then out of bed after 1 hour of upright position and finally 2 hours later after 15 minutes of seating. Minimal renin value was set at 5 μUI/mL. Referring to ARR cut-off of 23 pg/μUI, the sensitivity of seated ARR was 57.1% and specificity was 92.3%. The negative and positive predictive values were 95.1% and 45.2% respectively. Compared to these results, a cut-off of 19 improved sensitivity to 85.7% with a specificity of 89.7%. Negative and positive predictive values were 98.3% and 41.1% respectively. Seated ARR mean value was lower than supine and upright ARR mean values, due to an overall increase in renin at seating compared to the supine position by factor 1.9 while aldosterone just slightly increased by factor 1.2. Seated ARR correlated to supine and upright ARR: correlation coefficients (r) 0.90 and 0.93 respectively (P<0.001). Current recommended measurement of ARR in the seating position is fairly correlated to supine and upright ARR. A suggested cut-off value of 19 instead of 23 pg/μUI increased the discriminating power of this test. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

The effect of the magnetic nanoparticle's size dependence of the relaxation time constant on the specific loss power of magnetic nanoparticle hyperthermia

NASA Astrophysics Data System (ADS)

Harabech, Mariem; Leliaert, Jonathan; Coene, Annelies; Crevecoeur, Guillaume; Van Roost, Dirk; Dupré, Luc

2017-03-01

Magnetic nanoparticle hyperthermia is a cancer treatment in which magnetic nanoparticles (MNPs) are subjected to an alternating magnetic field to induce heat in the tumor. The generated heat of MNPs is characterized by the specific loss power (SLP) due to relaxation phenomena of the MNP. Up to now, several models have been proposed to predict the SLP, one of which is the Linear Response Theory. One parameter in this model is the relaxation time constant. In this contribution, we employ a macrospin model based on the Landau-Lifshitz-Gilbert equation to investigate the relation between the Gilbert damping parameter and the relaxation time constant. This relaxation time has a pre-factor τ0 which is often taken as a fixed value ranging between 10-8 and 10-12 s. However, in reality it has small size dependence. Here, the influence of this size dependence on the calculation of the SLP is demonstrated, consequently improving the accuracy of this estimate.

Iron Oxide Nanocrystals for Magnetic Hyperthermia Applications

PubMed Central

Armijo, Leisha M.; Brandt, Yekaterina I.; Mathew, Dimple; Yadav, Surabhi; Maestas, Salomon; Rivera, Antonio C.; Cook, Nathaniel C.; Withers, Nathan J.; Smolyakov, Gennady A.; Adolphi, Natalie; Monson, Todd C.; Huber, Dale L.; Smyth, Hugh D. C.; Osiński, Marek

2012-01-01

Magnetic nanocrystals have been investigated extensively in the past several years for several potential applications, such as information technology, MRI contrast agents, and for drug conjugation and delivery. A specific property of interest in biomedicine is magnetic hyperthermia—an increase in temperature resulting from the thermal energy released by magnetic nanocrystals in an external alternating magnetic field. Iron oxide nanocrystals of various sizes and morphologies were synthesized and tested for specific losses (heating power) using frequencies of 111.1 kHz and 629.2 kHz, and corresponding magnetic field strengths of 9 and 25 mT. Polymorphous nanocrystals as well as spherical nanocrystals and nanowires in paramagnetic to ferromagnetic size range exhibited good heating power. A remarkable 30 °C temperature increase was observed in a nanowire sample at 111 kHz and magnetic field of 25 mT (19.6 kA/m), which is very close to the typical values of 100 kHz and 20 mT used in medical treatments. PMID:28348300

Gasification of agricultural residues in a demonstrative plant: corn cobs.

PubMed

Biagini, Enrico; Barontini, Federica; Tognotti, Leonardo

2014-12-01

Biomass gasification couples the high power efficiency with the possibility of valuably using the byproducts heat and biochar. The use of agricultural wastes instead of woody feedstock extends the seasonal availability of biomasses. The downdraft type is the most used reactor but has narrow ranges of feedstock specifications (above all on moisture and particle size distribution), so tests on a demonstrative scale are conducted to prove the versatility of the gasifier. Measurements on pressure drops, syngas flow rate and composition are studied to assess the feasibility of such operations with corn cobs. Material and energy balances, and performance indexes are compared for the four tests carried out under different biomass loads (66-85 kg/h). A good operability of the plant and interesting results are obtained (gas specific production of 2 m3/kg, gas heating value 5.6-5.8 MJ/m3, cold gas efficiency in the range 66-68%, potential net power efficiency 21.1-21.6%). Copyright © 2014 Elsevier Ltd. All rights reserved.

A regenerative elastocaloric heat pump

NASA Astrophysics Data System (ADS)

Tušek, Jaka; Engelbrecht, Kurt; Eriksen, Dan; Dall'Olio, Stefano; Tušek, Janez; Pryds, Nini

2016-10-01

A large fraction of global energy use is for refrigeration and air-conditioning, which could be decarbonized if efficient renewable energy technologies could be found. Vapour-compression technology remains the most widely used system to move heat up the temperature scale after more than 100 years; however, caloric-based technologies (those using the magnetocaloric, electrocaloric, barocaloric or elastocaloric effect) have recently shown a significant potential as alternatives to replace this technology due to high efficiency and the use of green solid-state refrigerants. Here, we report a regenerative elastocaloric heat pump that exhibits a temperature span of 15.3 K on the water side with a corresponding specific heating power up to 800 W kg-1 and maximum COP (coefficient-of-performance) values of up to 7. The efficiency and specific heating power of this device exceeds those of other devices based on caloric effects. These results open up the possibility of using the elastocaloric effect in various cooling and heat-pumping applications.

The performance and emissions of diesel engines with biodiesel of sunan pecan seed and diesel oil blends

NASA Astrophysics Data System (ADS)

Ariani, F.; Sitorus, T. B.; Ginting, E.

2017-12-01

An observation was performed to evaluate the performance of direct injection stationary diesel engine which used a blends of biodiesel of Sunan pecan seed. The experiments were done with diesel oil, B5, B10, B15 and B20 in the engine speed variety. Results showed that the values of torque, power and thermal efficiency tend to decrease when the engine is using B5, B10, B15 and B20, compared to diesel oil. It also shown that the specific fuel consumption is increased when using B5, B10, B15 and B20. From the results of experiments and calculations, the maximum power of 3.08 kW, minimum specific fuel consumption of 189.93 g/kWh and maximum thermal efficiency of 45.53% when engine using diesel oil. However, exhaust gases were measured include opacity, carbon monoxide and hydrocarbon when the engine using biodiesel B5, B10, B15 and B20 decreased.

Special Pyrheliometer Shroud Development

NASA Technical Reports Server (NTRS)

Dennison, E. W.

1984-01-01

To insure that the insolation values accurately represent the input power to a power conversion unit the field of view (FOV) of the concentrator aperture and the insolation radiometer must be the same. The calculations, implementation, and results of this approach are covered. Three instruments were used to measure the insolation: an Eppley Normal Incidence Radiometer (NIP) and two versions of the kendall cavity radiometer. The shrouds used to limit the FOV of the radiometers were designed to simulate the FOV of the PDC-1 concentrater with the cold water cavity calorimeter. This technique of matching the FOV of an insolation radiometer to the FOV of a specific concentrater and receiver aperture appears to be both practical and effective. The efficiency of a power conversion unit will be too low if the insolation is measured with a radiometer which has a FOV which is larger than the FOV of the concentrator.

Feasibility and limitations of anti-fuses based on bistable non-volatile switches for power electronic applications

NASA Astrophysics Data System (ADS)

Erlbacher, T.; Huerner, A.; Bauer, A. J.; Frey, L.

2012-09-01

Anti-fuse devices based on non-volatile memory cells and suitable for power electronic applications are demonstrated for the first time using silicon technology. These devices may be applied as stand alone devices or integrated using standard junction-isolation into application-specific and smart-power integrated circuits. The on-resistance of such devices can be permanently switched by nine orders of magnitude by triggering the anti-fuse with a positive voltage pulse. Extrapolation of measurement data and 2D TCAD process and device simulations indicate that 20 A anti-fuses with 10 mΩ can be reliably fabricated in 0.35 μm technology with a footprint of 2.5 mm2. Moreover, this concept offers distinguished added-values compared to existing mechanical relays, e.g. pre-test, temporary and permanent reset functions, gradual turn-on mode, non-volatility, and extendibility to high voltage capability.

Annular Ion Engine Concept and Development Status

NASA Technical Reports Server (NTRS)

Patterson, Michael J.

2016-01-01

The Annular Ion Engine (AIE) concept represents an evolutionary development in gridded ion thruster technology with the potential for delivering revolutionary capabilities. It has this potential because the AIE concept: (a) enables scaling of ion thruster technology to high power at specific impulse (Isp) values of interest for near-term mission applications, 5000 sec; and (b) it enables an increase in both thrust density and thrust-to-power (FP) ratio exceeding conventional ion thrusters and other electric propulsion (EP) technology options, thereby yielding the highest performance over a broad range in Isp. The AIE concept represents a natural progression of gridded ion thruster technology beyond the capabilities embodied by NASAs Evolutionary Xenon Thruster (NEXT) [1]. The AIE would be appropriate for: (a) applications which require power levels exceeding NEXTs capabilities (up to about 14 kW [2]), with scalability potentially to 100s of kW; and/or (b) applications which require FP conditions exceeding NEXTs capabilities.

Simulation design of uniform low turn-on voltage and high reverse blocking AlGaN/GaN power field effect rectifier with trench heterojunction anode

NASA Astrophysics Data System (ADS)

Wang, Fangzhou; Chen, Wanjun; Wang, Zeheng; Sun, Ruize; Wei, Jin; Li, Xuan; Shi, Yijun; Jin, Xiaosheng; Xu, Xiaorui; Chen, Nan; Zhou, Qi; Zhang, Bo

2017-05-01

To achieve uniform low turn-on voltage and high reverse blocking capability, an AlGaN/GaN power field effect rectifier with trench heterojunction anode (THA-FER) is proposed and investigated in this work which includes only simulated data and no real experimental result. VT has a low saturation value when trench height (HT) is beyond 300 nm, confirming it is possible to control the VT accurately without precisely controlling the HT in the THA-FER. Meanwhile, high HT anode reduces reverse leakage current and yields high breakdown voltage (VB). A superior high Baliga's Figure of Merits (BFOM = VB2/Ron,sp, Ron,sp is specific-on resistance) of 1228 MW/cm2 reveals the THA-FER caters for the demands of high efficiency GaN power applications.

On the Possibility of the Existence of a Surface Electromagnetic Wave in the Permafrost Area

NASA Astrophysics Data System (ADS)

Balkhanov, V. K.; Bashkuev, Yu. B.; Advokatov, V. R.

2018-01-01

The results of measurements of the vertical component of electric field at a radio path with the permafrost at a frequency of 255 kHz have been interpreted. An analysis of the results has shown that the considered radio path exhibits the properties of a two-part impedance surface, i.e., it consists of two sections. At a distance of 70 km from a radiation source and at a frequency of 255 kHz of the electromagnetic wave, the field decreases with the distance R according to the power law as R -1.5 and a power index takes an intermediate value between the power indices for decreasing the field in free space R -2 and for the decrease in the field above an ideal conducting surface R -1. With further propagation at a distance of 70-220 km, the field shows the specific behavior of a surface electromagnetic wave.

Local instability driving extreme events in a pair of coupled chaotic electronic circuits

NASA Astrophysics Data System (ADS)

de Oliveira, Gilson F.; Di Lorenzo, Orlando; de Silans, Thierry Passerat; Chevrollier, Martine; Oriá, Marcos; Cavalcante, Hugo L. D. de Souza

2016-06-01

For a long time, extreme events happening in complex systems, such as financial markets, earthquakes, and neurological networks, were thought to follow power-law size distributions. More recently, evidence suggests that in many systems the largest and rarest events differ from the other ones. They are dragon kings, outliers that make the distribution deviate from a power law in the tail. Understanding the processes of formation of extreme events and what circumstances lead to dragon kings or to a power-law distribution is an open question and it is a very important one to assess whether extreme events will occur too often in a specific system. In the particular system studied in this paper, we show that the rate of occurrence of dragon kings is controlled by the value of a parameter. The system under study here is composed of two nearly identical chaotic oscillators which fail to remain in a permanently synchronized state when coupled. We analyze the statistics of the desynchronization events in this specific example of two coupled chaotic electronic circuits and find that modifying a parameter associated to the local instability responsible for the loss of synchronization reduces the occurrence of dragon kings, while preserving the power-law distribution of small- to intermediate-size events with the same scaling exponent. Our results support the hypothesis that the dragon kings are caused by local instabilities in the phase space.

A Method for Determining Pseudo-measurement State Values for Topology Observability of State Estimation in Power Systems

NASA Astrophysics Data System (ADS)

Urano, Shoichi; Mori, Hiroyuki

This paper proposes a new technique for determining of state values in power systems. Recently, it is useful for carrying out state estimation with data of PMU (Phasor Measurement Unit). The authors have developed a method for determining state values with artificial neural network (ANN) considering topology observability in power systems. ANN has advantage to approximate nonlinear functions with high precision. The method evaluates pseudo-measurement state values of the data which are lost in power systems. The method is successfully applied to the IEEE 14-bus system.

Cross ranking of cities and regions: population versus income

NASA Astrophysics Data System (ADS)

Cerqueti, Roy; Ausloos, Marcel

2015-07-01

This paper explores the relationship between the inner economical structure of communities and their population distribution through a rank-rank analysis of official data, along statistical physics ideas within two techniques. The data is taken on Italian cities. The analysis is performed both at a global (national) and at a more local (regional) level in order to distinguish ‘macro’ and ‘micro’ aspects. First, the rank-size rule is found not to be a standard power law, as in many other studies, but a doubly decreasing power law. Next, the Kendall τ and the Spearman ρ rank correlation coefficients which measure pair concordance and the correlation between fluctuations in two rankings, respectively,—as a correlation function does in thermodynamics, are calculated for finding rank correlation (if any) between demography and wealth. Results show non only global disparities for the whole (country) set, but also (regional) disparities, when comparing the number of cities in regions, the number of inhabitants in cities and that in regions, as well as when comparing the aggregated tax income of the cities and that of regions. Different outliers are pointed out and justified. Interestingly, two classes of cities in the country and two classes of regions in the country are found. ‘Common sense’ social, political, and economic considerations sustain the findings. More importantly, the methods show that they allow to distinguish communities, very clearly, when specific criteria are numerically sound. A specific modeling for the findings is presented, i.e. for the doubly decreasing power law and the two phase system, based on statistics theory, e.g. urn filling. The model ideas can be expected to hold when similar rank relationship features are observed in fields. It is emphasized that the analysis makes more sense than one through a Pearson Π value-value correlation analysis

Stakeholder Values and Perspectives when Implementing Led Lights on Navy Ships

DTIC Science & Technology

2014-06-01

Additionally, the M1 IntelliTube is a retrofit lamp , 32 which works with line power or any of the legacy ballasts.” ( LED /IntelliTube NAVSEA: LED ...only factor taken into consideration, then break-even point for LED lighting, Navy- wide, is approximately one hour to change the lamp . Of note...Energy Focus. (2013, July 3). Energy Focus: Specifications: IntelliTube LED replacement lamp , 24”, T12 LED lamp . Retrieved from http

I-DIRT, a general method for distinguishing between specific and nonspecific protein interactions.

PubMed

Tackett, Alan J; DeGrasse, Jeffrey A; Sekedat, Matthew D; Oeffinger, Marlene; Rout, Michael P; Chait, Brian T

2005-01-01

Isolation of protein complexes via affinity-tagged proteins provides a powerful tool for studying biological systems, but the technique is often compromised by co-enrichment of nonspecifically interacting proteins. We describe a new technique (I-DIRT) that distinguishes contaminants from bona fide interactors in immunopurifications, overcoming this most challenging problem in defining protein complexes. I-DIRT will be of broad value for studying protein complexes in biological systems that can be metabolically labeled.

Experimental determination of the frequency and field dependence of Specific Loss Power in Magnetic Fluid Hyperthermia

NASA Astrophysics Data System (ADS)

Cobianchi, M.; Guerrini, A.; Avolio, M.; Innocenti, C.; Corti, M.; Arosio, P.; Orsini, F.; Sangregorio, C.; Lascialfari, A.

2017-12-01

Magnetic nanoparticles are promising systems for biomedical applications and in particular for Magnetic Fluid Hyperthermia, a therapy that utilizes the heat released by such systems to damage tumor cells. We present an experimental study of the physical properties that influences the capability of heat release, i.e. the Specific Loss Power, SLP, of three biocompatible ferrofluid samples having a magnetic core of maghemite with different diameter d = 10.2, 14.6 and 19.7 nm. The SLP was measured as a function of frequency f and intensity H of the applied alternating magnetic field, and it turned out to depend on the core diameter, as expected. The results allowed us to highlight experimentally that the physical mechanism responsible for the heating is size-dependent and to establish, at applied constant frequency, the phenomenological functional relationship SLP = c·Hx, with 2 ≤ x<3 for all samples. The x-value depends on sample size and field frequency, here chosen in the typical range of operating magnetic hyperthermia devices. For the smallest sample, the effective relaxation time τeff ≈ 19.5 ns obtained from SLP data is in agreement with the value estimated from magnetization data, thus confirming the validity of the Linear Response Theory model for this system at properly chosen field intensity and frequency.

Cultural values and health service quality in China.

PubMed

Polsa, Pia; Fuxiang, Wei; Sääksjärvi, Maria; Shuyuan, Pei

2013-01-01

Several service quality studies show how cultural features may influence the way service quality is perceived. However, few studies specifically describe culture's influence on health service quality. Also, there are few studies that take into account patients' health service quality perceptions. This article seeks to present a first step to fill these gaps by examining patients' cultural values and their health service quality assessments. The study draws on published work and applies its ideas to Chinese healthcare settings. Data consist of hospital service perceptions in the People's Republic of China (PRC), a society that is socially, economically and culturally undergoing major changes. In total, 96 patients were surveyed. Data relationships were tested using partial least square (PLS) analysis. Findings show that Chinese patients' cultural values and their health service assessments are related and that the cultural values themselves seem to be changing. Additionally, further analyses provided interesting results pointing to which cultural values influenced service quality perceptions. The strongest service quality predictor was power distance. The sample is relatively small and collected from only one major hospital in China. Therefore, future research should extend the sample size and scope. Follow-up research could also include cross-cultural investigations of perceived health service quality to substantiate cultural influences on health service quality perceptions. In line with similar research in other contexts, the study confirms that power distance has a significant relationship with service quality perceptions. The study contributes to existing health service literature by offering patients' views on health service quality and by describing relationships between health service perceptions and cultural values--the study's main contribution.

Specific absorption rate dependence on temperature in magnetic field hyperthermia measured by dynamic hysteresis losses (ac magnetometry)

NASA Astrophysics Data System (ADS)

Garaio, Eneko; Sandre, Olivier; Collantes, Juan-Mari; Garcia, Jose Angel; Mornet, Stéphane; Plazaola, Fernando

2015-01-01

Magnetic nanoparticles (NPs) are intensively studied for their potential use for magnetic hyperthermia, a treatment that has passed a phase II clinical trial against severe brain cancer (glioblastoma) at the end of 2011. Their heating power, characterized by the ‘specific absorption rate (SAR)’, is often considered temperature independent in the literature, mainly because of the difficulties that arise from the measurement methodology. Using a dynamic magnetometer presented in a recent paper, we measure here the thermal dependence of SAR for superparamagnetic iron oxide (maghemite) NPs of four different size-ranges corresponding to mean diameters around 12 nm, 14 nm, 15 nm and 16 nm. The article reports a parametrical study extending from 10 to 60 {}^\\circ C in temperature, from 75 to 1031 kHz in frequency, and from 2 to 24 kA m-1 in magnetic field strength. It was observed that SAR values of smaller NPs decrease with temperature whereas for the larger sample (16 nm) SAR values increase with temperature. The measured variation of SAR with temperature is frequency dependent. This behaviour is fully explained within the scope of linear response theory based on Néel and Brown relaxation processes, using independent magnetic measurements of the specific magnetization and the magnetic anisotropy constant. A good quantitative agreement between experimental values and theoretical values is confirmed in a tri-dimensional space that uses as coordinates the field strength, the frequency and the temperature.

Power management system

DOEpatents

Algrain, Marcelo C.; Johnson, Kris W.; Akasam, Sivaprasad; Hoff, Brian D.

2007-10-02

A method of managing power resources for an electrical system of a vehicle may include identifying enabled power sources from among a plurality of power sources in electrical communication with the electrical system and calculating a threshold power value for the enabled power sources. A total power load placed on the electrical system by one or more power consumers may be measured. If the total power load exceeds the threshold power value, then a determination may be made as to whether one or more additional power sources is available from among the plurality of power sources. At least one of the one or more additional power sources may be enabled, if available.

26 CFR 1.423-2 - Employee stock purchase plan defined.

Code of Federal Regulations, 2010 CFR

2010-04-01

... employee owns stock possessing 5 percent or more of the total combined voting power or value of all classes... granted, owns stock possessing 5 percent or more of the total combined voting power or value of all... the percentage of the total combined voting power or value of all classes of stock of the employer...

Dyadic Power Profiles: Power-Contingent Strategies for Value Creation in Negotiation

ERIC Educational Resources Information Center

Olekalns, Mara; Smith, Philip Leigh

2013-01-01

Using a simulated employment negotiation, we tested the conditional relationships among dyadic power profiles (symmetric high, symmetric low, and asymmetric), the choice and sequencing of strategies, and value creation. We showed that negotiators in symmetric high, symmetric low, and asymmetric power dyads took distinctly different paths to value…

Grid flexibility: The quiet revolution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hsieh, Eric; Anderson, Robert

The concept of flexibility describes the capability of the power system to maintain balance between generation and load under uncertainty. While the grid has historically incorporated flexibility-specific resources such as pumped hydro to complement nuclear generators, modern trends and the increased deployment of variable energy resources (VERs) are increasing the need for a transparent market value of flexibility. A review of analyses, docket filings, tariffs, and business practice manuals from the past several years finds substantial flexibility-related activity. These activities are categorized as market and financial structures; incorporation of new operations or technology; and legal or procedural reforms. The cumulativemore » outcome of these incremental changes will be a major transformation to power systems that can rapidly adapt to new needs, technologies, and conditions.« less

Ultra-Low Power Optical Sensor for Xylophagous Insect Detection in Wood.

PubMed

Perles, Angel; Mercado, Ricardo; Capella, Juan V; Serrano, Juan José

2016-11-23

The early detection of pests is key for the maintenance of high-value masterpieces and historical buildings made of wood. In this work, we the present detailed design of an ultra-low power sensor device that permits the continuous monitoring of the presence of termites and other xylophagous insects. The operating principle of the sensor is based on the variations of reflected light induced by the presence of termites, and specific processing algorithms that deal with the behavior of the electronics and the natural ageing of components. With a typical CR2032 lithium battery, the device lasts more than nine years, and is ideal for incorporation in more complex monitoring systems where maintenance tasks should be minimized.

Ultra-Low Power Optical Sensor for Xylophagous Insect Detection in Wood

PubMed Central

Perles, Angel; Mercado, Ricardo; Capella, Juan V.; Serrano, Juan José

2016-01-01

The early detection of pests is key for the maintenance of high-value masterpieces and historical buildings made of wood. In this work, we the present detailed design of an ultra-low power sensor device that permits the continuous monitoring of the presence of termites and other xylophagous insects. The operating principle of the sensor is based on the variations of reflected light induced by the presence of termites, and specific processing algorithms that deal with the behavior of the electronics and the natural ageing of components. With a typical CR2032 lithium battery, the device lasts more than nine years, and is ideal for incorporation in more complex monitoring systems where maintenance tasks should be minimized. PMID:27886082

Grid flexibility: The quiet revolution

DOE PAGES

Hsieh, Eric; Anderson, Robert

2017-02-16

The concept of flexibility describes the capability of the power system to maintain balance between generation and load under uncertainty. While the grid has historically incorporated flexibility-specific resources such as pumped hydro to complement nuclear generators, modern trends and the increased deployment of variable energy resources (VERs) are increasing the need for a transparent market value of flexibility. A review of analyses, docket filings, tariffs, and business practice manuals from the past several years finds substantial flexibility-related activity. These activities are categorized as market and financial structures; incorporation of new operations or technology; and legal or procedural reforms. The cumulativemore » outcome of these incremental changes will be a major transformation to power systems that can rapidly adapt to new needs, technologies, and conditions.« less

Age dependent electroencephalographic changes in attention-deficit/hyperactivity disorder (ADHD).

PubMed

Poil, S-S; Bollmann, S; Ghisleni, C; O'Gorman, R L; Klaver, P; Ball, J; Eich-Höchli, D; Brandeis, D; Michels, L

2014-08-01

Objective biomarkers for attention-deficit/hyperactivity disorder (ADHD) could improve diagnostics or treatment monitoring of this psychiatric disorder. The resting electroencephalogram (EEG) provides non-invasive spectral markers of brain function and development. Their accuracy as ADHD markers is increasingly questioned but may improve with pattern classification. This study provides an integrated analysis of ADHD and developmental effects in children and adults using regression analysis and support vector machine classification of spectral resting (eyes-closed) EEG biomarkers in order to clarify their diagnostic value. ADHD effects on EEG strongly depend on age and frequency. We observed typical non-linear developmental decreases in delta and theta power for both ADHD and control groups. However, for ADHD adults we found a slowing in alpha frequency combined with a higher power in alpha-1 (8-10Hz) and beta (13-30Hz). Support vector machine classification of ADHD adults versus controls yielded a notable cross validated sensitivity of 67% and specificity of 83% using power and central frequency from all frequency bands. ADHD children were not classified convincingly with these markers. Resting state electrophysiology is altered in ADHD, and these electrophysiological impairments persist into adulthood. Spectral biomarkers may have both diagnostic and prognostic value. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Study of heat generation and cutting force according to minimization of grain size (500 nm to 180 nm) of WC ball endmill using FEM

NASA Astrophysics Data System (ADS)

Byeon, J. H.; Ahmed, F.; Ko, T. J.; lee, D. K.; Kim, J. S.

2018-03-01

As the industry develops, miniaturization and refinement of products are important issues. Precise machining is required for cutting, which is a typical method of machining a product. The factor determining the workability of the cutting process is the material of the tool. Tool materials include carbon tool steel, alloy tool steel, high-speed steel, cemented carbide, and ceramics. In the case of a carbide material, the smaller the particle size, the better the mechanical properties with higher hardness, strength and toughness. The specific heat, density, and thermal diffusivity are also changed through finer particle size of the material. In this study, finite element analysis was performed to investigate the change of heat generation and cutting power depending on the physical properties (specific heat, density, thermal diffusivity) of tool material. The thermal conductivity coefficient was obtained by measuring the thermal diffusivity, specific heat, and density of the material (180 nm) in which the particle size was finer and the particle material (0.05 μm) in the conventional size. The coefficient of thermal conductivity was calculated as 61.33 for 180nm class material and 46.13 for 0.05μm class material. As a result of finite element analysis using this value, the average temperature of exothermic heat of micronized particle material (180nm) was 532.75 °C and the temperature of existing material (0.05μm) was 572.75 °C. Cutting power was also compared but not significant. Therefore, if the thermal conductivity is increased through particle refinement, the surface power can be improved and the tool life can be prolonged by lowering the temperature generated in the tool during machining without giving a great influence to the cutting power.

Discussion about different cut-off values of conventional hamstring-to-quadriceps ratio used in hamstring injury prediction among professional male football players

PubMed Central

Michałowska, Martyna; Walczak, Tomasz; Owen, Adam; Grabski, Jakub Krzysztof; Pyda, Andrzej; Piontek, Tomasz; Kotwicki, Tomasz

2017-01-01

Objective To measure the sensitivity and specificity of differences cut-off values for isokinetic Hcon/Qcon ratio in order to improve the capacity to evaluate (retrospectively) the injury of hamstring muscles in professional soccer screened with knee isokinetic tests. Design Retrospective study. Methods Medical and biomechanical data of professional football players playing for the same team for at least one season between 2010 and 2016 were analysed. Hamstring strain injury cases and the reports generated via isokinetic testing were investigated. Isokinetic concentric(con) hamstring(H) and quadriceps(Q) absolute strength in addition with Hcon/Qcon ratio were examined for the injured versus uninjured limbs among injured players, and for the injured and non-injured players. 2 x 2 contingency table was used for comparing variables: predicted injured or predicted uninjured with actual injured or actual uninjured. Sensitivity, specificity, accuracy, positive and negative predictive values, and positive and negative likelihood ratio were calculated for three different cut-off values (0.47 vs. 0.6 vs. 0.658) to compare the discriminative power of an isokinetic test, whilst examining the key value of Hcon/Qcon ratio which may indicate the highest level of ability to predispose a player to injury. McNemar’s chi2 test with Yates’s correction was used to determine agreement between the tests. PQStat software was used for all statistical analysis, and an alpha level of p <0.05 was used for all statistical comparisons. Results 340 isokinetic test reports on both limbs of 66 professional soccer players were analysed. Eleven players suffered hamstring injuries during the analysed period. None of these players sustained recurrence of hamstring injury. One player sustained hamstring strain injury on both legs, thus the total number of injuries was 12. Application of different cut-off values for Hcon/Qcon significantly affected the sensitivity and specificity of isokinetic test used as a tool for muscle injury detection. The use of 0.47 of Hcon/Qcon as a discriminate value resulted in significantly lower sensitivity when compared to 0.658 threshold (sensitivity of 16.7% vs. 91.7%, respectively; t = 6.125,p = 0.0133). Calculated values of specificity (when three different cut-off were applied) were also significantly different. Threshold of 0.6 of Hcon/Qcon resulted with significantly lower specificity compared to 0.47 value (specificity of 46.9% vs. 94.5%, respectively; t = 153.0,p<0.0001), and significantly higher specificity when compared to 0.658 (specificity of 46.9% vs. 24.1%, respectively; t = 229.0, p<0.0001). Conclusion The use of different cut-off values for Hcon/Qcon significantly affected the sensitivity and specificity of isokinetic testing. The interpretation of usefulness of isokinetic test as a screening tool in a group of male professional football players to predict hamstring injury occurrence within the next 12 months might be therefore significantly biased due to the different threshold values of Hcon/Qcon. Using one “normative” value as a cut-off (e.g. 0.47 or 0.60, or 0.658) to quantify soccer players (or not) to the group with a higher risk of knee injury might result in biased outcomes due to the natural strength asymmetry that is observed within the group of soccer players. PMID:29216241

Discussion about different cut-off values of conventional hamstring-to-quadriceps ratio used in hamstring injury prediction among professional male football players.

PubMed

Grygorowicz, Monika; Michałowska, Martyna; Walczak, Tomasz; Owen, Adam; Grabski, Jakub Krzysztof; Pyda, Andrzej; Piontek, Tomasz; Kotwicki, Tomasz

2017-01-01

To measure the sensitivity and specificity of differences cut-off values for isokinetic Hcon/Qcon ratio in order to improve the capacity to evaluate (retrospectively) the injury of hamstring muscles in professional soccer screened with knee isokinetic tests. Retrospective study. Medical and biomechanical data of professional football players playing for the same team for at least one season between 2010 and 2016 were analysed. Hamstring strain injury cases and the reports generated via isokinetic testing were investigated. Isokinetic concentric(con) hamstring(H) and quadriceps(Q) absolute strength in addition with Hcon/Qcon ratio were examined for the injured versus uninjured limbs among injured players, and for the injured and non-injured players. 2 x 2 contingency table was used for comparing variables: predicted injured or predicted uninjured with actual injured or actual uninjured. Sensitivity, specificity, accuracy, positive and negative predictive values, and positive and negative likelihood ratio were calculated for three different cut-off values (0.47 vs. 0.6 vs. 0.658) to compare the discriminative power of an isokinetic test, whilst examining the key value of Hcon/Qcon ratio which may indicate the highest level of ability to predispose a player to injury. McNemar's chi2 test with Yates's correction was used to determine agreement between the tests. PQStat software was used for all statistical analysis, and an alpha level of p <0.05 was used for all statistical comparisons. 340 isokinetic test reports on both limbs of 66 professional soccer players were analysed. Eleven players suffered hamstring injuries during the analysed period. None of these players sustained recurrence of hamstring injury. One player sustained hamstring strain injury on both legs, thus the total number of injuries was 12. Application of different cut-off values for Hcon/Qcon significantly affected the sensitivity and specificity of isokinetic test used as a tool for muscle injury detection. The use of 0.47 of Hcon/Qcon as a discriminate value resulted in significantly lower sensitivity when compared to 0.658 threshold (sensitivity of 16.7% vs. 91.7%, respectively; t = 6.125,p = 0.0133). Calculated values of specificity (when three different cut-off were applied) were also significantly different. Threshold of 0.6 of Hcon/Qcon resulted with significantly lower specificity compared to 0.47 value (specificity of 46.9% vs. 94.5%, respectively; t = 153.0,p<0.0001), and significantly higher specificity when compared to 0.658 (specificity of 46.9% vs. 24.1%, respectively; t = 229.0, p<0.0001). The use of different cut-off values for Hcon/Qcon significantly affected the sensitivity and specificity of isokinetic testing. The interpretation of usefulness of isokinetic test as a screening tool in a group of male professional football players to predict hamstring injury occurrence within the next 12 months might be therefore significantly biased due to the different threshold values of Hcon/Qcon. Using one "normative" value as a cut-off (e.g. 0.47 or 0.60, or 0.658) to quantify soccer players (or not) to the group with a higher risk of knee injury might result in biased outcomes due to the natural strength asymmetry that is observed within the group of soccer players.

Diagnostic value of cerebrospinal fluid Aβ ratios in preclinical Alzheimer's disease.

PubMed

Adamczuk, Katarzyna; Schaeverbeke, Jolien; Vanderstichele, Hugo M J; Lilja, Johan; Nelissen, Natalie; Van Laere, Koen; Dupont, Patrick; Hilven, Kelly; Poesen, Koen; Vandenberghe, Rik

2015-12-18

In this study of preclinical Alzheimer's disease (AD) we assessed the added diagnostic value of using cerebrospinal fluid (CSF) Aβ ratios rather than Aβ42 in isolation for detecting individuals who are positive on amyloid positron emission tomography (PET). Thirty-eight community-recruited cognitively intact older adults (mean age 73, range 65-80 years) underwent (18)F-flutemetamol PET and CSF measurement of Aβ1-42, Aβ1-40, Aβ1-38, and total tau (ttau). (18)F-flutemetamol retention was quantified using standardized uptake value ratios in a composite cortical region (SUVRcomp) with reference to cerebellar grey matter. Based on a prior autopsy validation study, the SUVRcomp cut-off was 1.57. Sensitivities, specificities and cut-offs were defined based on receiver operating characteristic analysis with CSF analytes as variables of interest and (18)F-flutemetamol positivity as the classifier. We also determined sensitivities and CSF cut-off values at fixed specificities of 90 % and 95 %. Seven out of 38 subjects (18 %) were positive on amyloid PET. Aβ42/ttau, Aβ42/Aβ40, Aβ42/Aβ38, and Aβ42 had the highest accuracy to identify amyloid-positive subjects (area under the curve (AUC) ≥ 0.908). Aβ40 and Aβ38 had significantly lower discriminative power (AUC = 0.571). When specificity was fixed at 90 % and 95 %, Aβ42/ttau had the highest sensitivity among the different CSF markers (85.71 % and 71.43 %, respectively). Sensitivity of Aβ42 alone was significantly lower under these conditions (57.14 % and 42.86 %, respectively). For the CSF-based definition of preclinical AD, if a high specificity is required, our data support the use of Aβ42/ttau rather than using Aβ42 in isolation.

Pool power control in remelting systems

DOEpatents

Williamson, Rodney L [Albuquerque, NM; Melgaard, David K [Albuquerque, NM; Beaman, Joseph J [Austin, TX

2011-12-13

An apparatus for and method of controlling a remelting furnace comprising adjusting current supplied to an electrode based upon a predetermined pool power reference value and adjusting the electrode drive speed based upon the predetermined pool power reference value.

The Defense Logistics Agency Properly Awarded Power Purchase Agreements and the Army Obtained Fair Market Value for Leases Supporting Power Purchase Agreements

DTIC Science & Technology

2016-09-28

Fair Market Value for Leases Supporting Power Purchase Agreements I N T E G R I T Y  E F F I C I E N C Y  A C C O U N T A B I L I T Y  E X... Market Value for Leases Supporting Power Purchase Agreements Visit us at www.dodig.mil September 28, 2016 Objective We determined whether the...Department of the Army properly awarded and obtained fair market value for leases supporting energy production projects. We conducted this audit in

Power Laws are Disguised Boltzmann Laws

NASA Astrophysics Data System (ADS)

Richmond, Peter; Solomon, Sorin

Using a previously introduced model on generalized Lotka-Volterra dynamics together with some recent results for the solution of generalized Langevin equations, we derive analytically the equilibrium mean field solution for the probability distribution of wealth and show that it has two characteristic regimes. For large values of wealth, it takes the form of a Pareto style power law. For small values of wealth, w<=wm, the distribution function tends sharply to zero. The origin of this law lies in the random multiplicative process built into the model. Whilst such results have been known since the time of Gibrat, the present framework allows for a stable power law in an arbitrary and irregular global dynamics, so long as the market is ``fair'', i.e., there is no net advantage to any particular group or individual. We further show that the dynamics of relative wealth is independent of the specific nature of the agent interactions and exhibits a universal character even though the total wealth may follow an arbitrary and complicated dynamics. In developing the theory, we draw parallels with conventional thermodynamics and derive for the system some new relations for the ``thermodynamics'' associated with the Generalized Lotka-Volterra type of stochastic dynamics. The power law that arises in the distribution function is identified with new additional logarithmic terms in the familiar Boltzmann distribution function for the system. These are a direct consequence of the multiplicative stochastic dynamics and are absent for the usual additive stochastic processes.

Comparison of direct 13C and indirect 1H-[13C] MR detection methods for the study of dynamic metabolic turnover in the human brain

NASA Astrophysics Data System (ADS)

Chen, Hao; De Feyter, Henk M.; Brown, Peter B.; Rothman, Douglas L.; Cai, Shuhui; de Graaf, Robin A.

2017-10-01

A wide range of direct 13C and indirect 1H-[13C] MR detection methods exist to probe dynamic metabolic pathways in the human brain. Choosing an optimal detection method is difficult as sequence-specific features regarding spatial localization, broadband decoupling, spectral resolution, power requirements and sensitivity complicate a straightforward comparison. Here we combine density matrix simulations with experimentally determined values for intrinsic 1H and 13C sensitivity, T1 and T2 relaxation and transmit efficiency to allow selection of an optimal 13C MR detection method for a given application and magnetic field. The indirect proton-observed, carbon-edited (POCE) detection method provides the highest accuracy at reasonable RF power deposition both at 4 T and 7 T. The various polarization transfer methods all have comparable performances, but may become infeasible at 7 T due to the high RF power deposition. 2D MR methods have limited value for the metabolites considered (primarily glutamate, glutamine and γ-amino butyric acid (GABA)), but may prove valuable when additional information can be extracted, such as isotopomers or lipid composition. While providing the lowest accuracy, the detection of non-protonated carbons is the simplest to implement with the lowest RF power deposition. The magnetic field homogeneity is one of the most important parameters affecting the detection accuracy for all metabolites and all acquisition methods.

Sex Differences in Perceptions of the Implications of Power.

ERIC Educational Resources Information Center

Nelson, Lori J.; And Others

Values are guiding principles in an individual's life that transcend situations and guide selection and evaluation of behaviors and events. Frequently women are assumed to be less likely than men to make use of power. Several explanations may account for any sex differences in power values or power behavior. Women have not traditionally been…

18 CFR 11.12 - Determination of section 10(f) costs.

Code of Federal Regulations, 2010 CFR

2010-04-01

... costs of the project. (2) If power is not an authorized function of the headwater project, the section... costs designated as the joint-use power cost, derived by deeming a power function at the project. The value of the benefits assigned to the deemed power function, for purposes of determining the value of...

18 CFR 11.12 - Determination of section 10(f) costs.

Code of Federal Regulations, 2012 CFR

2012-04-01

... costs of the project. (2) If power is not an authorized function of the headwater project, the section... costs designated as the joint-use power cost, derived by deeming a power function at the project. The value of the benefits assigned to the deemed power function, for purposes of determining the value of...

18 CFR 11.12 - Determination of section 10(f) costs.

Code of Federal Regulations, 2011 CFR

2011-04-01

... costs of the project. (2) If power is not an authorized function of the headwater project, the section... costs designated as the joint-use power cost, derived by deeming a power function at the project. The value of the benefits assigned to the deemed power function, for purposes of determining the value of...

18 CFR 11.12 - Determination of section 10(f) costs.

Code of Federal Regulations, 2014 CFR

2014-04-01

... costs of the project. (2) If power is not an authorized function of the headwater project, the section... costs designated as the joint-use power cost, derived by deeming a power function at the project. The value of the benefits assigned to the deemed power function, for purposes of determining the value of...

18 CFR 11.12 - Determination of section 10(f) costs.

Code of Federal Regulations, 2013 CFR

2013-04-01

... costs of the project. (2) If power is not an authorized function of the headwater project, the section... costs designated as the joint-use power cost, derived by deeming a power function at the project. The value of the benefits assigned to the deemed power function, for purposes of determining the value of...

An improved human anxiety process biomarker: characterization of frequency band, personality and pharmacology

PubMed Central

Shadli, S M; Glue, P; McIntosh, J; McNaughton, N

2015-01-01

Anxiety disorders are among the most common mental illness in the western world with a major impact on disability. But their diagnosis has lacked objective biomarkers. We previously demonstrated a human anxiety process biomarker, goal-conflict-specific electroencephalography (EEG) rhythmicity (GCSR) in the stop-signal task (SST). Here we have developed and characterized an improved test appropriate for clinical group testing. We modified the SST to produce balanced numbers of trials in clearly separated stop-signal delay groups. As previously, right frontal (F8) GCSR was extracted as the difference in EEG log Fourier power between matching stop and go trials (that is, stop-signal-specific power) of a quadratic contrast of the three delay values (that is, power when stopping and going are in balanced conflict compared with the average of when stopping or going is greater). Separate experiments assessed drug sensitivity (n=34) and personality relations (n=59). GCSR in this new SST was reduced by three chemically distinct anxiolytic drugs (administered double-blind): buspirone (10 mg), triazolam (0.25 mg) and pregabalin (75 mg); had a frequency range (4–12 Hz) consistent with rodent model data; and positively correlated significantly with neuroticism and nonsignificantly with trait anxiety scores. GCSR, measured in our new form of the SST, should be suitable as a biomarker for one specific anxiety process in the testing of clinical groups and novel drugs and in the development of measures suitable for individual diagnosis. PMID:26670284

Strong, light, multifunctional fibers of carbon nanotubes with ultrahigh conductivity.

PubMed

Behabtu, Natnael; Young, Colin C; Tsentalovich, Dmitri E; Kleinerman, Olga; Wang, Xuan; Ma, Anson W K; Bengio, E Amram; ter Waarbeek, Ron F; de Jong, Jorrit J; Hoogerwerf, Ron E; Fairchild, Steven B; Ferguson, John B; Maruyama, Benji; Kono, Junichiro; Talmon, Yeshayahu; Cohen, Yachin; Otto, Marcin J; Pasquali, Matteo

2013-01-11

Broader applications of carbon nanotubes to real-world problems have largely gone unfulfilled because of difficult material synthesis and laborious processing. We report high-performance multifunctional carbon nanotube (CNT) fibers that combine the specific strength, stiffness, and thermal conductivity of carbon fibers with the specific electrical conductivity of metals. These fibers consist of bulk-grown CNTs and are produced by high-throughput wet spinning, the same process used to produce high-performance industrial fibers. These scalable CNT fibers are positioned for high-value applications, such as aerospace electronics and field emission, and can evolve into engineered materials with broad long-term impact, from consumer electronics to long-range power transmission.

Examining personal values in extreme environment contexts: Revisiting the question of generalizability

NASA Astrophysics Data System (ADS)

Smith, N.; Sandal, G. M.; Leon, G. R.; Kjærgaard, A.

2017-08-01

Land-based extreme environments (e.g. polar expeditions, Antarctic research stations, confinement chambers) have often been used as analog settings for spaceflight. These settings share similarities with the conditions experienced during space missions, including confinement, isolation and limited possibilities for evacuation. To determine the utility of analog settings for understanding human spaceflight, researchers have examined the extent to which the individual characteristics (e.g., personality) of people operating in extreme environments can be generalized across contexts (Sandal, 2000) [1]. Building on previous work, and utilising new and pre-existing data, the present study examined the extent to which personal value motives could be generalized across extreme environments. Four populations were assessed; mountaineers (N =59), military personnel (N = 25), Antarctic over-winterers (N = 21) and Mars simulation participants (N = 12). All participants completed the Portrait Values Questionnaire (PVQ; Schwartz; 2) capturing information on 10 personal values. Rank scores suggest that all groups identified Self-direction, Stimulation, Universalism and Benevolence as important values and acknowledged Power and Tradition as being low priorities. Results from difference testing suggest the extreme environment groups were most comparable on Self-direction, Stimulation, Benevolence, Tradition and Security. There were significant between-group differences on five of the ten values. Overall, findings pinpointed specific values that may be important for functioning in challenging environments. However, the differences that emerged on certain values highlight the importance of considering the specific population when comparing results across extreme settings. We recommend that further research examine the impact of personal value motives on indicators of adjustment, group working, and performance. Information from such studies could then be used to aid selection and training processes for personnel operating in extreme settings, and in space.

Oxygen-iodine ejector laser with a centrifugal bubbling singlet-oxygen generator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zagidullin, M V; Nikolaev, V D; Svistun, M I

2005-10-31

It is shown that if a supersonic oxygen-iodine ejector laser is fed by singlet oxygen from a centrifugal bubbling generator operating at a centrifugal acceleration of {approx}400g, the laser output power achieves a value 1264 W at a chemical efficiency of 24.6% for an alkaline hydrogen peroxide flow rate of 208 cm{sup 3}s{sup -1} and a specific chlorine load of 1.34 mmol s{sup -1} per square centimetre of the bubble layer. (lasers)

5 new ways to look at generating revenue.

PubMed

Sturm, Arthur C

2009-11-01

A healthcare organization's "strategic pie" has four pieces: physician retention, brand, patient retention, and patient acquisition. When allocating strategic effort among these pieces of the pie, leading hospitals are following the lead of other industries, focusing on concepts such as churn rate, downstream value, strategic halo, promotable products, and the relative power of different metrics. A risk-reward metric offers an important means of assessing factors that would influence how much you would be willing to spend for specific purposes, such as acquiring new patients.

An architecture for object-oriented intelligent control of power systems in space

NASA Technical Reports Server (NTRS)

Holmquist, Sven G.; Jayaram, Prakash; Jansen, Ben H.

1993-01-01

A control system for autonomous distribution and control of electrical power during space missions is being developed. This system should free the astronauts from localizing faults and reconfiguring loads if problems with the power distribution and generation components occur. The control system uses an object-oriented simulation model of the power system and first principle knowledge to detect, identify, and isolate faults. Each power system component is represented as a separate object with knowledge of its normal behavior. The reasoning process takes place at three different levels of abstraction: the Physical Component Model (PCM) level, the Electrical Equivalent Model (EEM) level, and the Functional System Model (FSM) level, with the PCM the lowest level of abstraction and the FSM the highest. At the EEM level the power system components are reasoned about as their electrical equivalents, e.g, a resistive load is thought of as a resistor. However, at the PCM level detailed knowledge about the component's specific characteristics is taken into account. The FSM level models the system at the subsystem level, a level appropriate for reconfiguration and scheduling. The control system operates in two modes, a reactive and a proactive mode, simultaneously. In the reactive mode the control system receives measurement data from the power system and compares these values with values determined through simulation to detect the existence of a fault. The nature of the fault is then identified through a model-based reasoning process using mainly the EEM. Compound component models are constructed at the EEM level and used in the fault identification process. In the proactive mode the reasoning takes place at the PCM level. Individual components determine their future health status using a physical model and measured historical data. In case changes in the health status seem imminent the component warns the control system about its impending failure. The fault isolation process uses the FSM level for its reasoning base.

Predictive factors of the nursing diagnosis sedentary lifestyle in people with high blood pressure.

PubMed

Guedes, Nirla Gomes; Lopes, Marcos Venícios de Oliveira; Araujo, Thelma Leite de; Moreira, Rafaella Pessoa; Martins, Larissa Castelo Guedes

2011-01-01

To verify the reproducibility of defining the characteristics and related factors in order to identify a sedentary lifestyle in patients with high blood pressure. A cross-sectional study. 310 patients diagnosed with high blood pressure. Socio-demographics and variables related to defining the characteristics and related factors of a sedentary lifestyle. The coefficient Kappa was utilized to analyze the reproducibility. The sensitivity, specificity, and predictive value of the defining characteristics were also analyzed. Logistic regression was applied in the analysis of possible predictors. The defining characteristic with the greatest sensitivity was demonstrates physical deconditioning (98.92%). The characteristics chooses a daily routine lacking physical exercise and verbalizes preference for activities low in physical activity presented higher values of specificity (99.21% and 95.97%, respectively). The following indicators were identified as powerful predictors (85.2%) for the identification of a sedentary lifestyle: demonstrates physical deconditioning, verbalizes preference for activities low in physical activity, and lack of training for accomplishment of physical exercise. © 2010 Wiley Periodicals, Inc.

Evaluation of a Mobile Phone-Based Microscope for Screening of Schistosoma haematobium Infection in Rural Ghana.

PubMed

Bogoch, Isaac I; Koydemir, Hatice C; Tseng, Derek; Ephraim, Richard K D; Duah, Evans; Tee, Joseph; Andrews, Jason R; Ozcan, Aydogan

2017-06-01

AbstractSchistosomiasis affects over 170 million people in Africa. Here we compare a novel, low-cost mobile phone microscope to a conventional light microscope for the label-free diagnosis of Schistosoma haematobium infections in a rural Ghanaian school setting. We tested the performance of our handheld microscope using 60 slides that were randomly chosen from an ongoing epidemiologic study in school-aged children. The mobile phone microscope had a sensitivity of 72.1% (95% confidence interval [CI]: 56.1-84.2), specificity of 100% (95% CI: 75.9-100), positive predictive value of 100% (95% CI: 86.3-100), and a negative predictive value of 57.1% (95% CI: 37.4-75.0). With its modest sensitivity and high specificity, this handheld and cost-effective mobile phone-based microscope is a stepping-stone toward developing a powerful tool in clinical and public health settings where there is limited access to conventional laboratory diagnostic support.

Anatomical parameterization for volumetric meshing of the liver

NASA Astrophysics Data System (ADS)

Vera, Sergio; González Ballester, Miguel A.; Gil, Debora

2014-03-01

A coordinate system describing the interior of organs is a powerful tool for a systematic localization of injured tissue. If the same coordinate values are assigned to specific anatomical landmarks, the coordinate system allows integration of data across different medical image modalities. Harmonic mappings have been used to produce parametric coordinate systems over the surface of anatomical shapes, given their flexibility to set values at specific locations through boundary conditions. However, most of the existing implementations in medical imaging restrict to either anatomical surfaces, or the depth coordinate with boundary conditions is given at sites of limited geometric diversity. In this paper we present a method for anatomical volumetric parameterization that extends current harmonic parameterizations to the interior anatomy using information provided by the volume medial surface. We have applied the methodology to define a common reference system for the liver shape and functional anatomy. This reference system sets a solid base for creating anatomical models of the patient's liver, and allows comparing livers from several patients in a common framework of reference.

Driving personalized medicine: capturing maximum net present value and optimal return on investment.

PubMed

Roth, Mollie; Keeling, Peter; Smart, Dave

2010-01-01

In order for personalized medicine to meet its potential future promise, a closer focus on the work being carried out today and the foundation it will provide for that future is imperative. While big picture perspectives of this still nascent shift in the drug-development process are important, it is more important that today's work on the first wave of targeted therapies is used to build specific benchmarking and financial models against which further such therapies may be more effectively developed. Today's drug-development teams need a robust tool to identify the exact drivers that will ensure the successful launch and rapid adoption of targeted therapies, and financial metrics to determine the appropriate resource levels to power those drivers. This special report will describe one such benchmarking and financial model that is specifically designed for the personalized medicine field and will explain how the use of this or similar models can help to capture the maximum net present value of targeted therapies and help to realize optimal return on investment.

TiO2 Nanostructures as Anode Materials for Li/Na-ion Batteries.

PubMed

Vazquez-Santos, Maria B; Tartaj, Pedro; Morales, Enrique; Amarilla, Jose Manuel

2018-03-14

Here we summarize some results on the use of TiO 2 nanostructures as anode materials for more efficient Li-ion (LIBs) and Na-ion (NIBs) batteries. LIBs are the leader to power portable electronic devices, and represent in the short-term the most adequate technology to power electrical vehicles, while NIBs hold promise for large storage of energy generated from renewable sources. Specifically, TiO 2 an abundant, low cost, chemically stable and environmentally safe oxide represents in LIBs an alternative to graphite for applications in which safety is mandatory. For NIBs, TiO 2 anodes (or more precisely negative electrodes) work at low voltage, assuring acceptable energy density values. Finally, assembling different TiO 2 polymorphs in the form of nanostructures decreases diffusion distances, increases the number of contacts and offering additional sites for Na + storage, helping to improve power efficiency. More specifically, in this contribution we highlighted our work on TiO 2 anatase mesocrystals of colloidal size. These sophisticate materials; showing excellent textural properties, have remarkable electrochemical performance as anodes for Li/Na-ion batteries, with conventional alkyl carbonates electrolytes and safe electrolytes based on ionic liquids. © 2018 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Flow of “stress power-law” fluids between parallel rotating discs with distinct axes

DOE PAGES

Srinivasan, Shriram; Karra, Satish

2015-04-16

The problem of flow between parallel rotating discs with distinct axes corresponds to the case of flow in an orthogonal rheometer and has been studied extensively for different fluids since the instrument's inception. All the prior studies presume a constitutive prescription of the fluid stress in terms of the kinematical variables. In this paper, we approach the problem from a different perspective, i.e., a constitutive specification of the symmetric part of the velocity gradient in terms of the Cauchy stress. Such an approach ensures that the boundary conditions can be incorporated in a manner quite faithful to real world experimentsmore » with the instrument. Interestingly, the choice of the boundary condition is critical to the solvability of the problem for the case of creeping/Stokes flow. Furthermore, when the no-slip condition is enforced at the boundaries, depending on the model parameters and axes offset, the fluid response can show non-uniqueness or unsolvability, features which are absent in a conventional constitutive specification. In case of creeping/Stokes flow with prescribed values of the stress, the fluid response is indeterminate. We also record the response of a particular case of the given “stress power-law” fluid; one that cannot be attained by the conventional power-law fluids.« less

Goodness-of-Fit Tests for Generalized Normal Distribution for Use in Hydrological Frequency Analysis

NASA Astrophysics Data System (ADS)

Das, Samiran

2018-04-01

The use of three-parameter generalized normal (GNO) as a hydrological frequency distribution is well recognized, but its application is limited due to unavailability of popular goodness-of-fit (GOF) test statistics. This study develops popular empirical distribution function (EDF)-based test statistics to investigate the goodness-of-fit of the GNO distribution. The focus is on the case most relevant to the hydrologist, namely, that in which the parameter values are unidentified and estimated from a sample using the method of L-moments. The widely used EDF tests such as Kolmogorov-Smirnov, Cramer von Mises, and Anderson-Darling (AD) are considered in this study. A modified version of AD, namely, the Modified Anderson-Darling (MAD) test, is also considered and its performance is assessed against other EDF tests using a power study that incorporates six specific Wakeby distributions (WA-1, WA-2, WA-3, WA-4, WA-5, and WA-6) as the alternative distributions. The critical values of the proposed test statistics are approximated using Monte Carlo techniques and are summarized in chart and regression equation form to show the dependence of shape parameter and sample size. The performance results obtained from the power study suggest that the AD and a variant of the MAD (MAD-L) are the most powerful tests. Finally, the study performs case studies involving annual maximum flow data of selected gauged sites from Irish and US catchments to show the application of the derived critical values and recommends further assessments to be carried out on flow data sets of rivers with various hydrological regimes.

Computer-aided diagnostic system for diffuse liver diseases with ultrasonography by neural networks

NASA Astrophysics Data System (ADS)

Ogawa, K.; Fukushima, M.; Kubota, K.; Hisa, N.

1998-12-01

The aim of the study is to establish a computer-aided diagnostic system for diffuse liver diseases such as chronic active hepatitis (CAH) and liver cirrhosis (LC). The authors introduced an artificial neural network in the classification of these diseases. In this system the neural network was trained by feature parameters extracted from B-mode ultrasonic images of normal liver (NL), CAH and LC. For input data the authors used six parameters calculated by a region of interest (ROI) and a parameter calculated by five ROIs in each image. They were variance of pixel values, coefficient of variation, annular Fourier power spectrum, longitudinal Fourier power spectrum which were calculated for the ROI, and variation of the means of the five ROIs. In addition, the authors used two more parameters calculated from a co-occurrence matrix of pixel values in the ROI. The results showed that the neural network classifier was 83.8% in sensitivity for LC, 90.0% in sensitivity for CAH and 93.6% in specificity, and the system was considered to be helpful for clinical and educational use.

Experimental Demonstration of Higher Precision Weak-Value-Based Metrology Using Power Recycling

NASA Astrophysics Data System (ADS)

Wang, Yi-Tao; Tang, Jian-Shun; Hu, Gang; Wang, Jian; Yu, Shang; Zhou, Zong-Quan; Cheng, Ze-Di; Xu, Jin-Shi; Fang, Sen-Zhi; Wu, Qing-Lin; Li, Chuan-Feng; Guo, Guang-Can

2016-12-01

The weak-value-based metrology is very promising and has attracted a lot of attention in recent years because of its remarkable ability in signal amplification. However, it is suggested that the upper limit of the precision of this metrology cannot exceed that of classical metrology because of the low sample size caused by the probe loss during postselection. Nevertheless, a recent proposal shows that this probe loss can be reduced by the power-recycling technique, and thus enhance the precision of weak-value-based metrology. Here we experimentally realize the power-recycled interferometric weak-value-based beam-deflection measurement and obtain the amplitude of the detected signal and white noise by discrete Fourier transform. Our results show that the detected signal can be strengthened by power recycling, and the power-recycled weak-value-based signal-to-noise ratio can surpass the upper limit of the classical scheme, corresponding to the shot-noise limit. This work sheds light on higher precision metrology and explores the real advantage of the weak-value-based metrology over classical metrology.

New two-tier low pressure turbine for heavy duty steam turbines

NASA Astrophysics Data System (ADS)

Zaryankin, A. E.; Rogalev, A. N.; Osipov, S. K.; Bychkov, N. M.

2017-11-01

Among factors characterising steam turbine units of power plants, a specific metal content which value decreases inversely to turbine power is of substantive importance. In turn, their maximum power depends on the capacity of low pressure turbines. It is traditionally managed to increase either by installation of larger number of low pressure turbines or by lengthening the exhaust blades. It is worth noting that the above-mentioned methods have some technical restrictions by the number of rotors to be connected. Currently some works aimed at solving the stated technical problems appear in the literature for the purpose of increasing the unit power of turbomachines, for example, by using exhaust blades with the length of 1 500 mm and longer. However, it is to be understood that increasing the exhaust area of turbomachine only by lengthening exhaust blades cannot provide a cost-effective and reliable work of the turbine flow part. Here new problems appear: losses rise abruptly due to the stage fan-out, the turbomachine dimensions increase, etc. In this connection, an issue of development of new, technically implementable ways of turbo-units power increase is very acute today.

Leader-team congruence in power distance values and team effectiveness: the mediating role of procedural justice climate.

PubMed

Cole, Michael S; Carter, Min Z; Zhang, Zhen

2013-11-01

We examine the effect of (in)congruence between leaders' and teams' power distance values on team effectiveness. We hypothesize that the (in)congruence between these values would differentially predict team effectiveness, with procedural justice climate serving as a mediator. Using multisource data and polynomial regression, we found that similarities (and differences) between leaders' and their teams' power distance values can have consequential effects on teams' justice climate and, ultimately, their effectiveness (viz., team performance and team organizational citizenship behavior). We conclude that to fully understand the implications of power distance, one should consider the multiple perspectives of both leaders and team members. (c) 2013 APA, all rights reserved.

Analysis of specific absorption rate and internal electric field in human biological tissues surrounding an air-core coil-type transcutaneous energy transmission transformer.

PubMed

Shiba, Kenji; Zulkifli, Nur Elina Binti; Ishioka, Yuji

2017-06-01

In this study, we analyzed the internal electric field E and specific absorption rate (SAR) of human biological tissues surrounding an air-core coil transcutaneous energy transmission transformer. Using an electromagnetic simulator, we created a model of human biological tissues consisting of a dry skin, wet skin, fat, muscle, and cortical bone. A primary coil was placed on the surface of the skin, and a secondary coil was located subcutaneously inside the body. The E and SAR values for the model representing a 34-year-old male subject were analyzed using electrical frequencies of 0.3-1.5 MHz. The transmitting power was 15 W, and the load resistance was 38.4 Ω. The results showed that the E values were below the International Commission on Non-ionizing Radiation Protection (ICNIRP) limit for the general public exposure between the frequencies of 0.9 and 1.5 MHz, and SAR values were well below the limit prescribed by the ICNIRP for the general public exposure between the frequencies of 0.3 and 1.2 MHz.

Is Preoperative Biochemical Testing for Pheochromocytoma Necessary for All Adrenal Incidentalomas?

PubMed Central

Jun, Joo Hyun; Ahn, Hyun Joo; Lee, Sangmin M.; Kim, Jie Ae; Park, Byung Kwan; Kim, Jee Soo; Kim, Jung Han

2015-01-01

Abstract This study examined whether imaging phenotypes obtained from computed tomography (CT) can replace biochemical tests to exclude pheochromocytoma among adrenal incidentalomas (AIs) in the preoperative setting. We retrospectively reviewed the medical records of all patients (n = 251) who were admitted for operations and underwent adrenal-protocol CT for an incidentally discovered adrenal mass from January 2011 to December 2012. Various imaging phenotypes were assessed for their screening power for pheochromocytoma. Final diagnosis was confirmed by biopsy, biochemical tests, and follow-up CT. Pheochromocytomas showed similar imaging phenotypes as malignancies, but were significantly different from adenomas. Unenhanced attenuation values ≤10 Hounsfield units (HU) showed the highest specificity (97%) for excluding pheochromocytoma as a single phenotype. A combination of size ≤3 cm, unenhanced attenuation values ≤ 10 HU, and absence of suspicious morphology showed 100% specificity for excluding pheochromocytoma. Routine noncontrast CT can be used as a screening tool for pheochromocytoma by combining 3 imaging phenotypes: size ≤3 cm, unenhanced attenuation values ≤10 HU, and absence of suspicious morphology, and may substitute for biochemical testing in the preoperative setting. PMID:26559265

Pharmacognostic Specification, Chlorogenic Acid Content, and In vitro Antioxidant Activities of Lonicera japonica Flowering Bud.

PubMed

Chaowuttikul, Chayanon; Palanuvej, Chanida; Ruangrungsi, Nijsiri

2017-01-01

Lonicera japonica Thunb. or Japanese Honeysuckle has been widely used in traditional medicine for antipyretic. To establish the pharmacognostic specification of L. japonica flowering bud in Thailand and to determine its chlorogenic acid content and in vitro antioxidant activities. Dried L. japonica flowering bud from 15 various herbal drugstores throughout Thailand were investigated for pharmacognostic specification. Their chlorogenic acid contents were quantitatively analyzed by thin layer chromatography (TLC) densitometry with winCATS software. The mobile phase for TLC development consisted of ethyl acetate: formic acid: acetic acid: water (10:1.1:1.1:2.6). Antioxidant activities were investigated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, ferric ion reducing antioxidant power assay, nitric oxide scavenging assay, and β-carotene bleaching assays. Qualified L. japonica flowering bud in Thailand was presented that the contents of loss on drying, total ash, acid-insoluble ash, and water should not be >10.11%, 6.59%, 1.14%, and 10.82% by weight, respectively. The ethanol and water soluble extractive values should not be < 16.46% and 28.88% by weight, respectively. Chlorogenic acid content in L. japonica flowering bud was found to be 2.24 ± 0.50 g/100 g of crude drug. L. japonica flowering bud showed DPPH and nitric oxide scavenging activities as well as reducing power property. This pharmacognostic specification with special reference to the chlorogenic acid content can be used for quality control of L. japonica flowering bud in Thailand. The potential antioxidant of this crude drug was demonstrated in vitro . Pharmacognostic specification of Lonicera japonica flowering bud in Thailand has been establishedThe chlorogenic acid content has been quantified by thin layer chromatography-densitometryThe ethanolic extract of L. japonica flowering bud showed antioxidation potential, especially on reducing power property. Abbreviations Used: TLC: Thin layer chromatography, DPPH: 2,2-diphenyl-1-picrylhydrazyl, FRAP: Ferric ion Reducing Antioxidant Power, WHO: World Health Organization, ICH: International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use; LOD: Limit of detection; LOQ: Limit of quantitation; BHT: Butylated hydroxytoluene; FeSO 4 : Iron(II) sulfate; DMSO: Dimethyl sulfoxide; TPTZ: 2,4,6-tripyridyl-s-triazine.

Power analysis to detect treatment effect in longitudinal studies with heterogeneous errors and incomplete data.

PubMed

Vallejo, Guillermo; Ato, Manuel; Fernández García, Paula; Livacic Rojas, Pablo E; Tuero Herrero, Ellián

2016-08-01

 S. Usami (2014) describes a method to realistically determine sample size in longitudinal research using a multilevel model. The present research extends the aforementioned work to situations where it is likely that the assumption of homogeneity of the errors across groups is not met and the error term does not follow a scaled identity covariance structure.   For this purpose, we followed a procedure based on transforming the variance components of the linear growth model and the parameter related to the treatment effect into specific and easily understandable indices. At the same time, we provide the appropriate statistical machinery for researchers to use when data loss is unavoidable, and changes in the expected value of the observed responses are not linear.   The empirical powers based on unknown variance components were virtually the same as the theoretical powers derived from the use of statistically processed indexes.   The main conclusion of the study is the accuracy of the proposed method to calculate sample size in the described situations with the stipulated power criteria.

The dependence of divertor power sharing on magnetic flux balance in near double-null configurations on Alcator C-Mod

NASA Astrophysics Data System (ADS)

Brunner, D.; Kuang, A. Q.; LaBombard, B.; Terry, J. L.

2018-07-01

Management of power exhaust will be a crucial task for tokamak fusion reactors. Reactor concepts are often proposed with double-null divertors, i.e. having two magnetic separatrices in an up-down symmetric configuration. This arrangement is potentially advantageous since the majority of the tokamak exhaust power tends to flow to the outer pair of divertor legs at large major radius, where the geometry is favorable for spreading the heat over a large surface area and there is more room for advanced divertor configurations. Despite the importance, there have been relatively few studies of divertor power sharing in near double null configurations and no studies at the poloidal magnetic fields and scrape-off layer power widths anticipated for a reactor. Motivated by this need we have undertaken a systematic study on Alcator C-Mod, examining the effect of magnetic flux balance on the power sharing among the four divertor legs in near double-null plasmas. Ohmic L-modes at three values of plasma current and ICRF-heated enhanced D-alpha (EDA) H-modes and I-modes at a single value of plasma current are explored, producing poloidal magnetic fields of 0.42, 0.62 and 0.85 Tesla. For Ohmic L-modes and ICRF-heated EDA H-modes, we find that the point of equal power sharing between upper and lower divertors occurs remarkably close to a balanced double null. Power sharing amongst the outer (upper versus lower) and inner (upper versus lower) pairs of divertors can be described in terms of a logistic function of magnetic flux balance, consistent with heat flux mapping along magnetic field lines to the outer midplane. Power sharing between inner and outer legs is found to follow a Gaussian-like function of magnetic flux balance with non-zero power to the inner divertors at double null. The overall behavior of H-modes operated near double null and for I-modes operating to within one heat flux e-folding of double null are found similar to Ohmic L-modes, with a significant reduction of power on the inner divertor legs. The results are encapsulated in terms of empirically-informed analytic functions of magnetic flux balance. When combined with magnetic equilibrium control system specifications, these relationships can be used to specify the power flux handling requirements for each of the four divertor target plates.

Influence of upper-body external loading on anaerobic exercise performance.

PubMed

Inacio, Mario; Dipietro, Loretta; Visek, Amanda J; Miller, Todd A

2011-04-01

The purpose of this study was to assess the threshold where simulated adipose tissue weight gain significantly affects performance in common anaerobic tasks and determine whether differences exist between men and women. Forty-six subjects (men = 21; women = 25) were tested for vertical jump, 20- and 40-yd dash, and 20-yd shuttle tests under 6 different loading conditions (0, 2, 4, 6, 8, and 10% of added body weight). Results were compared to each subject's baseline values (0% loading condition). Results demonstrate significant decrements in performance, starting at the 2% loading condition, for both genders, in every performance test (p < 0.05). On average, subjects jumped 4.91 ± 0.29 to 9.83 ± 0.30 cm less, increased agility test times from 5.49 ± 0.56 to 5.86 ± 0.61 seconds, and increased sprint times from 7.80 ± 0.96 to 8.39 ± 1.07 seconds (2-10%, respectively; p < 0.05). When lower-body power was corrected for total body mass, men exerted significantly more power than women did in every loading condition. Conversely, when lower-body power was corrected for lean body mass, men exerted significantly more power than did women only at the 2% loading condition. This study demonstrates that for the specific anaerobic performance tests performed, increases in external loading as low as 2% of body weight results in significant decreases in performance. Moreover, for these specific tests, men and women tend to express the same threshold in performance decrements.

A VVWBO-BVO-based GM (1,1) and its parameter optimization by GRA-IGSA integration algorithm for annual power load forecasting

PubMed Central

Wang, Hongguang

2018-01-01

Annual power load forecasting is not only the premise of formulating reasonable macro power planning, but also an important guarantee for the safety and economic operation of power system. In view of the characteristics of annual power load forecasting, the grey model of GM (1,1) are widely applied. Introducing buffer operator into GM (1,1) to pre-process the historical annual power load data is an approach to improve the forecasting accuracy. To solve the problem of nonadjustable action intensity of traditional weakening buffer operator, variable-weight weakening buffer operator (VWWBO) and background value optimization (BVO) are used to dynamically pre-process the historical annual power load data and a VWWBO-BVO-based GM (1,1) is proposed. To find the optimal value of variable-weight buffer coefficient and background value weight generating coefficient of the proposed model, grey relational analysis (GRA) and improved gravitational search algorithm (IGSA) are integrated and a GRA-IGSA integration algorithm is constructed aiming to maximize the grey relativity between simulating value sequence and actual value sequence. By the adjustable action intensity of buffer operator, the proposed model optimized by GRA-IGSA integration algorithm can obtain a better forecasting accuracy which is demonstrated by the case studies and can provide an optimized solution for annual power load forecasting. PMID:29768450

New approach for correction of error associated with keratometric estimation of corneal power in keratoconus.

PubMed

Camps, Vicente J; Piñero, David P; Caravaca-Arens, Esteban; de Fez, Dolores; Pérez-Cambrodí, Rafael J; Artola, Alberto

2014-09-01

The aim of this study was to obtain the exact value of the keratometric index (nkexact) and to clinically validate a variable keratometric index (nkadj) that minimizes this error. The nkexact value was determined by obtaining differences (ΔPc) between keratometric corneal power (Pk) and Gaussian corneal power ((Equation is included in full-text article.)) equal to 0. The nkexact was defined as the value associated with an equivalent difference in the magnitude of ΔPc for extreme values of posterior corneal radius (r2c) for each anterior corneal radius value (r1c). This nkadj was considered for the calculation of the adjusted corneal power (Pkadj). Values of r1c ∈ (4.2, 8.5) mm and r2c ∈ (3.1, 8.2) mm were considered. Differences of True Net Power with (Equation is included in full-text article.), Pkadj, and Pk(1.3375) were calculated in a clinical sample of 44 eyes with keratoconus. nkexact ranged from 1.3153 to 1.3396 and nkadj from 1.3190 to 1.3339 depending on the eye model analyzed. All the nkadj values adjusted perfectly to 8 linear algorithms. Differences between Pkadj and (Equation is included in full-text article.)did not exceed ±0.7 D (Diopter). Clinically, nk = 1.3375 was not valid in any case. Pkadj and True Net Power and Pk(1.3375) and Pkadj were statistically different (P < 0.01), whereas no differences were found between (Equation is included in full-text article.)and Pkadj (P > 0.01). The use of a single value of nk for the calculation of the total corneal power in keratoconus has been shown to be imprecise, leading to inaccuracies in the detection and classification of this corneal condition. Furthermore, our study shows the relevance of corneal thickness in corneal power calculations in keratoconus.

A hand-powered, portable, low-cost centrifuge for diagnosing anemia in low-resource settings.

PubMed

Brown, Jocelyn; Theis, Lauren; Kerr, Lila; Zakhidova, Nazima; O'Connor, Kelly; Uthman, Margaret; Oden, Z Maria; Richards-Kortum, Rebecca

2011-08-01

This report describes the development of a hand-powered centrifuge to determine hematocrit values in low-resource settings. A hand-powered centrifuge was constructed by using a salad spinner. Hematocrit values were measured by using the hand-powered device, and results were compared with those of a benchtop centrifuge. The packed cell volume (PCV) measured with the hand-powered device correlated linearly with results obtained with a benchtop centrifuge (r = 0.986, P < 0.001). The PCVs measured with the hand-powered centrifuge were consistently 1.14 times higher than those measured with the benchtop system. The 14% increase in PCV measured with the hand-powered centrifuge is caused by increased plasma trapped in the cell column. The reader card was adjusted to compensate for trapped plasma. A hand-powered centrifuge and calibrated reader card can be constructed for U.S. $35 and can accurately determine hematocrit values. It is suitable for use in low-resource settings because it is mechanically-powered, inexpensive, and accurate.

A Hand-Powered, Portable, Low-Cost Centrifuge for Diagnosing Anemia in Low-Resource Settings

PubMed Central

Brown, Jocelyn; Theis, Lauren; Kerr, Lila; Zakhidova, Nazima; O'Connor, Kelly; Uthman, Margaret; Oden, Z. Maria; Richards-Kortum, Rebecca

2011-01-01

This report describes the development of a hand-powered centrifuge to determine hematocrit values in low-resource settings. A hand-powered centrifuge was constructed by using a salad spinner. Hematocrit values were measured by using the hand-powered device, and results were compared with those of a benchtop centrifuge. The packed cell volume (PCV) measured with the hand-powered device correlated linearly with results obtained with a benchtop centrifuge (r = 0.986, P < 0.001). The PCVs measured with the hand-powered centrifuge were consistently 1.14 times higher than those measured with the benchtop system. The 14% increase in PCV measured with the hand-powered centrifuge is caused by increased plasma trapped in the cell column. The reader card was adjusted to compensate for trapped plasma. A hand-powered centrifuge and calibrated reader card can be constructed for U.S. $35 and can accurately determine hematocrit values. It is suitable for use in low-resource settings because it is mechanically-powered, inexpensive, and accurate. PMID:21813855

Circuit for Communication over DC Power Line Using High Temperature Electronics

NASA Technical Reports Server (NTRS)

Krasowski, Michael J. (Inventor); Prokop, Norman F. (Inventor)

2014-01-01

A high temperature communications circuit includes a power conductor for concurrently conducting electrical energy for powering circuit components and transmitting a modulated data signal, and a demodulator for demodulating the data signal and generating a serial bit stream based on the data signal. The demodulator includes an absolute value amplifier for conditionally inverting or conditionally passing a signal applied to the absolute value amplifier. The absolute value amplifier utilizes no diodes to control the conditional inversion or passing of the signal applied to the absolute value amplifier.

Improved Controllers For Heaters In Toxic-Gas Combustors

NASA Technical Reports Server (NTRS)

Wishard, James; Lamb, James; Fortier, Edward; Velasquez, Hugo; Waltman, Doug

1995-01-01

Commercial electronic proportional controllers installed in place of mechanical power controllers for electric heaters in toxic-gas combustors at NASA's Jet Propulsion Laboratory. Designed to maintain temperature of heater at preset value by turning power fully on or fully off when temperature falls below or rises above that value, respectively. Solid-state power controllers overcome deficiencies of mechanical power controllers.

Synthesis and properties of ternary mixture of nickel/cobalt/tin oxides for supercapacitors

NASA Astrophysics Data System (ADS)

Ferreira, C. S.; Passos, R. R.; Pocrifka, L. A.

2014-12-01

The present study reports the synthesis and morphological, structural and electrochemical characterization of ternary oxides mixture containing nickel, cobalt and tin. The ternary oxide is synthesized by Pechini method with subsequent deposition onto a titanium substrate in a thin-film form. XRD and EDS analysis confirm the formation of ternary film with amorphous nature. SEM analysis show that cracks on the film favor the gain of the surface area that is an interesting feature for electrochemical capacitors. The ternary film is investigated in KOH electrolyte solution using cyclic voltammetry and charge-discharge study with a specific capacitance of 328 F g-1, and a capacitance retention of 86% over 600 cycles. The values of specific power and specific energy was 345.7 W kg-1 and 18.92 Wh kg-1, respectively.

ERBS fuel addendum: Pollution reduction technology program small jet aircraft engines, phase 3

NASA Technical Reports Server (NTRS)

Bruce, T. W.; Davis, F. G.; Kuhn, T. E.; Mongia, H. C.

1982-01-01

A Model TFE731-2 engine with a low emission, variable geometry combustion system was tested to compare the effects of operating the engine on Commercial Jet-A aviation turbine fuel and experimental referee broad specification (ERBS) fuels. Low power emission levels were essentially identical while the high power NOx emission indexes were approximately 15% lower with the EBRS fuel. The exhaust smoke number was approximately 50% higher with ERBS at the takeoff thrust setting; however, both values were still below the EPA limit of 40 for the Model TFE731 engine. Primary zone liner wall temperature ran an average of 25 K higher with ERBS fuel than with Jet-A. The possible adoption of broadened proprties fuels for gas turbine applications is suggested.

Power and On-Board Propulsion System Benefit Studies at NASA GRC

NASA Technical Reports Server (NTRS)

Hoffman, David J.

2000-01-01

This paper discusses the value of systems studies that provide unbiased 'honest broker' assessments of the quantified benefits afforded by advanced technologies for specific missions. The organization, format, and approach used by the NASA Glenn Research Center (GRC) Systems Assessment Team (SAT) to perform system studies for the GRC advanced power and on-board propulsion technology development program is described. Three levels of assessments and a sensitivity analysis are explained and example results are presented. The impact of system studies results and some of the main challenges associated with systems studies are identified. A call for collaboration is made where system studies of all types from all organizations can be reviewed, providing a forum for the widest peer review to ensure accurate and unbiased technical content, and to avoid needless duplication.

Quantity, Revisited: An Object-Oriented Reusable Class

NASA Technical Reports Server (NTRS)

Funston, Monica Gayle; Gerstle, Walter; Panthaki, Malcolm

1998-01-01

"Quantity", a prototype implementation of an object-oriented class, was developed for two reasons: to help engineers and scientists manipulate the many types of quantities encountered during routine analysis, and to create a reusable software component to for large domain-specific applications. From being used as a stand-alone application to being incorporated into an existing computational mechanics toolkit, "Quantity" appears to be a useful and powerful object. "Quantity" has been designed to maintain the full engineering meaning of values with respect to units and coordinate systems. A value is a scalar, vector, tensor, or matrix, each of which is composed of Value Components, each of which may be an integer, floating point number, fuzzy number, etc., and its associated physical unit. Operations such as coordinate transformation and arithmetic operations are handled by member functions of "Quantity". The prototype has successfully tested such characteristics as maintaining a numeric value, an associated unit, and an annotation. In this paper we further explore the design of "Quantity", with particular attention to coordinate systems.

Lee-Carter state space modeling: Application to the Malaysia mortality data

NASA Astrophysics Data System (ADS)

Zakiyatussariroh, W. H. Wan; Said, Z. Mohammad; Norazan, M. R.

2014-06-01

This article presents an approach that formalizes the Lee-Carter (LC) model as a state space model. Maximum likelihood through Expectation-Maximum (EM) algorithm was used to estimate the model. The methodology is applied to Malaysia's total population mortality data. Malaysia's mortality data was modeled based on age specific death rates (ASDR) data from 1971-2009. The fitted ASDR are compared to the actual observed values. However, results from the comparison of the fitted and actual values between LC-SS model and the original LC model shows that the fitted values from the LC-SS model and original LC model are quite close. In addition, there is not much difference between the value of root mean squared error (RMSE) and Akaike information criteria (AIC) from both models. The LC-SS model estimated for this study can be extended for forecasting ASDR in Malaysia. Then, accuracy of the LC-SS compared to the original LC can be further examined by verifying the forecasting power using out-of-sample comparison.

Some remarks on nonminimal coupling of the inflaton

NASA Astrophysics Data System (ADS)

Mahajan, Namit

2014-08-01

The nonminimal coupling of the inflaton is known to alleviate the smallness of the quartic coupling λ in the chaotic inflation with ϕ4 potential. A large ξ is required to obtain the cosmic microwave background (CMB) power spectrum while a small value 1/6 seems to be preferred from spectral index. There are issues related to conformal transformations, choice of frame and natural value(s) of ξ for a given potential. We revisit some of these issues and invoke field theoretic arguments (which exist in different context and have not been employed previously in the context of inflation) in order to address the same. A rather strong and general conclusion reached, based on the requirements of renormalizability and finiteness of specific matrix elements in a quantum theory, is that it is generically not possible to eliminate the nonminimal coupling by going from the Jordan to the Einstein frame via conformal transformations. We also comment on Higgs inflation.

Pediatric radiation dosimetry for positron-emitting radionuclides using anthropomorphic phantoms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xie, Tianwu; Bolch, Wesley E.; Lee, Choonsik

2013-10-15

Purpose: Positron emission tomography (PET) plays an important role in the diagnosis, staging, treatment, and surveillance of clinically localized diseases. Combined PET/CT imaging exhibits significantly higher sensitivity, specificity, and accuracy than conventional imaging when it comes to detecting malignant tumors in children. However, the radiation dose from positron-emitting radionuclide to the pediatric population is a matter of concern since children are at a particularly high risk when exposed to ionizing radiation.Methods: The authors evaluate the absorbed fractions and specific absorbed fractions (SAFs) of monoenergy photons/electrons as well as S-values of 9 positron-emitting radionuclides (C-11, N-13, O-15, F-18, Cu-64, Ga-68, Rb-82,more » Y-86, and I-124) in 48 source regions for 10 anthropomorphic pediatric hybrid models, including the reference newborn, 1-, 5-, 10-, and 15-yr-old male and female models, using the Monte Carlo N-Particle eXtended general purpose Monte Carlo transport code.Results: The self-absorbed SAFs and S-values for most organs were inversely related to the age and body weight, whereas the cross-dose terms presented less correlation with body weight. For most source/target organ pairs, Rb-82 and Y-86 produce the highest self-absorbed and cross-absorbed S-values, respectively, while Cu-64 produces the lowest S-values because of the low-energy and high-frequency of electron emissions. Most of the total self-absorbed S-values are contributed from nonpenetrating particles (electrons and positrons), which have a linear relationship with body weight. The dependence of self-absorbed S-values of the two annihilation photons varies to the reciprocal of 0.76 power of the mass, whereas the self-absorbed S-values of positrons vary according to the reciprocal mass.Conclusions: The produced S-values for common positron-emitting radionuclides can be exploited for the assessment of radiation dose delivered to the pediatric population from various PET radiotracers used in clinical and research settings. The mass scaling method for positron-emitters can be used to derive patient-specific S-values from data of reference phantoms.« less

How coagulation zone size is underestimated in computer modeling of RF ablation by ignoring the cooling phase just after RF power is switched off.

PubMed

Irastorza, Ramiro M; Trujillo, Macarena; Berjano, Enrique

2017-11-01

All the numerical models developed for radiofrequency ablation so far have ignored the possible effect of the cooling phase (just after radiofrequency power is switched off) on the dimensions of the coagulation zone. Our objective was thus to quantify the differences in the minor radius of the coagulation zone computed by including and ignoring the cooling phase. We built models of RF tumor ablation with 2 needle-like electrodes: a dry electrode (5 mm long and 17G in diameter) with a constant temperature protocol (70°C) and a cooled electrode (30 mm long and 17G in diameter) with a protocol of impedance control. We observed that the computed coagulation zone dimensions were always underestimated when the cooling phase was ignored. The mean values of the differences computed along the electrode axis were always lower than 0.15 mm for the dry electrode and 1.5 mm for the cooled electrode, which implied a value lower than 5% of the minor radius of the coagulation zone (which was 3 mm for the dry electrode and 30 mm for the cooled electrode). The underestimation was found to be dependent on the tissue characteristics: being more marked for higher values of specific heat and blood perfusion and less marked for higher values of thermal conductivity. Copyright © 2017 John Wiley & Sons, Ltd.

Power of data mining methods to detect genetic associations and interactions.

PubMed

Molinaro, Annette M; Carriero, Nicholas; Bjornson, Robert; Hartge, Patricia; Rothman, Nathaniel; Chatterjee, Nilanjan

2011-01-01

Genetic association studies, thus far, have focused on the analysis of individual main effects of SNP markers. Nonetheless, there is a clear need for modeling epistasis or gene-gene interactions to better understand the biologic basis of existing associations. Tree-based methods have been widely studied as tools for building prediction models based on complex variable interactions. An understanding of the power of such methods for the discovery of genetic associations in the presence of complex interactions is of great importance. Here, we systematically evaluate the power of three leading algorithms: random forests (RF), Monte Carlo logic regression (MCLR), and multifactor dimensionality reduction (MDR). We use the algorithm-specific variable importance measures (VIMs) as statistics and employ permutation-based resampling to generate the null distribution and associated p values. The power of the three is assessed via simulation studies. Additionally, in a data analysis, we evaluate the associations between individual SNPs in pro-inflammatory and immunoregulatory genes and the risk of non-Hodgkin lymphoma. The power of RF is highest in all simulation models, that of MCLR is similar to RF in half, and that of MDR is consistently the lowest. Our study indicates that the power of RF VIMs is most reliable. However, in addition to tuning parameters, the power of RF is notably influenced by the type of variable (continuous vs. categorical) and the chosen VIM. Copyright © 2011 S. Karger AG, Basel.

Biometric parameters in different stages of primary angle closure using low-coherence interferometry.

PubMed

Yazdani, Shahin; Akbarian, Shadi; Pakravan, Mohammad; Doozandeh, Azadeh; Afrouzifar, Mohsen

2015-03-01

To compare ocular biometric parameters using low-coherence interferometry among siblings affected with different degrees of primary angle closure (PAC). In this cross-sectional comparative study, a total of 170 eyes of 86 siblings from 47 families underwent low-coherence interferometry (LenStar 900; Haag-Streit, Koeniz, Switzerland) to determine central corneal thickness, anterior chamber depth (ACD), aqueous depth (AD), lens thickness (LT), vitreous depth, and axial length (AL). Regression coefficients were applied to show the trend of the measured variables in different stages of angle closure. To evaluate the discriminative power of the parameters, receiver operating characteristic curves were used. Best cutoff points were selected based on the Youden index. Sensitivity, specificity, positive and negative predicative values, positive and negative likelihood ratios, and diagnostic accuracy were determined for each variable. All biometric parameters changed significantly from normal eyes to PAC suspects, PAC, and PAC glaucoma; there was a significant stepwise decrease in central corneal thickness, ACD, AD, vitreous depth, and AL, and an increase in LT and LT/AL. Anterior chamber depth and AD had the best diagnostic power for detecting angle closure; best levels of sensitivity and specificity were obtained with cutoff values of 3.11 mm for ACD and 2.57 mm for AD. Biometric parameters measured by low-coherence interferometry demonstrated a significant and stepwise change among eyes affected with various degrees of angle closure. Although the current classification scheme for angle closure is based on anatomical features, it has excellent correlation with biometric parameters.

Scale-dependent CMB power asymmetry from primordial speed of sound and a generalized δ N formalism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Dong-Gang; Cai, Yi-Fu; Zhao, Wen

2016-02-01

We explore a plausible mechanism that the hemispherical power asymmetry in the CMB is produced by the spatial variation of the primordial sound speed parameter. We suggest that in a generalized approach of the δ N formalism the local e-folding number may depend on some other primordial parameters besides the initial values of inflaton. Here the δ N formalism is extended by considering the effects of a spatially varying sound speed parameter caused by a super-Hubble perturbation of a light field. Using this generalized δ N formalism, we systematically calculate the asymmetric primordial spectrum in the model of multi-speed inflation by taking intomore » account the constraints of primordial non-Gaussianities. We further discuss specific model constraints, and the corresponding asymmetry amplitudes are found to be scale-dependent, which can accommodate current observations of the power asymmetry at different length scales.« less

Effect of global warming on willingness to pay for uninterrupted electricity supply in European nations

NASA Astrophysics Data System (ADS)

Cohen, Jed; Moeltner, Klaus; Reichl, Johannes; Schmidthaler, Michael

2018-01-01

Predicted changes in temperature and other weather events may damage the electricity grid and cause power outages. Understanding the costs of power outages and how these costs change over time with global warming can inform outage-mitigation-investment decisions. Here we show that across 19 EU nations the value of uninterrupted electricity supply is strongly related to local temperatures, and will increase as the climate warms. Bayesian hierarchical modelling of data from a choice experiment and respondent-specific temperature measures reveals estimates of willingness to pay (WTP) to avoid an hour of power outage between €0.32 and €1.86 per household. WTP varies on the basis of season and is heterogeneous between European nations. Winter outages currently cause larger per household welfare losses than summer outages per hour of outage. However, this dynamic will begin to shift under plausible future climates, with summer outages becoming substantially more costly and winter outages becoming slightly less costly on a per-household, per-hour basis.

Silicon oxynitride films deposited by reactive high power impulse magnetron sputtering using nitrous oxide as a single-source precursor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hänninen, Tuomas, E-mail: tuoha@ifm.liu.se; Schmidt, Susann; Jensen, Jens

2015-09-15

Silicon oxynitride thin films were synthesized by reactive high power impulse magnetron sputtering of silicon in argon/nitrous oxide plasmas. Nitrous oxide was employed as a single-source precursor supplying oxygen and nitrogen for the film growth. The films were characterized by elastic recoil detection analysis, x-ray photoelectron spectroscopy, x-ray diffraction, x-ray reflectivity, scanning electron microscopy, and spectroscopic ellipsometry. Results show that the films are silicon rich, amorphous, and exhibit a random chemical bonding structure. The optical properties with the refractive index and the extinction coefficient correlate with the film elemental composition, showing decreasing values with increasing film oxygen and nitrogen content.more » The total percentage of oxygen and nitrogen in the films is controlled by adjusting the gas flow ratio in the deposition processes. Furthermore, it is shown that the film oxygen-to-nitrogen ratio can be tailored by the high power impulse magnetron sputtering-specific parameters pulse frequency and energy per pulse.« less

Space rocket engine on the base of the reactor-pumped laser for the interplanetary flights and earth orbital applications

NASA Astrophysics Data System (ADS)

Gulevich, Andrey V.; Dyachenko, Peter P.; Kukharchuk, Oleg F.; Zrodnikov, Anatoly V.

2000-01-01

In this report the concept of vehicle-based reactor-laser engine for long time interplanetary and interorbital (LEO to GEO) flights is proposed. Reactor-pumped lasers offer the perspective way to create on the base of modern nuclear and lasers technologies the low mass and high energy density, repetitively pulsed vehicle-based laser of average power 100 kW. Nowadays the efficiency of nuclear-to-optical energy conversion reached the value of 2-3%. The demo model of reactor-pumped laser facility is under construction in Institute for Physics and Power Engineering (Obninsk, Russia). It enable us to hope that using high power laser on board of the vehicle could make the effective space laser engine possible. Such engine may provide the high specific impulse ~1000-2000 s with the thrust up to 10-100 n. Some calculation results of the characteristics of vehicle-based reactor-laser thermal engine concept are also presented. .

The potential for increased power from combining P-values testing the same hypothesis.

PubMed

Ganju, Jitendra; Julie Ma, Guoguang

2017-02-01

The conventional approach to hypothesis testing for formal inference is to prespecify a single test statistic thought to be optimal. However, we usually have more than one test statistic in mind for testing the null hypothesis of no treatment effect but we do not know which one is the most powerful. Rather than relying on a single p-value, combining p-values from prespecified multiple test statistics can be used for inference. Combining functions include Fisher's combination test and the minimum p-value. Using randomization-based tests, the increase in power can be remarkable when compared with a single test and Simes's method. The versatility of the method is that it also applies when the number of covariates exceeds the number of observations. The increase in power is large enough to prefer combined p-values over a single p-value. The limitation is that the method does not provide an unbiased estimator of the treatment effect and does not apply to situations when the model includes treatment by covariate interaction.

Accelerated optical polymer aging studies for LED luminaire applications

NASA Astrophysics Data System (ADS)

Estupiñán, Edgar; Wendling, Peter; Kostrun, Marijan; Garner, Richard

2013-09-01

There is a need in the lighting industry to design and implement accelerated aging methods that accurately simulate the aging process of LED luminaire components. In response to this need, we have built a flexible and reliable system to study the aging characteristics of optical polymer materials, and we have employed it to study a commercially available LED luminaire diffuser made of PMMA. The experimental system consists of a "Blue LED Emitter" and a working surface. Both the temperatures of the samples and the optical powers of the LEDs are appropriately characterized in the system. Several accelerated aging experiments are carried out at different temperatures and optical powers over a 90 hour period and the measured transmission values are used as inputs to a degradation model derived using plausibility arguments. This model seems capable of predicting the behavior of the material as a function of time, temperature and optical power. The model satisfactorily predicts the measured transmission values of diffusers aged in luminaires at two different times and thus can be used to make application recommendations for this material. Specifically, at 35000 hours (the manufacturer's stated life of the luminaire) and at the typical operational temperature of the diffuser, the model predicts a transmission loss of only a few percent over the original transmission of the material at 450 nm, which renders this material suitable for this application.

Desired emotions across cultures: A value-based account.

PubMed

Tamir, Maya; Schwartz, Shalom H; Cieciuch, Jan; Riediger, Michaela; Torres, Claudio; Scollon, Christie; Dzokoto, Vivian; Zhou, Xiaolu; Vishkin, Allon

2016-07-01

Values reflect how people want to experience the world; emotions reflect how people actually experience the world. Therefore, we propose that across cultures people desire emotions that are consistent with their values. Whereas prior research focused on the desirability of specific affective states or 1 or 2 target emotions, we offer a broader account of desired emotions. After reporting initial evidence for the potential causal effects of values on desired emotions in a preliminary study (N = 200), we tested the predictions of our proposed model in 8 samples (N = 2,328) from distinct world cultural regions. Across cultural samples, we found that people who endorsed values of self-transcendence (e.g., benevolence) wanted to feel more empathy and compassion, people who endorsed values of self-enhancement (e.g., power) wanted to feel more anger and pride, people who endorsed values of openness to change (e.g., self-direction) wanted to feel more interest and excitement, and people who endorsed values of conservation (e.g., tradition) wanted to feel more calmness and less fear. These patterns were independent of differences in emotional experience. We discuss the implications of our value-based account of desired emotions for understanding emotion regulation, culture, and other individual differences. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Cost and performance of coal-based energy in Brazil

DOE Office of Scientific and Technical Information (OSTI.GOV)

Temchin, J.; DeLallo, M.R.

1998-07-01

As part of the US Department of Energy's (DOE) efforts to establish the strategic benefits of Clean Coal Technologies (CCT), there is a need to evaluate the specific market potential where coal is a viable option. One such market is Brazil, where significant growth in economic development requires innovative and reliable technologies to support the use of domestic coal. While coal is Brazil's most abundant and economic fossil energy resource, it is presently under utilized in the production of electrical power. This report presents conceptual design for pulverized coal (PC) and circulating fluidized-bed combustion (CFBC) options with resulting capital, operatingmore » and financial parameters based on Brazil application conditions. Recent PC and CFBC plant capital costs have dropped with competition in the generation market and have established a competitive position in power generation. Key issues addressed in this study include: Application of market based design approach for FBC and PC, which is competitive within the current domestic, and international power generation markets. Design, fabrication, purchase, and construction methods which reduce capital investment while maintaining equipment quality and plant availability. Impact on coast and performance from application of Brazilian coals, foreign trade and tax policies, construction logistics, and labor requirements. Nominal production values of 200 MWe and 400 MWe were selected for the CFBC power plant and 400 MWe for the PC. The 400 MWe size was chosen to be consistent with the two largest Brazilian PC units. Fluidized bed technology, with limited experience in single units over 200 MW, would consist of two 200 MWe circulating fluidized bed boilers supplying steam to one steam turbine for the 400 MWe capacity. A 200 MWe capacity unit was also developed for CFBC option to support opportunities in re-powering and where specific site or other infrastructure constraints limit production.« less

Effects of age and muscle action type on acute strength and power recovery following fatigue of the leg flexors.

PubMed

Thompson, Brennan J; Conchola, Eric C; Stock, Matt S

2015-12-01

Short-term strength and power recovery patterns following fatigue have received little research attention, particularly as they pertain to age-specific responses, and the leg flexors (i.e., hamstrings) muscle group. Thus, research is warranted addressing these issues because both age-related alterations in the neuromuscular system and mode of muscle action (e.g., eccentric, concentric, isometric) may differentially influence recovery responses from fatigue. The aim of this study was to investigate the strength and power recovery responses for eccentric, concentric, and isometric muscle actions of the leg flexors in young and older men following an isometric, intermittent fatigue-inducing protocol. Nineteen young (age = 25 ± 3 years) and nineteen older (71 ± 4) men performed maximal voluntary contractions (MVCs) for eccentric, concentric, and isometric muscle actions followed by a fatigue protocol of intermittent (0.6 duty cycle) isometric contractions of the leg flexors at 60% of isometric MVC. MVCs of each muscle action were performed at 0, 7, 15, and 30 min following fatigue. Peak torque (PT) and mean power values were calculated from the MVCs and the eccentric/concentric ratio (ECR) was derived. For PT and mean power, young men showed incomplete recovery at all time phases, whereas the older men had recovered by 7 min. Eccentric and isometric muscle actions showed incomplete recovery at all time phases, but concentric recovered by 7 min, independent of age. The ECR was depressed for up to 30 min following fatigue. More rapid and pronounced recovery in older men and concentric contractions may be related to physiological differences specific to aging and muscle action motor unit patterns. Individuals and clinicians may use these time course responses as a guide for recovery following activity-induced fatigue.

Load controller and method to enhance effective capacity of a photovoltaic power supply

DOEpatents

Perez, Richard

2000-01-01

A load controller and method are provided for maximizing effective capacity of a non-controllable, renewable power supply coupled to a variable electrical load also coupled to a conventional power grid. Effective capacity is enhanced by monitoring power output of the renewable supply and loading, and comparing the loading against the power output and a load adjustment threshold determined from an expected peak loading. A value for a load adjustment parameter is calculated by subtracting the renewable supply output and the load adjustment parameter from the current load. This value is then employed to control the variable load in an amount proportional to the value of the load control parameter when the parameter is within a predefined range. By so controlling the load, the effective capacity of the non-controllable, renewable power supply is increased without any attempt at operational feedback control of the renewable supply. The renewable supply may comprise, for example, a photovoltaic power supply or a wind-based power supply.

Effectiveness of the surgical torque limiter: a model comparing drill- and hand-based screw insertion into locking plates.

PubMed

Ioannou, Christopher; Knight, Matthew; Daniele, Luca; Flueckiger, Lee; Tan, Ezekiel S L

2016-10-17

The objective of this study is to analyse the effectiveness of the surgical torque limiter during operative use. The study also investigates the potential differences in torque between hand and drill-based screw insertion into locking plates using a standardised torque limiter. Torque for both hand and power screw insertion was measured through a load cell, registering 6.66 points per second. This was performed in a controlled environment using synthetic bone, a locking plate and locking screws to simulate plate fixation. Screws were inserted by hand and by drill with torque values measured. The surgical torque limiter (1.5 Nm) was effective as the highest recorded reading in the study was 1.409 Nm. Comparatively, there is a statistically significant difference between screw insertion methods. Torque produced for manually driven screw insertion into locking plates was 1.289 Nm (95 % CI 1.269-1.308) with drill-powered screw insertion at 0.740 Nm (95 % CI 0.723-0.757). The surgical torque limiter proved to be effective as per product specifications. Screws inserted under power produce significantly less torque when compared to manual insertion by hand. This is likely related to the mechanism of the torque limiter when being used at higher speeds for which it was designed. We conclude that screws may be inserted using power to the plate with the addition of a torque limiter. It is recommended that all screws inserted by drill be hand tightened to achieve adequate torque values.

Cationic composition and acid-base state of the extracellular fluid, and specific buffer value of hemoglobin from the branchiopod crustacean Triops cancriformis.

PubMed

Pirow, Ralph; Buchen, Ina; Richter, Marc; Allmer, Carsten; Nunes, Frank; Günsel, Andreas; Heikens, Wiebke; Lamkemeyer, Tobias; von Reumont, Björn M; Hetz, Stefan K

2009-04-01

Recent insights into the allosteric control of oxygen binding in the extracellular hemoglobin (Hb) of the tadpole shrimp Triops cancriformis raised the question about the physico-chemical properties of the protein's native environment. This study determined the cationic composition and acid-base state of the animal's extracellular fluid. The physiological concentrations of potential cationic effectors (calcium, magnesium) were more than one order of magnitude below the level effective to increase Hb oxygen affinity. The extracellular fluid in the pericardial space had a typical bicarbonate concentration of 7.6 mM but a remarkably high CO(2) partial pressure of 1.36 kPa at pH 7.52 and 20 degrees C. The discrepancy between this high CO(2) partial pressure and the comparably low values for water-breathing decapods could not solely be explained by the hemolymph-sampling procedure but may additionally arise from differences in cardiovascular complexity and efficiency. T. cancriformis hemolymph had a non-bicarbonate buffer value of 2.1 meq L(-1) pH(-1). Hb covered 40-60% of the non-bicarbonate buffering power. The specific buffer value of Hb of 1.1 meq (mmol heme)(-1) pH(-1) suggested a minimum requirement of two titratable histidines per heme-binding domain, which is supported by available information from N-terminal sequencing and expressed sequence tags.

Predicting the Performance of Chain Saw Machines Based on Shore Scleroscope Hardness

NASA Astrophysics Data System (ADS)

Tumac, Deniz

2014-03-01

Shore hardness has been used to estimate several physical and mechanical properties of rocks over the last few decades. However, the number of researches correlating Shore hardness with rock cutting performance is quite limited. Also, rather limited researches have been carried out on predicting the performance of chain saw machines. This study differs from the previous investigations in the way that Shore hardness values (SH1, SH2, and deformation coefficient) are used to determine the field performance of chain saw machines. The measured Shore hardness values are correlated with the physical and mechanical properties of natural stone samples, cutting parameters (normal force, cutting force, and specific energy) obtained from linear cutting tests in unrelieved cutting mode, and areal net cutting rate of chain saw machines. Two empirical models developed previously are improved for the prediction of the areal net cutting rate of chain saw machines. The first model is based on a revised chain saw penetration index, which uses SH1, machine weight, and useful arm cutting depth as predictors. The second model is based on the power consumed for only cutting the stone, arm thickness, and specific energy as a function of the deformation coefficient. While cutting force has a strong relationship with Shore hardness values, the normal force has a weak or moderate correlation. Uniaxial compressive strength, Cerchar abrasivity index, and density can also be predicted by Shore hardness values.

Validity of Simpson-Angus Scale (SAS) in a naturalistic schizophrenia population.

PubMed

Janno, Sven; Holi, Matti M; Tuisku, Katinka; Wahlbeck, Kristian

2005-03-17

Simpson-Angus Scale (SAS) is an established instrument for neuroleptic-induced parkinsonism (NIP), but its statistical properties have been studied insufficiently. Some shortcomings concerning its content have been suggested as well. According to a recent report, the widely used SAS mean score cut-off value 0.3 of for NIP detection may be too low. Our aim was to evaluate SAS against DSM-IV diagnostic criteria for NIP and objective motor assessment (actometry). Ninety-nine chronic institutionalised schizophrenia patients were evaluated during the same interview by standardised actometric recording and SAS. The diagnosis of NIP was based on DSM-IV criteria. Internal consistency measured by Cronbach's alpha, convergence to actometry and the capacity for NIP case detection were assessed. Cronbach's alpha for the scale was 0.79. SAS discriminated between DSM-IV NIP and non-NIP patients. The actometric findings did not correlate with SAS. ROC-analysis yielded a good case detection power for SAS mean score. The optimal threshold value of SAS mean score was between 0.65 and 0.95, i.e. clearly higher than previously suggested threshold value. We conclude that SAS seems a reliable and valid instrument. The previously commonly used cut-off mean score of 0.3 has been too low resulting in low specificity, and we suggest a new cut-off value of 0.65, whereby specificity could be doubled without loosing sensitivity.

Validity of Simpson-Angus Scale (SAS) in a naturalistic schizophrenia population

PubMed Central

Janno, Sven; Holi, Matti M; Tuisku, Katinka; Wahlbeck, Kristian

2005-01-01

Background Simpson-Angus Scale (SAS) is an established instrument for neuroleptic-induced parkinsonism (NIP), but its statistical properties have been studied insufficiently. Some shortcomings concerning its content have been suggested as well. According to a recent report, the widely used SAS mean score cut-off value 0.3 of for NIP detection may be too low. Our aim was to evaluate SAS against DSM-IV diagnostic criteria for NIP and objective motor assessment (actometry). Methods Ninety-nine chronic institutionalised schizophrenia patients were evaluated during the same interview by standardised actometric recording and SAS. The diagnosis of NIP was based on DSM-IV criteria. Internal consistency measured by Cronbach's α, convergence to actometry and the capacity for NIP case detection were assessed. Results Cronbach's α for the scale was 0.79. SAS discriminated between DSM-IV NIP and non-NIP patients. The actometric findings did not correlate with SAS. ROC-analysis yielded a good case detection power for SAS mean score. The optimal threshold value of SAS mean score was between 0.65 and 0.95, i.e. clearly higher than previously suggested threshold value. Conclusion We conclude that SAS seems a reliable and valid instrument. The previously commonly used cut-off mean score of 0.3 has been too low resulting in low specificity, and we suggest a new cut-off value of 0.65, whereby specificity could be doubled without loosing sensitivity. PMID:15774006

Assessing Capacity Value of Wind Power

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frew, Bethany A.

This presentation provides a high-level overview of assessing capacity value of wind power, including Impacts of multiple-year data sets, impacts of transmission assumptions, and future research needs.

High power density supercapacitors based on the carbon dioxide activated D-glucose derived carbon electrodes and 1-ethyl-3-methylimidazolium tetrafluoroborate ionic liquid

NASA Astrophysics Data System (ADS)

Tooming, T.; Thomberg, T.; Kurig, H.; Jänes, A.; Lust, E.

2015-04-01

The electrochemical impedance spectroscopy, cyclic voltammetry, constant current charge/discharge and the constant power discharge methods have been applied to establish the electrochemical characteristics of the electrical double-layer capacitor (EDLC) consisting of the 1-ethyl-3-methylimidazolium tetrafluoroborate (EMImBF4) ionic liquid and microporous carbon electrodes. Microporous carbon material used for preparation of electrodes (GDAC - glucose derived activated carbon), has been synthesised from D-(+)-glucose by the hydrothermal carbonization method, including subsequent pyrolysis, carbon dioxide activation and surface cleaning step with hydrogen. The Brunauer-Emmett-Teller specific surface area (SBET = 1540 m2 g-1), specific surface area calculated using the non-local density functional theory in conjunction with stable adsorption integral equation using splines (SAIEUS) model SSAIEUS = 1820 m2 g-1, micropore surface area (Smicro = 1535 m2 g-1), total pore volume (Vtot = 0.695 cm3 g-1) and the pore size distribution were obtained from the N2 sorption data. The SBET, Smicro and Vtot values have been correlated with the electrochemical characteristics strongly dependent on the carbon activation conditions applied for EDLCs. Wide region of ideal polarizability (ΔV ≤ 3.2 V), very short charging/discharging time constant (2.7 s), and high specific series capacitance (158 F g-1) have been calculated for the optimized carbon material GDAC-10h (activation of GDAC with CO2 during 10 h) in EMImBF4 demonstrating that this system can be used for completing the EDLC with high energy- and power densities.

Energy and Quality-Aware Multimedia Signal Processing

NASA Astrophysics Data System (ADS)

Emre, Yunus

Today's mobile devices have to support computation-intensive multimedia applications with a limited energy budget. In this dissertation, we present architecture level and algorithm-level techniques that reduce energy consumption of these devices with minimal impact on system quality. First, we present novel techniques to mitigate the effects of SRAM memory failures in JPEG2000 implementations operating in scaled voltages. We investigate error control coding schemes and propose an unequal error protection scheme tailored for JPEG2000 that reduces overhead without affecting the performance. Furthermore, we propose algorithm-specific techniques for error compensation that exploit the fact that in JPEG2000 the discrete wavelet transform outputs have larger values for low frequency subband coefficients and smaller values for high frequency subband coefficients. Next, we present use of voltage overscaling to reduce the data-path power consumption of JPEG codecs. We propose an algorithm-specific technique which exploits the characteristics of the quantized coefficients after zig-zag scan to mitigate errors introduced by aggressive voltage scaling. Third, we investigate the effect of reducing dynamic range for datapath energy reduction. We analyze the effect of truncation error and propose a scheme that estimates the mean value of the truncation error during the pre-computation stage and compensates for this error. Such a scheme is very effective for reducing the noise power in applications that are dominated by additions and multiplications such as FIR filter and transform computation. We also present a novel sum of absolute difference (SAD) scheme that is based on most significant bit truncation. The proposed scheme exploits the fact that most of the absolute difference (AD) calculations result in small values, and most of the large AD values do not contribute to the SAD values of the blocks that are selected. Such a scheme is highly effective in reducing the energy consumption of motion estimation and intra-prediction kernels in video codecs. Finally, we present several hybrid energy-saving techniques based on combination of voltage scaling, computation reduction and dynamic range reduction that further reduce the energy consumption while keeping the performance degradation very low. For instance, a combination of computation reduction and dynamic range reduction for Discrete Cosine Transform shows on average, 33% to 46% reduction in energy consumption while incurring only 0.5dB to 1.5dB loss in PSNR.

Optical fiber designs for beam shaping

NASA Astrophysics Data System (ADS)

Farley, Kevin; Conroy, Michael; Wang, Chih-Hao; Abramczyk, Jaroslaw; Campbell, Stuart; Oulundsen, George; Tankala, Kanishka

2014-03-01

A large number of power delivery applications for optical fibers require beams with very specific output intensity profiles; in particular applications that require a focused high intensity beam typically image the near field (NF) intensity distribution at the exit surface of an optical fiber. In this work we discuss optical fiber designs that shape the output beam profile to more closely correspond to what is required in many real world industrial applications. Specifically we present results demonstrating the ability to transform Gaussian beams to shapes required for industrial applications and how that relates to system parameters such as beam product parameter (BPP) values. We report on the how different waveguide structures perform in the NF and show results on how to achieve flat-top with circular outputs.

Control of base-excited dynamical systems through piezoelectric energy harvesting absorber

NASA Astrophysics Data System (ADS)

Abdelmoula, H.; Dai, H. L.; Abdelkefi, A.; Wang, L.

2017-09-01

The spring-mass absorber usually offers a good control to dynamical systems under direct base excitations for a specific value of the excitation frequency. As the vibrational energy of a primary dynamical system is transferred to the absorber, it gets dissipated. In this study, this energy is no longer dissipated but converted to available electrical power by designing efficient energy harvesters. A novel design of a piezoelectric beam installed inside an elastically-mounted dynamical system undergoing base excitations is considered. A design is carried out in order to determine the properties and dimensions of the energy harvester with the constraint of simultaneously decreasing the oscillating amplitudes of the primary dynamical system and increasing the harvested power of the energy harvesting absorber. An analytical model for the coupled system is constructed using Euler-Lagrange principle and Galerkin discretization. Different strategies for controlling the primary structure displacement and enhancing the harvested power as functions of the electrical load resistance and thickness of the beam substrate are performed. The linear polynomial approximation of the system’s key parameters as a function of the beam’s substrate thickness is first carried out. Then, the gradient method is applied to determine the adequate values of the electrical load resistance and thickness of the substrate under the constraints of minimizing the amplitudes of the primary structure or maximizing the levels of the harvested power. After that, an iterative strategy is considered in order to simultaneously minimize the amplitudes of the primary structure and maximize the levels of the harvested power as functions of the thickness of the substrate and electrical load resistance. In addition to harmonic excitations, the coupled system subjected to a white noise is explored. Through this analysis, the load resistance and thickness of the substrate of the piezoelectric energy harvester are determined. It is shown that, in addition to efficiently control the oscillating amplitudes of the primary structure, broadband resonance regions can take place and hence high levels of the harvested power are obtained.

Comparison of the economic impact of different wind power forecast systems for producers

NASA Astrophysics Data System (ADS)

Alessandrini, S.; Davò, F.; Sperati, S.; Benini, M.; Delle Monache, L.

2014-05-01

Deterministic forecasts of wind production for the next 72 h at a single wind farm or at the regional level are among the main end-users requirement. However, for an optimal management of wind power production and distribution it is important to provide, together with a deterministic prediction, a probabilistic one. A deterministic forecast consists of a single value for each time in the future for the variable to be predicted, while probabilistic forecasting informs on probabilities for potential future events. This means providing information about uncertainty (i.e. a forecast of the PDF of power) in addition to the commonly provided single-valued power prediction. A significant probabilistic application is related to the trading of energy in day-ahead electricity markets. It has been shown that, when trading future wind energy production, using probabilistic wind power predictions can lead to higher benefits than those obtained by using deterministic forecasts alone. In fact, by using probabilistic forecasting it is possible to solve economic model equations trying to optimize the revenue for the producer depending, for example, on the specific penalties for forecast errors valid in that market. In this work we have applied a probabilistic wind power forecast systems based on the "analog ensemble" method for bidding wind energy during the day-ahead market in the case of a wind farm located in Italy. The actual hourly income for the plant is computed considering the actual selling energy prices and penalties proportional to the unbalancing, defined as the difference between the day-ahead offered energy and the actual production. The economic benefit of using a probabilistic approach for the day-ahead energy bidding are evaluated, resulting in an increase of 23% of the annual income for a wind farm owner in the case of knowing "a priori" the future energy prices. The uncertainty on price forecasting partly reduces the economic benefit gained by using a probabilistic energy forecast system.

Onshore Wind Farms: Value Creation for Stakeholders in Lithuania

NASA Astrophysics Data System (ADS)

Burinskienė, Marija; Rudzkis, Paulius; Kanopka, Adomas

With the costs of fossil fuel consistently rising worldwide over the last decade, the development of green technologies has become a major goal in many countries. Therefore the evaluation of wind power projects becomes a very important task. To estimate the value of the technologies based on renewable resources also means taking into consideration social, economic, environmental, and scientific value of such projects. This article deals with economic evaluation of electricity generation costs of onshore wind farms in Lithuania and the key factors that have influence on wind power projects and offer a better understanding of social-economic context behind wind power projects. To achieve these goals, this article makes use of empirical data of Lithuania's wind power farms as well as data about the investment environment of the country.Based on empirical data of wind power parks, the research investigates the average wind farm generation efficiency in Lithuania. Employing statistical methods the return on investments of wind farms in Lithuania is calculated. The value created for every party involved and the total value of the wind farm is estimated according to Stakeholder theory.

Exercise efficiency of low power output cycling.

PubMed

Reger, M; Peterman, J E; Kram, R; Byrnes, W C

2013-12-01

Exercise efficiency at low power outputs, energetically comparable to daily living activities, can be influenced by homeostatic perturbations (e.g., weight gain/loss). However, an appropriate efficiency calculation for low power outputs used in these studies has not been determined. Fifteen active subjects (seven females, eight males) performed 14, 5-min cycling trials: two types of seated rest (cranks vertical and horizontal), passive (motor-driven) cycling, no-chain cycling, no-load cycling, cycling at low (10, 20, 30, 40 W), and moderate (50, 60, 80, 100, 120 W) power outputs. Mean delta efficiency was 57% for low power outputs compared to 41.3% for moderate power outputs. Means for gross (3.6%) and net (5.7%) efficiencies were low at the lowest power output. At low power outputs, delta and work efficiency values exceeded theoretical values. In conclusion, at low power outputs, none of the common exercise efficiency calculations gave values comparable to theoretical muscle efficiency. However, gross efficiency and the slope and intercept of the metabolic power vs mechanical power output regression provide insights that are still valuable when studying homeostatic perturbations. © 2012 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

The predictive power of Japanese candlestick charting in Chinese stock market

NASA Astrophysics Data System (ADS)

Chen, Shi; Bao, Si; Zhou, Yu

2016-09-01

This paper studies the predictive power of 4 popular pairs of two-day bullish and bearish Japanese candlestick patterns in Chinese stock market. Based on Morris' study, we give the quantitative details of definition of long candlestick, which is important in two-day candlestick pattern recognition but ignored by several previous researches, and we further give the quantitative definitions of these four pairs of two-day candlestick patterns. To test the predictive power of candlestick patterns on short-term price movement, we propose the definition of daily average return to alleviate the impact of correlation among stocks' overlap-time returns in statistical tests. To show the robustness of our result, two methods of trend definition are used for both the medium-market-value and large-market-value sample sets. We use Step-SPA test to correct for data snooping bias. Statistical results show that the predictive power differs from pattern to pattern, three of the eight patterns provide both short-term and relatively long-term prediction, another one pair only provide significant forecasting power within very short-term period, while the rest three patterns present contradictory results for different market value groups. For all the four pairs, the predictive power drops as predicting time increases, and forecasting power is stronger for stocks with medium market value than those with large market value.

The perils of power in interpretive research.

PubMed

Cohn, Ellen S; Lyons, Kathleen Doyle

2003-01-01

Occupational therapy is based on core values of altruism, equality, and honoring the dignity of others. Embedded in these values is the ever-present negotiation of power. To honor the concern for the welfare of others, researchers are challenged to think about issues of power throughout the research process. This paper identifies dilemmas and raises questions researchers might ask themselves as they struggle to share power in the interpretive research process.

Site Specific Probable Maximum Precipitation Estimates and Professional Judgement

NASA Astrophysics Data System (ADS)

Hayes, B. D.; Kao, S. C.; Kanney, J. F.; Quinlan, K. R.; DeNeale, S. T.

2015-12-01

State and federal regulatory authorities currently rely upon the US National Weather Service Hydrometeorological Reports (HMRs) to determine probable maximum precipitation (PMP) estimates (i.e., rainfall depths and durations) for estimating flooding hazards for relatively broad regions in the US. PMP estimates for the contributing watersheds upstream of vulnerable facilities are used to estimate riverine flooding hazards while site-specific estimates for small water sheds are appropriate for individual facilities such as nuclear power plants. The HMRs are often criticized due to their limitations on basin size, questionable applicability in regions affected by orographic effects, their lack of consist methods, and generally by their age. HMR-51 for generalized PMP estimates for the United States east of the 105th meridian, was published in 1978 and is sometimes perceived as overly conservative. The US Nuclear Regulatory Commission (NRC), is currently reviewing several flood hazard evaluation reports that rely on site specific PMP estimates that have been commercially developed. As such, NRC has recently investigated key areas of expert judgement via a generic audit and one in-depth site specific review as they relate to identifying and quantifying actual and potential storm moisture sources, determining storm transposition limits, and adjusting available moisture during storm transposition. Though much of the approach reviewed was considered a logical extension of HMRs, two key points of expert judgement stood out for further in-depth review. The first relates primarily to small storms and the use of a heuristic for storm representative dew point adjustment developed for the Electric Power Research Institute by North American Weather Consultants in 1993 in order to harmonize historic storms for which only 12 hour dew point data was available with more recent storms in a single database. The second issue relates to the use of climatological averages for spatially interpolating 100-year dew point values rather than a more gauge-based approach. Site specific reviews demonstrated that both issues had potential for lowering the PMP estimate significantly by affecting the in-place and transposed moisture maximization value and, in turn, the final controlling storm for a given basin size and PMP estimate.

Very-short-term wind power prediction by a hybrid model with single- and multi-step approaches

NASA Astrophysics Data System (ADS)

Mohammed, E.; Wang, S.; Yu, J.

2017-05-01

Very-short-term wind power prediction (VSTWPP) has played an essential role for the operation of electric power systems. This paper aims at improving and applying a hybrid method of VSTWPP based on historical data. The hybrid method is combined by multiple linear regressions and least square (MLR&LS), which is intended for reducing prediction errors. The predicted values are obtained through two sub-processes:1) transform the time-series data of actual wind power into the power ratio, and then predict the power ratio;2) use the predicted power ratio to predict the wind power. Besides, the proposed method can include two prediction approaches: single-step prediction (SSP) and multi-step prediction (MSP). WPP is tested comparatively by auto-regressive moving average (ARMA) model from the predicted values and errors. The validity of the proposed hybrid method is confirmed in terms of error analysis by using probability density function (PDF), mean absolute percent error (MAPE) and means square error (MSE). Meanwhile, comparison of the correlation coefficients between the actual values and the predicted values for different prediction times and window has confirmed that MSP approach by using the hybrid model is the most accurate while comparing to SSP approach and ARMA. The MLR&LS is accurate and promising for solving problems in WPP.

Enhanced Imaging of Specific Cell-Surface Glycosylation Based on Multi-FRET.

PubMed

Yuan, Baoyin; Chen, Yuanyuan; Sun, Yuqiong; Guo, Qiuping; Huang, Jin; Liu, Jianbo; Meng, Xiangxian; Yang, Xiaohai; Wen, Xiaohong; Li, Zenghui; Li, Lie; Wang, Kemin

2018-05-15

Cell-surface glycosylation contains abundant biological information that reflects cell physiological state, and it is of great value to image cell-surface glycosylation to elucidate its functions. Here we present a hybridization chain reaction (HCR)-based multifluorescence resonance energy transfer (multi-FRET) method for specific imaging of cell-surface glycosylation. By installing donors through metabolic glycan labeling and acceptors through aptamer-tethered nanoassemblies on the same glycoconjugate, intramolecular multi-FRET occurs due to near donor-acceptor distance. Benefiting from amplified effect and spatial flexibility of the HCR nanoassemblies, enhanced multi-FRET imaging of specific cell-surface glycosylation can be obtained. With this HCR-based multi-FRET method, we achieved obvious contrast in imaging of protein-specific GalNAcylation on 7211 cell surfaces. In addition, we demonstrated the general applicability of this method by visualizing the protein-specific sialylation on CEM cell surfaces. Furthermore, the expression changes of CEM cell-surface protein-specific sialylation under drug treatment was accurately monitored. This developed imaging method may provide a powerful tool in researching glycosylation functions, discovering biomarkers, and screening drugs.

Repurposing Mass-produced Internal Combustion Engines Quantifying the Value and Use of Low-cost Internal Combustion Piston Engines for Modular Applications in Energy and Chemical Engineering Industries

NASA Astrophysics Data System (ADS)

L'Heureux, Zara E.

This thesis proposes that internal combustion piston engines can help clear the way for a transformation in the energy, chemical, and refining industries that is akin to the transition computer technology experienced with the shift from large mainframes to small personal computers and large farms of individually small, modular processing units. This thesis provides a mathematical foundation, multi-dimensional optimizations, experimental results, an engine model, and a techno-economic assessment, all working towards quantifying the value of repurposing internal combustion piston engines for new applications in modular, small-scale technologies, particularly for energy and chemical engineering systems. Many chemical engineering and power generation industries have focused on increasing individual unit sizes and centralizing production. This "bigger is better" concept makes it difficult to evolve and incorporate change. Large systems are often designed with long lifetimes, incorporate innovation slowly, and necessitate high upfront investment costs. Breaking away from this cycle is essential for promoting change, especially change happening quickly in the energy and chemical engineering industries. The ability to evolve during a system's lifetime provides a competitive advantage in a field dominated by large and often very old equipment that cannot respond to technology change. This thesis specifically highlights the value of small, mass-manufactured internal combustion piston engines retrofitted to participate in non-automotive system designs. The applications are unconventional and stem first from the observation that, when normalized by power output, internal combustion engines are one hundred times less expensive than conventional, large power plants. This cost disparity motivated a look at scaling laws to determine if scaling across both individual unit size and number of units produced would predict the two order of magnitude difference seen here. For the first time, this thesis provides a mathematical analysis of scaling with a combination of both changing individual unit size and varying the total number of units produced. Different paths to meet a particular cumulative capacity are analyzed and show that total costs are path dependent and vary as a function of the unit size and number of units produced. The path dependence identified is fairly weak, however, and for all practical applications, the underlying scaling laws seem unaffected. This analysis continues to support the interest in pursuing designs built around small, modular infrastructure. Building on the observation that internal combustion engines are an inexpensive power-producing unit, the first optimization in this thesis focuses on quantifying the value of engine capacity committing to deliver power in the day-ahead electricity and reserve markets, specifically based on pricing from the New York Independent System Operator (NYISO). An optimization was written in Python to determine, based on engine cost, fuel cost, engine wear, engine lifetime, and electricity prices, when and how much of an engine's power should be committed to a particular energy market. The optimization aimed to maximize profit for the engine and generator (engine genset) system acting as a price-taker. The result is an annual profit on the order of \\$30 per kilowatt. The most value in the engine genset is in its commitments to the spinning reserve market, where power is often committed but not always called on to deliver. This analysis highlights the benefits of modularity in energy generation and provides one example where the system is so inexpensive and short-lived, that the optimization views the engine replacement cost as a consumable operating expense rather than a capital cost. Having the opportunity to incorporate incremental technological improvements in a system's infrastructure throughout its lifetime allows introduction of new technology with higher efficiencies and better designs. An alternative to traditionally large infrastructure that locks in a design and today's state-of-the-art technology for the next 50 - 70 years, is a system designed to incorporate new technology in a modular fashion. The modular engine genset system used for power generation is one example of how this works in practice. The largest single component of this thesis is modeling, designing, retrofitting, and testing a reciprocating piston engine used as a compressor. Motivated again by the low cost of an internal combustion engine, this work looks at how an engine (which is, in its conventional form, essentially a reciprocating compressor) can be cost-effectively retrofitted to perform as a small-scale gas compressor. In the laboratory, an engine compressor was built by retrofitting a one-cylinder, 79 cc engine. Various retrofitting techniques were incorporated into the system design, and the engine compressor performance was quantified in each iteration. Because the retrofitted engine is now a power consumer rather than a power-producing unit, the engine compressor is driven in the laboratory with an electric motor. Experimentally, compressed air engine exhaust (starting at elevated inlet pressures) surpassed 650 psia (about 45 bar), which makes this system very attractive for many applications in chemical engineering and refining industries. A model of the engine compressor system was written in Python and incorporates experimentally-derived parameters to quantify gas leakage, engine friction, and flow (including backflow) through valves. The model as a whole was calibrated and verified with experimental data and is used to explore engine retrofits beyond what was tested in the laboratory. Along with the experimental and modeling work, a techno-economic assessment is included to compare the engine compressor system with state-of-the-art, commercially-available compressors. Included in the financial analysis is a case study where an engine compressor system is modeled to achieve specific compression needs. The result of the assessment is that, indeed, the low engine cost, even with the necessary retrofits, provides a cost advantage over incumbent compression technologies. Lastly, this thesis provides an algorithm and case study for another application of small-scale units in energy infrastructure, specifically in energy storage. This study focuses on quantifying the value of small-scale, onsite energy storage in shaving peak power demands. This case study focuses on university-level power demands. The analysis finds that, because peak power is so costly, even small amounts of energy storage, when dispatched optimally, can provide significant cost reductions. This provides another example of the value of small-scale implementations, particularly in energy infrastructure. While the study focuses on flywheels and batteries as the energy storage medium, engine gensets could also be used to deliver power and shave peak power demands. The overarching goal of this thesis is to introduce small-scale, modular infrastructure, with a particular focus on the opportunity to retrofit and repurpose inexpensive, mass-manufactured internal combustion engines in new and unconventional applications. The modeling and experimental work presented in this dissertation show very compelling results for engines incorporated into both energy generation infrastructure and chemical engineering industries via compression technologies. The low engine cost provides an opportunity to add retrofits whilst remaining cost competitive with the incumbent technology. This work supports the claim that modular infrastructure, built on the indivisible unit of an internal combustion engine, can revolutionize many industries by providing a low-cost mechanism for rapid change and promoting small-scale designs.

Global Communication, for the Powerful or the People? Media & Values 61.

ERIC Educational Resources Information Center

Silver, Rosalind, Ed.

1993-01-01

This issue of "Media & Values" explores the growing influence of mass media and how that influence is concentrated in the hands of a few powerful individuals or corporations. The essays present various interpretations of that influence and the implications for the world. Articles include: (1) "All Power to the Conglomerate"…

Numerical analysis of temperature field improvement with nanoparticles designed to achieve critical power dissipation in magnetic hyperthermia

NASA Astrophysics Data System (ADS)

Tang, Yundong; Flesch, Rodolfo C. C.; Jin, Tao

2017-07-01

Magnetic nanoparticle (MNP) hyperthermia is a promising emerging therapy for cancer treatment that is minimally invasive and has been successfully used to treat different types of tumors. The power dissipation of MNPs, which is one of the most important factors during a hyperthermia treatment, is determined by the properties of MNPs and characteristics of the magnetic field. This paper proposes a method based on the finite element analysis for determining the value of the power dissipation of particles (PDP) that can maximize the average temperature of the tumor during treatment and at the same time guarantee that the maximum temperature is within the therapeutic range. The application of the critical PDP value can improve the effectiveness of the treatment since it increases the average temperature in the tumor region while limiting the damage to the healthy tissue that surrounds it. After the critical PDP is determined for a specific model, it is shown how the properties of the MNPs can be chosen to achieve the desired PDP value. The transient behavior of the temperature distribution for two different models considering blood vessels is analyzed as a case study, showing that the presence of a blood vessel inside the tumor region can significantly decrease the uniformity of the temperature field and also increase the treatment duration given its cooling effects. To present a solution that does not depend upon a good model of the tumor region, an alternative method that uses MNPs with low Curie temperature is proposed, given the temperature self-regulating properties of such MNPs. The results demonstrate that the uniformity of the temperature field can be significantly increased by combining the optimization procedure proposed in this paper with the use of low-Curie-temperature MNPs.

Diagnostic potential of endotoxin scattering photometry for sepsis and septic shock.

PubMed

Shimizu, Tomoharu; Obata, Toru; Sonoda, Hiromichi; Akabori, Hiroya; Miyake, Tohru; Yamamoto, Hiroshi; Tabata, Takahisa; Eguchi, Yutaka; Tani, Tohru

2013-12-01

Endotoxin scattering photometry (ESP) is a novel Limulus amebocyte lysate (LAL) assay that uses a laser light-scattering particle-counting method. In the present study, we compared ESP, standard turbidimetric LAL assay, and procalcitonin assay for the evaluation of sepsis after emergency gastrointestinal surgery. A total of 174 samples were collected from 40 adult patients undergoing emergency gastrointestinal surgery and 10 patients with colorectal cancer undergoing elective surgery as nonseptic controls. Plasma endotoxin levels were measured with ESP and turbidimetric LAL assay, and plasma procalcitonin levels were assessed with a standard procalcitonin assay. Plasma endotoxin and procalcitonin levels increased corresponding to the degree of sepsis. Endotoxin scattering photometry significantly discriminated between patients with or without septic shock: sensitivity, 81.1%; specificity, 76.6%; positive predictive value, 48.4%; negative predictive value, 93.8%; and accuracy, 77.6%. The area under the receiver operating characteristic curve for septic shock with the ESP assay (endotoxin cutoff value, 23.8 pg/mL) was 0.8532 ± 0.0301 (95% confidence interval, 0.7841-0.9030; P < 0.0001). The predictive power of ESP was superior to that of turbidimetric assay (difference, 0.1965 ± 0.0588; 95% confidence interval, 0.0812-0.3117; P = 0.0008). There was no significant difference in predictive power between ESP and procalcitonin assay. Endotoxin scattering photometry also discriminated between patients with and without sepsis. Area under the receiver operating characteristic curve analysis showed that ESP had the best predictive power for diagnosing sepsis. In conclusion, compared with turbidimetric LAL assay, ESP more sensitively detected plasma endotoxin and significantly discriminated between sepsis and septic shock in patients undergoing gastrointestinal emergency surgery.

Bon-EV: an improved multiple testing procedure for controlling false discovery rates.

PubMed

Li, Dongmei; Xie, Zidian; Zand, Martin; Fogg, Thomas; Dye, Timothy

2017-01-03

Stability of multiple testing procedures, defined as the standard deviation of total number of discoveries, can be used as an indicator of variability of multiple testing procedures. Improving stability of multiple testing procedures can help to increase the consistency of findings from replicated experiments. Benjamini-Hochberg's and Storey's q-value procedures are two commonly used multiple testing procedures for controlling false discoveries in genomic studies. Storey's q-value procedure has higher power and lower stability than Benjamini-Hochberg's procedure. To improve upon the stability of Storey's q-value procedure and maintain its high power in genomic data analysis, we propose a new multiple testing procedure, named Bon-EV, to control false discovery rate (FDR) based on Bonferroni's approach. Simulation studies show that our proposed Bon-EV procedure can maintain the high power of the Storey's q-value procedure and also result in better FDR control and higher stability than Storey's q-value procedure for samples of large size(30 in each group) and medium size (15 in each group) for either independent, somewhat correlated, or highly correlated test statistics. When sample size is small (5 in each group), our proposed Bon-EV procedure has performance between the Benjamini-Hochberg procedure and the Storey's q-value procedure. Examples using RNA-Seq data show that the Bon-EV procedure has higher stability than the Storey's q-value procedure while maintaining equivalent power, and higher power than the Benjamini-Hochberg's procedure. For medium or large sample sizes, the Bon-EV procedure has improved FDR control and stability compared with the Storey's q-value procedure and improved power compared with the Benjamini-Hochberg procedure. The Bon-EV multiple testing procedure is available as the BonEV package in R for download at https://CRAN.R-project.org/package=BonEV .

Evaluating space weather forecasts of geomagnetic activity from a user perspective

NASA Astrophysics Data System (ADS)

Thomson, A. W. P.

2000-12-01

Decision Theory can be used as a tool for discussing the relative costs of complacency and false alarms with users of space weather forecasts. We describe a new metric for the value of space weather forecasts, derived from Decision Theory. In particular we give equations for the level of accuracy that a forecast must exceed in order to be useful to a specific customer. The technique is illustrated by simplified example forecasts for global geomagnetic activity and for geophysical exploration and power grid management in the British Isles.

Development of Army High-Energy Fuel for Diesel/Turbine-Powered Surface Equipment. Phase II

DTIC Science & Technology

1981-12-01

preparation. The same extracting procedure used with methylene chloride was then used with pen- tans. A 3.0-percent loss in weight was noted, and a residue...minimum time to reach the target, and minimum weight . Since small missiles, such as the cruise, are volume-limited, it is imperative that the fuel contains...tetrahydrodicyclopentadiene (C1 0 R1 6 ) Molecular Weight 136.2 C:H Ratio 0.62 r Specific Gravity @ 15.60C (60*F) 0.94 Heating Value, Btu/gal. 142,000

A new variable parallel holes collimator for scintigraphic device with validation method based on Monte Carlo simulations

NASA Astrophysics Data System (ADS)

Trinci, G.; Massari, R.; Scandellari, M.; Boccalini, S.; Costantini, S.; Di Sero, R.; Basso, A.; Sala, R.; Scopinaro, F.; Soluri, A.

2010-09-01

The aim of this work is to show a new scintigraphic device able to change automatically the length of its collimator in order to adapt the spatial resolution value to gamma source distance. This patented technique replaces the need for collimator change that standard gamma cameras still feature. Monte Carlo simulations represent the best tool in searching new technological solutions for such an innovative collimation structure. They also provide a valid analysis on response of gamma cameras performances as well as on advantages and limits of this new solution. Specifically, Monte Carlo simulations are realized with GEANT4 (GEometry ANd Tracking) framework and the specific simulation object is a collimation method based on separate blocks that can be brought closer and farther, in order to reach and maintain specific spatial resolution values for all source-detector distances. To verify the accuracy and the faithfulness of these simulations, we have realized experimental measurements with identical setup and conditions. This confirms the power of the simulation as an extremely useful tool, especially where new technological solutions need to be studied, tested and analyzed before their practical realization. The final aim of this new collimation system is the improvement of the SPECT techniques, with the real control of the spatial resolution value during tomographic acquisitions. This principle did allow us to simulate a tomographic acquisition of two capillaries of radioactive solution, in order to verify the possibility to clearly distinguish them.

Proof of concept and dose estimation with binary responses under model uncertainty.

PubMed

Klingenberg, B

2009-01-30

This article suggests a unified framework for testing Proof of Concept (PoC) and estimating a target dose for the benefit of a more comprehensive, robust and powerful analysis in phase II or similar clinical trials. From a pre-specified set of candidate models, we choose the ones that best describe the observed dose-response. To decide which models, if any, significantly pick up a dose effect, we construct the permutation distribution of the minimum P-value over the candidate set. This allows us to find critical values and multiplicity adjusted P-values that control the familywise error rate of declaring any spurious effect in the candidate set as significant. Model averaging is then used to estimate a target dose. Popular single or multiple contrast tests for PoC, such as the Cochran-Armitage, Dunnett or Williams tests, are only optimal for specific dose-response shapes and do not provide target dose estimates with confidence limits. A thorough evaluation and comparison of our approach to these tests reveal that its power is as good or better in detecting a dose-response under various shapes with many more additional benefits: It incorporates model uncertainty in PoC decisions and target dose estimation, yields confidence intervals for target dose estimates and extends to more complicated data structures. We illustrate our method with the analysis of a Phase II clinical trial. Copyright (c) 2008 John Wiley & Sons, Ltd.

Load controller and method to enhance effective capacity of a photovoltaic power supply using a dynamically determined expected peak loading

DOEpatents

Perez, Richard

2005-05-03

A load controller and method are provided for maximizing effective capacity of a non-controllable, renewable power supply coupled to a variable electrical load also coupled to a conventional power grid. Effective capacity is enhanced by monitoring power output of the renewable supply and loading, and comparing the loading against the power output and a load adjustment threshold determined from an expected peak loading. A value for a load adjustment parameter is calculated by subtracting the renewable supply output and the load adjustment parameter from the current load. This value is then employed to control the variable load in an amount proportional to the value of the load control parameter when the parameter is within a predefined range. By so controlling the load, the effective capacity of the non-controllable, renewable power supply is increased without any attempt at operational feedback control of the renewable supply.

Radiation Hardened, Modulator ASIC for High Data Rate Communications

NASA Technical Reports Server (NTRS)

McCallister, Ron; Putnam, Robert; Andro, Monty; Fujikawa, Gene

2000-01-01

Satellite-based telecommunication services are challenged by the need to generate down-link power levels adequate to support high quality (BER approx. equals 10(exp 12)) links required for modem broadband data services. Bandwidth-efficient Nyquist signaling, using low values of excess bandwidth (alpha), can exhibit large peak-to-average-power ratio (PAPR) values. High PAPR values necessitate high-power amplifier (HPA) backoff greater than the PAPR, resulting in unacceptably low HPA efficiency. Given the high cost of on-board prime power, this inefficiency represents both an economical burden, and a constraint on the rates and quality of data services supportable from satellite platforms. Constant-envelope signals offer improved power-efficiency, but only by imposing a severe bandwidth-efficiency penalty. This paper describes a radiation- hardened modulator which can improve satellite-based broadband data services by combining the bandwidth-efficiency of low-alpha Nyquist signals with high power-efficiency (negligible HPA backoff).

Case Studies of Extreme Space Weather Effects on the New York State (NYS) Electric Power System

NASA Astrophysics Data System (ADS)

Chantale Damas, M.; Mohamed, Ahmed; Ngwira, Chigomyezo

2017-04-01

New York State (NYS) is home to one of the largest urban cities in the world, New York City (NYC). Understanding and mitigating the effects of extreme space weather events are important to reduce the vulnerabilities of the NYS present bulk power system, which includes NYC. Extreme space weather events perturb Earth's magnetic field and generate geo-electric fields that result in the flow of Geomagnetically Induced Currents (GICs) through transmission lines, followed by transformers and ground. GICs find paths to ground through transformer grounding wires causing half-cycle saturation to their magnetic cores. This causes transformers to overheat, inject harmonics to the grid and draw more reactive power than normal. Overheating, if sustained for a long duration, may lead to transformer failure or lifetime reduction. Presented work uses results from simulations performed by the Global SWMF-generated ground geomagnetic field perturbations. Results from computed values of simulated induced geo-electric fields at specific ground-based active INTERMAGNET magnetometer sites, combined with NYS electricity transmission network real data are used to examine the vulnerabilities of the NYS power grid. As an urban city with a large population, NYC is especially vulnerable and the results from this research can be used to model power systems for other urban cities.

Memory-efficient table look-up optimized algorithm for context-based adaptive variable length decoding in H.264/advanced video coding

NASA Astrophysics Data System (ADS)

Wang, Jianhua; Cheng, Lianglun; Wang, Tao; Peng, Xiaodong

2016-03-01

Table look-up operation plays a very important role during the decoding processing of context-based adaptive variable length decoding (CAVLD) in H.264/advanced video coding (AVC). However, frequent table look-up operation can result in big table memory access, and then lead to high table power consumption. Aiming to solve the problem of big table memory access of current methods, and then reduce high power consumption, a memory-efficient table look-up optimized algorithm is presented for CAVLD. The contribution of this paper lies that index search technology is introduced to reduce big memory access for table look-up, and then reduce high table power consumption. Specifically, in our schemes, we use index search technology to reduce memory access by reducing the searching and matching operations for code_word on the basis of taking advantage of the internal relationship among length of zero in code_prefix, value of code_suffix and code_lengh, thus saving the power consumption of table look-up. The experimental results show that our proposed table look-up algorithm based on index search can lower about 60% memory access consumption compared with table look-up by sequential search scheme, and then save much power consumption for CAVLD in H.264/AVC.

An Integrated Multilevel Converter with Sigma Delta Control for LED Lighting

NASA Astrophysics Data System (ADS)

Gerber, Daniel L.

High brightness LEDs have become a mainstream lighting technology due to their efficiency, life span, and environmental benefits. As such, the lighting industry values LED drivers with low cost, small form factor, and long life span. Additional specifications that define a high quality LED driver are high efficiency, high power factor, wide-range dimming, minimal flicker, and a galvanically isolated output. The flyback LED driver is a popular topology that satisfies all these specifications, but it requires a bulky and costly flyback transformer. In addition, its passive methods for cancelling AC power ripple require electrolytic capacitors, which have been known to have life span issues. This dissertation details the design, construction, and verification of a novel LED driver that satisfies all the specifications. In addition, it does not require a flyback transformer or electrolytic capacitors, thus marking an improvement over the flyback driver on size, cost, and life span. This dissertation presents an integrated circuit (IC) LED driver, which features a pair of generalized multilevel converters that are controlled via sigma-delta modulation. The first is a multilevel rectifier responsible for power factor correction (PFC) and dimming. The PFC rectifier employs a second order sigma-delta loop to precisely control the input current harmonics and amplitude. The second is a bidirectional multilevel inverter used to cancel AC power ripple from the DC bus. This ripple-cancellation module transfers energy to and from a storage capacitor. It uses a first order sigma-delta loop with a preprogrammed waveform to swing the storage capacitor voltage. The system also contains an output stage that powers the LEDs with DC and provides for galvanic isolation. The output stage consists of an H-bridge stack that connects to the output through a small toroid transformer. The IC LED driver was simulated and prototyped on an ABCD silicon test chip. Testing and verification indicates functional performance for all the modules in the LED driver. The driver exhibits moderate efficiency at half voltage. Although the part was only testable to half voltage, loss models predict that its efficiency would be much higher at full voltage. The driver also meets specifications on the line current harmonics and ripple cancellation. This dissertation introduces multilevel circuit techniques to the IC and LED research space. The prototype's functional performance indicates that integrated multilevel converters are a viable topology for lighting and other similar applications.

Generalized Differential Calculus and Applications to Optimization

NASA Astrophysics Data System (ADS)

Rector, Robert Blake Hayden

This thesis contains contributions in three areas: the theory of generalized calculus, numerical algorithms for operations research, and applications of optimization to problems in modern electric power systems. A geometric approach is used to advance the theory and tools used for studying generalized notions of derivatives for nonsmooth functions. These advances specifically pertain to methods for calculating subdifferentials and to expanding our understanding of a certain notion of derivative of set-valued maps, called the coderivative, in infinite dimensions. A strong understanding of the subdifferential is essential for numerical optimization algorithms, which are developed and applied to nonsmooth problems in operations research, including non-convex problems. Finally, an optimization framework is applied to solve a problem in electric power systems involving a smart solar inverter and battery storage system providing energy and ancillary services to the grid.

Oceanographic and meteorological research based on the data products of SEASAT

NASA Technical Reports Server (NTRS)

Pierson, W. J., Jr.

1985-01-01

Reservations were expressed concerning the sum of squares wind recovery algorithm and the power law model function. The SAS sum of squares (SOS) method for recovering winds from backscatter data leads to inconsistent results when V pol and H pol winds are compared. A model function that does not use a power law and that accounts for sea surface temperature is needed and is under study both theoretically and by means of the SASS mode 4 data. Aspects of the determination of winds by means of scatterometry and of the utilization of vector wind data for meteorological forecasts are elaborated. The operational aspect of an intermittent assimilation scheme currently utilized for the specification of the initial value field is considered with focus on quantifying the absolute 12-hour linear displacement error of the movement of low centers.

Hydroelectric System Response to Part Load Vortex Rope Excitation

NASA Astrophysics Data System (ADS)

Alligné, S.; Nicolet, C.; Bégum, A.; Landry, C.; Gomes, J.; Avellan, F.

2016-11-01

The prediction of pressure and output power fluctuations amplitudes on Francis turbine prototype is a challenge for hydro-equipment industry since it is subjected to guarantees to ensure smooth and reliable operation of the hydro units. The European FP7 research project Hyperbole aims to setup a methodology to transpose the pressure fluctuations induced by the cavitation vortex rope on the reduced scale model to the prototype generating units. A Francis turbine unit of 444MW with a specific speed value of v = 0.29, is considered as case study. A SIMSEN model of the power station including electrical system, controllers, rotating train and hydraulic system with transposed draft tube excitation sources is setup. Based on this model, a frequency analysis of the hydroelectric system is performed to analyse potential interactions between hydraulic excitation sources and electrical components.

Helicon Plasma Source Optimization Studies for VASIMR

NASA Technical Reports Server (NTRS)

Goulding, R. H.; Baity, F. W.; Barber, G. C.; Carter, M. D.; ChangDiaz, F. R.; Pavarin, D.; Sparks, D. O.; Squire J. P.

1999-01-01

A helicon plasma source at Oak Ridge National Laboratory is being used to investigate operating scenarios relevant to the VASIMR (VAriable Specific Impulse Magnetoplasma Rocket). These include operation at high magnetic field (> = 0.4 T), high frequency (<= 30 MHz), high power (< = 3 kW), and with light ions (He+, H+). To date, He plasmas have been produced with n(sub e0) = 1.7 x 10(exp 19)/cu m (measured with an axially movable 4mm microwave interferometer), with Pin = I kW at f = 13.56 MHz and absolute value of B(sub 0) = 0.16 T. In the near future, diagnostics including a mass flow meter and a gridded energy analyzer array will be added to investigate fueling efficiency and the source power balance. The latest results, together with modeling results using the EMIR rf code, will be presented.

Microbatteries for Combinatorial Studies of Conventional Lithium-Ion Batteries

NASA Technical Reports Server (NTRS)

West, William; Whitacre, Jay; Bugga, Ratnakumar

2003-01-01

Integrated arrays of microscopic solid-state batteries have been demonstrated in a continuing effort to develop microscopic sources of power and of voltage reference circuits to be incorporated into low-power integrated circuits. Perhaps even more importantly, arrays of microscopic batteries can be fabricated and tested in combinatorial experiments directed toward optimization and discovery of battery materials. The value of the combinatorial approach to optimization and discovery has been proven in the optoelectronic, pharmaceutical, and bioengineering industries. Depending on the specific application, the combinatorial approach can involve the investigation of hundreds or even thousands of different combinations; hence, it is time-consuming and expensive to attempt to implement the combinatorial approach by building and testing full-size, discrete cells and batteries. The conception of microbattery arrays makes it practical to bring the advantages of the combinatorial approach to the development of batteries.

Analyzing small data sets using Bayesian estimation: the case of posttraumatic stress symptoms following mechanical ventilation in burn survivors

PubMed Central

van de Schoot, Rens; Broere, Joris J.; Perryck, Koen H.; Zondervan-Zwijnenburg, Mariëlle; van Loey, Nancy E.

2015-01-01

Background The analysis of small data sets in longitudinal studies can lead to power issues and often suffers from biased parameter values. These issues can be solved by using Bayesian estimation in conjunction with informative prior distributions. By means of a simulation study and an empirical example concerning posttraumatic stress symptoms (PTSS) following mechanical ventilation in burn survivors, we demonstrate the advantages and potential pitfalls of using Bayesian estimation. Methods First, we show how to specify prior distributions and by means of a sensitivity analysis we demonstrate how to check the exact influence of the prior (mis-) specification. Thereafter, we show by means of a simulation the situations in which the Bayesian approach outperforms the default, maximum likelihood and approach. Finally, we re-analyze empirical data on burn survivors which provided preliminary evidence of an aversive influence of a period of mechanical ventilation on the course of PTSS following burns. Results Not suprisingly, maximum likelihood estimation showed insufficient coverage as well as power with very small samples. Only when Bayesian analysis, in conjunction with informative priors, was used power increased to acceptable levels. As expected, we showed that the smaller the sample size the more the results rely on the prior specification. Conclusion We show that two issues often encountered during analysis of small samples, power and biased parameters, can be solved by including prior information into Bayesian analysis. We argue that the use of informative priors should always be reported together with a sensitivity analysis. PMID:25765534

Analyzing small data sets using Bayesian estimation: the case of posttraumatic stress symptoms following mechanical ventilation in burn survivors.

PubMed

van de Schoot, Rens; Broere, Joris J; Perryck, Koen H; Zondervan-Zwijnenburg, Mariëlle; van Loey, Nancy E

2015-01-01

Background : The analysis of small data sets in longitudinal studies can lead to power issues and often suffers from biased parameter values. These issues can be solved by using Bayesian estimation in conjunction with informative prior distributions. By means of a simulation study and an empirical example concerning posttraumatic stress symptoms (PTSS) following mechanical ventilation in burn survivors, we demonstrate the advantages and potential pitfalls of using Bayesian estimation. Methods : First, we show how to specify prior distributions and by means of a sensitivity analysis we demonstrate how to check the exact influence of the prior (mis-) specification. Thereafter, we show by means of a simulation the situations in which the Bayesian approach outperforms the default, maximum likelihood and approach. Finally, we re-analyze empirical data on burn survivors which provided preliminary evidence of an aversive influence of a period of mechanical ventilation on the course of PTSS following burns. Results : Not suprisingly, maximum likelihood estimation showed insufficient coverage as well as power with very small samples. Only when Bayesian analysis, in conjunction with informative priors, was used power increased to acceptable levels. As expected, we showed that the smaller the sample size the more the results rely on the prior specification. Conclusion : We show that two issues often encountered during analysis of small samples, power and biased parameters, can be solved by including prior information into Bayesian analysis. We argue that the use of informative priors should always be reported together with a sensitivity analysis.

Comparison of the Walz Nomogram and Presence of Secondary Circulating Prostate Cells for Predicting Early Biochemical Failure after Radical Prostatectomy for Prostate Cancer in Chilean Men.

PubMed

Murray, Nigel P; Reyes, Eduardo; Orellana, Nelson; Fuentealba, Cynthia; Jacob, Omar

2015-01-01

To determine the utility of secondary circulating prostate cells for predicting early biochemical failure after radical prostatectomy for prostate cancer and compare the results with the Walz nomagram. A single centre, prospective study of men with prostate cancer treated with radical prostatectomy between 2004 and 2014 was conducted, with registration of clinical-pathological details, total serum PSA pre-surgery, Gleason score, extracapsular extension, positive surgical margins, infiltration of lymph nodes, seminal vesicles and pathological stage. Secondary circulating prostate cells were obtained using differential gel centrifugation and assessed using standard immunocytochemistry with anti-PSA. Biochemical failure was defined as a PSA >0.2ng/ml, predictive values werecalculated using the Walz nomagram and CPC detection. A total of 326 men participated, with a median follow up of 5 years; 64 had biochemical failure within two years. Extracapsular extension, positive surgical margins, pathological stage, Gleason score ≥ 8, infiltration of seminal vesicles and lymph nodes were all associated with higher risk of biochemical failure. The discriminative value for the nomogram and circulating prostate cells was high (AUC >0.80), predictive values were higher for circulating prostate cell detection, with a negative predictive value of 99%, sensitivity of 96% and specificity of 75%. The nomagram had good predictive power to identify men with a high risk of biochemical failure within two years. The presence of circulating prostate cells had the same predictive power, with a higher sensitivity and negative predictive value. The presence of secondary circulating prostate cells identifies a group of men with a high risk of early biochemical failure. Those negative for secondary CPCs have a very low risk of early biochemical failure.

1000 Norms Project: protocol of a cross-sectional study cataloging human variation.

PubMed

McKay, Marnee J; Baldwin, Jennifer N; Ferreira, Paulo; Simic, Milena; Vanicek, Natalie; Hiller, Claire E; Nightingale, Elizabeth J; Moloney, Niamh A; Quinlan, Kate G; Pourkazemi, Fereshteh; Sman, Amy D; Nicholson, Leslie L; Mousavi, Seyed J; Rose, Kristy; Raymond, Jacqueline; Mackey, Martin G; Chard, Angus; Hübscher, Markus; Wegener, Caleb; Fong Yan, Alycia; Refshauge, Kathryn M; Burns, Joshua

2016-03-01

Clinical decision-making regarding diagnosis and management largely depends on comparison with healthy or 'normal' values. Physiotherapists and researchers therefore need access to robust patient-centred outcome measures and appropriate reference values. However there is a lack of high-quality reference data for many clinical measures. The aim of the 1000 Norms Project is to generate a freely accessible database of musculoskeletal and neurological reference values representative of the healthy population across the lifespan. In 2012 the 1000 Norms Project Consortium defined the concept of 'normal', established a sampling strategy and selected measures based on clinical significance, psychometric properties and the need for reference data. Musculoskeletal and neurological items tapping the constructs of dexterity, balance, ambulation, joint range of motion, strength and power, endurance and motor planning will be collected in this cross-sectional study. Standardised questionnaires will evaluate quality of life, physical activity, and musculoskeletal health. Saliva DNA will be analysed for the ACTN3 genotype ('gene for speed'). A volunteer cohort of 1000 participants aged 3 to 100 years will be recruited according to a set of self-reported health criteria. Descriptive statistics will be generated, creating tables of mean values and standard deviations stratified for age and gender. Quantile regression equations will be used to generate age charts and age-specific centile values. This project will be a powerful resource to assist physiotherapists and clinicians across all areas of healthcare to diagnose pathology, track disease progression and evaluate treatment response. This reference dataset will also contribute to the development of robust patient-centred clinical trial outcome measures. Copyright © 2015 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

Sensitivity and specificity of ultrasonography and low-field magnetic resonance imaging for diagnosing arthritis.

PubMed

Broll, Matthias; Albrecht, Katinka; Tarner, Ingo; Müller-Ladner, Ulf; Strunk, Johannes

2012-01-01

To evaluate the value of grey-scale ultrasonography (US) including power Doppler ultrasonography (PDUS) and low-field magnetic resonance imaging (MRI) for the diagnosis of arthritis in a diagnostic phase III study. Fifty consecutive patients with suspected arthritis were included in the study. Following a standardised protocol, US of the carpus and the metacarpophalangeal (MCP) joints of the dominant hand was performed. Subsequently, low-field MRI was done using standard sequences, with contrast agent (Gadolinium DTPA) administered to 29 patients. In 32 out of 50 patients a clinical diagnosis of arthritis was established. In grey-scale ultrasonography including PDUS, sensitivity and specificity were determined as 0.94 and 0.5, respectively, for synovitis (effusion and hypertrophy), 0.72 and 0.94, respectively, for Doppler signals, and 0.38 and 1.0, respectively, for bone erosions. In low-field MRI, sensitivity and specificity values were 0.77 and 0.75, respectively, for synovitis (when using contrast agent), 0.48 and 0.78, respectively, for bone marrow oedema, and 0.58 and 0.83, respectively, for bone erosion. Both grey-scale ultrasonography including PDUS and low-field MRI are suitable imaging methods for diagnosing arthritis at an early stage. However, PDUS displays a higher specificity and almost the same sensitivity as compared to contrast-enhanced MRI, while being a much simpler and less costly procedure.

Preliminary design of a solar central receiver for a site-specific repowering application (Saguaro Power Plant). Volume III. Specifications. Final report, October 1982-September 1983

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weber, E.R.

1983-09-01

This volume on specifications for the Saguaro Power Plant includes the following: subsystem interface definition document; solar collector subsystem specification; receiver specification; thermal energy storage specification; solar steam generator specification; and master control system specification.

Vehicle-to-grid power implementation: From stabilizing the grid to supporting large-scale renewable energy

NASA Astrophysics Data System (ADS)

Kempton, Willett; Tomić, Jasna

Vehicle-to-grid power (V2G) uses electric-drive vehicles (battery, fuel cell, or hybrid) to provide power for specific electric markets. This article examines the systems and processes needed to tap energy in vehicles and implement V2G. It quantitatively compares today's light vehicle fleet with the electric power system. The vehicle fleet has 20 times the power capacity, less than one-tenth the utilization, and one-tenth the capital cost per prime mover kW. Conversely, utility generators have 10-50 times longer operating life and lower operating costs per kWh. To tap V2G is to synergistically use these complementary strengths and to reconcile the complementary needs of the driver and grid manager. This article suggests strategies and business models for doing so, and the steps necessary for the implementation of V2G. After the initial high-value, V2G markets saturate and production costs drop, V2G can provide storage for renewable energy generation. Our calculations suggest that V2G could stabilize large-scale (one-half of US electricity) wind power with 3% of the fleet dedicated to regulation for wind, plus 8-38% of the fleet providing operating reserves or storage for wind. Jurisdictions more likely to take the lead in adopting V2G are identified.

The reliability of isoinertial force-velocity-power profiling and maximal strength assessment in youth.

PubMed

Meylan, César M P; Cronin, John B; Oliver, Jon L; Hughes, Michael M G; Jidovtseff, Boris; Pinder, Shane

2015-03-01

The purpose of this study was to quantify the inter-session reliability of force-velocity-power profiling and estimated maximal strength in youth. Thirty-six males (11-15 years old) performed a ballistic supine leg press test at five randomized loads (80%, 100%, 120%, 140%, and 160% body mass) on three separate occasions. Peak and mean force, power, velocity, and peak displacement were collected with a linear position transducer attached to the weight stack. Mean values at each load were used to calculate different regression lines and estimate maximal strength, force, velocity, and power. All variables were found reliable (change in the mean [CIM] = - 1 to 14%; coefficient of variation [CV] = 3-18%; intraclass correlation coefficient [ICC] = 0.74-0.99), but were likely to benefit from a familiarization, apart from the unreliable maximal force/velocity ratio (CIM = 0-3%; CV = 23-25%; ICC = 0.35-0.54) and load at maximal power (CIM = - 1 to 2%; CV = 10-13%; ICC = 0.26-0.61). Isoinertial force-velocity-power profiling and maximal strength in youth can be assessed after a familiarization session. Such profiling may provide valuable insight into neuromuscular capabilities during growth and maturation and may be used to monitor specific training adaptations.

Measuring radio-signal power accurately

NASA Technical Reports Server (NTRS)

Goldstein, R. M.; Newton, J. W.; Winkelstein, R. A.

1979-01-01

Absolute value of signal power in weak radio signals is determined by computer-aided measurements. Equipment operates by averaging received signal over several-minute period and comparing average value with noise level of receiver previously calibrated.

Televising Supreme Court and Other Federal Court Proceedings: Legislation and Issues

DTIC Science & Technology

2006-11-08

proceedings, including the possible effect on judicial proceedings, separation of powers concerns, the purported educational value of such coverage, and...for Adverse Effects on Judicial Proceedings . . . . . . . . . . . . 11 Separation of Powers Concerns...proponents and opponents on myriad issues in the electronic media coverage debate — democratic values of government transparency, separation of powers , due

Baseline and Target Values for PV Forecasts: Toward Improved Solar Power Forecasting: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Jie; Hodge, Bri-Mathias; Lu, Siyuan

2015-08-05

Accurate solar power forecasting allows utilities to get the most out of the solar resources on their systems. To truly measure the improvements that any new solar forecasting methods can provide, it is important to first develop (or determine) baseline and target solar forecasting at different spatial and temporal scales. This paper aims to develop baseline and target values for solar forecasting metrics. These were informed by close collaboration with utility and independent system operator partners. The baseline values are established based on state-of-the-art numerical weather prediction models and persistence models. The target values are determined based on the reductionmore » in the amount of reserves that must be held to accommodate the uncertainty of solar power output. forecasting metrics. These were informed by close collaboration with utility and independent system operator partners. The baseline values are established based on state-of-the-art numerical weather prediction models and persistence models. The target values are determined based on the reduction in the amount of reserves that must be held to accommodate the uncertainty of solar power output.« less

Site-specific tumor grading system in colorectal cancer: multicenter pathologic review of the value of quantifying poorly differentiated clusters.

PubMed

Ueno, Hideki; Hase, Kazuo; Hashiguchi, Yojiro; Shimazaki, Hideyuki; Tanaka, Masafumi; Miyake, Ohki; Masaki, Tadahiko; Shimada, Yoshifumi; Kinugasa, Yusuke; Mori, Yoshiyuki; Kishimoto, Mitsuo; Kameoka, Shingo; Sato, Yu; Matsuda, Keiji; Nakadoi, Koichi; Shinto, Eiji; Nakamura, Takahiro; Sugihara, Kenichi

2014-02-01

The study aimed to determine the value of a novel site-specific grading system based on quantifying poorly differentiated clusters (PDC; Grade(PDC)) in colorectal cancer (CRC). A multicenter pathologic review involving 12 institutions was performed on 3243 CRC cases (stage I, 583; II, 1331; III, 1329). Cancer clusters of ≥5 cancer cells and lacking a gland-like structure (PDCs) were counted under a ×20 objective lens in a field containing the maximum clusters. Tumors with <5, 5 to 9, and ≥10 PDCs were classified as grades G1, G2, and G3, respectively. According to Grade(PDC), 1594, 1005, and 644 tumors were classified as G1, G2, and G3 and had 5-year recurrence-free survival rates of 91.6%, 75.4%, and 59.6%, respectively (P<0.0001). Multivariate analysis showed that Grade exerted an influence on prognostic outcome independently of TNM staging; approximately 20% and 46% of stage I and II patients, respectively, were selected by Grade(PDC) as a population whose survival estimate was comparable to or even worse than that of stage III patients. Grade(PDC) surpassed TNM staging in the ability to stratify patients by recurrence-free survival (Akaike information criterion, 2915.6 vs. 2994.0) and had a higher prognostic value than American Joint Committee on Cancer (AJCC) grading (Grade(AJCC)) at all stages. Regarding judgment reproducibility of grading tumors, weighted κ among the 12 institutions was 0.40 for Grade(AJCC) and 0.52 for Grade(PDC). Grade(PDC) has a robust prognostic power and promises to be of sufficient clinical value to merit implementation as a site-specific grading system in CRC.

Diagnostic value of immunoglobulin G antibodies against Candida enolase and fructose-bisphosphate aldolase for candidemia

PubMed Central

2013-01-01

Background The yeast Candida is one of the most frequent pathogens isolated from bloodstream infections and is associated with significant morbidity and mortality. Problems with clinical and microbiological diagnosis of invasive candidiasis (IC) have prompted the development of non-culture-based laboratory methods. Previous reports suggest that serological detection of antibodies might be useful for diagnosing systemic candidiasis. Methods Diagnosis of IC using antibodies against recombinant Candida albicans enolase (Eno) and fructose-bisphosphate aldolase (Fba1) was evaluated. Using recombinant Eno and Fba1 as coating antigens, enzyme-linked immunosorbent assays (ELISAs) were used to analyze sera from patients with candidemia (n = 101), Candida colonization (n = 50), bacteremia (n = 84), invasive aspergillosis (n = 40); and from healthy controls (n = 200). Results The results demonstrated that ELISA detection of anti-Eno and anti-Fba1 IgG distinguished IC from other pathogenic infections in patients and healthy individuals. The sensitivity, specificity, and positive and negative predictive values were 72.3%, 94.7%, 78.5% and 93% for anti-Eno, and 87.1%, 92.8%, 76.5% and 96.4% for anti-Fba1 antibodies, respectively. Combining these two tests improved sensitivity up to 90.1% and negative predictive value up to 97.1%, with specificity and positive predictive values of 90.6% and 72.2%. The tests were specific to the Candida genus and antibody titers were higher for candidemia patients than for controls. Positive antibody tests were obtained before blood culture results for 42.2% of patients for anti-Eno and 51.1% for anti-Fba1. Conclusion These data suggest that tests that detect IgG antibodies against Candida enolase and fructose-bisphosphate aldolase, especially when used in combination, could be a powerful tool for diagnosing IC. PMID:23725337

Diagnostic value of immunoglobulin G antibodies against Candida enolase and fructose-bisphosphate aldolase for candidemia.

PubMed

Li, Fang-Qiu; Ma, Chun-Fang; Shi, Li-Ning; Lu, Jing-Fen; Wang, Ying; Huang, Mei; Kong, Qian-Qian

2013-05-31

The yeast Candida is one of the most frequent pathogens isolated from bloodstream infections and is associated with significant morbidity and mortality. Problems with clinical and microbiological diagnosis of invasive candidiasis (IC) have prompted the development of non-culture-based laboratory methods. Previous reports suggest that serological detection of antibodies might be useful for diagnosing systemic candidiasis. Diagnosis of IC using antibodies against recombinant Candida albicans enolase (Eno) and fructose-bisphosphate aldolase (Fba1) was evaluated. Using recombinant Eno and Fba1 as coating antigens, enzyme-linked immunosorbent assays (ELISAs) were used to analyze sera from patients with candidemia (n = 101), Candida colonization (n = 50), bacteremia (n = 84), invasive aspergillosis (n = 40); and from healthy controls (n = 200). The results demonstrated that ELISA detection of anti-Eno and anti-Fba1 IgG distinguished IC from other pathogenic infections in patients and healthy individuals. The sensitivity, specificity, and positive and negative predictive values were 72.3%, 94.7%, 78.5% and 93% for anti-Eno, and 87.1%, 92.8%, 76.5% and 96.4% for anti-Fba1 antibodies, respectively. Combining these two tests improved sensitivity up to 90.1% and negative predictive value up to 97.1%, with specificity and positive predictive values of 90.6% and 72.2%. The tests were specific to the Candida genus and antibody titers were higher for candidemia patients than for controls. Positive antibody tests were obtained before blood culture results for 42.2% of patients for anti-Eno and 51.1% for anti-Fba1. These data suggest that tests that detect IgG antibodies against Candida enolase and fructose-bisphosphate aldolase, especially when used in combination, could be a powerful tool for diagnosing IC.

Usefulness of the Waist Circumference-to-Height Ratio in Screening for Obesity and Metabolic Syndrome among Korean Children and Adolescents: Korea National Health and Nutrition Examination Survey, 2010-2014.

PubMed

Choi, Dong-Hyun; Hur, Yang-Im; Kang, Jae-Heon; Kim, Kyoungwoo; Cho, Young Gyu; Hong, Soo-Min; Cho, Eun Byul

2017-03-10

The aims of this study were to assess the diagnostic value of the weight-to-height ratio (WHtR) for the detection of obesity and metabolic syndrome (MS) in Korean children and adolescents, and to determine the advantages of WHtR as a population-based screening tool in comparison with other obesity indicators, such as body mass index (BMI) and waist circumference (WC). We performed a cross-sectional analysis of data from 3057 children and adolescents (1625 boys, 1332 girls) aged 10-19 years who were included in the fifth Korean National Health and Nutrition Examination Survey (KNHANES, 2010-2012) up to the second year of the sixth KNHANES (2013-2014). Receiver operation characteristic (ROC) curves were generated to determine the optimal cutoff value and accuracy of WHtR for predicting individual obesity indicators or more than two non-WC components of MS. The area under the ROC curve (AUC) is a measure of the diagnostic power of a test. A perfect test will have an AUC of 1.0, and an AUC equal to 0.5 means that the test performs no better than chance. The optimal WHtR cutoff for the evaluation of general obesity and central obesity was 0.50 in boys and 0.47-0.48 in girls, and the AUC was 0.9. Regarding the assessment of each MS risk factor, the optimal WHtR cutoff was 0.43-0.50 in boys and 0.43-0.49 in girls, and these cutoffs were statistically significant only for the detection of high triglyceride and low High-density lipoprotein (HDL) cholesterol levels. When a pairwise comparison of the AUCs was conducted between WHtR and BMI/WC percentiles to quantify the differences in power for MS screening, the WHtR AUC values (boys, 0.691; girls, 0.684) were higher than those of other indices; however, these differences were not statistically significant (boys, p = 0.467; girls, p = 0.51). The WHtR cutoff value was 0.44 (sensitivity, 67.7%; specificity, 64.6%) for boys and 0.43 (sensitivity, 66.4%; specificity, 66.9%) for girls. There was no significant difference between the diagnostic power of WHtR and that of BMI/WC when screening for MS. Although the use of WHtR was not superior, WHtR is still useful as a screening tool for metabolic problems related to obesity because of its convenience.

Test module development to detect the flase call probe pins on microeprocessor test equipment

NASA Astrophysics Data System (ADS)

Tang, L. W.; Ong, N. R.; Mohamad, I. S. B.; Alcain, J. B.; Retnasamy, V.

2017-09-01

Probe pins are useful for electrical testing of microelectronic components, printed circuit board assembly (PCBA), microprocessors and other electronic devices due to it provides the conductivity test based on specific device circuit design. During the repeatable test runs, the load of test modules, contact failures and the current conductivity induces layer wear off all the tip of probe pins contact. Contamination will be build-up on probe pins and increased contact resistivity which results of cost loss and time loss for rectifying programs, rectifying testers and exchanging new probe pins. In this study, a resistivity approach will be developed to provide "Testing of Test Probes". The test module based on "Four-wire Ohm measurement" method with two alternative ways of applying power supply, that are 9V from a single power supply and 5V from Arduino UNO power supply were demonstrated to measure the small resistance value of microprocessor probe pin. A microcontroller with VEE Pro software was used to record the measurement data. The accuracy of both test modules were calibrated under different temperature conditions and result shows that 9V from a single power supply test module has higher measurement accuracy.

Characterization of sp3 bond content of carbon films deposited by high power gas injection magnetron sputtering method by UV and VIS Raman spectroscopy.

PubMed

Zdunek, Krzysztof; Chodun, Rafał; Wicher, Bartosz; Nowakowska-Langier, Katarzyna; Okrasa, Sebastian

2018-04-05

This paper presents the results of investigations of carbon films deposited by a modified version of the magnetron sputtering method - HiPGIMS (High Power Gas Injection Magnetron Sputtering). In this experiment, the magnetron system with inversely polarized electrodes (sputtered cathode at ground potential and positively biased, spatially separated anode) was used. This arrangement allowed us to conduct the experiment using voltages ranging from 1 to 2kV and a power supply system equipped with 25/50μF capacitor battery. Carbon films were investigated by VIS/UV Raman spectroscopy. Sp 3 /sp 2 bonding ratio was evaluated basing the elementary components of registered spectra. Our investigation showed that sp 3 bond content increases with discharge power but up to specific value only. In extreme conditions of generating plasma impulses, we detected a reversed relation of the sp 3 /sp 2 ratio. In our opinion, a energy of plasma pulse favors nucleation of a sp 3 phase because of a relatively higher ionization state but in extreme cases the influence of energy is reversed. Copyright © 2018 Elsevier B.V. All rights reserved.

Life cycle assessment of overhead and underground primary power distribution.

PubMed

Bumby, Sarah; Druzhinina, Ekaterina; Feraldi, Rebe; Werthmann, Danae; Geyer, Roland; Sahl, Jack

2010-07-15

Electrical power can be distributed in overhead or underground systems, both of which generate a variety of environmental impacts at all stages of their life cycles. While there is considerable literature discussing the trade-offs between both systems in terms of aesthetics, safety, cost, and reliability, environmental assessments are relatively rare and limited to power cable production and end-of-life management. This paper assesses environmental impacts from overhead and underground medium voltage power distribution systems as they are currently built and managed by Southern California Edison (SCE). It uses process-based life cycle assessment (LCA) according to ISO 14044 (2006) and SCE-specific primary data to the extent possible. Potential environmental impacts have been calculated using a wide range of midpoint indicators, and robustness of the results has been investigated through sensitivity analysis of the most uncertain and potentially significant parameters. The studied underground system has higher environmental impacts in all indicators and for all parameter values, mostly due to its higher material intensity. For both systems and all indicators the majority of impact occurs during cable production. Promising strategies for impact reduction are thus cable failure rate reduction for overhead and cable lifetime extension for underground systems.

SAR in human head model due to resonant wireless power transfer system.

PubMed

Zhang, Chao; Liu, Guoqiang; Li, Yanhong; Song, Xianjin

2016-04-29

Efficient mid-range wireless power transfer between transmitter and the receiver has been achieved based on the magnetic resonant coupling method. The influence of electromagnetic field on the human body due to resonant wireless power transfer system (RWPT) should be taken into account during the design process of the system. To analyze the transfer performance of the RWPT system and the change rules of the specific absorption rate (SAR) in the human head model due to the RWPT system. The circuit-field coupling method for a RWPT system with consideration of the displacement current was presented. The relationship between the spiral coil parameters and transfer performance was studied. The SAR in the human head model was calculated under two different exposure conditions. A system with output power higher than 10 W at 0.2 m distance operating at a frequency of approximately 1 MHz was designed. The FEM simulation results show the peak SAR value is below the safety limit which appeared when the human head model is in front of the transmitter. The simulation results agreed well with the experimental results, which verified the validity of the analysis and design.

Adaptive Transcutaneous Power Transfer to Implantable Devices: A State of the Art Review

PubMed Central

Bocan, Kara N.; Sejdić, Ervin

2016-01-01

Wireless energy transfer is a broad research area that has recently become applicable to implantable medical devices. Wireless powering of and communication with implanted devices is possible through wireless transcutaneous energy transfer. However, designing wireless transcutaneous systems is complicated due to the variability of the environment. The focus of this review is on strategies to sense and adapt to environmental variations in wireless transcutaneous systems. Adaptive systems provide the ability to maintain performance in the face of both unpredictability (variation from expected parameters) and variability (changes over time). Current strategies in adaptive (or tunable) systems include sensing relevant metrics to evaluate the function of the system in its environment and adjusting control parameters according to sensed values through the use of tunable components. Some challenges of applying adaptive designs to implantable devices are challenges common to all implantable devices, including size and power reduction on the implant, efficiency of power transfer and safety related to energy absorption in tissue. Challenges specifically associated with adaptation include choosing relevant and accessible parameters to sense and adjust, minimizing the tuning time and complexity of control, utilizing feedback from the implanted device and coordinating adaptation at the transmitter and receiver. PMID:26999154

Adaptive Transcutaneous Power Transfer to Implantable Devices: A State of the Art Review.

PubMed

Bocan, Kara N; Sejdić, Ervin

2016-03-18

Wireless energy transfer is a broad research area that has recently become applicable to implantable medical devices. Wireless powering of and communication with implanted devices is possible through wireless transcutaneous energy transfer. However, designing wireless transcutaneous systems is complicated due to the variability of the environment. The focus of this review is on strategies to sense and adapt to environmental variations in wireless transcutaneous systems. Adaptive systems provide the ability to maintain performance in the face of both unpredictability (variation from expected parameters) and variability (changes over time). Current strategies in adaptive (or tunable) systems include sensing relevant metrics to evaluate the function of the system in its environment and adjusting control parameters according to sensed values through the use of tunable components. Some challenges of applying adaptive designs to implantable devices are challenges common to all implantable devices, including size and power reduction on the implant, efficiency of power transfer and safety related to energy absorption in tissue. Challenges specifically associated with adaptation include choosing relevant and accessible parameters to sense and adjust, minimizing the tuning time and complexity of control, utilizing feedback from the implanted device and coordinating adaptation at the transmitter and receiver.

Analysis of SAR distribution in human head of antenna used in wireless power transform based on magnetic resonance.

PubMed

Gong, Feixiang; Wei, Zhiqiang; Cong, Yanping; Chi, Haokun; Yin, Bo; Sun, Mingui

2017-07-20

In this paper, a novel wireless power transfer antenna system was designed for human head implantable devices. The antenna system used the structure of three plates and four coils and operated at low frequencies to transfer power via near field. In order to verify the electromagnetic radiation safety on the human head, the electromagnetic intensity and specific absorption rate (SAR) were studied by finite-difference-time-domain (FDTD) method. A three-layer model of human head including skin, bone and brain tissues was constructed. The transmitting and receiving antenna were set outside and inside the model. The local and average SAR were simulated at the resonance frequency of 18.67 MHz in two situations, in one scenario both transmitting and receiving coil worked, while in the other scenario only the transmitting coil worked. The results showed that the maximum of 10 g SAR average value of human thoracic were 0.142 W/kg and 0.148 W/kg, respectively, both were lower than the international safety standards for human body of the ICNIRP and FCC, which verified the safety of the human body in wireless power transmission based on magnetic coupling resonance.

Phase matters: A role for the subthalamic network during gait.

PubMed

Arnulfo, Gabriele; Pozzi, Nicolò Gabriele; Palmisano, Chiara; Leporini, Alice; Canessa, Andrea; Brumberg, Joachim; Pezzoli, Gianni; Matthies, Cordula; Volkmann, Jens; Isaias, Ioannis Ugo

2018-01-01

The role of the subthalamic nucleus in human locomotion is unclear although relevant, given the troublesome management of gait disturbances with subthalamic deep brain stimulation in patients with Parkinson's disease. We investigated the subthalamic activity and inter-hemispheric connectivity during walking in eight freely-moving subjects with Parkinson's disease and bilateral deep brain stimulation. In particular, we compared the subthalamic power spectral densities and coherence, amplitude cross-correlation and phase locking value between resting state, upright standing, and steady forward walking. We observed a phase locking value drop in the β-frequency band (≈13-35Hz) during walking with respect to resting and standing. This modulation was not accompanied by specific changes in subthalamic power spectral densities, which was not related to gait phases or to striatal dopamine loss measured with [123I]N-ω-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl)nortropane and single-photon computed tomography. We speculate that the subthalamic inter-hemispheric desynchronization in the β-frequency band reflects the information processing of each body side separately, which may support linear walking. This study also suggests that in some cases (i.e. gait) the brain signal, which could allow feedback-controlled stimulation, might derive from network activity.

Graphene-enhanced thermal interface materials for heat removal from photovoltaic solar cells

NASA Astrophysics Data System (ADS)

Saadah, M.; Gamalath, D.; Hernandez, E.; Balandin, A. A.

2016-09-01

The increase in the temperature of photovoltaic (PV) solar cells affects negatively their power conversion efficiency and decreases their lifetime. The negative effects are particularly pronounced in concentrator solar cells. Therefore, it is crucial to limit the PV cell temperature by effectively removing the excess heat. Conventional thermal phase change materials (PCMs) and thermal interface materials (TIMs) do not possess the thermal conductivity values sufficient for thermal management of the next generation of PV cells. In this paper, we report the results of investigation of the increased efficiency of PV cells with the use of graphene-enhanced TIMs. Graphene reveals the highest values of the intrinsic thermal conductivity. It was also shown that the thermal conductivity of composites can be increased via utilization of graphene fillers. We prepared TIMs with up to 6% of graphene designed specifically for PV cell application. The solar cells were tested using the solar simulation module. It was found that the drop in the output voltage of the solar panel under two-sun concentrated illumination can be reduced from 19% to 6% when grapheneenhanced TIMs are used. The proposed method can recover up to 75% of the power loss in solar cells.

Physiological pattern changes in response to a simulated competition in elite women artistic gymnasts.

PubMed

Isacco, Laurie; Ennequin, Gaël; Cassirame, Johan; Tordi, Nicolas

2017-08-04

The outstanding progress in women's artistic gymnastics in recent decades has led to increased technical and physiological demands. The aim of this study was to investigate i) the physiological demands of elite French gymnasts and ii) the impact of a competitive routine on physiological pattern changes. Fourteen French elite female gymnasts performed anthropometric measurements, physical fitness tests and a simulated four event competition. Heart rate (HR) was continuously recorded throughout the duration of the simulated competition. Blood lactate concentrations were assessed at rest, before the beginning and at 2, 4 and 10 min after completion of the routine on each apparatus. Isometric handgrip strength and anaerobic endurance and power were assessed during the simulated competition. The highest values of HR and blood lactate concentrations were reached during the floor and uneven bar exercises. Blood lactate concentrations and HR kinetics were apparatus dependent and values remained significantly increased at 10 min of recovery compared with resting data. Anaerobic endurance and power decreased significantly as the competition progressed (P <0.001). The present results show specifically cardiorespiratory and anaerobic apparatus- dependent responses throughout a simulated competition. Recovery approaches appear relevant to prevent and/or minimize fatigue and optimize performance in these athletes.

Compact planar monopole antenna for wearable wireless applications

NASA Astrophysics Data System (ADS)

Andriamiharivolamena, Tsitoha; Lemaître-Auger, Pierre; Tedjini, Smail; Tirard, Franck

2015-11-01

We report in this paper the design and the realization of a compact wearable monopole antenna directly placed over an Artificial Magnetic Conductor (AMC), which is located directly on the body. The major contribution is that there is no space between the monopole and the AMC, or between the AMC and the body. Simulation results and measurements are in good agreement and show that the antenna's performances are as good as the best ones reported so far in the literature, while having a smaller volume. The antenna operates at 1.92 GHz with a bandwidth of 8%. The reflection coefficient of the antenna is - 35 dB. The measurement of the antenna gain provides a value of 4.3 dBi with a half-power beamwidth of 70° and a front-to-back radiation ratio of 15.8 dB. Measurement and simulation results also show that the AMC isolates well the monopole from the body: the localized Specific Absorption Rate (SAR) value calculated with 1 g of tissue is 0.34 W/kg with an injected power of 1 W. The antenna with the AMC is well adapted for wearable applications.

Physical fitness profile of professional Italian firefighters: differences among age groups.

PubMed

Perroni, Fabrizio; Cignitti, Lamberto; Cortis, Cristina; Capranica, Laura

2014-05-01

Firefighters perform many tasks which require a high level of fitness and their personal safety may be compromised by the physiological aging process. The aim of the study was to evaluate strength (bench-press), power (countermovement jump), sprint (20 m) and endurance (with and without Self Contained Breathing Apparatus - S.C.B.A.) of 161 Italian firefighters recruits in relation to age groups (<25 yr; 26-30 yr; 31-35 yr; 36-40 yr; 41-42 yr). Descriptive statistics and an ANOVA were calculated to provide the physical fitness profile for each parameter and to assess differences (p < 0.05) among age groups. Anthropometric values showed an age-effect for height and BMI, while performances values showed statistical differences for strength, power, sprint tests and endurance test with S.C.B.A. Wearing the S.C.B.A., 14% of all recruits failed to complete the endurance test. We propose that the firefighters should participate in an assessment of work capacity and specific fitness programs aimed to maintain an optimal fitness level for all ages. Copyright © 2013 Elsevier Ltd and The Ergonomics Society. All rights reserved.

MR Fingerprinting Using The Quick Echo Splitting NMR Imaging Technique

PubMed Central

Jiang, Yun; Ma, Dan; Jerecic, Renate; Duerk, Jeffrey; Seiberlich, Nicole; Gulani, Vikas; Griswold, Mark A.

2016-01-01

Purpose The purpose of the study is to develop a quantitative method for the relaxation properties with a reduced radio frequency (RF) power deposition by combining Magnetic Resonance Fingerprinting (MRF) technique with Quick Echo Splitting NMR Imaging Technique (QUEST). Methods A QUEST-based MRF sequence was implemented to acquire high order echoes by increasing the gaps between RF pulses. Bloch simulations were used to calculate a dictionary containing the range of physically plausible signal evolutions using a range of T1 and T2 values based on the pulse sequence. MRF-QUEST was evaluated by comparing to the results of spin-echo methods. The SAR of QUEST-MRF was compared to the clinically available methods. Results MRF-QUEST quantifies the relaxation properties with good accuracy at the estimated head Specific Absorption Rate (SAR) of 0.03 W/kg. T1 and T2 values estimated by MRF-QUEST are in good agreement with the traditional methods. Conclusion The combination of the MRF and the QUEST provides an accurate quantification of T1 and T2 simultaneously with reduced RF power deposition. The resulting lower SAR may provide a new acquisition strategy for MRF when RF energy deposition is problematic. PMID:26924639

Capacity value assessments of wind power: Capacity value assessments of wind power

DOE Office of Scientific and Technical Information (OSTI.GOV)

Milligan, Michael; Frew, Bethany; Ibanez, Eduardo

This article describes some of the recent research into the capacity value of wind power. With the worldwide increase in wind power during the past several years, there is increasing interest and significance regarding its capacity value because this has a direct influence on the amount of other (nonwind) capacity that is needed. We build on previous reviews from IEEE and IEA Wind Task 25a and examine recent work that evaluates the impact of multiple-year data sets and the impact of interconnected systems on resource adequacy. We also provide examples that explore the use of alternative reliability metrics for windmore » capacity value calculations. We show how multiple-year data sets significantly increase the robustness of results compared to single-year assessments. Assumptions regarding the transmission interconnections play a significant role. To date, results regarding which reliability metric to use for probabilistic capacity valuation show little sensitivity to the metric.« less

Effect of platykurtic and leptokurtic distributions in the random-field Ising model: mean-field approach.

PubMed

Duarte Queirós, Sílvio M; Crokidakis, Nuno; Soares-Pinto, Diogo O

2009-07-01

The influence of the tail features of the local magnetic field probability density function (PDF) on the ferromagnetic Ising model is studied in the limit of infinite range interactions. Specifically, we assign a quenched random field whose value is in accordance with a generic distribution that bears platykurtic and leptokurtic distributions depending on a single parameter tau<3 to each site. For tau<5/3, such distributions, which are basically Student-t and r distribution extended for all plausible real degrees of freedom, present a finite standard deviation, if not the distribution has got the same asymptotic power-law behavior as a alpha-stable Lévy distribution with alpha=(3-tau)/(tau-1). For every value of tau, at specific temperature and width of the distribution, the system undergoes a continuous phase transition. Strikingly, we impart the emergence of an inflexion point in the temperature-PDF width phase diagrams for distributions broader than the Cauchy-Lorentz (tau=2) which is accompanied with a divergent free energy per spin (at zero temperature).

Robustness of optimal random searches in fragmented environments

NASA Astrophysics Data System (ADS)

Wosniack, M. E.; Santos, M. C.; Raposo, E. P.; Viswanathan, G. M.; da Luz, M. G. E.

2015-05-01

The random search problem is a challenging and interdisciplinary topic of research in statistical physics. Realistic searches usually take place in nonuniform heterogeneous distributions of targets, e.g., patchy environments and fragmented habitats in ecological systems. Here we present a comprehensive numerical study of search efficiency in arbitrarily fragmented landscapes with unlimited visits to targets that can only be found within patches. We assume a random walker selecting uniformly distributed turning angles and step lengths from an inverse power-law tailed distribution with exponent μ . Our main finding is that for a large class of fragmented environments the optimal strategy corresponds approximately to the same value μopt≈2 . Moreover, this exponent is indistinguishable from the well-known exact optimal value μopt=2 for the low-density limit of homogeneously distributed revisitable targets. Surprisingly, the best search strategies do not depend (or depend only weakly) on the specific details of the fragmentation. Finally, we discuss the mechanisms behind this observed robustness and comment on the relevance of our results to both the random search theory in general, as well as specifically to the foraging problem in the biological context.

Mixture optimization for mixed gas Joule-Thomson cycle

NASA Astrophysics Data System (ADS)

Detlor, J.; Pfotenhauer, J.; Nellis, G.

2017-12-01

An appropriate gas mixture can provide lower temperatures and higher cooling power when used in a Joule-Thomson (JT) cycle than is possible with a pure fluid. However, selecting gas mixtures to meet specific cooling loads and cycle parameters is a challenging design problem. This study focuses on the development of a computational tool to optimize gas mixture compositions for specific operating parameters. This study expands on prior research by exploring higher heat rejection temperatures and lower pressure ratios. A mixture optimization model has been developed which determines an optimal three-component mixture based on the analysis of the maximum value of the minimum value of isothermal enthalpy change, ΔhT , that occurs over the temperature range. This allows optimal mixture compositions to be determined for a mixed gas JT system with load temperatures down to 110 K and supply temperatures above room temperature for pressure ratios as small as 3:1. The mixture optimization model has been paired with a separate evaluation of the percent of the heat exchanger that exists in a two-phase range in order to begin the process of selecting a mixture for experimental investigation.

Advanced Radioisotope Power Systems Segmented Thermoelectric Research

NASA Technical Reports Server (NTRS)

Caillat, Thierry

2004-01-01

Flight times are long; - Need power systems with >15 years life. Mass is at an absolute premium; - Need power systems with high specific power and scalability. 3 orders of magnitude reduction in solar irradiance from Earth to Pluto. Nuclear power sources preferable. The Overall objective is to develop low mass, high efficiency, low-cost Advanced Radioisotope Power System with double the Specific Power and Efficiency over state-of-the-art Radioisotope Thermoelectric Generators (RTGs).

Does a bout of strength training affect 2,000 m rowing ergometer performance and rowing-specific maximal power 24 h later?

PubMed

Gee, Thomas I; French, Duncan N; Howatson, Glyn; Payton, Stephen J; Berger, Nicolas J; Thompson, Kevin G

2011-11-01

Rowers regularly undertake rowing training within 24 h of performing bouts of strength training; however, the effect of this practice has not been investigated. This study evaluated the impact of a bout of high-intensity strength training on 2,000 m rowing ergometer performance and rowing-specific maximal power. Eight highly trained male club rowers performed baseline measures of five separate, static squat jumps (SSJ) and countermovement jumps (CMJ), maximal rowing ergometer power strokes (PS) and a single 2,000 m rowing ergometer test (2,000 m). Subsequently, participants performed a high-intensity strength training session consisting of various multi-joint barbell exercises. The 2,000 m test was repeated at 24 and 48 h post-ST, in addition SSJ, CMJ and PS tests were performed at these time points and also at 2 h post-ST. Muscle soreness, serum creatine kinase (CK) and lactate dehydrogenase (LDH) were assessed pre-ST and 2, 24 and 48 h post-ST. Following the ST, there were significant elevations in muscle soreness (2 and 24 h, P < 0.01), CK (2, 24 and 48 h, P < 0.01), and LDH (2 h, P < 0.05) in comparison to baseline values. There were significant decrements across all time points for SSJ, CMJ and PS, which ranged between 3 and 10% (P < 0.05). However, 2,000 m performance and related measurements of heart rate and blood lactate were not significantly affected by ST. In summary, a bout of high-intensity strength training resulted in symptoms of muscle damage and decrements in rowing-specific maximal power, but this did not affect 2,000 m rowing ergometer performance in highly trained rowers.

Nanoporous separators for supercapacitor using activated carbon monolith electrode from oil palm empty fruit bunches

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nor, N. S. M., E-mail: madra@ukm.my; Deraman, M., E-mail: madra@ukm.my; Omar, R., E-mail: madra@ukm.my

Activated porous carbon electrode prepared from fibres of oil palm empty fruit bunches was used for preparing the carbon based supercapacitor cells. The symmetrical supercapacitor cells were fabricated using carbon electrodes, stainless steel current collector, H{sub 2}SO{sub 4} electrolyte, and three types of nanoporous separators. Cells A, B and C were fabricated using polypropylene, eggshell membrane, and filter paper, respectively. Electrochemical characterizations data from Electrochemical Impedance Spectroscopy, Cyclic Voltammetry, and Galvanic Charge Discharge techniques showed that specific capacitance, specific power and specific energy for cell A were 122 F g{sup −1}, 177 W kg{sup −1}, 3.42 Wh kg{sup −1}, cellmore » B; 125 F g{sup −1}, 179 W kg{sup −1}, and 3.64 Wh kg{sup −1}, and cell C; 180 F g{sup −1}, 178 W kg{sup −1}, 4.27 Wh kg{sup −1}. All the micrographs from Field Emission Scanning Electron Microscope showed that the different in nanoporous structure of the separators lead to a significant different in influencing the values of specific capacitance, power and energy of supercapacitors, which is associated with the mobility of ion into the pore network. These results indicated that the filter paper was superior than the eggshell membrane and polypropylene nanoporous separators. However, we found that in terms of acidic resistance, polypropylene was the best nanoporous separator for acidic medium.« less

Power control of SAFE reactor using fuzzy logic

NASA Astrophysics Data System (ADS)

Irvine, Claude

2002-01-01

Controlling the 100 kW SAFE (Safe Affordable Fission Engine) reactor consists of design and implementation of a fuzzy logic process control system to regulate dynamic variables related to nuclear system power. The first phase of development concentrates primarily on system power startup and regulation, maintaining core temperature equilibrium, and power profile matching. This paper discusses the experimental work performed in those areas. Nuclear core power from the fuel elements is simulated using resistive heating elements while heat rejection is processed by a series of heat pipes. Both axial and radial nuclear power distributions are determined from neuronic modeling codes. The axial temperature profile of the simulated core is matched to the nuclear power profile by varying the resistance of the heating elements. The SAFE model establishes radial temperature profile equivalence by establishing 32 control zones as the nodal coordinates. Control features also allow for slow warm up, since complete shutoff can occur in the heat pipes if heat-source temperatures drop/rise below a certain minimum value, depending on the specific fluid and gas combination in the heat pipe. The entire system is expected to be self-adaptive, i.e., capable of responding to long-range changes in the space environment. Particular attention in the development of the fuzzy logic algorithm shall ensure that the system process remains at set point, virtually eliminating overshoot on start-up and during in-process disturbances. The controller design will withstand harsh environments and applications where it might come in contact with water, corrosive chemicals, radiation fields, etc. .

Injuries Associated with Specific Motor Vehicle Hazards: Radiators, Batteries, Power Windows, and Power Roofs

DOT National Transportation Integrated Search

1997-07-01

This report provides estimates of the numbers of persons injured as a result of : hazards involving four specific motor vehicle components: radiators, batteries, : power windows, and power roofs. The injury estimates are based upon data from : the Co...

Evaluation of the resistive index of prostatic blood flow in benign prostatic hyperplasia.

PubMed

Abdelwahab, Osama; El-Barky, Ehab; Khalil, Mostafa Mahmoud; Kamar, Ahmad

2012-01-01

The aim of this work is to study the resistive index (RI) of prostatic blood flow by transrectal power Doppler sonography in benign prostatic hyperplasia (BPH) to determine its correlation with other parameters of BPH. Eighty-two male patients aged 52-86 years with lower urinary tract symptoms (LUTS) due to BPH were included in the study. Patients with prostate cancer, neurogenic bladder, or with other pathology (e.g. prostatitis, bladder stone) were excluded from the study. All patients were evaluated by full history including Internatinoal Prostate Symptoms Score (IPSS), general and local examination (DRE), neurologic examination, uroflowmetry, laboratory investigations including urine analysis, routine laboratory tests and serum prostate specific antigen (PSA). Transrectal ultrasonography was used to calculate the total prostatic volume. Transrectal Power Doppler Ultrasound (PUD) was used to identify the capsular and urethral arteries of the prostate and to measures the RI value. The mean prostate volume was 75.1 ± 44.7 g. The mean RI of the right and left capsular arteries were 0.76 ± 0.06 and 0.76 ± 0.07, respectively. The mean RI of the urethral arteries was 0.76 ± 0.08. There was a high significative correlation between the increase of the RI of the right and left capsular and urethral arteries and the degree of obstruction (P value < 0.001), severity of symptoms (P value < 0.001) and also the prostatic volume (P value < 0.001). Resistive index of the prostatic blood flow can be applied as an easy and non-invasive tool to evaluate the lower urinary tract obstruction due to BPH.

Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices

DOEpatents

Chassin, David P [Pasco, WA; Donnelly, Matthew K [Kennewick, WA; Dagle, Jeffery E [Richland, WA

2011-12-06

Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices are described. In one aspect, an electrical power distribution control method includes providing electrical energy from an electrical power distribution system, applying the electrical energy to a load, providing a plurality of different values for a threshold at a plurality of moments in time and corresponding to an electrical characteristic of the electrical energy, and adjusting an amount of the electrical energy applied to the load responsive to an electrical characteristic of the electrical energy triggering one of the values of the threshold at the respective moment in time.

Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices

DOEpatents

Chassin, David P.; Donnelly, Matthew K.; Dagle, Jeffery E.

2006-12-12

Electrical power distribution control methods, electrical energy demand monitoring methods, and power management devices are described. In one aspect, an electrical power distribution control method includes providing electrical energy from an electrical power distribution system, applying the electrical energy to a load, providing a plurality of different values for a threshold at a plurality of moments in time and corresponding to an electrical characteristic of the electrical energy, and adjusting an amount of the electrical energy applied to the load responsive to an electrical characteristic of the electrical energy triggering one of the values of the threshold at the respective moment in time.

CONTROL AND FAULT DETECTOR CIRCUIT

DOEpatents

Winningstad, C.N.

1958-04-01

A power control and fault detectcr circuit for a radiofrequency system is described. The operation of the circuit controls the power output of a radio- frequency power supply to automatically start the flow of energizing power to the radio-frequency power supply and to gradually increase the power to a predetermined level which is below the point where destruction occurs upon the happening of a fault. If the radio-frequency power supply output fails to increase during such period, the control does not further increase the power. On the other hand, if the output of the radio-frequency power supply properly increases, then the control continues to increase the power to a maximum value. After the maximumn value of radio-frequency output has been achieved. the control is responsive to a ''fault,'' such as a short circuit in the radio-frequency system being driven, so that the flow of power is interrupted for an interval before the cycle is repeated.

Air-Cooled Heat Exchanger for High-Temperature Power Electronics: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Waye, S. K.; Lustbader, J.; Musselman, M.

2015-05-06

This work demonstrates a direct air-cooled heat exchanger strategy for high-temperature power electronic devices with an application specific to automotive traction drive inverters. We present experimental heat dissipation and system pressure curves versus flow rate for baseline and optimized sub-module assemblies containing two ceramic resistance heaters that provide device heat fluxes. The maximum allowable junction temperature was set to 175 deg.C. Results were extrapolated to the inverter scale and combined with balance-of-inverter components to estimate inverter power density and specific power. The results exceeded the goal of 12 kW/L and 12 kW/kg for power density and specific power, respectively.

Suppressed power saturation due to optimized optical confinement in 9xx nm high-power diode lasers that use extreme double asymmetric vertical designs

NASA Astrophysics Data System (ADS)

Kaul, T.; Erbert, G.; Maaßdorf, A.; Knigge, S.; Crump, P.

2018-03-01

Broad area lasers with novel extreme double asymmetric structure (EDAS) vertical designs featuring increased optical confinement in the quantum well, Γ, are shown to have improved temperature stability without compromising series resistance, internal efficiency or losses. Specifically, we present here vertical design considerations for the improved continuous wave (CW) performance of devices operating at 940 nm, based on systematically increasing Γ from 0.26% to 1.1%, and discuss the impact on power saturation mechanisms. The results indicate that key power saturation mechanisms at high temperatures originate in high threshold carrier densities, which arise in the quantum well at low Γ. The characteristic temperatures, T 0 and T 1, are determined under short pulse conditions and are used to clarify the thermal contribution to power limiting mechanisms. Although increased Γ reduces thermal power saturation, it is accompanied by increased optical absorption losses in the active region, which has a significant impact on the differential external quantum efficiency, {η }{{diff}}. To quantify the impact of internal optical losses contributed by the quantum well, a resonator length-dependent simulation of {η }{{diff}} is performed and compared to the experiment, which also allows the estimation of experimental values for the light absorption cross sections of electrons and holes inside the quantum well. Overall, the analysis enables vertical designs to be developed, for devices with maximized power conversion efficiency at high CW optical power and high temperatures, in a trade-off between absorption in the well and power saturation. The best balance to date is achieved in devices using EDAS designs with {{Γ }}=0.54 % , which deliver efficiencies of 50% at 14 W optical output power at an elevated junction temperature of 105 °C.

Pharmacognostic Specification, Chlorogenic Acid Content, and In vitro Antioxidant Activities of Lonicera japonica Flowering Bud

PubMed Central

Chaowuttikul, Chayanon; Palanuvej, Chanida; Ruangrungsi, Nijsiri

2017-01-01

Background: Lonicera japonica Thunb. or Japanese Honeysuckle has been widely used in traditional medicine for antipyretic. Objective: To establish the pharmacognostic specification of L. japonica flowering bud in Thailand and to determine its chlorogenic acid content and in vitro antioxidant activities. Materials and Methods: Dried L. japonica flowering bud from 15 various herbal drugstores throughout Thailand were investigated for pharmacognostic specification. Their chlorogenic acid contents were quantitatively analyzed by thin layer chromatography (TLC) densitometry with winCATS software. The mobile phase for TLC development consisted of ethyl acetate: formic acid: acetic acid: water (10:1.1:1.1:2.6). Antioxidant activities were investigated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, ferric ion reducing antioxidant power assay, nitric oxide scavenging assay, and β-carotene bleaching assays. Results: Qualified L. japonica flowering bud in Thailand was presented that the contents of loss on drying, total ash, acid-insoluble ash, and water should not be >10.11%, 6.59%, 1.14%, and 10.82% by weight, respectively. The ethanol and water soluble extractive values should not be < 16.46% and 28.88% by weight, respectively. Chlorogenic acid content in L. japonica flowering bud was found to be 2.24 ± 0.50 g/100 g of crude drug. L. japonica flowering bud showed DPPH and nitric oxide scavenging activities as well as reducing power property. Conclusion: This pharmacognostic specification with special reference to the chlorogenic acid content can be used for quality control of L. japonica flowering bud in Thailand. The potential antioxidant of this crude drug was demonstrated in vitro. SUMMARY Pharmacognostic specification of Lonicera japonica flowering bud in Thailand has been establishedThe chlorogenic acid content has been quantified by thin layer chromatography-densitometryThe ethanolic extract of L. japonica flowering bud showed antioxidation potential, especially on reducing power property. Abbreviations Used: TLC: Thin layer chromatography, DPPH: 2,2-diphenyl-1-picrylhydrazyl, FRAP: Ferric ion Reducing Antioxidant Power, WHO: World Health Organization, ICH: International Conference on Harmonisation of Technical Requirements for Registration of Pharmaceuticals for Human Use; LOD: Limit of detection; LOQ: Limit of quantitation; BHT: Butylated hydroxytoluene; FeSO4: Iron(II) sulfate; DMSO: Dimethyl sulfoxide; TPTZ: 2,4,6-tripyridyl-s-triazine. PMID:28539735

10 CFR 50.36a - Technical specifications on effluents from nuclear power reactors.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 1 2012-01-01 2012-01-01 false Technical specifications on effluents from nuclear power reactors. 50.36a Section 50.36a Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF PRODUCTION AND...; Ineligibility of Certain Applicants § 50.36a Technical specifications on effluents from nuclear power reactors...

10 CFR 50.36a - Technical specifications on effluents from nuclear power reactors.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 1 2013-01-01 2013-01-01 false Technical specifications on effluents from nuclear power reactors. 50.36a Section 50.36a Energy NUCLEAR REGULATORY COMMISSION DOMESTIC LICENSING OF PRODUCTION AND...; Ineligibility of Certain Applicants § 50.36a Technical specifications on effluents from nuclear power reactors...

Subjective global assessment of nutritional status in children.

PubMed

Mahdavi, Aida Malek; Ostadrahimi, Alireza; Safaiyan, Abdolrasool

2010-10-01

This study was aimed to compare the subjective and objective nutritional assessments and to analyse the performance of subjective global assessment (SGA) of nutritional status in diagnosing undernutrition in paediatric patients. One hundred and forty children (aged 2-12 years) hospitalized consecutively in Tabriz Paediatric Hospital from June 2008 to August 2008 underwent subjective assessment using the SGA questionnaire and objective assessment, including anthropometric and biochemical measurements. Agreement between two assessment methods was analysed by the kappa (κ) statistic. Statistical indicators including (sensitivity, specificity, predictive values, error rates, accuracy, powers, likelihood ratios and odds ratio) between SGA and objective assessment method were determined. The overall prevalence of undernutrition according to the SGA (70.7%) was higher than that by objective assessment of nutritional status (48.5%). Agreement between the two evaluation methods was only fair to moderate (κ = 0.336, P < 0.001). The sensitivity, specificity, positive and negative predictive value of the SGA method for screening undernutrition in this population were 88.235%, 45.833%, 60.606% and 80.487%, respectively. Accuracy, positive and negative power of the SGA method were 66.428%, 56.074% and 41.25%, respectively. Likelihood ratio positive, likelihood ratio negative and odds ratio of the SGA method were 1.628, 0.256 and 6.359, respectively. Our findings indicated that in assessing nutritional status of children, there is not a good level of agreement between SGA and objective nutritional assessment. In addition, SGA is a highly sensitive tool for assessing nutritional status and could identify children at risk of developing undernutrition. © 2009 Blackwell Publishing Ltd.

Conformal Coating Strategy Comprising N-doped Carbon and Conventional Graphene for Achieving Ultrahigh Power and Cyclability of LiFePO4.

PubMed

Zhang, Kan; Lee, Jeong-Taik; Li, Ping; Kang, Byoungwoo; Kim, Jung Hyun; Yi, Gi-Ra; Park, Jong Hyeok

2015-10-14

Surface carbon coating to improve the inherent poor electrical conductivity of lithium iron phosphate (LiFePO4, LFP) has been considered as most efficient strategy. Here, we also report one of the conventional methods for LFP but exhibiting a specific capacity beyond the theoretical value, ultrahigh rate performance, and excellent long-term cyclability: the specific capacity is 171.9 mAh/g (70 μm-thick electrode with ∼10 mg/cm(2) loading mass) at 0.1 C (17 mA/g) and retains 143.7 mAh/g at 10 C (1.7 A/g) and 95.8% of initial capacity at 10 C after 1000 cycles. It was found that the interior conformal N-C coating enhances the intrinsic conductivity of LFP nanorods (LFP NR) and the exterior reduced graphene oxide coating acts as an electrically conducting secondary network to electrically connect the entire electrode. The great electron transport mutually promoted with shorten Li diffusion length on (010) facet exposed LFP NR represents the highest specific capacity value recorded to date at 10 C and ultralong-term cyclability. This conformal carbon coating approach can be a promising strategy for the commercialization of LFP cathode in lithium ion batteries.

26 CFR 25.2503-3 - Future interests in property.

Code of Federal Regulations, 2014 CFR

2014-04-01

... disregarded in computing the value of the present interest, to the extent that no part of such interest will... power in the trustee is disregarded in determining the value of F's present interest. The power would... Future interests in property. (a) No part of the value of a gift of a future interest may be excluded in...

26 CFR 25.2503-3 - Future interests in property.

Code of Federal Regulations, 2011 CFR

2011-04-01

... disregarded in computing the value of the present interest, to the extent that no part of such interest will... power in the trustee is disregarded in determining the value of F's present interest. The power would... Future interests in property. (a) No part of the value of a gift of a future interest may be excluded in...

26 CFR 25.2503-3 - Future interests in property.

Code of Federal Regulations, 2010 CFR

2010-04-01

... disregarded in computing the value of the present interest, to the extent that no part of such interest will... power in the trustee is disregarded in determining the value of F's present interest. The power would... Future interests in property. (a) No part of the value of a gift of a future interest may be excluded in...

18 CFR 12.35 - Specific inspection requirements.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 18 Conservation of Power and Water Resources 1 2010-04-01 2010-04-01 false Specific inspection requirements. 12.35 Section 12.35 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY REGULATIONS UNDER THE FEDERAL POWER ACT SAFETY OF WATER POWER PROJECTS AND...

Cooperativeness and competitiveness as two distinct constructs: validating the Cooperative and Competitive Personality Scale in a social dilemma context.

PubMed

Lu, Su; Au, Wing-Tung; Jiang, Feng; Xie, Xiaofei; Yam, Paton

2013-01-01

The present research validated the construct and criterion validities of the Cooperative and Competitive Personality Scale (CCPS) in a social dilemma context. The results from three studies supported the notion that cooperativeness and competitiveness are two independent dimensions, challenging the traditional view that they are two ends of a single continuum. First, confirmatory factor analyses revealed that a two-factor structure fit the data significantly better than a one-factor structure. Moreover, cooperativeness and competitiveness were either not significantly correlated (Studies 1 and 3) or only moderately positively correlated (Study 2). Second, cooperativeness and competitiveness were differentially associated with Schwartz's Personal Values. These results further supported the idea that cooperativeness and competitiveness are two distinct constructs. Specifically, the individuals who were highly cooperative emphasized self-transcendent values (i.e., universalism and benevolence) more, whereas the individuals who were highly competitive emphasized self-enhancement values (i.e., power and achievement) more. Finally, the CCPS, which adheres to the trait perspective of personality, was found to be a useful supplement to more prevalent social motive measures (i.e., social value orientation) in predicting cooperative behaviors. Specifically, in Study 2, when social value orientation was controlled for, the CCPS significantly predicted cooperative behaviors in a public goods dilemma (individuals who score higher on cooperativeness scale contributed more to the public goods). In Study 3, when social value orientation was controlled for, the CCPS significantly predicted cooperative behaviors in commons dilemmas (individuals who score higher on cooperativeness scale requested fewer resources from the common resource pool). The practical implications of the CCPS in conflict resolution, as well as in recruitment and selection settings, are discussed.

iASeq: integrative analysis of allele-specificity of protein-DNA interactions in multiple ChIP-seq datasets

PubMed Central

2012-01-01

Background ChIP-seq provides new opportunities to study allele-specific protein-DNA binding (ASB). However, detecting allelic imbalance from a single ChIP-seq dataset often has low statistical power since only sequence reads mapped to heterozygote SNPs are informative for discriminating two alleles. Results We develop a new method iASeq to address this issue by jointly analyzing multiple ChIP-seq datasets. iASeq uses a Bayesian hierarchical mixture model to learn correlation patterns of allele-specificity among multiple proteins. Using the discovered correlation patterns, the model allows one to borrow information across datasets to improve detection of allelic imbalance. Application of iASeq to 77 ChIP-seq samples from 40 ENCODE datasets and 1 genomic DNA sample in GM12878 cells reveals that allele-specificity of multiple proteins are highly correlated, and demonstrates the ability of iASeq to improve allelic inference compared to analyzing each individual dataset separately. Conclusions iASeq illustrates the value of integrating multiple datasets in the allele-specificity inference and offers a new tool to better analyze ASB. PMID:23194258

High power tapered lasers with optimized photonic crystal structure for low divergence and high efficiency

NASA Astrophysics Data System (ADS)

Ma, Xiaolong; Qu, Hongwei; Qi, Aiyi; Zhou, Xuyan; Ma, Pijie; Liu, Anjin; Zheng, Wanhua

2018-04-01

High power tapered lasers are designed and fabricated. A one-dimensional photonic crystal structure in the vertical direction is adopted to narrow the far field divergence. The thickness of the defect layer and the photonic crystal layers are optimized by analyzing the optical field theoretically. For tapered lasers, the continuous-wave power is 7.3 W and the pulsed power is 17 W. A maximum wall-plug efficiency of 46% under continuous-wave operation and 49.3% in pulsed mode are obtained. The beam divergences are around 11° and 6° for the vertical and lateral directions, respectively. High beam qualities are also obtained with a vertical M2 value of 1.78 and a lateral M2 value of 1.62. As the current increases, the lateral M2 value increases gradually while the vertical M2 value remains around 2.

Effect of acoustic frequency and power density on the aqueous ultrasonic-assisted extraction of grape pomace (Vitis vinifera L.) - a response surface approach.

PubMed

González-Centeno, María Reyes; Knoerzer, Kai; Sabarez, Henry; Simal, Susana; Rosselló, Carmen; Femenia, Antoni

2014-11-01

Aqueous ultrasound-assisted extraction (UAE) of grape pomace was investigated by Response Surface Methodology (RSM) to evaluate the effect of acoustic frequency (40, 80, 120kHz), ultrasonic power density (50, 100, 150W/L) and extraction time (5, 15, 25min) on total phenolics, total flavonols and antioxidant capacity. All the process variables showed a significant effect on the aqueous UAE of grape pomace (p<0.05). The Box-Behnken Design (BBD) generated satisfactory mathematical models which accurately explain the behavior of the system; allowing to predict both the extraction yield of phenolic and flavonol compounds, and also the antioxidant capacity of the grape pomace extracts. The optimal UAE conditions for all response factors were a frequency of 40kHz, a power density of 150W/L and 25min of extraction time. Under these conditions, the aqueous UAE would achieve a maximum of 32.31mg GA/100g fw for total phenolics and 2.04mg quercetin/100g fw for total flavonols. Regarding the antioxidant capacity, the maximum predicted values were 53.47 and 43.66mg Trolox/100g fw for CUPRAC and FRAP assays, respectively. When comparing with organic UAE, in the present research, from 12% to 38% of total phenolic bibliographic values were obtained, but using only water as the extraction solvent, and applying lower temperatures and shorter extraction times. To the best of the authors' knowledge, no studies specifically addressing the optimization of both acoustic frequency and power density during aqueous-UAE of plant materials have been previously published. Copyright © 2014 Elsevier B.V. All rights reserved.

Modelling and assessment of the electric field strength caused by mobile phone to the human head.

PubMed

Buckus, Raimondas; Strukcinskiene, Birute; Raistenskis, Juozas; Stukas, Rimantas

2016-06-01

Electromagnetic field exposure is the one of the most important physical agents that actively affects live organisms and environment. Active use of mobile phones influences the increase of electromagnetic field radiation. The aim of the study was to measure and assess the electric field strength caused by mobile phones to the human head. In this paper the software "COMSOL Multiphysics" was used to establish the electric field strength created by mobile phones around the head. The second generation (2G) Global System for Mobile (GSM) phones that operate in the frequency band of 900 MHz and reach the power of 2 W have a stronger electric field than (2G) GSM mobile phones that operate in the higher frequency band of 1,800 MHz and reach the power up to 1 W during conversation. The third generation of (3G) UMTS smart phones that effectively use high (2,100 MHz) radio frequency band emit the smallest electric field strength values during conversation. The highest electric field strength created by mobile phones is around the ear, i.e. the mobile phone location. The strength of mobile phone electric field on the phantom head decreases exponentially while moving sidewards from the center of the effect zone (the ear), and constitutes 1-12% of the artificial head's surface. The highest electric field strength values of mobile phones are associated with their higher power, bigger specific energy absorption rate (SAR) and lower frequency of mobile phone. The stronger electric field emitted by the more powerful mobile phones takes a higher percentage of the head surface. The highest electric field strength created by mobile phones is distributed over the user's ear.

Kinetic and kinematic differences between squats performed with and without elastic bands.

PubMed

Israetel, Michael A; McBride, Jeffrey M; Nuzzo, James L; Skinner, Jared W; Dayne, Andrea M

2010-01-01

The purpose of this investigation was to compare kinetic and kinematic variables between squats performed with and without elastic bands equalized for total work. Ten recreationally weight trained males completed 1 set of 5 squats without (Wht) and with (Band) elastic bands as resistance. Squats were completed while standing on a force platform with bar displacement measured using 2 potentiometers. Electromyography (EMG) was obtained from the vastus lateralis. Average force-time, velocity-time, power-time, and EMG-time graphs were generated and statistically analyzed for mean differences in values between the 2 conditions during the eccentric and concentric phases. The Band condition resulted in significantly higher forces in comparison to the Wht condition during the first 25% of the eccentric phase and the last 10% of the concentric phase (p < or = 0.05). However, the Wht condition resulted in significantly higher forces during the last 5% of the eccentric phase and the first 5% of the concentric phase in comparison to the Band condition. The Band condition resulted in significantly higher power and velocity values during the first portion of the eccentric phase and the latter portion of the concentric phase. Vastus lateralis muscle activity during the Band condition was significantly greater during the first portion of the eccentric phase and latter portion of the concentric phase as well. This investigation indicates that squats equalized for total work with and without elastic bands significantly alter the force-time, power-time, velocity-time, and EMG-time curves associated with the movements. Specifically, elastic bands seem to increase force, power, and muscle activity during the early portions of the eccentric phase and latter portions of the concentric phase.

Atmospheric turbulence power spectral measurements to long wavelengths for several meteorological conditions

NASA Technical Reports Server (NTRS)

Rhyne, R. H.; Murrow, H. N.; Sidwell, K.

1976-01-01

Use of power spectral design techniques for supersonic transports requires accurate definition of atmospheric turbulence in the long wavelength region below the knee of the power spectral density function curve. Examples are given of data obtained from a current turbulence flight sampling program. These samples are categorized as (1) convective, (2) wind shear, (3) rotor, and (4) mountain-wave turbulence. Time histories, altitudes, root-mean-square values, statistical degrees of freedom, power spectra, and integral scale values are shown and discussed.

Power and sensitivity of alternative fit indices in tests of measurement invariance.

PubMed

Meade, Adam W; Johnson, Emily C; Braddy, Phillip W

2008-05-01

Confirmatory factor analytic tests of measurement invariance (MI) based on the chi-square statistic are known to be highly sensitive to sample size. For this reason, G. W. Cheung and R. B. Rensvold (2002) recommended using alternative fit indices (AFIs) in MI investigations. In this article, the authors investigated the performance of AFIs with simulated data known to not be invariant. The results indicate that AFIs are much less sensitive to sample size and are more sensitive to a lack of invariance than chi-square-based tests of MI. The authors suggest reporting differences in comparative fit index (CFI) and R. P. McDonald's (1989) noncentrality index (NCI) to evaluate whether MI exists. Although a general value of change in CFI (.002) seemed to perform well in the analyses, condition specific change in McDonald's NCI values exhibited better performance than a single change in McDonald's NCI value. Tables of these values are provided as are recommendations for best practices in MI testing. PsycINFO Database Record (c) 2008 APA, all rights reserved.

Mechanisms of Habitual Approach

PubMed Central

Anderson, Brian A.; Folk, Charles L.; Garrison, Rebecca; Rogers, Leeland

2016-01-01

Reward learning has a powerful influence on the attention system, causing previously reward-associated stimuli to automatically capture attention. Difficulty ignoring stimuli associated with drug reward has been linked to addiction relapse, and the attention system of drug-dependent patients seems especially influenced by reward history. This and other evidence suggests that value-driven attention has consequences for behavior and decision-making, facilitating a bias to approach and consume the previously reward-associated stimulus even when doing so runs counter to current goals and priorities. Yet, a mechanism linking value-driven attention to behavioral responding and a general approach bias is lacking. Here we show that previously reward-associated stimuli escape inhibitory processing in a go/no-go task. Control experiments confirmed that this value-dependent failure of goal-directed inhibition could not be explained by search history or residual motivation, but depended specifically on the learned association between particular stimuli and reward outcome. When a previously high-value stimulus is encountered, the response codes generated by that stimulus are automatically afforded high priority, bypassing goal-directed cognitive processes involved in suppressing task-irrelevant behavior. PMID:27054684

[The power of values. A question of professionalism].

PubMed

Durán Escribano, Marta

2004-03-01

In order to include the term on which my thoughts shall turn, related to professionalism, I strive to find the words which project a specific sense to the concrete aspect of what I want to express integrating values inherently when I say profession. My point of reference is Stephen. Toulmin, an interesting English philosopher and disciple of Ludwig Wittgenstein, who in his last known publication develops his thoughts about rationality and coins the term reasonability, which he defines as the capacity to be sensitive to the thousands of ways the same situation can be presented and he points out its meaning with these words: "One hopes that the human values of reasonability are self-justified in rationality". Following this same line of thinking, I propose that the human values of professionalism be self-justified by the professionalism nurses have. Based on this reflection, I open for debate the concept of PROFESSIONALISM, hoping to arrive beyond the norms which can determine the future professional, since these shall always be limited by one's own personal experiences and by the review of our short bibliography on this issue.

Professional, generational, and gender differences in perception of organisational values among Israeli physicians and nurses: Implications for retention.

PubMed

Warshawski, Sigalit; Barnoy, Sivia; Kagan, Ilya

2017-11-01

The global health workforce today is more age diverse than ever before and spans three generations: baby boomers, X and Y generations. Each generation has a distinct set of characteristics, values, and beliefs. This diversity can lead to increased creativity and a greater richness of values and skills, but at the same time it can also lead to value clashes, disrespect, and conflicts. This study aimed to examine professional, generational, and gender differences in the perception of the importance of organisational values among nurses and physicians working in both hospitals and outpatient clinics in Israel. Data were collected from a large sample of nurses and physicians (N = 603) from 11 hospitals and community services across Israel. The participants completed a self-administered questionnaire rating the perceived importance of 20 organisational values, such as leadership, risk-taking, competition, power, and collaboration. The five values ranked most important were performance quality, cooperation, commitment, effectiveness, and efficiency. The five values ranked least important were competition, marketing, power, risk-taking, and assertiveness. Significant value differences were found by profession, generation, and gender. Nurses scored efficiency, assertiveness, risk-taking, power, and marketing higher than physicians did. The Y generation scored power higher and marketing lower than the two older generations. Women ranked the values of cooperation, commitment, innovativeness, vision, and marketing significantly higher than men did. Understanding differences between professions, generations, and gender is a useful first step in improving employees' job satisfaction, productivity, and retention.

The Origin and Role of Trust in Local Policy Elites' Perceptions of High-Voltage Power Line Installations in the State of Arkansas.

PubMed

Tumlison, Creed; Moyer, Rachael M; Song, Geoboo

2017-05-01

The debate over an installation of high-voltage power lines (HVPLs) has been intense, particularly in northwest Arkansas. Detractors claim that the installation will negatively affect both the natural environment and the local economy, which contains a large tourism component. By contrast, those in favor of installing HVPLs claim that the installation is necessary in order to reliably support the increasing demand for electric power. Using original data collected from a recent statewide Internet survey of 420 local policy elites in Arkansas, this article focuses on two key aspects. First, we examine how local policy elites' perceptions of risks versus benefits of HVPL installation in their communities are influenced by their levels of trust toward information provided by various sources (e.g., energy industry, environmental groups, and government). Second, we utilize cultural theory to explain how the cultural worldviews of policy elites--specifically, egalitarianism, individualism, hierarchism, and fatalism--shape these levels of trust and HVPL benefit-risk perceptions, while controlling for other factors claimed by previous literature, including levels of knowledge on energy-related issues and demographic characteristics. In general, our analysis indicates that policy elites' value-oriented formation of HVPL benefit-risk perceptions is partially due to the influence cultural values have on trust in information sources. We conclude this article by discussing broader implications for the origin and role of trust in policy elites' decisions throughout the policy-making process. © 2016 Society for Risk Analysis.

PVUSA: The value of photovoltaics in the distribution system. The Kerman Grid-Support Project

NASA Astrophysics Data System (ADS)

Wenger, Howard J.; Hoff, Thomas E.

1995-05-01

As part of the Photovoltaics for Utility Scale Applications Applications (PVUSA) Project Pacific Gas Electric Company (PG&E) built the Kerman 500-kW photovoltaic power plant. Located near the end of a distribution feeder in a rural section of Fresno County, the plant was not built so much to demonstrate PV technology, but to evaluate its interaction with the local distribution grid and quantify available nontraditional grid-support benefits (those other than energy and capacity). As demand for new generation began to languish in the 1980s, and siting and permitting of power plants and transmission lines became more involved, utilities began considering smaller, distributed power sources. Potential benefits include shorter construction lead time, less capital outlay, and better utilization of existing assets. The results of a PG&E study in 1990/1991 of the benefits from a PV system to the distribution grid prompted the PVUSA Project to construct a plant at Kerman. Completed in 1993, the plant is believed to be the first one specifically built to evaluate the multiple benefits to the grid of a strategically sited plant. Each of nine discrete benefits were evaluated in detail by first establishing the technical impact, then translating the results into present economic value. Benefits span the entire system from distribution feeder to the generation fleet. This work breaks new ground in evaluation of distributed resources, and suggests that resource planning practices be expanded to account for these non-traditional benefits.

Effectiveness of urine fibronectin as a non-invasive diagnostic biomarker in bladder cancer patients: a systematic review and meta-analysis.

PubMed

Dong, Fan; Shen, Yifan; Xu, Tianyuan; Wang, Xianjin; Gao, Fengbin; Zhong, Shan; Chen, Shanwen; Shen, Zhoujun

2018-03-21

Previous researches pointed out that the measurement of urine fibronectin (Fn) could be a potential diagnostic test for bladder cancer (BCa). We conducted this meta-analysis to fully assess the diagnostic value of urine Fn for BCa detection. A systematic literature search in PubMed, ISI Web of Science, EMBASE, Cochrane library, and CBM was carried out to identify eligible studies evaluating the urine Fn in diagnosing BCa. Pooled sensitivity, specificity, and diagnostic odds ratio (DOR) with their 95% confidence intervals (CIs) were calculated, and summary receiver operating characteristic (SROC) curves were established. We applied the STATA 13.0, Meta-Disc 1.4, and RevMan 5.3 software to the meta-analysis. Eight separate studies with 744 bladder cancer patients were enrolled in this meta-analysis. The pooled sensitivity, specificity, and DOR were 0.80 (95%CI = 0.77-0.83), 0.79 (95%CI = 0.73-0.84), and 15.18 (95%CI = 10.07-22.87), respectively, and the area under the curve (AUC) of SROC was 0.83 (95%CI = 0.79-0.86). The diagnostic power of a combined method (urine Fn combined with urine cytology) was also evaluated, and its sensitivity and AUC were significantly higher (0.86 (95%CI = 0.82-0.90) and 0.89 (95%CI = 0.86-0.92), respectively). Meta-regression along with subgroup analysis based on various covariates revealed the potential sources of the heterogeneity and the detailed diagnostic value of each subgroup. Sensitivity analysis supported that the result was robust. No threshold effect and publication bias were found in this meta-analysis. Urine Fn may become a promising non-invasive biomarker for bladder cancer with a relatively satisfactory diagnostic power. And the combination of urine Fn with cytology could be an alternative option for detecting BCa in clinical practice. The potential value of urine Fn still needs to be validated in large, multi-center, and prospective studies.

Formulation, Pretreatment, and Densification Options to Improve Biomass Specifications for Co-Firing High Percentages with Coal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jaya Shankar Tumuluru; J Richard Hess; Richard D. Boardman

2012-06-01

There is a growing interest internationally to use more biomass for power generation, given the potential for significant environmental benefits and long-term fuel sustainability. However, the use of biomass alone for power generation is subject to serious challenges, such as feedstock supply reliability, quality, and stability, as well as comparative cost, except in situations in which biomass is locally sourced. In most countries, only a limited biomass supply infrastructure exists. Alternatively, co-firing biomass alongwith coal offers several advantages; these include reducing challenges related to biomass quality, buffering the system against insufficient feedstock quantity, and mitigating the costs of adapting existingmore » coal power plants to feed biomass exclusively. There are some technical constraints, such as low heating values, low bulk density, and grindability or size-reduction challenges, as well as higher moisture, volatiles, and ash content, which limit the co-firing ratios in direct and indirect co-firing. To achieve successful co-firing of biomass with coal, biomass feedstock specifications must be established to direct pretreatment options in order to modify biomass materials into a format that is more compatible with coal co-firing. The impacts on particle transport systems, flame stability, pollutant formation, and boiler-tube fouling/corrosion must also be minimized by setting feedstock specifications, which may include developing new feedstock composition by formulation or blending. Some of the issues, like feeding, co-milling, and fouling, can be overcome by pretreatment methods including washing/leaching, steam explosion, hydrothermal carbonization, and torrefaction, and densification methods such as pelletizing and briquetting. Integrating formulation, pretreatment, and densification will help to overcome issues related to physical and chemical composition, storage, and logistics to successfully co-fire higher percentages of biomass ( > 40%) with coal.« less

Prognostic value of cardiac power output to left ventricular mass in patients with left ventricular dysfunction and dobutamine stress echo negative by wall motion criteria.

PubMed

Cortigiani, Lauro; Sorbo, Simone; Miccoli, Mario; Scali, Maria Chiara; Simioniuc, Anca; Morrone, Doralisa; Bovenzi, Francesco; Marzilli, Mario; Dini, Frank Lloyd

2017-02-01

Cardiac power output to left ventricular mass (power/mass) is an index of myocardial efficiency reflecting the rate at which cardiac work is delivered with respect to the potential energy stored in the left ventricular mass. In the present study, we sought to investigate the capability of power/mass assessed at peak of dobutamine stress echocardiography to predict mortality in patients with ischaemic cardiomyopathy and no inducible ischaemia. One-hundred eleven patients (95 males; age 68 ± 10 years) with 35 ± 7% mean left ventricular ejection fraction and a dobutamine stress echocardiography (up to 40 µg/kg/min) negative by wall motion criteria formed the study population. Power/mass at peak stress was obtained as the product of a constant (K = 2.22 × 10 -1 ) with cardiac output and the mean arterial pressure divided by left ventricular mass to convert the units to W/100 g. Patients were followed up for a median of 29 months (inter-quartile range 16-72 months). All-cause mortality was the only accepted clinical end point. Mean peak-stress power/mass was 0.70 ± 0.31 W/100 g. During follow-up, 29 deaths (26%) were registered. With a receiver operating characteristic analysis, a peak-stress power/mass ≤0.50 W/100 g [area under curve 0.72 (95% CI 0.63; 0.80), sensitivity 59%, specificity 80%] was the best value for predicting mortality. Univariate prognostic indicators were age, male sex, peak-stress ejection fraction, peak-stress stroke volume, peak-stress cardiac output, peak-stress cardiac power output ≤1.48 W, and peak-stress power/mass ≤0.50 W/100 g. At multivariate analysis, age (HR 1.08, 95% CI 1.04; 1.14; P = 0.004) and peak-stress power/mass ≤0.50 W/100 g (HR 4.05, 95% CI 1.36; 12.00; P = 0.01) provided independent prognostic information. Three-year mortality was 14% in patients with peak-stress power/mass >0.50 W/100 g and 47% in those with peak-stress power/mass ≤0.50 W/100 g (log-rank 20.4; P < 0.0001). Power/mass assessed at peak of dobutamine stress echocardiography allows effective prognostication in patients with ischaemic cardiomyopathy and test result negative by wall motion criteria. In particular, a peak-stress power/mass ≤50 W/100 g is a strong and multivariable predictor of mortality. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2016. For permissions please email: journals.permissions@oup.com.

Grid regulation services for energy storage devices based on grid frequency

DOEpatents

Pratt, Richard M; Hammerstrom, Donald J; Kintner-Meyer, Michael C.W.; Tuffner, Francis K

2013-07-02

Disclosed herein are representative embodiments of methods, apparatus, and systems for charging and discharging an energy storage device connected to an electrical power distribution system. In one exemplary embodiment, a controller monitors electrical characteristics of an electrical power distribution system and provides an output to a bi-directional charger causing the charger to charge or discharge an energy storage device (e.g., a battery in a plug-in hybrid electric vehicle (PHEV)). The controller can help stabilize the electrical power distribution system by increasing the charging rate when there is excess power in the electrical power distribution system (e.g., when the frequency of an AC power grid exceeds an average value), or by discharging power from the energy storage device to stabilize the grid when there is a shortage of power in the electrical power distribution system (e.g., when the frequency of an AC power grid is below an average value).

Grid regulation services for energy storage devices based on grid frequency

DOEpatents

Pratt, Richard M.; Hammerstrom, Donald J.; Kintner-Meyer, Michael C. W.; Tuffner, Francis K.

2017-09-05

Disclosed herein are representative embodiments of methods, apparatus, and systems for charging and discharging an energy storage device connected to an electrical power distribution system. In one exemplary embodiment, a controller monitors electrical characteristics of an electrical power distribution system and provides an output to a bi-directional charger causing the charger to charge or discharge an energy storage device (e.g., a battery in a plug-in hybrid electric vehicle (PHEV)). The controller can help stabilize the electrical power distribution system by increasing the charging rate when there is excess power in the electrical power distribution system (e.g., when the frequency of an AC power grid exceeds an average value), or by discharging power from the energy storage device to stabilize the grid when there is a shortage of power in the electrical power distribution system (e.g., when the frequency of an AC power grid is below an average value).

Grid regulation services for energy storage devices based on grid frequency

DOEpatents

Pratt, Richard M; Hammerstrom, Donald J; Kintner-Meyer, Michael C.W.; Tuffner, Francis K

2014-04-15

Disclosed herein are representative embodiments of methods, apparatus, and systems for charging and discharging an energy storage device connected to an electrical power distribution system. In one exemplary embodiment, a controller monitors electrical characteristics of an electrical power distribution system and provides an output to a bi-directional charger causing the charger to charge or discharge an energy storage device (e.g., a battery in a plug-in hybrid electric vehicle (PHEV)). The controller can help stabilize the electrical power distribution system by increasing the charging rate when there is excess power in the electrical power distribution system (e.g., when the frequency of an AC power grid exceeds an average value), or by discharging power from the energy storage device to stabilize the grid when there is a shortage of power in the electrical power distribution system (e.g., when the frequency of an AC power grid is below an average value).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee Cadwallader

The safety of personnel at existing fusion experiments is an important concern that requires diligence. Looking to the future, fusion experiments will continue to increase in power and operating time until steady state power plants are achieved; this causes increased concern for personnel safety. This paper addresses four important aspects of personnel safety in the present and extrapolates these aspects to future power plants. The four aspects are personnel exposure to ionizing radiation, chemicals, magnetic fields, and radiofrequency (RF) energy. Ionizing radiation safety is treated well for present and near-term experiments by the use of proven techniques from other nuclearmore » endeavors. There is documentation that suggests decreasing the annual ionizing radiation exposure limits that have remained constant for several decades. Many chemicals are used in fusion research, for parts cleaning, as use as coolants, cooling water cleanliness control, lubrication, and other needs. In present fusion experiments, a typical chemical laboratory safety program, such as those instituted in most industrialized countries, is effective in protecting personnel from chemical exposures. As fusion facilities grow in complexity, the chemical safety program must transition from a laboratory scale to an industrial scale program that addresses chemical use in larger quantity. It is also noted that allowable chemical exposure concentrations for workers have decreased over time and, in some cases, now pose more stringent exposure limits than those for ionizing radiation. Allowable chemical exposure concentrations have been the fastest changing occupational exposure values in the last thirty years. The trend of more restrictive chemical exposure regulations is expected to continue into the future. Other issues of safety importance are magnetic field exposure and RF energy exposure. Magnetic field exposure limits are consensus values adopted as best practices for worker safety; a typical exposure value is ~1000 times the Earth’s magnetic field, but the Earth’s field is a very low value. Allowable static magnetic field exposure limits have remained constant over the recent past and would appear to remain constant for the foreseeable future. Some existing fusion experiments have suffered from RF energy leakage from waveguides, the typical practice to protect personnel is establishing personnel exclusion areas when systems are operating. RF exposure limits have remained fairly constant for overall body exposures, but have become more specific in the exposure frequency values. This paper describes the occupational limits for those types of exposure, how these exposures are managed, and also discusses the likelihood of more restrictive regulations being promulgated that will affect the design of future fusion power plants and safety of their personnel.« less

Gender differences in joint biomechanics during walking: normative study in young adults.

PubMed

Kerrigan, D C; Todd, M K; Della Croce, U

1998-01-01

The effect of gender on specific joint biomechanics during gait has been largely unexplored. Given the perceived, subjective, and temporal differences in walking between genders, we hypothesized that quantitative analysis would reveal specific gender differences in joint biomechanics as well. Sagittal kinematic (joint motion) and kinetic (joint torque and power) data from the lower limbs during walking were collected and analyzed in 99 young adult subjects (49 females), aged 20 to 40 years, using an optoelectronic motion analysis and force platform system. Kinetic data were normalized for both height and weight. Female and male data were compared graphically and statistically to assess differences in all major peak joint kinematic and kinetic values. Females had significantly greater hip flexion and less knee extension before initial contact, greater knee flexion moment in pre-swing, and greater peak mechanical joint power absorption at the knee in pre-swing (P < 0.0019 for each parameter). Other differences were noted (P < 0.05) that were not statistically significant when accounting for multiple comparisons. These gender differences may provide new insights into walking dynamics and may be important for both clinical and research studies in motivating the development of separate biomechanical reference databases for males and females.

Comparative study of cluster Ag17Cu2 by instantaneous normal mode analysis and by isothermal Brownian-type molecular dynamics simulation.

PubMed

Tang, Ping-Han; Wu, Ten-Ming; Yen, Tsung-Wen; Lai, S K; Hsu, P J

2011-09-07

We perform isothermal Brownian-type molecular dynamics simulations to obtain the velocity autocorrelation function and its time Fourier-transformed power spectral density for the metallic cluster Ag(17)Cu(2). The temperature dependences of these dynamical quantities from T = 0 to 1500 K were examined and across this temperature range the cluster melting temperature T(m), which we define to be the principal maximum position of the specific heat is determined. The instantaneous normal mode analysis is then used to dissect the cluster dynamics by calculating the vibrational instantaneous normal mode density of states and hence its frequency integrated value I(j) which is an ensemble average of all vibrational projection operators for the jth atom in the cluster. In addition to comparing the results with simulation data, we look more closely at the entities I(j) of all atoms using the point group symmetry and diagnose their temperature variations. We find that I(j) exhibit features that may be used to deduce T(m), which turns out to agree very well with those inferred from the power spectral density and specific heat. © 2011 American Institute of Physics

Cultural factors influencing Japanese nurses' assertive communication: Part 2 - hierarchy and power.

PubMed

Omura, Mieko; Stone, Teresa E; Levett-Jones, Tracy

2018-03-23

Hierarchy and power characterize health-care relationships around the world, constituting a barrier to assertive communication and a risk to patient safety. This issue is more problematic and complex in countries such as Japan, where deep-seated cultural values related to hierarchy and power persist. The current paper is the second of two that present the findings from a study exploring Japanese nurses' views and experiences of how cultural values impact assertive communication for health-care professionals. We conducted semistructured interviews with 23 registered nurses, following which data were analyzed using directed content analysis. Two overarching themes emerged from the analysis: hierarchy/power and collectivism. In the present study, we focus on cultural values related to hierarchy and power, including differences in professional status, gender imbalance, seniority/generation gap, bullying, and humility/modesty. The findings from our research provide meaningful insights into how Japanese cultural values influence and constrain nurses' communication and speaking up behaviors, and can be used to inform educational programs designed to teach assertiveness skills. © 2018 John Wiley & Sons Australia, Ltd.

Prediction of Francis Turbine Prototype Part Load Pressure and Output Power Fluctuations with Hydroelectric Model

NASA Astrophysics Data System (ADS)

Alligné, S.; Nicolet, C.; Béguin, A.; Landry, C.; Gomes, J.; Avellan, F.

2017-04-01

The prediction of pressure and output power fluctuations amplitudes on Francis turbine prototype is a challenge for hydro-equipment industry since it is subjected to guarantees to ensure smooth and reliable operation of the hydro units. The European FP7 research project Hyperbole aims to setup a methodology to transpose the pressure fluctuations induced by the cavitation vortex rope from the reduced scale model to the prototype generating units. A Francis turbine unit of 444MW with a specific speed value of ν = 0.29, is considered as case study. A SIMSEN model of the power station including electrical system, controllers, rotating train and hydraulic system with transposed draft tube excitation sources is setup. Based on this model, a frequency analysis of the hydroelectric system is performed for all technologies to analyse potential interactions between hydraulic excitation sources and electrical components. Three technologies have been compared: the classical fixed speed configuration with Synchronous Machine (SM) and the two variable speed technologies which are Doubly Fed Induction Machine (DFIM) and Full Size Frequency Converter (FSFC).

An Analytic Approximation to Very High Specific Impulse and Specific Power Interplanetary Space Mission Analysis

NASA Technical Reports Server (NTRS)

Williams, Craig Hamilton

1995-01-01

A simple, analytic approximation is derived to calculate trip time and performance for propulsion systems of very high specific impulse (50,000 to 200,000 seconds) and very high specific power (10 to 1000 kW/kg) for human interplanetary space missions. The approach assumed field-free space, constant thrust/constant specific power, and near straight line (radial) trajectories between the planets. Closed form, one dimensional equations of motion for two-burn rendezvous and four-burn round trip missions are derived as a function of specific impulse, specific power, and propellant mass ratio. The equations are coupled to an optimizing parameter that maximizes performance and minimizes trip time. Data generated for hypothetical one-way and round trip human missions to Jupiter were found to be within 1% and 6% accuracy of integrated solutions respectively, verifying that for these systems, credible analysis does not require computationally intensive numerical techniques.

The generation of simple compliance boundaries for mobile communication base station antennas using formulae for SAR estimation.

PubMed

Thors, B; Hansson, B; Törnevik, C

2009-07-07

In this paper, a procedure is proposed for generating simple and practical compliance boundaries for mobile communication base station antennas. The procedure is based on a set of formulae for estimating the specific absorption rate (SAR) in certain directions around a class of common base station antennas. The formulae, given for both whole-body and localized SAR, require as input the frequency, the transmitted power and knowledge of antenna-related parameters such as dimensions, directivity and half-power beamwidths. With knowledge of the SAR in three key directions it is demonstrated how simple and practical compliance boundaries can be generated outside of which the exposure levels do not exceed certain limit values. The conservativeness of the proposed procedure is discussed based on results from numerical radio frequency (RF) exposure simulations with human body phantoms from the recently developed Virtual Family.

Experimental verification of ion stopping power prediction from dual energy CT data in tissue surrogates

NASA Astrophysics Data System (ADS)

Farace, Paolo

2014-11-01

A two-steps procedure is presented to convert dual-energy CT data to stopping power ratio (SPR), relative to water. In the first step the relative electron density (RED) is calculated from dual-energy CT-numbers by means of a bi-linear relationship: RED = a HUscH + b HUscL + c, where HUscH and HUscL are scaled units (HUsc = HU + 1000) acquired at high and low energy respectively, and the three parameters a, b and c has to be determined for each CT scanner. In the second step the RED values were converted into SPR by means of published poly-line functions, which are invariant as they do not depend on a specific CT scanner. The comparison with other methods provides encouraging results, with residual SPR error on human tissue within 1%. The distinctive features of the proposed method are its simplicity and the generality of the conversion functions.

Diagnostic efficiency of DSM-IV criteria for obsessive compulsive personality disorder in patients with binge eating disorder.

PubMed

Grilo, C M

2004-01-01

This study examined the diagnostic efficiency of the DSM-IV criteria for obsessive compulsive personality disorder (OCPD) in patients with binge eating disorder (BED). Two hundred and eleven consecutive adult patients with axis I diagnoses of BED were reliably assessed with semi-structured diagnostic interviews. Conditional probabilities-sensitivity, specificity, positive predictive power (PPP), and negative predictive power (NPP)-were calculated for each of the eight criteria for OCPD, using the 'best-estimate' OCPD diagnosis as the standard. The diagnostic efficiencies of the OCPD criteria were variable, with three criteria failing to have predictive value (PPP<0.50). The best inclusion criterion (highest PPP) was 'Perfectionism,' which was also the overall most predictive criterion. The findings suggest ordering of the DSM-IV criteria for OCPD based on performance and call into question the utility of some criteria.

An Extreme Meteorological Events Analysis For Nuclear Power Plant (NPP) Siting Project at Bangka Island, Indonesia

NASA Astrophysics Data System (ADS)

Septiadi, Deni; S, Yarianto Sugeng B.; Sriyana; Anzhar, Kurnia; Suntoko, Hadi

2018-03-01

The potential sources of meteorological phenomena in Nuclear Power Plant (NPP) area of interest are identified and the extreme values of the possible resulting hazards associated which such phenomena are evaluated to derive the appropriate design bases for the NPP. The appropriate design bases shall be determined according to the Nuclear Energy Regulatory Agency (Bapeten) applicable regulations, which presently do not indicate quantitative criteria for purposes of determining the design bases for meteorological hazards. These meteorological investigations are also carried out to evaluate the regional and site specific meteorological parameters which affect the transport and dispersion of radioactive effluents on the environment of the region around the NPP site. The meteorological hazards are to be monitored and assessed periodically over the lifetime of the plant to ensure that consistency with the design assumptions is maintained throughout the full lifetime of the facility.

Experimental verification of ion stopping power prediction from dual energy CT data in tissue surrogates.

PubMed

Farace, Paolo

2014-11-21

A two-steps procedure is presented to convert dual-energy CT data to stopping power ratio (SPR), relative to water. In the first step the relative electron density (RED) is calculated from dual-energy CT-numbers by means of a bi-linear relationship: RED=a HUscH+b HUscL+c, where HUscH and HUscL are scaled units (HUsc=HU+1000) acquired at high and low energy respectively, and the three parameters a, b and c has to be determined for each CT scanner. In the second step the RED values were converted into SPR by means of published poly-line functions, which are invariant as they do not depend on a specific CT scanner. The comparison with other methods provides encouraging results, with residual SPR error on human tissue within 1%. The distinctive features of the proposed method are its simplicity and the generality of the conversion functions.

NASA electrothermal auxiliary propulsion technology

NASA Technical Reports Server (NTRS)

Stone, J. R.

1986-01-01

Electrothermal auxiliary propulsion systems provide high performance options which can have major mission benefits. There are several electrothermal concepts which offer a range of characteristics and benefits. Resistojets are the highest thrust to power option and are currently operational at mission average values of specific impulse, I sub sp approximately 295 sec. Long life, multipropellant resistojets are being developed for the space station, and resistojet technology advancements are being pursued to improve the I sub sp by more than 20 percent for resistojets used in satellite applications. Direct current arcjets have the potential of I sub sp over 400 sec with storable propellants and should provide over 1000 sec with hydrogen. Advanced concepts are being investigated to provide high power density options and possible growth to primary propulsion applications. Broad based experimental and analytical research and technology programs of NASA are summarized and recent significant advances are reviewed.

Controllable Grid Interface for Testing Ancillary Service Controls and Fault Performance of Utility-Scale Wind Power Generation: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gevorgian, Vahan; Koralewicz, Przemyslaw; Wallen, Robb

The rapid expansion of wind power has led many transmission system operators to demand modern wind power plants to comply with strict interconnection requirements. Such requirements involve various aspects of wind power plant operation, including fault ride-through and power quality performance as well as the provision of ancillary services to enhance grid reliability. During recent years, the National Renewable Energy Laboratory (NREL) of the U.S. Department of Energy has developed a new, groundbreaking testing apparatus and methodology to test and demonstrate many existing and future advanced controls for wind generation (and other renewable generation technologies) on the multimegawatt scale andmore » medium-voltage levels. This paper describes the capabilities and control features of NREL's 7-MVA power electronic grid simulator (also called a controllable grid interface, or CGI) that enables testing many active and reactive power control features of modern wind turbine generators -- including inertial response, primary and secondary frequency responses, and voltage regulation -- under a controlled, medium-voltage grid environment. In particular, this paper focuses on the specifics of testing the balanced and unbalanced fault ride-through characteristics of wind turbine generators under simulated strong and weak medium-voltage grid conditions. In addition, this paper provides insights on the power hardware-in-the-loop feature implemented in the CGI to emulate (in real time) the conditions that might exist in various types of electric power systems under normal operations and/or contingency scenarios. Using actual test examples and simulation results, this paper describes the value of CGI as an ultimate modeling validation tool for all types of 'grid-friendly' controls by wind generation.« less

Effects of phencyclidine (PCP) and MK 801 on the EEGq in the prefrontal cortex of conscious rats; antagonism by clozapine, and antagonists of AMPA-, alpha(1)- and 5-HT(2A)-receptors.

PubMed

Sebban, Claude; Tesolin-Decros, Brigitte; Ciprian-Ollivier, Jorge; Perret, Laurent; Spedding, Michael

2002-01-01

1. The electroencephalographic (EEG) effects of the propsychotic agent phencyclidine (PCP), were studied in conscious rats using power spectra (0 - 30 Hz), from the prefrontal cortex or sensorimotor cortex. PCP (0.1 - 3 mg kg(-1) s.c.) caused a marked dose-dependent increase in EEG power in the frontal cortex at 1 - 3 Hz with decreases in power at higher frequencies (9 - 30 Hz). At high doses (3 mg kg(-1) s.c.) the entire spectrum shifted to more positive values, indicating an increase in cortical synchronization. MK 801 (0.05 - 0.1 mg kg(-1) i.p.) caused similar effects but with lesser changes in power. 2. In contrast, the non-competitive AMPA antagonists GYKI 52466 and GYKI 53655 increased EEG power over the whole power spectrum (1 - 10 mg kg(-1) i.p.). The atypical antipsychotic clozapine (0.2 mg kg(-1) s.c.) synchronized the EEG (peak 8 Hz). The 5-HT(2A)-antagonist, M100907, specifically increased EEG power at 2 - 3 Hz at low doses (10 and 50 microg kg(-1) s.c.), whereas at higher doses (0.1 mg kg(-1) s.c.) the profile resembled that of clozapine. 3. Clozapine (0.2 mg kg(-1) s.c. ), GYKI 53655 (5 mg kg(-1) i.p.), prazosin (0.05 and 0.1 mg kg(-1) i.p.), and M100907 (0.01 and 0.05 mg kg(-1) s.c.) antagonized the decrease in power between 5 and 30 Hz caused by PCP (1 mg kg(-1) s.c.), but not the increase in power at 1 - 3 Hz in prefrontal cortex.

Harmonic analysis of electric locomotive and traction power system based on wavelet singular entropy

NASA Astrophysics Data System (ADS)

Dun, Xiaohong

2018-05-01

With the rapid development of high-speed railway and heavy-haul transport, the locomotive and traction power system has become the main harmonic source of China's power grid. In response to this phenomenon, the system's power quality issues need timely monitoring, assessment and governance. Wavelet singular entropy is an organic combination of wavelet transform, singular value decomposition and information entropy theory, which combines the unique advantages of the three in signal processing: the time-frequency local characteristics of wavelet transform, singular value decomposition explores the basic modal characteristics of data, and information entropy quantifies the feature data. Based on the theory of singular value decomposition, the wavelet coefficient matrix after wavelet transform is decomposed into a series of singular values that can reflect the basic characteristics of the original coefficient matrix. Then the statistical properties of information entropy are used to analyze the uncertainty of the singular value set, so as to give a definite measurement of the complexity of the original signal. It can be said that wavelet entropy has a good application prospect in fault detection, classification and protection. The mat lab simulation shows that the use of wavelet singular entropy on the locomotive and traction power system harmonic analysis is effective.

Oxygenation, local muscle oxygen consumption and joint specific power in cycling: the effect of cadence at a constant external work rate.

PubMed

Skovereng, Knut; Ettema, Gertjan; van Beekvelt, Mireille C P

2016-06-01

The present study investigates the effect of cadence on joint specific power and oxygenation and local muscle oxygen consumption in the vastus lateralis and vastus medialis in addition to the relationship between joint specific power and local muscle oxygen consumption (mVO2). Seventeen recreationally active cyclists performed 6 stages of constant load cycling using cadences of 60, 70, 80, 90, 100 and 110 rpm. Joint specific power was calculated using inverse dynamics and mVO2 and oxygenation were measured using near-infrared spectroscopy. Increasing cadence led to increased knee joint power and decreased hip joint power while the ankle joint was unaffected. Increasing cadence also led to an increased deoxygenation in both the vastus lateralis and vastus medialis. Vastus lateralis mVO2 increased when cadence was increased. No effect of cadence was found for vastus medialis mVO2. This study demonstrates a different effect of cadence on the mVO2 of the vastus lateralis and vastus medialis. The combined mVO2 of the vastus lateralis and medialis showed a linear increase with increasing knee joint specific power, demonstrating that the muscles combined related to power generated over the joint.

Power output measurement during treadmill cycling.

PubMed

Coleman, D A; Wiles, J D; Davison, R C R; Smith, M F; Swaine, I L

2007-06-01

The study aim was to consider the use of a motorised treadmill as a cycling ergometry system by assessing predicted and recorded power output values during treadmill cycling. Fourteen male cyclists completed repeated cycling trials on a motorised treadmill whilst riding their own bicycle fitted with a mobile ergometer. The speed, gradient and loading via an external pulley system were recorded during 20-s constant speed trials and used to estimate power output with an assumption about the contribution of rolling resistance. These values were then compared with mobile ergometer measurements. To assess the reliability of measured power output values, four repeated trials were conducted on each cyclist. During level cycling, the recorded power output was 257.2 +/- 99.3 W compared to the predicted power output of 258.2 +/- 99.9 W (p > 0.05). For graded cycling, there was no significant difference between measured and predicted power output, 268.8 +/- 109.8 W vs. 270.1 +/- 111.7 W, p > 0.05, SEE 1.2 %. The coefficient of variation for mobile ergometer power output measurements during repeated trials ranged from 1.5 % (95 % CI 1.2 - 2.0 %) to 1.8 % (95 % CI 1.5 - 2.4 %). These results indicate that treadmill cycling can be used as an ergometry system to assess power output in cyclists with acceptable accuracy.

Demonstration of Essential Reliability Services by a 300-MW Solar Photovoltaic Power Plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Loutan, Clyde; Klauer, Peter; Chowdhury, Sirajul

The California Independent System Operator (CAISO), First Solar, and the National Renewable Energy Laboratory (NREL) conducted a demonstration project on a large utility-scale photovoltaic (PV) power plant in California to test its ability to provide essential ancillary services to the electric grid. With increasing shares of solar- and wind-generated energy on the electric grid, traditional generation resources equipped with automatic governor control (AGC) and automatic voltage regulation controls -- specifically, fossil thermal -- are being displaced. The deployment of utility-scale, grid-friendly PV power plants that incorporate advanced capabilities to support grid stability and reliability is essential for the large-scale integrationmore » of PV generation into the electric power grid, among other technical requirements. A typical PV power plant consists of multiple power electronic inverters and can contribute to grid stability and reliability through sophisticated 'grid-friendly' controls. In this way, PV power plants can be used to mitigate the impact of variability on the grid, a role typically reserved for conventional generators. In August 2016, testing was completed on First Solar's 300-MW PV power plant, and a large amount of test data was produced and analyzed that demonstrates the ability of PV power plants to use grid-friendly controls to provide essential reliability services. These data showed how the development of advanced power controls can enable PV to become a provider of a wide range of grid services, including spinning reserves, load following, voltage support, ramping, frequency response, variability smoothing, and frequency regulation to power quality. Specifically, the tests conducted included various forms of active power control such as AGC and frequency regulation; droop response; and reactive power, voltage, and power factor controls. This project demonstrated that advanced power electronics and solar generation can be controlled to contribute to system-wide reliability. It was shown that the First Solar plant can provide essential reliability services related to different forms of active and reactive power controls, including plant participation in AGC, primary frequency control, ramp rate control, and voltage regulation. For AGC participation in particular, by comparing the PV plant testing results to the typical performance of individual conventional technologies, we showed that regulation accuracy by the PV plant is 24-30 points better than fast gas turbine technologies. The plant's ability to provide volt-ampere reactive control during periods of extremely low power generation was demonstrated as well. The project team developed a pioneering demonstration concept and test plan to show how various types of active and reactive power controls can leverage PV generation's value from being a simple variable energy resource to a resource that provides a wide range of ancillary services. With this project's approach to a holistic demonstration on an actual, large, utility-scale, operational PV power plant and dissemination of the obtained results, the team sought to close some gaps in perspectives that exist among various stakeholders in California and nationwide by providing real test data.« less

Fuzzy regulator design for wind turbine yaw control.

PubMed

Theodoropoulos, Stefanos; Kandris, Dionisis; Samarakou, Maria; Koulouras, Grigorios

2014-01-01

This paper proposes the development of an advanced fuzzy logic controller which aims to perform intelligent automatic control of the yaw movement of wind turbines. The specific fuzzy controller takes into account both the wind velocity and the acceptable yaw error correlation in order to achieve maximum performance efficacy. In this way, the proposed yaw control system is remarkably adaptive to the existing conditions. In this way, the wind turbine is enabled to retain its power output close to its nominal value and at the same time preserve its yaw system from pointless movement. Thorough simulation tests evaluate the proposed system effectiveness.

Wind utilization in remote regions: An economic study. [for comparison with diesel engines

NASA Technical Reports Server (NTRS)

Vansant, J. H.

1973-01-01

A wind driven generator was considered as a supplement to a diesel group, for the purpose of economizing fuel when wind power is available. A specific location on Hudson's Bay, Povognituk, was selected. Technical and economic data available for a wind machine of 10-kilowatt nominal capacity and available wind data for that region were used for the study. After subtracting the yearly wind machine costs from savings in fuel costs, a net savings of $1400 per year is realized. These values are approximate, but are though to be highly conservative.

Biomarkers of sepsis and their potential value in diagnosis, prognosis and treatment

PubMed Central

Sandquist, Mary; Wong, Hector R

2015-01-01

Biomarkers have great potential to improve the diagnosis and treatment of sepsis. The available literature supports the potential utility of sTREM-1, IL-27, suPAR, neutrophil CD64, presepsin, cfDNA and miRNAs as novel diagnostic, prognostic and treatment response biomarkers. The future of sepsis biomarkers lies in extensive validation studies of such novel biomarkers across heterogeneous populations and exploration of their power in combination. Furthermore, the use of a companion diagnostics model may augment the ability of investigators to identify novel sepsis biomarkers and develop specific therapeutic strategies based on biomarker information. PMID:25142036

Radiation Specifications for Fission Power Conversion Component Materials

NASA Technical Reports Server (NTRS)

Bowman, Cheryl L.; Shin, E. Eugene; Mireles, Omar R.; Radel, Ross F.; Qualls, A. Louis

2011-01-01

NASA has been supporting design studies and technology development that could provide power to an outpost on the moon, Mars, or an asteroid. One power-generation system that is independent of sunlight or power-storage limitations is a fission-based power plant. There is a wealth of terrestrial system heritage that can be transferred to the design and fabrication of a fission power system for space missions, but there are certain design aspects that require qualification. The radiation tolerance of the power conversion system requires scrutiny because the compact nature of a space power plant restricts the dose reduction methodologies compared to those used in terrestrial systems. An integrated research program has been conducted to establish the radiation tolerance of power conversion system-component materials. The radiation limit specifications proposed for a Fission Power System power convertor is 10 Mrad ionizing dose and 5 x 10(exp 14) neutron per square centimeter fluence for a convertor operating at 150 C. Specific component materials and their radiation tolerances are discussed. This assessment is for the power convertor hardware; electronic components are not covered here.

UNIFORMLY MOST POWERFUL BAYESIAN TESTS

PubMed Central

Johnson, Valen E.

2014-01-01

Uniformly most powerful tests are statistical hypothesis tests that provide the greatest power against a fixed null hypothesis among all tests of a given size. In this article, the notion of uniformly most powerful tests is extended to the Bayesian setting by defining uniformly most powerful Bayesian tests to be tests that maximize the probability that the Bayes factor, in favor of the alternative hypothesis, exceeds a specified threshold. Like their classical counterpart, uniformly most powerful Bayesian tests are most easily defined in one-parameter exponential family models, although extensions outside of this class are possible. The connection between uniformly most powerful tests and uniformly most powerful Bayesian tests can be used to provide an approximate calibration between p-values and Bayes factors. Finally, issues regarding the strong dependence of resulting Bayes factors and p-values on sample size are discussed. PMID:24659829

An Analytic Solution to the Computation of Power and Sample Size for Genetic Association Studies under a Pleiotropic Mode of Inheritance.

PubMed

Gordon, Derek; Londono, Douglas; Patel, Payal; Kim, Wonkuk; Finch, Stephen J; Heiman, Gary A

2016-01-01

Our motivation here is to calculate the power of 3 statistical tests used when there are genetic traits that operate under a pleiotropic mode of inheritance and when qualitative phenotypes are defined by use of thresholds for the multiple quantitative phenotypes. Specifically, we formulate a multivariate function that provides the probability that an individual has a vector of specific quantitative trait values conditional on having a risk locus genotype, and we apply thresholds to define qualitative phenotypes (affected, unaffected) and compute penetrances and conditional genotype frequencies based on the multivariate function. We extend the analytic power and minimum-sample-size-necessary (MSSN) formulas for 2 categorical data-based tests (genotype, linear trend test [LTT]) of genetic association to the pleiotropic model. We further compare the MSSN of the genotype test and the LTT with that of a multivariate ANOVA (Pillai). We approximate the MSSN for statistics by linear models using a factorial design and ANOVA. With ANOVA decomposition, we determine which factors most significantly change the power/MSSN for all statistics. Finally, we determine which test statistics have the smallest MSSN. In this work, MSSN calculations are for 2 traits (bivariate distributions) only (for illustrative purposes). We note that the calculations may be extended to address any number of traits. Our key findings are that the genotype test usually has lower MSSN requirements than the LTT. More inclusive thresholds (top/bottom 25% vs. top/bottom 10%) have higher sample size requirements. The Pillai test has a much larger MSSN than both the genotype test and the LTT, as a result of sample selection. With these formulas, researchers can specify how many subjects they must collect to localize genes for pleiotropic phenotypes. © 2017 S. Karger AG, Basel.

Mass transfer, physical, and mechanical characteristics of terebinth fruit (Pistacia atlantica L.) under convective infrared microwave drying

NASA Astrophysics Data System (ADS)

Kaveh, Mohammad; Abbaspour-Gilandeh, Yousef; Chayjan, Reza Amiri; Taghinezhad, Ebrahim; Mohammadigol, Reza

2018-01-01

This research was investigated to the thin-layer drying of terebinth fruit under convective infrared microwave (CIM) conditions with initial moisture content about 4.28% (g water/g dry matter). The effects of drying different conditions were studied on the effective moisture diffusivity, activation energy, specific energy, shrinkage, color, and mechanical properties of terebinth. Experiments were conducted at three air temperatures (45, 60, and 70 °C), three infrared power (500, 1000, and 1500 W) and three microwave power (270, 450 and 630 W). All these experiments were carried out under air velocity of 0.9 m/s. The effective moisture diffusivity of terebinth was obtained as 1.79 × 10-9 to 15.77 × 10-9 m2/s during drying. The activation energy of terebinth samples was measured to be 12.70 to 32.28 kJ/mol. To estimate the drying kinetic of terebinth, seven mathematical models were used to fit the experimental data of thin-layer drying. Results showed that the Midilli et al. model withR 2 = 0.9999, χ 2 = 0.0001 andRMSE = 0.0099 had the best performance in prediction of moisture content. Specific energy consumption was within the range of 127.62 to 678.90 MJ/kg. The maximum shrinkage during drying was calculated 69.88% at the air temperature 75 °C, infrared power of 1500 W, and microwave power 630 W. Moreover, the maximum values of the ΔL ∗ (15.89), Δa ∗ (12.28), Δb ∗(-0.12), and total color difference (ΔE= 17.44) were calculated in this work. Also, the maximum rupture force and energy for dried terebinth were calculated to be 149.2 N and 2845.4 N.mm, respectively.

Mass transfer, physical, and mechanical characteristics of terebinth fruit ( Pistacia atlantica L.) under convective infrared microwave drying

NASA Astrophysics Data System (ADS)

Kaveh, Mohammad; Abbaspour-Gilandeh, Yousef; Chayjan, Reza Amiri; Taghinezhad, Ebrahim; Mohammadigol, Reza

2018-07-01

This research was investigated to the thin-layer drying of terebinth fruit under convective infrared microwave (CIM) conditions with initial moisture content about 4.28% (g water/g dry matter). The effects of drying different conditions were studied on the effective moisture diffusivity, activation energy, specific energy, shrinkage, color, and mechanical properties of terebinth. Experiments were conducted at three air temperatures (45, 60, and 70 °C), three infrared power (500, 1000, and 1500 W) and three microwave power (270, 450 and 630 W). All these experiments were carried out under air velocity of 0.9 m/s. The effective moisture diffusivity of terebinth was obtained as 1.79 × 10-9 to 15.77 × 10-9 m2/s during drying. The activation energy of terebinth samples was measured to be 12.70 to 32.28 kJ/mol. To estimate the drying kinetic of terebinth, seven mathematical models were used to fit the experimental data of thin-layer drying. Results showed that the Midilli et al. model with R 2 = 0.9999, χ 2 = 0.0001 and RMSE = 0.0099 had the best performance in prediction of moisture content. Specific energy consumption was within the range of 127.62 to 678.90 MJ/kg. The maximum shrinkage during drying was calculated 69.88% at the air temperature 75 °C, infrared power of 1500 W, and microwave power 630 W. Moreover, the maximum values of the Δ L ∗ (15.89), Δ a ∗ (12.28), Δ b ∗(-0.12), and total color difference (Δ E= 17.44) were calculated in this work. Also, the maximum rupture force and energy for dried terebinth were calculated to be 149.2 N and 2845.4 N.mm, respectively.