Command Interface ASIC - Analog Interface ASIC Chip Set

NASA Technical Reports Server (NTRS)

Ruiz, Baldes; Jaffe, Burton; Burke, Gary; Lung, Gerald; Pixler, Gregory; Plummer, Joe; Katanyoutanant,, Sunant; Whitaker, William

2003-01-01

A command interface application-specific integrated circuit (ASIC) and an analog interface ASIC have been developed as a chip set for remote actuation and monitoring of a collection of switches, which can be used to control generic loads, pyrotechnic devices, and valves in a high-radiation environment. The command interface ASIC (CIA) can be used alone or in combination with the analog interface ASIC (AIA). Designed primarily for incorporation into spacecraft control systems, they are also suitable for use in high-radiation terrestrial environments (e.g., in nuclear power plants and facilities that process radioactive materials). The primary role of the CIA within a spacecraft or other power system is to provide a reconfigurable means of regulating the power bus, actuating all valves, firing all pyrotechnic devices, and controlling the switching of power to all switchable loads. The CIA is a mixed-signal (analog and digital) ASIC that includes an embedded microcontroller with supporting fault-tolerant switch control and monitoring circuitry that is capable of connecting to a redundant set of interintegrated circuit (I(sup 2)C) buses. Commands and telemetry requests are communicated to the CIA. Adherence to the I(sup 2)C bus standard helps to reduce development costs by facilitating the use of previously developed, commercially available components. The AIA is a mixed-signal ASIC that includes the analog circuitry needed to connect the CIA to a custom higher powered version of the I(sup 2)C bus. The higher-powered version is designed to enable operation with bus cables longer than those contemplated in the I(sup 2)C standard. If there are multiple higher-power I(sup 2)C-like buses, then there must an AIA between the CIA and each such bus. The AIA includes two identical interface blocks: one for the side-A I(sup 2)C clock and data buses and the other for the side B buses. All the AIAs on each side are powered from a common power converter module (PCM). Sides A and B of the I(sup 2)C buses are electrically isolated from each other (see figure). They are also isolated from the CIA by use of transformer coupling of signals between the AIA blocks and the CIA.

Work-Based Learning as a Field of Study

ERIC Educational Resources Information Center

Gibbs, Paul; Garnett, Jonathan

2007-01-01

This article addresses the challenges that Garnett suggests face higher education through the lens of Bourdieu. In taking up the challenge set by Garnett for higher education in the knowledge economy and responding to its powerful and primary artefact--intellectual capital--the article reviews and uses the analytical tool of Bourdieu's practice in…

Making Sense of Power Relations in a Malaysian English-as-a-Second-Language Academic Writing Classroom

ERIC Educational Resources Information Center

Abraham, Alison

2014-01-01

The role of power in an English-as-a-second-language classroom has yet to be fully explored by an action research practitioner, especially in a Malaysian higher education setting. This study aims to contribute to this gap by working within an academic literacies perspective to teaching academic writing, which propagates the understanding of…

Design study of a continuously variable roller cone traction CVT for electric vehicles

NASA Technical Reports Server (NTRS)

Mccoin, D. K.; Walker, R. D.

1980-01-01

Continuously variable ratio transmissions (CVT) featuring cone and roller traction elements and computerized controls are studied. The CVT meets or exceeds all requirements set forth in the design criteria. Further, a scalability analysis indicates the basic concept is applicable to lower and higher power units, with upward scaling for increased power being more readily accomplished.

Optimal Coordinated EV Charging with Reactive Power Support in Constrained Distribution Grids

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

Paudyal, Sumit; Ceylan, Oğuzhan; Bhattarai, Bishnu P.

Electric vehicle (EV) charging/discharging can take place in any P-Q quadrants, which means EVs could support reactive power to the grid while charging the battery. In controlled charging schemes, distribution system operator (DSO) coordinates with the charging of EV fleets to ensure grid’s operating constraints are not violated. In fact, this refers to DSO setting upper bounds on power limits for EV charging. In this work, we demonstrate that if EVs inject reactive power into the grid while charging, DSO could issue higher upper bounds on the active power limits for the EVs for the same set of grid constraints.more » We demonstrate the concept in an 33-node test feeder with 1,500 EVs. Case studies show that in constrained distribution grids in coordinated charging, average costs of EV charging could be reduced if the charging takes place in the fourth P-Q quadrant compared to charging with unity power factor.« less

Constructs of power and equity and their association with contraceptive use among men and women in rural Ethiopia and Kenya.

PubMed

Stephenson, Rob; Bartel, Doris; Rubardt, Marcie

2012-01-01

Using samples of reproductive aged men and women from rural Ethiopia and Kenya, this study examines the associations between two scales measuring balances of power and equitable attitudes within relationships and modern contraceptive use. The scales are developed from the Sexual and Reproductive Power Scale (SRPS) and Gender Equitable Male (GEM) scale, which were originally developed to measure relationship power (SRPS) among women and gender equitable attitudes (GEM) among men. With the exception of Ethiopian women, a higher score on the balance of power scale was associated with significantly higher odds of reporting modern contraceptive use. For men and women in both countries, a higher score on the equitable attitudes scale was associated with significantly higher odds of reporting modern contraceptive use. However, only the highest categories of the scales are associated with contraceptive use, suggesting a threshold effect in the relationships between power, equity and contraceptive use. The results presented here demonstrate how elements of the GEM and SRPS scales can be used to create scales measuring balances of power and equitable attitudes within relationships that are associated with self-reporting of modern contraceptive use in two resource-poor settings. However, further work with larger sample sizes is needed to confirm these findings, and to examine the extent to which these scales can be applied to other social and cultural contexts.

Dynamic characteristics of a multi-wavelength Brillouin-Raman fiber laser assisted by multiple four-wave mixing processes in a ring cavity

NASA Astrophysics Data System (ADS)

Shirazi, M. R.; Mohamed Taib, J.; De La Rue, R. M.; Harun, S. W.; Ahmad, H.

2015-03-01

Dynamic characteristics of a multi-wavelength Brillouin-Raman fiber laser (MBRFL) assisted by four-wave mixing have been investigated through the development of Stokes and anti-Stokes lines under different combinations of Brillouin and Raman pump power levels and different Raman pumping schemes in a ring cavity. For a Stokes line of order higher than three, the threshold power was less than the saturation power of its last-order Stokes line. By increasing the Brillouin pump power, the nth order anti-Stokes and the (n+4)th order Stokes power levels were unexpectedly increased almost the same before the Stokes line threshold power. It was also found out that the SBS threshold reduction (SBSTR) depended linearly on the gain factor for the 1st and 2nd Stokes lines, as the first set. This relation for the 3rd and 4th Stokes lines as the second set, however, was almost linear with the same slope before SBSTR -6 dB, then, it approached to the linear relation in the first set when the gain factor was increased to 50 dB. Therefore, the threshold power levels of Stokes lines for a given Raman gain can be readily estimated only by knowing the threshold power levels in which there is no Raman amplification.

SLIP: A Symmetric List Processing Language in PL-I.

ERIC Educational Resources Information Center

Leaf, William A.

SLIP (Symmetric List Processing) is a list processing system designed to be added to a higher order language (PL-1 in this version) so that the user has available to him list processing powers. The primary value of such a system is its data handling power. Through SLIP, one can set up lists of data, scan those lists, alter them, and read or write…

Flight investigation of the effects of an outboard wing-leading-edge modification on stall/spin characteristics of a low-wing, single-engine, T-tail light airplane

NASA Technical Reports Server (NTRS)

Stough, H. Paul, III; Dicarlo, Daniel J.; Patton, James M., Jr.

1987-01-01

Flight tests were performed to investigate the change in stall/spin characteristics due to the addition of an outboard wing-leading-edge modification to a four-place, low-wing, single-engine, T-tail, general aviation research airplane. Stalls and attempted spins were performed for various weights, center of gravity positions, power settings, flap deflections, and landing-gear positions. Both stall behavior and wind resistance were improved compared with the baseline airplane. The latter would readily spin for all combinations of power settings, flap deflections, and aileron inputs, but the modified airplane did not spin at idle power or with flaps extended. With maximum power and flaps retracted, the modified airplane did enter spins with abused loadings or for certain combinations of maneuver and control input. The modified airplane tended to spin at a higher angle of attack than the baseline airplane.

The effects of training with loads that maximise power output and individualised repetitions vs. traditional power training

PubMed Central

Moya-Ramón, M.; Hernández-Davó, J. L.; Fernandez-Fernandez, J.; Sabido, R.

2017-01-01

Background It has been suggested that strength training effects (i.e. neural or structural) vary, depending on the total repetitions performed and velocity loss in each training set. Purpose The aim of this study is to compare the effects of two training programmes (i.e. one with loads that maximise power output and individualised repetitions, and the other following traditional power training). Methods Twenty-five males were divided into three groups (optimum power [OP = 10], traditional training [TT = 9] and control group [CG = 6]). The training load used for OP was individualised using loads that maximised power output (41.7% ± 5.8 of one repetition maximum [1RM]) and repetitions at maximum power (4 to 9 repetitions, or ‘reps’). Volume (sets x repetitions) was the same for both experimental groups, while intensity for TT was that needed to perform only 50% of the maximum number of possible repetitions (i.e. 61.1%–66.6% of 1RM). The training programme ran over 11 weeks (2 sessions per week; 4–5 sets per session; 3-minute rests between sets), with pre-, intermediate and post-tests which included: anthropometry, 1RM, peak power output (PPO) with 30%, 40% and 50% of 1RM in the bench press throw, and salivary testosterone (ST) and cortisol (SC) concentrations. Rate of perceived exertion (RPE) and power output were recorded in all sessions. Results Following the intermediate test, PPO was increased in the OP group for each load (10.9%–13.2%). Following the post-test, both experimental groups had increased 1RM (11.8%–13.8%) and PPO for each load (14.1%–19.6%). Significant decreases in PPO were found for the TT group during all sets (4.9%–15.4%), along with significantly higher RPE (37%). Conclusion OP appears to be a more efficient method of training, with less neuromuscular fatigue and lower RPE. PMID:29053725

Effects of different set configurations on barbell velocity and displacement during a clean pull.

PubMed

Haff, G Gregory; Whitley, Adrian; McCoy, Lora B; O'Bryant, Harold S; Kilgore, J Lon; Haff, Erin E; Pierce, Kyle; Stone, Michael H

2003-02-01

The effects of 3 types of set configurations (cluster, traditional, and undulating) on barbell kinematics were investigated in the present study. Thirteen men (track and field = 8; Olympic weightlifters = 5) (mean +/- SEM age, 23.4 +/- 1.1 years; height, 181.3 +/- 2.1 cm; body mass, 89.8 +/- 4.2 kg) performed 1 set of 5 repetitions in a cluster, traditional, and undulating fashion at 90 and 120% of their 1 repetition maximum (1RM) power clean (119.0 +/- 4.3 kg). All data were collected at 50 Hz and analyzed with a V-Scope Weightlifting Analysis System. Peak velocity (PV) and peak displacement (PD) were analyzed for each repetition and averaged for each set type. Results indicated that a significantly (p < 0.016) higher PV occurred during the cluster set when compared with the traditional sets at both intensities. PD was significantly higher than traditional sets at the 120% intensity. The present study suggests set configuration can affect PV and PD during clean pulls.

NREL Helps Streamline Solar Power Installations for Local Governments |

Science.gov Websites

derived from examples set by model cities, such as Austin and San Francisco. Certain prerequisites mandate serves to push communities forward that want a higher designation. One city interested in the addition of

Measured radiofrequency exposure during various mobile-phone use scenarios.

PubMed

Kelsh, Michael A; Shum, Mona; Sheppard, Asher R; McNeely, Mark; Kuster, Niels; Lau, Edmund; Weidling, Ryan; Fordyce, Tiffani; Kühn, Sven; Sulser, Christof

2011-01-01

Epidemiologic studies of mobile phone users have relied on self reporting or billing records to assess exposure. Herein, we report quantitative measurements of mobile-phone power output as a function of phone technology, environmental terrain, and handset design. Radiofrequency (RF) output data were collected using software-modified phones that recorded power control settings, coupled with a mobile system that recorded and analyzed RF fields measured in a phantom head placed in a vehicle. Data collected from three distinct routes (urban, suburban, and rural) were summarized as averages of peak levels and overall averages of RF power output, and were analyzed using analysis of variance methods. Technology was the strongest predictor of RF power output. The older analog technology produced the highest RF levels, whereas CDMA had the lowest, with GSM and TDMA showing similar intermediate levels. We observed generally higher RF power output in rural areas. There was good correlation between average power control settings in the software-modified phones and power measurements in the phantoms. Our findings suggest that phone technology, and to a lesser extent, degree of urbanization, are the two stronger influences on RF power output. Software-modified phones should be useful for improving epidemiologic exposure assessment.

Neural Classifiers for Learning Higher-Order Correlations

NASA Astrophysics Data System (ADS)

Güler, Marifi

1999-01-01

Studies by various authors suggest that higher-order networks can be more powerful and are biologically more plausible with respect to the more traditional multilayer networks. These architectures make explicit use of nonlinear interactions between input variables in the form of higher-order units or product units. If it is known a priori that the problem to be implemented possesses a given set of invariances like in the translation, rotation, and scale invariant pattern recognition problems, those invariances can be encoded, thus eliminating all higher-order terms which are incompatible with the invariances. In general, however, it is a serious set-back that the complexity of learning increases exponentially with the size of inputs. This paper reviews higher-order networks and introduces an implicit representation in which learning complexity is mainly decided by the number of higher-order terms to be learned and increases only linearly with the input size.

Fluidized-bed technology enabling the integration of high temperature solar receiver CSP systems with steam and advanced power cycles

DOE PAGES

Sakadjian, B.; Hu, S.; Maryamchik, M.; ...

2015-06-05

Solar Particle Receivers (SPR) are under development to drive concentrating solar plants (CSP) towards higher operating temperatures to support higher efficiency power conversion cycles. The novel high temperature SPR-based CSP system uses solid particles as the heat transfer medium (HTM) in place of the more conventional fluids such as molten salt or steam used in current state-of-the-art CSP plants. The solar particle receiver (SPR) is designed to heat the HTM to temperatures of 800 °C or higher which is well above the operating temperatures of nitrate-based molten salt thermal energy storage (TES) systems. The solid particles also help overcome somemore » of the other challenges associated with molten salt-based systems such as freezing, instability and degradation. The higher operating temperatures and use of low cost HTM and higher efficiency power cycles are geared towards reducing costs associated with CSP systems. This paper describes the SPR-based CSP system with a focus on the fluidized-bed (FB) heat exchanger and its integration with various power cycles. Furthermore, the SPR technology provides a potential pathway to achieving the levelized cost of electricity (LCOE) target of $0.06/kWh that has been set by the U.S. Department of Energy's SunShot initiative.« less

Fluidized-bed technology enabling the integration of high temperature solar receiver CSP systems with steam and advanced power cycles

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

Sakadjian, B.; Hu, S.; Maryamchik, M.

Solar Particle Receivers (SPR) are under development to drive concentrating solar plants (CSP) towards higher operating temperatures to support higher efficiency power conversion cycles. The novel high temperature SPR-based CSP system uses solid particles as the heat transfer medium (HTM) in place of the more conventional fluids such as molten salt or steam used in current state-of-the-art CSP plants. The solar particle receiver (SPR) is designed to heat the HTM to temperatures of 800 °C or higher which is well above the operating temperatures of nitrate-based molten salt thermal energy storage (TES) systems. The solid particles also help overcome somemore » of the other challenges associated with molten salt-based systems such as freezing, instability and degradation. The higher operating temperatures and use of low cost HTM and higher efficiency power cycles are geared towards reducing costs associated with CSP systems. This paper describes the SPR-based CSP system with a focus on the fluidized-bed (FB) heat exchanger and its integration with various power cycles. Furthermore, the SPR technology provides a potential pathway to achieving the levelized cost of electricity (LCOE) target of $0.06/kWh that has been set by the U.S. Department of Energy's SunShot initiative.« less

Enhanced distributed energy resource system

DOEpatents

Atcitty, Stanley [Albuquerque, NM; Clark, Nancy H [Corrales, NM; Boyes, John D [Albuquerque, NM; Ranade, Satishkumar J [Las Cruces, NM

2007-07-03

A power transmission system including a direct current power source electrically connected to a conversion device for converting direct current into alternating current, a conversion device connected to a power distribution system through a junction, an energy storage device capable of producing direct current connected to a converter, where the converter, such as an insulated gate bipolar transistor, converts direct current from an energy storage device into alternating current and supplies the current to the junction and subsequently to the power distribution system. A microprocessor controller, connected to a sampling and feedback module and the converter, determines when the current load is higher than a set threshold value, requiring triggering of the converter to supply supplemental current to the power transmission system.

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.

When does power disparity help or hurt group performance?

PubMed

Tarakci, Murat; Greer, Lindred L; Groenen, Patrick J F

2016-03-01

Power differences are ubiquitous in social settings. However, the question of whether groups with higher or lower power disparity achieve better performance has thus far received conflicting answers. To address this issue, we identify 3 underlying assumptions in the literature that may have led to these divergent findings, including a myopic focus on static hierarchies, an assumption that those at the top of hierarchies are competent at group tasks, and an assumption that equality is not possible. We employ a multimethod set of studies to examine these assumptions and to understand when power disparity will help or harm group performance. First, our agent-based simulation analyses show that by unpacking these common implicit assumptions in power research, we can explain earlier disparate findings--power disparity benefits group performance when it is dynamically aligned with the power holder's task competence, and harms group performance when held constant and/or is not aligned with task competence. Second, our empirical findings in both a field study of fraud investigation groups and a multiround laboratory study corroborate the simulation results. We thereby contribute to research on power by highlighting a dynamic understanding of power in groups and explaining how current implicit assumptions may lead to opposing findings. (c) 2016 APA, all rights reserved).

[Cytogenetic analysis of genotoxic effects in subjects employed in heat power industry].

PubMed

Savchenko, Ia A; Druzhinin, V G; Minina, V I; Glushkov, A N; Akhmat'ianova, V R; Ostaptseva, A V; Shibaldin, A V; Vetrova, I V

2008-06-01

Chromosomal aberration rate has been estimated in peripheral blood lymphocytes of subjects occupationally exposed to a set of hazardous factors (employees of the Kemerovo Heat Power Plant). The frequency of metaphases with aberrations in the workers (3.23 +/- 0.26%, N = 104) is significantly higher than in control subjects (2.11 +/- 0.28%, N = 70). The cytogenetic aberrations did not depend on the sex, age, duration of employment, or smoking.

Sacred Circles.

ERIC Educational Resources Information Center

Merkel, Jeanean

1998-01-01

States that people feel spiritual longing, expressed in belief in a God or higher power, to feel whole in a fragmented society. Recommends setting aside a sacred space, being still, and finding a spiritual community as rituals to reconnect with God and integrate the inner and outer lives. (VWC)

Energy Metabolism during Repeated Sets of Leg Press Exercise Leading to Failure or Not

PubMed Central

Gorostiaga, Esteban M.; Navarro-Amézqueta, Ion; Calbet, José A. L.; Hellsten, Ylva; Cusso, Roser; Guerrero, Mario; Granados, Cristina; González-Izal, Miriam; Ibañez, Javier; Izquierdo, Mikel

2012-01-01

This investigation examined the influence of the number of repetitions per set on power output and muscle metabolism during leg press exercise. Six trained men (age 34±6 yr) randomly performed either 5 sets of 10 repetitions (10REP), or 10 sets of 5 repetitions (5REP) of bilateral leg press exercise, with the same initial load and rest intervals between sets. Muscle biopsies (vastus lateralis) were taken before the first set, and after the first and the final sets. Compared with 5REP, 10REP resulted in a markedly greater decrease (P<0.05) of the power output, muscle PCr and ATP content, and markedly higher (P<0.05) levels of muscle lactate and IMP. Significant correlations (P<0.01) were observed between changes in muscle PCr and muscle lactate (R2 = 0.46), between changes in muscle PCr and IMP (R2 = 0.44) as well as between changes in power output and changes in muscle ATP (R2 = 0.59) and lactate (R2 = 0.64) levels. Reducing the number of repetitions per set by 50% causes a lower disruption to the energy balance in the muscle. The correlations suggest that the changes in PCr and muscle lactate mainly occur simultaneously during exercise, whereas IMP only accumulates when PCr levels are low. The decrease in ATP stores may contribute to fatigue. PMID:22808209

A study to determine whether cavitation occurs around dental ultrasonic scaling instruments.

PubMed

Lea, S C; Price, G J; Walmsley, A D

2005-02-01

The aim of this investigation was to determine if cavitation occurred around dental ultrasonic scalers and to estimate the amount of cavitation occurring. Three styles of tip (3 x TFI-10, 3 x TFI-3, 3 x TFI-1) were used, in conjunction with a Cavitron SPS ultrasonic generator (Dentsply, USA), to insonate terephthalic acid solution. The hydroxyl radical, [*OH], concentration, produced due to cavitation from the scaler tips, was monitored by fluorescence spectroscopy. Cavitational activity was enhanced at higher power settings and at longer operating times. The tip dimensions and geometry as well as the generator power setting are both important factors that affect the production of cavitation.

A power-efficient ZF precoding scheme for multi-user indoor visible light communication systems

NASA Astrophysics Data System (ADS)

Zhao, Qiong; Fan, Yangyu; Deng, Lijun; Kang, Bochao

2017-02-01

In this study, we propose a power-efficient ZF precoding scheme for visible light communication (VLC) downlink multi-user multiple-input-single-output (MU-MISO) systems, which incorporates the zero-forcing (ZF) and the characteristics of VLC systems. The main idea of this scheme is that the channel matrix used to perform pseudoinverse comes from the set of optical Access Points (APs) shared by more than one user, instead of the set of all involved serving APs as the existing ZF precoding schemes often used. By doing this, the waste of power, which is caused by the transmission of one user's data in the un-serving APs, can be avoided. In addition, the size of the channel matrix needs to perform pseudoinverse becomes smaller, which helps to reduce the computation complexity. Simulation results in two scenarios show that the proposed ZF precoding scheme has higher power efficiency, better bit error rate (BER) performance and lower computation complexity compared with traditional ZF precoding schemes.

Learning Communities and the Completion Agenda

ERIC Educational Resources Information Center

Johnson, Kathy E.

2013-01-01

Learning communities are widely recognized as a powerful pedagogy that promotes deep learning and student engagement, while also addressing a range of challenges that plague higher education. The Completion Agenda represents a complex set of intersecting priorities advocated by federal and state government, nonprofit organizations, colleges, and…

Making Stories, Making Sense.

ERIC Educational Resources Information Center

Rubin, Andee

1980-01-01

Describes a set of tools (called Story Maker, Pre-Fab Story Maker, and Story Maker Maker) for teaching creative writing that takes advantage of the potential power of the social situation in the classroom, focuses on higher-level structures in text, and integrates reading and writing in school. (AEA)

Fully moderated T-statistic for small sample size gene expression arrays.

PubMed

Yu, Lianbo; Gulati, Parul; Fernandez, Soledad; Pennell, Michael; Kirschner, Lawrence; Jarjoura, David

2011-09-15

Gene expression microarray experiments with few replications lead to great variability in estimates of gene variances. Several Bayesian methods have been developed to reduce this variability and to increase power. Thus far, moderated t methods assumed a constant coefficient of variation (CV) for the gene variances. We provide evidence against this assumption, and extend the method by allowing the CV to vary with gene expression. Our CV varying method, which we refer to as the fully moderated t-statistic, was compared to three other methods (ordinary t, and two moderated t predecessors). A simulation study and a familiar spike-in data set were used to assess the performance of the testing methods. The results showed that our CV varying method had higher power than the other three methods, identified a greater number of true positives in spike-in data, fit simulated data under varying assumptions very well, and in a real data set better identified higher expressing genes that were consistent with functional pathways associated with the experiments.

Optimal Capacitor Bank Capacity and Placement in Distribution Systems with High Distributed Solar Power Penetration

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

Hodge, Brian S; Mather, Barry A; Cho, Gyu-Jung

Capacitor banks have been generally installed and utilized to support distribution voltage during period of higher load or on longer, higher impedance, feeders. Installations of distributed energy resources in distribution systems are rapidly increasing, and many of these generation resources have variable and uncertain power output. These generators can significantly change the voltage profile across a feeder, and therefore when a new capacitor bank is needed analysis of optimal capacity and location of the capacitor bank is required. In this paper, we model a particular distribution system including essential equipment. An optimization method is adopted to determine the best capacitymore » and location sets of the newly installed capacitor banks, in the presence of distributed solar power generation. Finally we analyze the optimal capacitor banks configuration through the optimization and simulation results.« less

The Positive Effect of Authoritarian Leadership on Employee Performance: The Moderating Role of Power Distance.

PubMed

Wang, Honglei; Guan, Bichen

2018-01-01

Based on goal setting theory, this study explores the positive effect and influencing process of authoritarian leadership on employee performance, as well as the moderating role of individual power distance in this process. Data from 211 supervisor-subordinate dyads in Chinese organizations indicates that authoritarian leadership is positively associated with employee performance, and learning goal orientation mediates this relationship. Furthermore, power distance moderates the effect of authoritarian leadership on learning goal orientation, such that the effect was stronger when individual power distance was higher. The indirect effect of authoritarian leadership on employee performance via learning goal orientation is also moderated by power distance. Theoretical and managerial implications and future directions are also discussed.

The Positive Effect of Authoritarian Leadership on Employee Performance: The Moderating Role of Power Distance

PubMed Central

Wang, Honglei; Guan, Bichen

2018-01-01

Based on goal setting theory, this study explores the positive effect and influencing process of authoritarian leadership on employee performance, as well as the moderating role of individual power distance in this process. Data from 211 supervisor-subordinate dyads in Chinese organizations indicates that authoritarian leadership is positively associated with employee performance, and learning goal orientation mediates this relationship. Furthermore, power distance moderates the effect of authoritarian leadership on learning goal orientation, such that the effect was stronger when individual power distance was higher. The indirect effect of authoritarian leadership on employee performance via learning goal orientation is also moderated by power distance. Theoretical and managerial implications and future directions are also discussed. PMID:29628902

Separating Turbofan Engine Noise Sources Using Auto and Cross Spectra from Four Microphones

NASA Technical Reports Server (NTRS)

Miles, Jeffrey Hilton

2008-01-01

The study of core noise from turbofan engines has become more important as noise from other sources such as the fan and jet were reduced. A multiple-microphone and acoustic-source modeling method to separate correlated and uncorrelated sources is discussed. The auto- and cross spectra in the frequency range below 1000 Hz are fitted with a noise propagation model based on a source couplet consisting of a single incoherent monopole source with a single coherent monopole source or a source triplet consisting of a single incoherent monopole source with two coherent monopole point sources. Examples are presented using data from a Pratt& Whitney PW4098 turbofan engine. The method separates the low-frequency jet noise from the core noise at the nozzle exit. It is shown that at low power settings, the core noise is a major contributor to the noise. Even at higher power settings, it can be more important than jet noise. However, at low frequencies, uncorrelated broadband noise and jet noise become the important factors as the engine power setting is increased.

NASA Prediction of Worldwide Energy Resource High Resolution Meteorology Data For Sustainable Building Design

NASA Technical Reports Server (NTRS)

Chandler, William S.; Hoell, James M.; Westberg, David; Zhang, Taiping; Stackhouse, Paul W., Jr.

2013-01-01

A primary objective of NASA's Prediction of Worldwide Energy Resource (POWER) project is to adapt and infuse NASA's solar and meteorological data into the energy, agricultural, and architectural industries. Improvements are continuously incorporated when higher resolution and longer-term data inputs become available. Climatological data previously provided via POWER web applications were three-hourly and 1x1 degree latitude/longitude. The NASA Modern Era Retrospective-analysis for Research and Applications (MERRA) data set provides higher resolution data products (hourly and 1/2x1/2 degree) covering the entire globe. Currently POWER solar and meteorological data are available for more than 30 years on hourly (meteorological only), daily, monthly and annual time scales. These data may be useful to several renewable energy sectors: solar and wind power generation, agricultural crop modeling, and sustainable buildings. A recent focus has been working with ASHRAE to assess complementing weather station data with MERRA data. ASHRAE building design parameters being investigated include heating/cooling degree days and climate zones.

Way-Scaling to Reduce Power of Cache with Delay Variation

NASA Astrophysics Data System (ADS)

Goudarzi, Maziar; Matsumura, Tadayuki; Ishihara, Tohru

The share of leakage in cache power consumption increases with technology scaling. Choosing a higher threshold voltage (Vth) and/or gate-oxide thickness (Tox) for cache transistors improves leakage, but impacts cell delay. We show that due to uncorrelated random within-die delay variation, only some (not all) of cells actually violate the cache delay after the above change. We propose to add a spare cache way to replace delay-violating cache-lines separately in each cache-set. By SPICE and gate-level simulations in a commercial 90nm process, we show that choosing higher Vth, Tox and adding one spare way to a 4-way 16KB cache reduces leakage power by 42%, which depending on the share of leakage in total cache power, gives up to 22.59% and 41.37% reduction of total energy respectively in L1 instruction- and L2 unified-cache with a negligible delay penalty, but without sacrificing cache capacity or timing-yield.

The Generalized Higher Criticism for Testing SNP-Set Effects in Genetic Association Studies

PubMed Central

Barnett, Ian; Mukherjee, Rajarshi; Lin, Xihong

2017-01-01

It is of substantial interest to study the effects of genes, genetic pathways, and networks on the risk of complex diseases. These genetic constructs each contain multiple SNPs, which are often correlated and function jointly, and might be large in number. However, only a sparse subset of SNPs in a genetic construct is generally associated with the disease of interest. In this article, we propose the generalized higher criticism (GHC) to test for the association between an SNP set and a disease outcome. The higher criticism is a test traditionally used in high-dimensional signal detection settings when marginal test statistics are independent and the number of parameters is very large. However, these assumptions do not always hold in genetic association studies, due to linkage disequilibrium among SNPs and the finite number of SNPs in an SNP set in each genetic construct. The proposed GHC overcomes the limitations of the higher criticism by allowing for arbitrary correlation structures among the SNPs in an SNP-set, while performing accurate analytic p-value calculations for any finite number of SNPs in the SNP-set. We obtain the detection boundary of the GHC test. We compared empirically using simulations the power of the GHC method with existing SNP-set tests over a range of genetic regions with varied correlation structures and signal sparsity. We apply the proposed methods to analyze the CGEM breast cancer genome-wide association study. Supplementary materials for this article are available online. PMID:28736464

Promoting self-exploration and function through an individualized power mobility training program.

PubMed

Kenyon, Lisa K; Farris, John; Brockway, Kaelee; Hannum, Nanette; Proctor, Kevin

2015-01-01

This case report describes the development and implementation of an intervention program that used a Power Wheelchair Trainer (Trainer) to enable an individual with severe impairments to participate in power mobility training. The participant was an 18 year-old female with spastic quadriplegic cerebral palsy, Gross Motor Function Classification Level V. The examination included the Power Mobility Screen and the Caregiver Priorities & Child Health Index of Life with Disabilities (CPCHILD). Switches on the participant's headrest provided control of the Trainer. Intervention consisted of power mobility training in an engaging environment that was set-up to focus on specific power mobility skills. Scores on the Power Mobility Screen and the CPCHILD were higher after intervention. The outcomes of this case report appear to support the use of the Trainer, which allowed the participant to practice power mobility skills and participate in self-exploration of her environment.

Optimal Battery Utilization Over Lifetime for Parallel Hybrid Electric Vehicle to Maximize Fuel Economy

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

Patil, Chinmaya; Naghshtabrizi, Payam; Verma, Rajeev

This paper presents a control strategy to maximize fuel economy of a parallel hybrid electric vehicle over a target life of the battery. Many approaches to maximizing fuel economy of parallel hybrid electric vehicle do not consider the effect of control strategy on the life of the battery. This leads to an oversized and underutilized battery. There is a trade-off between how aggressively to use and 'consume' the battery versus to use the engine and consume fuel. The proposed approach addresses this trade-off by exploiting the differences in the fast dynamics of vehicle power management and slow dynamics of batterymore » aging. The control strategy is separated into two parts, (1) Predictive Battery Management (PBM), and (2) Predictive Power Management (PPM). PBM is the higher level control with slow update rate, e.g. once per month, responsible for generating optimal set points for PPM. The considered set points in this paper are the battery power limits and State Of Charge (SOC). The problem of finding the optimal set points over the target battery life that minimize engine fuel consumption is solved using dynamic programming. PPM is the lower level control with high update rate, e.g. a second, responsible for generating the optimal HEV energy management controls and is implemented using model predictive control approach. The PPM objective is to find the engine and battery power commands to achieve the best fuel economy given the battery power and SOC constraints imposed by PBM. Simulation results with a medium duty commercial hybrid electric vehicle and the proposed two-level hierarchical control strategy show that the HEV fuel economy is maximized while meeting a specified target battery life. On the other hand, the optimal unconstrained control strategy achieves marginally higher fuel economy, but fails to meet the target battery life.« less

Measurement of black carbon emissions from in-use diesel-electric passenger locomotives in California

NASA Astrophysics Data System (ADS)

Tang, N. W.; Kirchstetter, T.; Martien, P. T.; Apte, J.

2015-12-01

Black carbon (BC) emission factors were measured for a California commuter rail line fleet of diesel-electric passenger locomotives (Caltrain). The emission factors are based on BC and carbon dioxide (CO2) concentrations in the exhaust plumes of passing locomotives, which were measured from pedestrian overpasses using portable analyzers. Each of the 29 locomotives in the fleet was sampled on 4-20 separate occasions at different locations to characterize different driving modes. The average emission factor expressed as g BC emitted per kg diesel consumed was 0.87 ± 0.66 g kg-1 (±1 standard deviation, n = 362 samples). BC emission factors tended to be higher for accelerating locomotives traveling at higher speeds with engines in higher notch settings. Higher fuel-based BC emission factors (g kg-1) were measured for locomotives equipped with separate "head-end" power generators (SEP-HEPs), which power the passenger cars, while higher time-based emission factors (g h-1) were measured for locomotives without SEP-HEPs, whose engines are continuously operated at high speeds to provide both head-end and propulsion power. PM10 emission factors, estimated assuming a BC/PM10 emission ratio of 0.6 and a typical power output-to-fuel consumption ratio, were generally in line with the Environmental Protection Agency's locomotive exhaust emission standards. Per passenger mile, diesel-electric locomotives in this study emit only 20% of the CO2 emitted by typical gasoline-powered light-duty vehicles (i.e., cars). However, the reduction in carbon footprint (expressed in terms of CO2 equivalents) due to CO2 emissions avoidance from a passenger commuting by train rather than car is appreciably offset by the locomotive's higher BC emissions.

Measurement of black carbon emissions from in-use diesel-electric passenger locomotives in California

NASA Astrophysics Data System (ADS)

Tang, Nicholas W.; Apte, Joshua S.; Martien, Philip T.; Kirchstetter, Thomas W.

2015-08-01

Black carbon (BC) emission factors were measured for a California commuter rail line fleet of diesel-electric passenger locomotives (Caltrain). The emission factors are based on BC and carbon dioxide (CO2) concentrations in the exhaust plumes of passing locomotives, which were measured from pedestrian overpasses using portable analyzers. Each of the 29 locomotives in the fleet was sampled on 4-20 separate occasions at different locations to characterize different driving modes. The average emission factor expressed as g BC emitted per kg diesel consumed was 0.87 ± 0.66 g kg-1 (±1 standard deviation, n = 362 samples). BC emission factors tended to be higher for accelerating locomotives traveling at higher speeds with engines in higher notch settings. Higher fuel-based BC emission factors (g kg-1) were measured for locomotives equipped with separate ;head-end; power generators (SEP-HEPs), which power the passenger cars, while higher time-based emission factors (g h-1) were measured for locomotives without SEP-HEPs, whose engines are continuously operated at high speeds to provide both head-end and propulsion power. PM10 emission factors, estimated assuming a BC/PM10 emission ratio of 0.6 and a typical power output-to-fuel consumption ratio, were generally in line with the Environmental Protection Agency's locomotive exhaust emission standards. Per passenger mile, diesel-electric locomotives in this study emit only 20% of the CO2 emitted by typical gasoline-powered light-duty vehicles (i.e., cars). However, the reduction in carbon footprint (expressed in terms of CO2 equivalents) due to CO2 emissions avoidance from a passenger commuting by train rather than car is appreciably offset by the locomotive's higher BC emissions.

The Quest for Powerful Learning Environments in Higher Education

ERIC Educational Resources Information Center

Slabbert, J. A.; Gouws, D. G.

2006-01-01

An introductory course in on tertiary level inadvertently sets the scene for the demands of the corresponding profession. Unfortunately, it seems as though these courses do not prepare learners adequately to acquire the demanding professional competences required for professional success. This problem has been a subject of contention especially in…

Maximum thrust mode evaluation

NASA Technical Reports Server (NTRS)

Orme, John S.; Nobbs, Steven G.

1995-01-01

Measured reductions in acceleration times which resulted from the application of the F-15 performance seeking control (PSC) maximum thrust mode during the dual-engine test phase is presented as a function of power setting and flight condition. Data were collected at altitudes of 30,000 and 45,000 feet at military and maximum afterburning power settings. The time savings for the supersonic acceleration is less than at subsonic Mach numbers because of the increased modeling and control complexity. In addition, the propulsion system was designed to be optimized at the mid supersonic Mach number range. Recall that even though the engine is at maximum afterburner, PSC does not trim the afterburner for the maximum thrust mode. Subsonically at military power, time to accelerate from Mach 0.6 to 0.95 was cut by between 6 and 8 percent with a single engine application of PSC, and over 14 percent when both engines were optimized. At maximum afterburner, the level of thrust increases were similar in magnitude to the military power results, but because of higher thrust levels at maximum afterburner and higher aircraft drag at supersonic Mach numbers the percentage thrust increase and time to accelerate was less than for the supersonic accelerations. Savings in time to accelerate supersonically at maximum afterburner ranged from 4 to 7 percent. In general, the maximum thrust mode has performed well, demonstrating significant thrust increases at military and maximum afterburner power. Increases of up to 15 percent at typical combat-type flight conditions were identified. Thrust increases of this magnitude could be useful in a combat situation.

Predicting fatty acid profiles in blood based on food intake and the FADS1 rs174546 SNP.

PubMed

Hallmann, Jacqueline; Kolossa, Silvia; Gedrich, Kurt; Celis-Morales, Carlos; Forster, Hannah; O'Donovan, Clare B; Woolhead, Clara; Macready, Anna L; Fallaize, Rosalind; Marsaux, Cyril F M; Lambrinou, Christina-Paulina; Mavrogianni, Christina; Moschonis, George; Navas-Carretero, Santiago; San-Cristobal, Rodrigo; Godlewska, Magdalena; Surwiłło, Agnieszka; Mathers, John C; Gibney, Eileen R; Brennan, Lorraine; Walsh, Marianne C; Lovegrove, Julie A; Saris, Wim H M; Manios, Yannis; Martinez, Jose Alfredo; Traczyk, Iwona; Gibney, Michael J; Daniel, Hannelore

2015-12-01

A high intake of n-3 PUFA provides health benefits via changes in the n-6/n-3 ratio in blood. In addition to such dietary PUFAs, variants in the fatty acid desaturase 1 (FADS1) gene are also associated with altered PUFA profiles. We used mathematical modeling to predict levels of PUFA in whole blood, based on multiple hypothesis testing and bootstrapped LASSO selected food items, anthropometric and lifestyle factors, and the rs174546 genotypes in FADS1 from 1607 participants (Food4Me Study). The models were developed using data from the first reported time point (training set) and their predictive power was evaluated using data from the last reported time point (test set). Among other food items, fish, pizza, chicken, and cereals were identified as being associated with the PUFA profiles. Using these food items and the rs174546 genotypes as predictors, models explained 26-43% of the variability in PUFA concentrations in the training set and 22-33% in the test set. Selecting food items using multiple hypothesis testing is a valuable contribution to determine predictors, as our models' predictive power is higher compared to analogue studies. As unique feature, we additionally confirmed our models' power based on a test set. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mapping of power consumption and friction reduction in piezoelectrically-assisted ultrasonic lubrication

NASA Astrophysics Data System (ADS)

Dong, Sheng; Dapino, Marcelo J.

2015-04-01

Ultrasonic lubrication has been proven effective in reducing dynamic friction. This paper investigates the relationship between friction reduction, power consumption, linear velocity, and normal stress. A modified pin-on-disc tribometer was adopted as the experimental set-up, and a Labview system was utilized for signal generation and data acquisition. Friction reduction was quantified for 0.21 to 5.31 W of electric power, 50 to 200 mm/s of linear velocity, and 23 to 70 MPa of normal stress. Friction reduction near 100% can be achieved under certain conditions. Lower linear velocity and higher electric power result in greater friction reduction, while normal stress has little effect on friction reduction. Contour plots of friction reduction, power consumption, linear velocity, and normal stress were created. An efficiency coefficient was proposed to calculate power requirements for a certain friction reduction or reduced friction for a given electric power.

Cooperation in multicultural negotiations: How the cultures of people with low and high power interact.

PubMed

Kopelman, Shirli; Hardin, Ashley E; Myers, Christopher G; Tost, Leigh Plunkett

2016-05-01

This study examined whether the cultures of low- and high-power negotiators interact to influence cooperative behavior of low-power negotiators. Managers from 4 different cultural groups (Germany, Hong Kong, Israel, and the United States) negotiated face-to-face in a simulated power-asymmetric commons dilemma. Results supported an interaction effect in which cooperation of people with lower power was influenced by both their culture and the culture of the person with higher power. In particular, in a multicultural setting, low-power managers from Hong Kong, a vertical-collectivist culture emphasizing power differences and group alignment, adjusted their cooperation depending on the culture of the high-power manager with whom they interacted. This study contributes to understanding how culture shapes behavior of people with relatively low power, illustrates how a logic of appropriateness informs cooperation, and highlights the importance of studying multicultural social interactions in the context of negotiations, work teams, and global leadership. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

The future of nuclear power: A world-wide perspective

NASA Astrophysics Data System (ADS)

Aktar, Ismail

This study analyzes the future of commercial nuclear electric generation worldwide using the Environmental Kuznets Curve (EKC) concept. The Tobit panel data estimation technique is applied to analyze the data between 1980 and 1998 for 105 countries. EKC assumes that low-income countries increase their nuclear reliance in total electric production whereas high-income countries decrease their nuclear reliance. Hence, we expect that high-income countries should shut down existing nuclear reactors and/or not build any new ones. We encounter two reasons for shutdowns: economic or political/environmental concerns. To distinguish these two effects, reasons for shut down are also investigated by using the Hazard Model technique. Hence, the load factor of a reactor is used as an approximation for economic reason to shut down the reactor. If a shut downed reactor had high load factor, this could be attributable to political/environmental concern or else economic concern. The only countries with nuclear power are considered in this model. The two data sets are created. In the first data set, the single entry for each reactor is created as of 1998 whereas in the second data set, the multiple entries are created for each reactor beginning from 1980 to 1998. The dependent variable takes 1 if operational or zero if shut downed. The empirical findings provide strong evidence for EKC relationship for commercial nuclear electric generation. Furthermore, higher natural resources suggest alternative electric generation methods rather than nuclear power. Economic index as an institutional variable suggests higher the economic freedom, lower the nuclear electric generation as expected. This model does not support the idea to cut the carbon dioxide emission via increasing nuclear share. The Hazard Model findings suggest that higher the load factor is, less likely the reactor will shut down. However, if it is still permanently closed downed, then this could be attributable to political hostility against nuclear power. There are also some projections indicating which reactors are most/least likely to be shut downed from the logit model. We also project which countries are most likely to increase/decrease their nuclear reliance from the residuals of EKC model.

Plasma and cyclotron frequency effects on output power of the plasma wave-pumped free-electron lasers

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

Zolghadr, S. H.; Jafari, S., E-mail: sjafari@guilan.ac.ir; Raghavi, A.

2016-05-15

Significant progress has been made employing plasmas in the free-electron lasers (FELs) interaction region. In this regard, we study the output power and saturation length of the plasma whistler wave-pumped FEL in a magnetized plasma channel. The small wavelength of the whistler wave (in sub-μm range) in plasma allows obtaining higher radiation frequency than conventional wiggler FELs. This configuration has a higher tunability by adjusting the plasma density relative to the conventional ones. A set of coupled nonlinear differential equations is employed which governs on the self-consistent evolution of an electromagnetic wave. The electron bunching process of the whistler-pumped FELmore » has been investigated numerically. The result reveals that for a long wiggler length, the bunching factor can appreciably change as the electron beam propagates through the wiggler. The effects of plasma frequency (or plasma density) and cyclotron frequency on the output power and saturation length have been studied. Simulation results indicate that with increasing the plasma frequency, the power increases and the saturation length decreases. In addition, when density of background plasma is higher than the electron beam density (i.e., for a dense plasma channel), the plasma effects are more pronounced and the FEL-power is significantly high. It is also found that with increasing the strength of the external magnetic field frequency, the power decreases and the saturation length increases, noticeably.« less

Anatomy of Process-Based Writing Center Tutorials with NNES Writers: What Writers Take Away

ERIC Educational Resources Information Center

Vickers, Jason C.

2012-01-01

Non-native English speaking (NNES) students in higher educational settings face difficulties writing academic papers and, in response to these difficulties, often seek assistance in understanding cultural, rhetorical, linguistic aspect of writing in English (Harris & Silva, 1993; Powers & Nelson, 1995). One resource available to them is…

Cycling performance is superior for time-to-exhaustion versus time-trial in endurance laboratory tests.

PubMed

Coakley, Sarah L; Passfield, Louis

2018-06-01

Time-to-exhaustion (TTE) trials are used in a laboratory setting to measure endurance performance. However, there is some concern with their ecological validity compared with time-trials (TT). Consequently, we aimed to compare cycling performance in TTE and TT where the duration of the trials was matched. Seventeen trained male cyclists completed three TTE trials at 80, 100 and 105% of maximal aerobic power (MAP). On a subsequent visit they performed three TT over the same duration as the TTE. Participants were blinded to elapsed time, power output, cadence and heart rate (HR). Average TTE was 865 ± 345 s, 165 ± 98 s and 117 ± 45 s for the 80, 100 and 105% trials respectively. Average power output was higher for TTE (294 ± 44 W) compared to TT (282 ± 43 W) at 80% MAP (P < 0.01), but not at 100 and 105% MAP (P > 0.05). There was no difference in cadence, HR, or RPE for any trial (P > 0.05). Critical power (CP) was also higher when derived from TTE compared to TT (P < 0.01). It is concluded that TTE results in a higher average power output compared to TT at 80% MAP. When determining CP, TTE rather than TT protocols appear superior.

Predictive analysis of beer quality by correlating sensory evaluation with higher alcohol and ester production using multivariate statistics methods.

PubMed

Dong, Jian-Jun; Li, Qing-Liang; Yin, Hua; Zhong, Cheng; Hao, Jun-Guang; Yang, Pan-Fei; Tian, Yu-Hong; Jia, Shi-Ru

2014-10-15

Sensory evaluation is regarded as a necessary procedure to ensure a reproducible quality of beer. Meanwhile, high-throughput analytical methods provide a powerful tool to analyse various flavour compounds, such as higher alcohol and ester. In this study, the relationship between flavour compounds and sensory evaluation was established by non-linear models such as partial least squares (PLS), genetic algorithm back-propagation neural network (GA-BP), support vector machine (SVM). It was shown that SVM with a Radial Basis Function (RBF) had a better performance of prediction accuracy for both calibration set (94.3%) and validation set (96.2%) than other models. Relatively lower prediction abilities were observed for GA-BP (52.1%) and PLS (31.7%). In addition, the kernel function of SVM played an essential role of model training when the prediction accuracy of SVM with polynomial kernel function was 32.9%. As a powerful multivariate statistics method, SVM holds great potential to assess beer quality. Copyright © 2014 Elsevier Ltd. All rights reserved.

Laboratory- and Field-Based Assessment of Maximal Aerobic Power of Elite Stand-Up Paddle-Board Athletes.

PubMed

Schram, Ben; Hing, Wayne; Climstein, Mike

2016-01-01

Stand-up paddle boarding (SUP) is a rapidly growing sport and recreational activity for which only anecdotal evidence exists on its proposed health, fitness, and injury-rehabilitation benefits. 10 internationally and nationally ranked elite SUP athletes. Participants were assessed for their maximal aerobic power on an ergometer in a laboratory and compared with other water-based athletes. Field-based assessments were subsequently performed using a portable gas-analysis system, and a correlation between the 2 measures was performed. Maximal aerobic power (relative) was significantly higher (P = .037) when measured in the field with a portable gas-analysis system (45.48 ± 6.96 mL · kg(-1) · min(-1)) than with laboratory-based metabolic-cart measurements (43.20 ± 6.67 mL · kg(-1) · min(-1)). There was a strong, positive correlation (r = .907) between laboratory and field maximal aerobic power results. Significantly higher (P = .000) measures of SUP paddling speed were found in the field than with the laboratory ergometer (+42.39%). There were no significant differences in maximal heart rate between the laboratory and field settings (P = .576). The results demonstrate the maximal aerobic power representative of internationally and nationally ranked SUP athletes and show that SUP athletes can be assessed for maximal aerobic power in the laboratory with high correlation to field-based measures. The field-based portable gas-analysis unit has a tendency to consistently measure higher oxygen consumption. Elite SUP athletes display aerobic power outputs similar to those of other upper-limb-dominant elite water-based athletes (surfing, dragon-boat racing, and canoeing).

Heat profiling of phacoemulsification tip using a thermal scanning camera.

PubMed

Ngo, Wei Kiong; Lim, Louis W; Tan, Colin S H; Heng, Wee Jin

2013-12-01

An experimental study to measure the heat profile of the phacoemulsification (phaco) tip using standard continuous phaco and hyperpulse phaco with and without waveform power modulation in the Millennium Microsurgical System with Custom Control Software (CCS). The phaco tip was imaged in air using a thermal camera. The highest temperature was measured 15 s after application of phaco power. Continuous, hyperpulse and waveform power modulations of the Millennium Microsurgical System were used with different power settings (20, 50 and 100 %) and duty cycles (40, 60 and 90 %), with the irrigation turned on and off. Using continuous phaco with the irrigation on, the phaco tip temperature remains <28.0 °C. With irrigation off, the temperature is higher compared to irrigation on but still remains <45.0 °C. Comparing the temperatures for all three power modulations when irrigation is on, at each phaco power and duty cycle setting, the temperature of the phaco tip is highest with continuous phaco, followed by hyperpulse with rise time 1, then hyperpulse with rise time 2. When irrigation is off, the highest temperatures are recorded using the hyperpulse with rise time 2, followed by continuous phaco, then hyperpulse with rise time 1. Hyperpulse and waveform modulations reduce heat generation compared to the continuous mode when irrigation is turned on. Lower duty cycles and lower ultrasound power produce less heat at the phaco tip.

Performance of large area xenon ion thrusters for orbit transfer missions

NASA Technical Reports Server (NTRS)

Rawlin, Vincent K.

1989-01-01

Studies have indicated that xenon ion propulsion systems can enable the use of smaller Earth-launch vehicles for satellite placement which results in significant cost savings. These analyses have assumed the availability of advanced, high power ion thrusters operating at about 10 kW or higher. A program was initiated to explore the viability of operating 50 cm diameter ion thrusters at this power level. Operation with several discharge chamber and ion extraction grid set combinations has been demonstrated and data were obtained at power levels to 16 kW. Fifty cm diameter thrusters using state of the art 30 cm diameter grids or advanced technology 50 cm diameter grids allow discharge power and beam current densities commensurate with long life at power levels up to 10 kW. In addition, 50 cm diameter thrusters are shown to have the potential for growth in thrust and power levels beyond 10 KW.

Clinical nutrition managers have access to sources of empowerment.

PubMed

Mislevy, J M; Schiller, M R; Wolf, K N; Finn, S C

2000-09-01

To ascertain perceived access of dietitians to power in the workplace. The conceptual framework was Kanter's theory of organizational power. The Conditions for Work Effectiveness Questionnaire was used to measure perceived access to sources of power: information, support, resources, and opportunities. Demographic data were collected to identify factors that may enhance empowerment. The questionnaire was sent to a random sample of 348 dietitians chosen from members of the Clinical Nutrition Management dietetic practice group of the American Dietetic Association. Blank questionnaires were returned by 99 (28.4%) people not working as clinical nutrition managers, which left 249 in the sample. Descriptive statistics were used to organize and summarize data. One-way analysis of variance and t tests were performed to identify differences in responses based on levels of education, work setting, and information technology skills. Usable questionnaires were received from 178 people (71.5%). On a 5-point scale, scores for access to information (mean +/- standard deviation [SD] = 3.8 +/- 0.7), opportunity (mean +/- SD = 3.6 +/- 0.7), support (mean +/- SD = 3.2 +/- 0.9), and resources (mean +/- SD = 3.1 +/- 0.8) demonstrated that clinical nutrition managers perceived themselves as having substantial access to sources of empowerment. Those having higher levels of education, working in larger hospitals, having better-developed information technology skills, and using information technology more frequently had statistically significant higher empowerment scores (P = < or = .05) than contrasting groups in each category. Clinical nutrition managers are empowered and able to assume leadership roles in today's health care settings. Their power may be enhanced by asserting more pressure to gain greater access to sources of power: support, information, resources, and opportunities.

A cautionary note on the power of the test for the indirect effect in mediation analysis.

PubMed

Loeys, Tom; Moerkerke, Beatrijs; Vansteelandt, Stijn

2014-01-01

Recent simulation studies have pointed to the higher power of the test for the mediated effect vs. the test for the total effect, even in the presence of a direct effect. This has motivated applied researchers to investigate mediation in settings where there is no evidence of a total effect. In this paper we provide analytical insight into the circumstances under which higher power of the test for the mediated effect vs. the test for the total effect can be expected in the absence of a direct effect. We argue that the acclaimed power gain is somewhat deceptive and comes with a big price. On the basis of the results, we recommend that when the primary interest lies in mediation only, a significant test for the total effect should not be used as a prerequisite for the test for the indirect effect. However, because the test for the indirect effect is vulnerable to bias when common causes of mediator and outcome are not measured or not accounted for, it should be evaluated in a sensitivity analysis.

A cautionary note on the power of the test for the indirect effect in mediation analysis

PubMed Central

Loeys, Tom; Moerkerke, Beatrijs; Vansteelandt, Stijn

2015-01-01

Recent simulation studies have pointed to the higher power of the test for the mediated effect vs. the test for the total effect, even in the presence of a direct effect. This has motivated applied researchers to investigate mediation in settings where there is no evidence of a total effect. In this paper we provide analytical insight into the circumstances under which higher power of the test for the mediated effect vs. the test for the total effect can be expected in the absence of a direct effect. We argue that the acclaimed power gain is somewhat deceptive and comes with a big price. On the basis of the results, we recommend that when the primary interest lies in mediation only, a significant test for the total effect should not be used as a prerequisite for the test for the indirect effect. However, because the test for the indirect effect is vulnerable to bias when common causes of mediator and outcome are not measured or not accounted for, it should be evaluated in a sensitivity analysis. PMID:25628585

Analysis of Co-Tunneling Current in Fullerene Single-Electron Transistor

NASA Astrophysics Data System (ADS)

KhademHosseini, Vahideh; Dideban, Daryoosh; Ahmadi, MohammadTaghi; Ismail, Razali

2018-05-01

Single-electron transistors (SETs) are nano devices which can be used in low-power electronic systems. They operate based on coulomb blockade effect. This phenomenon controls single-electron tunneling and it switches the current in SET. On the other hand, co-tunneling process increases leakage current, so it reduces main current and reliability of SET. Due to co-tunneling phenomenon, main characteristics of fullerene SET with multiple islands are modelled in this research. Its performance is compared with silicon SET and consequently, research result reports that fullerene SET has lower leakage current and higher reliability than silicon counterpart. Based on the presented model, lower co-tunneling current is achieved by selection of fullerene as SET island material which leads to smaller value of the leakage current. Moreover, island length and the number of islands can affect on co-tunneling and then they tune the current flow in SET.

Integrated Analysis of Pharmacologic, Clinical, and SNP Microarray Data using Projection onto the Most Interesting Statistical Evidence with Adaptive Permutation Testing

PubMed Central

Pounds, Stan; Cao, Xueyuan; Cheng, Cheng; Yang, Jun; Campana, Dario; Evans, William E.; Pui, Ching-Hon; Relling, Mary V.

2010-01-01

Powerful methods for integrated analysis of multiple biological data sets are needed to maximize interpretation capacity and acquire meaningful knowledge. We recently developed Projection Onto the Most Interesting Statistical Evidence (PROMISE). PROMISE is a statistical procedure that incorporates prior knowledge about the biological relationships among endpoint variables into an integrated analysis of microarray gene expression data with multiple biological and clinical endpoints. Here, PROMISE is adapted to the integrated analysis of pharmacologic, clinical, and genome-wide genotype data that incorporating knowledge about the biological relationships among pharmacologic and clinical response data. An efficient permutation-testing algorithm is introduced so that statistical calculations are computationally feasible in this higher-dimension setting. The new method is applied to a pediatric leukemia data set. The results clearly indicate that PROMISE is a powerful statistical tool for identifying genomic features that exhibit a biologically meaningful pattern of association with multiple endpoint variables. PMID:21516175

Association between power law coefficients of the anatomical noise power spectrum and lesion detectability in breast imaging modalities

NASA Astrophysics Data System (ADS)

Chen, Lin; Abbey, Craig K.; Boone, John M.

2013-03-01

Previous research has demonstrated that a parameter extracted from a power function fit to the anatomical noise power spectrum, β, may be predictive of breast mass lesion detectability in x-ray based medical images of the breast. In this investigation, the value of β was compared with a number of other more widely used parameters, in order to determine the relationship between β and these other parameters. This study made use of breast CT data sets, acquired on two breast CT systems developed in our laboratory. A total of 185 breast data sets in 183 women were used, and only the unaffected breast was used (where no lesion was suspected). The anatomical noise power spectrum computed from two-dimensional region of interests (ROIs), was fit to a power function (NPS(f) = α f-β), and the exponent parameter (β) was determined using log/log linear regression. Breast density for each of the volume data sets was characterized in previous work. The breast CT data sets analyzed in this study were part of a previous study which evaluated the receiver operating characteristic (ROC) curve performance using simulated spherical lesions and a pre-whitened matched filter computer observer. This ROC information was used to compute the detectability index as well as the sensitivity at 95% specificity. The fractal dimension was computed from the same ROIs which were used for the assessment of β. The value of β was compared to breast density, detectability index, sensitivity, and fractal dimension, and the slope of these relationships was investigated to assess statistical significance from zero slope. A statistically significant non-zero slope was considered to be a positive association in this investigation. All comparisons between β and breast density, detectability index, sensitivity at 95% specificity, and fractal dimension demonstrated statistically significant association with p < 0.001 in all cases. The value of β was also found to be associated with patient age and breast diameter, parameters both related to breast density. In all associations between other parameters, lower values of β were associated with increased breast cancer detection performance. Specifically, lower values of β were associated with lower breast density, higher detectability index, higher sensitivity, and lower fractal dimension values. While causality was not and probably cannot be demonstrated, the strong, statistically significant association between the β metric and the other more widely used parameters suggest that β may be considered as a surrogate measure for breast cancer detection performance. These findings are specific to breast parenchymal patterns and mass lesions only.

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.

Agent-based power sharing scheme for active hybrid power sources

NASA Astrophysics Data System (ADS)

Jiang, Zhenhua

The active hybridization technique provides an effective approach to combining the best properties of a heterogeneous set of power sources to achieve higher energy density, power density and fuel efficiency. Active hybrid power sources can be used to power hybrid electric vehicles with selected combinations of internal combustion engines, fuel cells, batteries, and/or supercapacitors. They can be deployed in all-electric ships to build a distributed electric power system. They can also be used in a bulk power system to construct an autonomous distributed energy system. An important aspect in designing an active hybrid power source is to find a suitable control strategy that can manage the active power sharing and take advantage of the inherent scalability and robustness benefits of the hybrid system. This paper presents an agent-based power sharing scheme for active hybrid power sources. To demonstrate the effectiveness of the proposed agent-based power sharing scheme, simulation studies are performed for a hybrid power source that can be used in a solar car as the main propulsion power module. Simulation results clearly indicate that the agent-based control framework is effective to coordinate the various energy sources and manage the power/voltage profiles.

Relevance of genetic relationship in GWAS and genomic prediction.

PubMed

Pereira, Helcio Duarte; Soriano Viana, José Marcelo; Andrade, Andréa Carla Bastos; Fonseca E Silva, Fabyano; Paes, Geísa Pinheiro

2018-02-01

The objective of this study was to analyze the relevance of relationship information on the identification of low heritability quantitative trait loci (QTLs) from a genome-wide association study (GWAS) and on the genomic prediction of complex traits in human, animal and cross-pollinating populations. The simulation-based data sets included 50 samples of 1000 individuals of seven populations derived from a common population with linkage disequilibrium. The populations had non-inbred and inbred progeny structure (50 to 200) with varying number of members (5 to 20). The individuals were genotyped for 10,000 single nucleotide polymorphisms (SNPs) and phenotyped for a quantitative trait controlled by 10 QTLs and 90 minor genes showing dominance. The SNP density was 0.1 cM and the narrow sense heritability was 25%. The QTL heritabilities ranged from 1.1 to 2.9%. We applied mixed model approaches for both GWAS and genomic prediction using pedigree-based and genomic relationship matrices. For GWAS, the observed false discovery rate was kept below the significance level of 5%, the power of detection for the low heritability QTLs ranged from 14 to 50%, and the average bias between significant SNPs and a QTL ranged from less than 0.01 to 0.23 cM. The QTL detection power was consistently higher using genomic relationship matrix. Regardless of population and training set size, genomic prediction provided higher prediction accuracy of complex trait when compared to pedigree-based prediction. The accuracy of genomic prediction when there is relatedness between individuals in the training set and the reference population is much higher than the value for unrelated individuals.

Understanding College and University Organization: Theories for Effective Policy and Practice. Two Volume Set

ERIC Educational Resources Information Center

Bess, James L.; Dee, Jay R.

2007-01-01

This two-volume work is intended to help readers develop powerful new ways of thinking about organizational principles, and apply them to policy-making and management in colleges and universities. The book is written with two audiences in mind: administrative and faculty leaders in institutions of higher learning, and students (both doctoral and…

"Observation Has Set In": Comparing Students and Peers as Reviewers of Teaching

ERIC Educational Resources Information Center

Huxham, Mark; Scoles, Jenny; Green, Ursula; Purves, Samantha; Welsh, Zoe; Gray, Andrew

2017-01-01

Peer review is a powerful method to enhance teaching in higher education. Peers, however, may not be the most relevant people in evaluating teaching success; as the most important stakeholders in learning, students' evaluations need to be heard. Whilst some efforts to capture "the student voice" are simplistic and may foster consumerist…

Flipped Classroom versus Traditional Textbook Instruction: Assessing Accuracy and Mental Effort at Different Levels of Mathematical Complexity

ERIC Educational Resources Information Center

Mattis, Kristina V.

2015-01-01

Flipped classrooms are an instructional technology trend mostly incorporated in higher education settings, with growing prominence in high school and middle school (Tucker in Leveraging the power of technology to create student-centered classrooms. Corwin, Thousand Oaks, 2012). Flipped classrooms are meant to effectively combine traditional and…

Organizing for Change: A Case Study of Grassroots Leadership at a Kentucky Community College

ERIC Educational Resources Information Center

Borregard, Andrea Rae

2016-01-01

Community colleges constitute a special type of higher education organization: their complex mission, dynamics, personnel structures, and values require a distinct set of understandings and skills to lead and manage them well. Most of the research on leadership in community colleges focuses on leaders in positions of power (presidents, provosts,…

Circuit Impedance Could Be a Crucial Factor Influencing Radiofrequency Ablation Efficacy and Safety: A Myocardial Phantom Study of the Problem and its Correction.

PubMed

Bhaskaran, Abhishek; Barry, M A; Pouliopoulos, Jim; Nalliah, Chrishan; Qian, Pierre; Chik, William; Thavapalachandran, Sujitha; Davis, Lloyd; McEwan, Alistair; Thomas, Stuart; Kovoor, Pramesh; Thiagalingam, Aravinda

2016-03-01

Circuit impedance could affect the safety and efficacy of radiofrequency (RF) ablation. To perform irrigated RF ablations with graded impedance to compare (1) lesion dimensions and overheated dimensions in fixed power ablations (2) and in power corrected ablations. Ablations were performed with irrigated Navistar Thermocool catheter and Stockert EP shuttle generator at settings of 40 W power for 60 seconds, in a previously validated myocardial phantom. The impedance of the circuit was set at 60 Ω, 80 Ω, 100 Ω, 120 Ω, 140 Ω, and 160 Ω. The lesion and overheated dimensions were measured at 53 °C and 80 °C isotherms, respectively. In the second set of ablations, power was corrected according to circuit impedance. In total, 70 ablations were performed. The lesion volume was 72.0 ± 4.8% and 44.7 ± 4.6% higher at 80 Ω and 100 Ω, respectively, compared to that at 120 Ω and it was 15.4 ± 1.2%, 28.1 ± 2.0%, and 38.0 ± 1.8% lower at 140 Ω, 160 Ω, and 180 Ω, respectively. The overheated volume was four times larger when impedance was reduced to 80 Ω from 100 Ω. It was absent at 120 Ω and above. In the power corrected ablations, the lesion volumes were similar to that of 40 W/120 Ω ablations and there was no evidence of overheating. The lesion and overheated dimensions were significantly larger with lower circuit impedance during irrigated RF ablation and the lesion size was smaller in high impedance ablations. Power delivery adjusted to impedance using a simple equation improved the consistency of lesion formation and prevented overheating. © 2015 Wiley Periodicals, Inc.

Analyzing endosonic root canal file oscillations: an in vitro evaluation.

PubMed

Lea, Simon C; Walmsley, A Damien; Lumley, Philip J

2010-05-01

Passive ultrasonic irrigation may be used to improve bacterial reduction within the root canal. The technique relies on a small file being driven to oscillate freely within the canal and activating an irrigant solution through biophysical forces such as microstreaming. There is limited information regarding a file's oscillation patterns when operated while surrounded by fluid as is the case within a canal root. Files of different sizes (#10 and #30, 27 mm and 31 mm) were connected to an ultrasound generator via a 120 degrees file holder. Files were immersed in a water bath, and a laser vibrometer set up with measurement lines superimposed over the files. The laser vibrometer was scanned over the oscillating files. Measurements were repeated 10 times for each file/power setting used. File mode shapes are comprised of a series of nodes/antinodes, with thinner, longer files producing more antinodes. The maximum vibration occurred at the free end of the file. Increasing generator power had no significant effect on this maximum amplitude (p > 0.20). Maximum displacement amplitudes were 17 to 22 microm (#10 file, 27 mm), 15 to 21 microm (#10 file, 31 mm), 6 to 9 microm (#30 file, 27 mm), and 5 to 7 microm (#30, 31 mm) for all power settings. Antinodes occurring along the remaining file length were significantly larger at generator power 1 than at powers 2 through 5 (p < 0.03). At higher generator powers, energy delivered to the file is dissipated in unwanted vibration resulting in reduced vibration displacement amplitudes. This may reduce the occurrence of the biophysical forces necessary to maximize the technique's effectiveness. Copyright (c) 2010 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Adaptive pitch control for variable speed wind turbines

DOEpatents

Johnson, Kathryn E [Boulder, CO; Fingersh, Lee Jay [Westminster, CO

2012-05-08

An adaptive method for adjusting blade pitch angle, and controllers implementing such a method, for achieving higher power coefficients. Average power coefficients are determined for first and second periods of operation for the wind turbine. When the average power coefficient for the second time period is larger than for the first, a pitch increment, which may be generated based on the power coefficients, is added (or the sign is retained) to the nominal pitch angle value for the wind turbine. When the average power coefficient for the second time period is less than for the first, the pitch increment is subtracted (or the sign is changed). A control signal is generated based on the adapted pitch angle value and sent to blade pitch actuators that act to change the pitch angle of the wind turbine to the new or modified pitch angle setting, and this process is iteratively performed.

Detector Powering in the 21st Century Why stay stuck with the Good old 20th Century methods?

NASA Astrophysics Data System (ADS)

Dhawan, Satish; Sumner, Richard

Future Collider Physics Detectors are envisioned with large granularity but we have a power delivery problem unless we fill a large fraction of the detector volume with copper conductors. LHC detector electronics is powered by transporting direct current over distances of 30 to 150 meters. This is how Thomas Alva Edison powered his light bulb. For example, CMS ECAL uses 50 kiloamps at 2.5 volts, supplied over a cable set with a transmission efficiency of only 30%. The transmission loss becomes waste heat in the detector that has to be removed. We have been exploring methods to transmit the DC power at higher voltage (low current), reducing to the final low voltage (high current) using DC-DC converters. These converters must operate in high magnetic fields and high radiation levels. This requires rad hard components and non-magnetic (air core) inductors.

Environmentally-induced voltage limitations in large space power systems

NASA Technical Reports Server (NTRS)

Stevens, N. J.

1984-01-01

Large power systems proposed for future space missions imply higher operating voltage requirements which, in turn, will interact with the space plasma environment. The effects of these interactions can only be inferred because of the limited data base of ground simulations, small test samples, and two space flight experiments. This report evaluates floating potentials for a 100 kW power system operating at 300, 500, 750, and 1000 volts in relation to this data base. Of primary concern is the possibility of discharging to space. The implications of such discharges were studied at the 500 volt operational setting. It was found that discharging can shut down the power system if the discharge current exceeds the array short circuit current. Otherwise, a power oscillation can result that ranges from 2 to 20 percent, depending upon the solar array area involved in the discharge. Means of reducing the effect are discussed.

Radiation tolerant power converter controls

NASA Astrophysics Data System (ADS)

Todd, B.; Dinius, A.; King, Q.; Uznanski, S.

2012-11-01

The Large Hadron Collider (LHC) at the European Organisation for Nuclear Research (CERN) is the world's most powerful particle collider. The LHC has several thousand magnets, both warm and super-conducting, which are supplied with current by power converters. Each converter is controlled by a purpose-built electronic module called a Function Generator Controller (FGC). The FGC allows remote control of the power converter and forms the central part of a closed-loop control system where the power converter voltage is set, based on the converter output current and magnet-circuit characteristics. Some power converters and FGCs are located in areas which are exposed to beam-induced radiation. There are numerous radiation induced effects, some of which lead to a loss of control of the power converter, having a direct impact upon the accelerator's availability. Following the first long shut down (LS1), the LHC will be able to run with higher intensity beams and higher beam energy. This is expected to lead to significantly increased radiation induced effects in materials close to the accelerator, including the FGC. Recent radiation tests indicate that the current FGC would not be sufficiently reliable. A so-called FGClite is being designed to work reliably in the radiation environment in the post-LS1 era. This paper outlines the concepts of power converter controls for machines such as the LHC, introduces the risks related to radiation and a radiation tolerant project flow. The FGClite is then described, with its key concepts and challenges: aiming for high reliability in a radiation field.

Endothelial protection: avoiding air bubble formation at the phacoemulsification tip.

PubMed

Kim, Eung Kweon; Cristol, Stephen M; Kang, Shin J; Edelhauser, Henry F; Yeon, Dong-Soo; Lee, Jae Bum

2002-03-01

To investigate the conditions under which bubbles form during phacoemulsification. Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea. In the first part of the study, the partial pressure of oxygen (pO(2)) was used as a surrogate measure for the partial pressure of air. Irrigation solutions packaged in glass and plastic containers were studied. A directly vented glass bottle was also tested. The pO(2) of the various irrigation solutions was measured as the containers were emptied. In the second part, phacoemulsification procedures were performed in rabbit eyes with different power settings and different irrigation solutions. Intracameral bubble formation during the procedure was recorded. Following the phacoemulsification procedures, the corneas were stained for F-actin and examined for endothelial injury. The initial pO(2) in irrigation solutions packaged in glass bottles was about half that at atmospheric levels; in solutions packaged in plastic, it was at atmospheric levels. As irrigation solutions were drained from the container, the pO(2) of the solution tended to rise toward atmospheric levels. The rate of pO(2) increase was markedly reduced by using a directly vented glass bottle. In the phacoemulsification procedures, bubble formation was most likely to occur with higher pO(2) and higher power settings. Observation of bubbles by the surgeon was highly correlated with endothelial damage. Keeping the pO(2) low reduced the risk of endothelial damage, especially at higher phacoemulsification powers. The packaging of irrigation solutions was the most important factor in controlling the initial pO(2) of the solution. The pO(2) can be minimized throughout a phacoemulsification procedure by using a directly vented glass bottle.

Coming to America: The Influence of College-Themed Movies on Perceptions of International Students

ERIC Educational Resources Information Center

Bourke, Brian

2013-01-01

Films represent a powerful medium for shaping and informing perceptions of a wide range of social structures and institutions, including higher education. Colleges and universities in the United States have been the subject or setting of dozens of films. The purpose of this article is to provide an analysis of a small group of films released in…

Prospective treatment planning to improve locoregional hyperthermia for oesophageal cancer.

PubMed

Kok, H P; van Haaren, P M A; van de Kamer, J B; Zum Vörde Sive Vörding, P J; Wiersma, J; Hulshof, M C C M; Geijsen, E D; van Lanschot, J J B; Crezee, J

2006-08-01

In the Academic Medical Center (AMC) Amsterdam, locoregional hyperthermia for oesophageal tumours is applied using the 70 MHz AMC-4 phased array system. Due to the occurrence of treatment-limiting hot spots in normal tissue and systemic stress at high power, the thermal dose achieved in the tumour can be sub-optimal. The large number of degrees of freedom of the heating device, i.e. the amplitudes and phases of the antennae, makes it difficult to avoid treatment-limiting hot spots by intuitive amplitude/phase steering. Prospective hyperthermia treatment planning combined with high resolution temperature-based optimization was applied to improve hyperthermia treatment of patients with oesophageal cancer. All hyperthermia treatments were performed with 'standard' clinical settings. Temperatures were measured systemically, at the location of the tumour and near the spinal cord, which is an organ at risk. For 16 patients numerically optimized settings were obtained from treatment planning with temperature-based optimization. Steady state tumour temperatures were maximized, subject to constraints to normal tissue temperatures. At the start of 48 hyperthermia treatments in these 16 patients temperature rise (DeltaT) measurements were performed by applying a short power pulse with the numerically optimized amplitude/phase settings, with the clinical settings and with mixed settings, i.e. numerically optimized amplitudes combined with clinical phases. The heating efficiency of the three settings was determined by the measured DeltaT values and the DeltaT-ratio between the DeltaT in the tumour (DeltaToes) and near the spinal cord (DeltaTcord). For a single patient the steady state temperature distribution was computed retrospectively for all three settings, since the temperature distributions may be quite different. To illustrate that the choice of the optimization strategy is decisive for the obtained settings, a numerical optimization on DeltaT-ratio was performed for this patient and the steady state temperature distribution for the obtained settings was computed. A higher DeltaToes was measured with the mixed settings compared to the calculated and clinical settings; DeltaTcord was higher with the mixed settings compared to the clinical settings. The DeltaT-ratio was approximately 1.5 for all three settings. These results indicate that the most effective tumour heating can be achieved with the mixed settings. DeltaT is proportional to the Specific Absorption Rate (SAR) and a higher SAR results in a higher steady state temperature, which implies that mixed settings are likely to provide the most effective heating at steady state as well. The steady state temperature distributions for the clinical and mixed settings, computed for the single patient, showed some locations where temperatures exceeded the normal tissue constraints used in the optimization. This demonstrates that the numerical optimization did not prescribe the mixed settings, because it had to comply with the constraints set to the normal tissue temperatures. However, the predicted hot spots are not necessarily clinically relevant. Numerical optimization on DeltaT-ratio for this patient yielded a very high DeltaT-ratio ( approximately 380), albeit at the cost of excessive heating of normal tissue and lower steady state tumour temperatures compared to the conventional optimization. Treatment planning can be valuable to improve hyperthermia treatments. A thorough discussion on clinically relevant objectives and constraints is essential.

Effect of different simulated altitudes on repeat-sprint performance in team-sport athletes.

PubMed

Goods P, S R; Dawson, Brian T; Landers, Grant J; Gore, Christopher J; Peeling, Peter

2014-09-01

This study aimed to assess the impact of 3 heights of simulated altitude exposure on repeat-sprint performance in team-sport athletes. Ten trained male team-sport athletes completed 3 sets of repeated sprints (9 × 4 s) on a nonmotorized treadmill at sea level and at simulated altitudes of 2000, 3000, and 4000 m. Participants completed 4 trials in a random order over 4 wk, with mean power output (MPO), peak power output (PPO), blood lactate concentration (Bla), and oxygen saturation (SaO2) recorded after each set. Each increase in simulated altitude corresponded with a significant decrease in SaO2. Total work across all sets was highest at sea level and correspondingly lower at each successive altitude (P < .05; sea level < 2000 m < 3000 m < 4000 m). In the first set, MPO was reduced only at 4000 m, but for subsequent sets, decreases in MPO were observed at all altitudes (P < .05; 2000 m < 3000 m < 4000 m). PPO was maintained in all sets except for set 3 at 4000 m (P < .05; vs sea level and 2000 m). BLa levels were highest at 4000 m and significantly greater (P < .05) than at sea level after all sets. These results suggest that "higher may not be better," as a simulated altitude of 4000 m may potentially blunt absolute training quality. Therefore, it is recommended that a moderate simulated altitude (2000-3000 m) be employed when implementing intermittent hypoxic repeat-sprint training for team-sport athletes.

The Himalayan hydro machine and space transmission power systems - An Asian dream of 21st century

NASA Astrophysics Data System (ADS)

Admoddie, M.

The advantages and disadvantages for the development of hydroelectric power are assessed for the Himalayan Rectangle, an area rising 1500 km north of a baseline between Karachi and Mandalay. This area has the potential for possessing one of the world's greatest power production capabilities. Among the disadvantages cited are the political instability and religious fundamentalism of the area, the bankrupt governments, environmental degradation, and inefficient power and irrigation systems. The advantages include the millions of talented and enterprising people in the region awaiting higher opportunities who are eager to improve their families' living standards and the large untapped hydropower resources. The concepts for hydropower development are discussed and go beyond the technologies of power and water. They include catchment ecodevelopment strategies with massive afforestation plans, setting up plans to strengthen village-level institutions to manage local natural biomass and water assets, the conversion of this regional hydropower potential into a subcontinental power system, and the exporting of power and the development of an interregional and international power grid by 2030, when both oil and local ecosystems would be dangerously depleted.

The design and performance of a 2.5-GHz telecommand link for wireless biomedical monitoring.

PubMed

Crumley, G C; Evans, N E; Scanlon, W G; Burns, J B; Trouton, T G

2000-12-01

This paper details the implementation and operational performance of a minimum-power 2.45-GHz pulse receiver and a companion on-off keyed transmitter for use in a semi-active, duplex RF biomedical transponder. A 50-ohm microstrip stub-matched zero-bias diode detector forms the heart of a body-worn receiver that has a (CMOS baseband amplifier consuming 20 microA from +3 V and achieves a tangential sensitivity of -53 dBm. The base transmitter generates 0.5 W of peak RF output power into 50 ohms. Both linear and right-hand circularly polarized Tx-Rx antenna sets were employed in system reliability trials carried out in a hospital Coronary Care Unit. For transmitting antenna heights between 0.3 and 2.2 m above floor level, transponder interrogations were 95% reliable within the 67-m2 area of the ward, falling to an average of 46% in the surrounding rooms and corridors. Overall, the circular antenna set gave the higher reliability and lower propagation power decay index.

Ground Tests of a Radial Air-Cooled Engine to Correct a Poor Circumferential Pressure-Recovery Distribution

NASA Technical Reports Server (NTRS)

Gallagher, James J.

1948-01-01

This report presents the results of the tests of a power-plant installation to improve the circumferential pressure-recovery distribution at the face of the engine. An underslung "C" cowling was tested with two propellers with full cuffs and with a modification to one set of cuffs. Little improvement was obtained because the base sections of the cuffs were stalled. A set of guide vanes boosted the over-all pressures and helped the pressure recoveries for a few of the cylinders. Making the underslung cowling into a symmetrical "C" cowling evened the pressure distribution; however, no increases in front pressures were obtained. The pressures at the top cylinders remained low and the high pressures at the bottom cylinders were reduced. At higher powers and engine speeds, the symmetrical cowling appeared best from the standpoint of over-all cooling characteristics.

'Real-world' compensatory behaviour with low nicotine concentration e-liquid: subjective effects and nicotine, acrolein and formaldehyde exposure.

PubMed

Dawkins, Lynne; Cox, Sharon; Goniewicz, Maciej; McRobbie, Hayden; Kimber, Catherine; Doig, Mira; Kośmider, Leon

2018-06-07

To compare the effects of i) high versus low nicotine concentration e-liquid, ii) fixed versus adjustable power and iii) the interaction between the two on: a) vaping behaviour, b) subjective effects, c) nicotine intake, and d) exposure to acrolein and formaldehyde in e-cigarette users vaping in their everyday setting. Counterbalanced, repeated measures with four conditions: i) low nicotine (6 mg/mL)/fixed power; ii) low nicotine/adjustable power; iii) high nicotine (18 mg/mL)/fixed power; iv) high nicotine/adjustable power. London and the South East, England. Twenty experienced e-cigarette users (recruited between September 2016 and February 2017) vaped ad libitum using an eVic Supreme™ with a 'Nautilus Aspire' tank over four weeks (one week per condition). Puffing patterns (daily puff number [PN], puff duration [PD], inter-puff interval [IPI]), mL of e-liquid consumed, changes to power (where permitted), and subjective effects (urge to vape, nicotine withdrawal symptoms) were measured in each condition. Nicotine intake was measured via salivary cotinine. 3-hydroxypropylmercapturic acid (3-HPMA), a metabolite of the toxicant acrolein, and formate, a metabolite of the carcinogen formaldehyde, were measured in urine. There was a significant nicotine concentration x power interaction for PD (p<0.01). PD was longer with low nicotine/fixed power compared with i) high nicotine/fixed power (p< 0.001 and ii) low nicotine/adjustable power (p< 0.01). PN and liquid consumed were higher in the low versus high nicotine condition (main effect of nicotine, p<0.05). Urge to vape and withdrawal symptoms were lower, and nicotine intake was higher, in the high nicotine condition (main effects of nicotine: p<0.01). Whilst acrolein levels did not differ, there was a significant nicotine x power interaction for formaldehyde (p<0.05). Use of a lower nicotine concentration e-liquid may be associated with compensatory behaviour (e.g., higher number and duration of puffs) and increases in negative affect, urge to vape, and formaldehyde exposure. This article is protected by copyright. All rights reserved.

The Power of Paradigms: A Discussion of the Absence of Bullying Research in the Context of the University Student Experience

ERIC Educational Resources Information Center

Coleyshaw, Liz

2010-01-01

The literature on bullying is vast and this social phenomenon has been studied in depth in relation to schooling and the workplace. Between school and workplace lies higher education (HE), but there is a marked absence of published work regarding undergraduate student-to-student bullying in this setting. This theoretical paper explores possible…

Solar-Powered Electric Propulsion Systems: Engineering and Applications

NASA Technical Reports Server (NTRS)

Stearns, J. W.; Kerrisk, D. J.

1966-01-01

Lightweight, multikilowatt solar power arrays in conjunction with electric propulsion offer potential improvements to space exploration, extending the usefulness of existing launch vehicles to higher-energy missions. Characteristics of solar-powered electric propulsion missions are outlined, and preliminary performance estimates are shown. Spacecraft system engineering is discussed with respect to parametric trade-offs in power and propulsion system design. Relationships between mission performance and propulsion system performance are illustrated. The present state of the art of electric propulsion systems is reviewed and related to the mission requirements identified earlier. The propulsion system design and test requirements for a mission spacecraft are identified and discussed. Although only ion engine systems are currently available, certain plasma propulsion systems offer some advantages in over-all system design. These are identified, and goals are set for plasma-thrustor systems to make them competitive with ion-engine systems for mission applications.

Emissions of Volatile Particulate Components from Turboshaft Engines running JP-8 and Fischer-Tropsch Fuels

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

Cheng, Mengdawn; Corporan, E.; DeWitt, M.

2009-01-01

Rotating-wing aircraft or helicopters are heavily used by the US military and also a wide range of commercial applications around the world, but emissions data for this class of engines are limited. In this study, we focus on emissions from T700-GE-700 and T700-GE-701C engines; T700 engine was run with military JP-8 and T701C run with both JP-8 and Fischer-Tropsch (FT) fuels. Each engine was run at three engine power settings from the idle to maximum power in sequence. Exhaust particles measured at the engine exhaust plane (EEP) have a peak mobility diameter less than 50nm in all engine power settings.more » At a 4-m downstream location, sulfate/sulfur measurements indicate all particulate sulfur exists practically as sulfate, and the particulate sulfur and sulfate contents increased as the engine power increased. The conversion of sulfur to sulfate was found not to be dependent on engine power setting. Analysis also showed that conversion of sulfur to sulfate was not by the adsorption of sulfur dioxide gas on the soot particles and then subsequently oxidized to form sulfate, but by gas-phase conversion of SO2 via OH or O then subsequently forming H2SO4 and condensing on soot particles. Without the sulfur and aromatic components, use of the FT fuel led to significant reduction of soot emissions as compared to that of the JP-8 fuel producing less number of particles than that of the JP-8 fuel; however, the FT fuel produced much higher number concentrations of particles smaller than 7nm than that of JP-8 in all engine power settings. This indicates non-aromatics components in the FT fuel could have contributed to the enhancement of emissions of particles smaller than 7nm. These small particles are volatile, not observed at the EEP, and may be important in playing a role for the formation of secondary particles in the atmosphere or serving as a site for effective cloud nuclei condensation to occur.« less

Economic demography in fuzzy spatial dilemmas and power laws

NASA Astrophysics Data System (ADS)

Fort, H.; Pérez, N.

2005-03-01

Adaptive agents, playing the iterated Prisoner's Dilemma (IPD) in a two-dimensional spatial setting and governed by Pavlovian strategies ("higher success-higher chance to stay"), are used to approach the problem of cooperation between self-interested individuals from a novel angle: We investigate the effect of different possible measures of success (MS) used by players to asses their performance in the game. These MS involve quantities such as: the player's utilities U, his cumulative score (or "capital") W, his neighborhood "welfare", etc. To handle an imprecise concept like "success" the agents use fuzzy logic. The degree of cooperation, the "economic demography" and the "efficiency" attained by the system depend dramatically on the MS. Specifically, patterns of "segregation" or "exploitation" are observed for some MS. On the other hand, power laws, that may be interpreted as signatures of critical self-organization (SOC), constitute a common feature for all the MS.

A normative set of 98 pairs of nonsensical pictures (droodles).

PubMed

Nishimoto, Takehiko; Ueda, Takashi; Miyawaki, Kaori; Une, Yuko; Takahashi, Masaru

2010-08-01

Our purpose in the present study is to provide a normative set of nonsensical pictures known as droodles and to demonstrate the role of semantic comprehension in facilitating recall of pictorial stimuli. The set consists of 98 pairs of droodles. Experiment 1 standardized these pictorial stimuli with respect to several variables, such as appropriateness of verbal labels, relationship between two droodles, and correct recall. Appropriateness of verbal labels was rated higher for pictures presented in pairs than for pictures presented singly. Experiment 2 used the standardized set of droodles in a recall experiment similar to those of Bower, Karlin, and Dueck (1975) and others. As we expected, semantic interpretation can strongly facilitate recall. Multiple regression analysis showed that several measures had significant power of explanation for recall performance. The full set of norms and pictures from this article may be downloaded from http://brm.psychonomic-journals.org/content/supplemental.

Hovering efficiency comparison of rotary and flapping flight for rigid rectangular wings via dimensionless multi-objective optimization.

PubMed

Bayiz, Yagiz; Ghanaatpishe, Mohammad; Fathy, Hosam; Cheng, Bo

2018-05-08

In this work, a multi-objective optimization framework is developed for optimizing low Reynolds number ([Formula: see text]) hovering flight. This framework is then applied to compare the efficiency of rigid revolving and flapping wings with rectangular shape under varying [Formula: see text] and Rossby number ([Formula: see text], or aspect ratio). The proposed framework is capable of generating sets of optimal solutions and Pareto fronts for maximizing the lift coefficient and minimizing the power coefficient in dimensionless space, explicitly revealing the trade-off between lift generation and power consumption. The results indicate that revolving wings are more efficient when the required average lift coefficient [Formula: see text] is low (<1 for [Formula: see text] and  <1.6 for [Formula: see text]), while flapping wings are more efficient in achieving higher [Formula: see text]. With the dimensionless power loading as the single-objective performance measure to be maximized, rotary flight is more efficient than flapping wings for [Formula: see text] regardless of the amount of energy storage assumed in the flapping wing actuation mechanism, while flapping flight is more efficient for [Formula: see text]. It is observed that wings with low [Formula: see text] perform better when higher [Formula: see text] is needed, whereas higher [Formula: see text] cases are more efficient at [Formula: see text] regions. However, for the selected geometry and [Formula: see text], the efficiency is weakly dependent on [Formula: see text] when the dimensionless power loading is maximized.

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.

Recent Developments in Niobium Containing Austenitic Stainless Steels for Thermal Power Plants

NASA Astrophysics Data System (ADS)

de Oliveira, Mariana Perez; Zhang, Wei; Yu, Hongyao; Bao, Hansheng; Xie, Xishan

The challenge of growing continuously in a sustainable way is the main driver to improve efficiency in the use of natural resources. The increasing demand for energy has made thermal power based countries to set audacious programs to increase efficiency of thermal power generation. In China, coal-burning accounts nowadays for approximately 65% of the total primary energy supply being responsible for around 25% of the countries' CO2 emission, this coal-based energy supply scenario is believed to continue until 2020. Therefore, the country has invested strongly in the last years in the construction of more efficient power plants. To attend higher operating temperatures and steam pressures, the application of higher performance materials is mandatory, presenting improved mechanical resistance — to stand the higher pressures applied — and having sufficient high temperature and corrosion resistance with the best cost-benefit relation possible. The present work addresses some research developments made in niobium containing austenitic stainless steels for super heaters and re-heater tubes in the past years as a joint effort between industry and academia to understand mechanisms and optimize the steel chemical composition, improving its performance. Niobium role has been studied in detail in heat resistant stainless steels TP347H, Super 304 and HR3C, a summary of such studies is presented in this paper. Niobium improves high temperature properties as it precipitates as nano-size MX and NbCrN, well dispersed in the matrix, hindering dislocation movement, increasing precipitation strengthening and creep resistance.

Changes in heart rate variability during anaesthesia induction using sevoflurane or isoflurane with nitrous oxide.

PubMed

Nishiyama, Tomoki

2016-01-01

The purpose of this study was to compare cardiac sympathetic and parasympathetic balance using heart rate variability (HRV) during induction of anaesthesia between sevoflurane and isoflurane in combination with nitrous oxide. 40 individuals aged from 30 to 60 years, scheduled for general anaesthesia were equally divided into sevoflurane or isoflurane groups. After 100% oxygen inhalation for a few minutes, anaesthesia was induced with nitrous oxide 3 L min-1, oxygen 3 L min-1 and sevoflurane or isoflurane. Sevoflurane or isoflurane concentration was increased by 0.5% every 2 to 3 breaths until 5% was attained for sevoflurane, or 3% for isoflurane. Vecuronium was administered to facilitate tracheal intubation. After intubation, sevoflurane was set to 2% while isoflurane was set to 1% with nitrous oxide with oxygen (1:1) for 5 min. Both sevoflurane and isoflurane provoked a decrease in blood pressure, total power, the low frequency component (LF), and high frequency component (HF) of HRV. Although the heart rate increased during isoflurane anaesthesia, it decreased under sevoflurane. The power of LF and HF also decreased in both groups. LF was higher in the isoflurane group while HF was higher in the sevoflurane group. The LF/HF ratio increased transiently in the isoflurane group, but decreased in the sevoflurane group. Anaesthesia induction with isoflurane-nitrous oxide transiently increased cardiac sympathetic activity, while sevoflurane-nitrous oxide decreased both cardiac sympathetic and parasympathetic activities. The balance of cardiac parasympathetic/sympathetic activity was higher in sevoflurane anaesthesia.

Optimizing results of lithotripsy using robust electromagnetic probe.

PubMed

Keeley, F X; Pye, S D; Smith, G; Tolley, D A

1999-05-01

A significant impediment to the measurement of the pressures and forces created by lithotripter shockwaves has been their destructive properties, which have rendered most measuring devices impractical. We have developed and tested a robust electromagnetic probe to measure cavitational forces in vitro in the focal zones of extracorporeal lithotripters. The probe responds to the pressure gradient generated by the radial motion of cavitation bubbles. The effects of shockwaves from the Dornier MPL 9000 electrohydraulic lithotripter were measured over the lifetime of multiple electrodes. The pulse energy from the electrodes dropped off rapidly after approximately 50% of the lifetime quoted by the manufacturer. The electrodes were more efficient at higher power settings. As a result, we altered our protocol for the treatment of ureteral stones to use a higher kilovoltage and a second electrode whenever necessary. Stone-free rates after shockwave lithotripsy (SWL) in situ for stones < 11 mm have increased from 68.2% to 83.3%, and the retreatment rate has dropped from 23% to 15%. Despite significantly higher power settings (23.7 kV v 18.7 kV; P < 0.0001), the need for sedoanalgesia has remained relatively constant (26% v 31%). Measurement of cavitational forces from lithotripters using a robust electromagnetic probe is useful in planning treatment strategy. We have demonstrated a clinically measurable improvement since implementing our new treatment protocol. Because the probe responds directly to cavitational forces, it should also prove useful for the objective comparison of different SWL machines.

Systematic Evaluation of Stochastic Methods in Power System Scheduling and Dispatch with Renewable Energy

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

Wang, Yishen; Zhou, Zhi; Liu, Cong

2016-08-01

As more wind power and other renewable resources are being integrated into the electric power grid, the forecast uncertainty brings operational challenges for the power system operators. In this report, different operational strategies for uncertainty management are presented and evaluated. A comprehensive and consistent simulation framework is developed to analyze the performance of different reserve policies and scheduling techniques under uncertainty in wind power. Numerical simulations are conducted on a modified version of the IEEE 118-bus system with a 20% wind penetration level, comparing deterministic, interval, and stochastic unit commitment strategies. The results show that stochastic unit commitment provides amore » reliable schedule without large increases in operational costs. Moreover, decomposition techniques, such as load shift factor and Benders decomposition, can help in overcoming the computational obstacles to stochastic unit commitment and enable the use of a larger scenario set to represent forecast uncertainty. In contrast, deterministic and interval unit commitment tend to give higher system costs as more reserves are being scheduled to address forecast uncertainty. However, these approaches require a much lower computational effort Choosing a proper lower bound for the forecast uncertainty is important for balancing reliability and system operational cost in deterministic and interval unit commitment. Finally, we find that the introduction of zonal reserve requirements improves reliability, but at the expense of higher operational costs.« less

Lower hybrid wave edge power loss quantification on the Alcator C-Mod tokamak

NASA Astrophysics Data System (ADS)

Faust, I. C.; Brunner, D.; LaBombard, B.; Parker, R. R.; Terry, J. L.; Whyte, D. G.; Baek, S. G.; Edlund, E.; Hubbard, A. E.; Hughes, J. W.; Kuang, A. Q.; Reinke, M. L.; Shiraiwa, S.; Wallace, G. M.; Walk, J. R.

2016-05-01

For the first time, the power deposition of lower hybrid RF waves into the edge plasma of a diverted tokamak has been systematically quantified. Edge deposition represents a parasitic loss of power that can greatly impact the use and efficiency of Lower Hybrid Current Drive (LHCD) at reactor-relevant densities. Through the use of a unique set of fast time resolution edge diagnostics, including innovative fast-thermocouples, an extensive set of Langmuir probes, and a Lyα ionization camera, the toroidal, poloidal, and radial structure of the power deposition has been simultaneously determined. Power modulation was used to directly isolate the RF effects due to the prompt ( t < τ E ) response of the scrape-off-layer (SOL) plasma to Lower Hybrid Radiofrequency (LHRF) power. LHRF power was found to absorb more strongly in the edge at higher densities. It is found that a majority of this edge-deposited power is promptly conducted to the divertor. This correlates with the loss of current drive efficiency at high density previously observed on Alcator C-Mod, and displaying characteristics that contrast with the local RF edge absorption seen on other tokamaks. Measurements of ionization in the active divertor show dramatic changes due to LHRF power, implying that divertor region can be a key for the LHRF edge power deposition physics. These observations support the existence of a loss mechanism near the edge for LHRF at high density ( n e > 1.0 × 10 20 (m-3)). Results will be shown addressing the distribution of power within the SOL, including the toroidal symmetry and radial distribution. These characteristics are important for deducing the cause of the reduced LHCD efficiency at high density and motivate the tailoring of wave propagation to minimize SOL interaction, for example, through the use of high-field-side launch.

Lower Hybrid wave edge power loss quantification on the Alcator C-Mod tokamak

NASA Astrophysics Data System (ADS)

Faust, I. C.

2015-11-01

For the first time, the power deposition of Lower Hybrid RF waves into the edge plasma of a diverted tokamak has been systematically quantified. Edge deposition represents a parasitic loss of power that can greatly impact the use and efficiency of Lower Hybrid Current Drive (LHCD) at reactor-relevant densities. Through the use of a unique set of fast time resolution edge diagnostics, including innovative fast-thermocouples, an extensive set of Langmuir probes, and a Lyα ionization camera, the toroidal, poloidal and radial structure of the power deposition has been simultaneously determined. Power modulation was used to directly isolate the RF effects due to the prompt (t <τE) response of the scrape-off-layer (SOL) plasma to LHRF power. LHRF power was found to absorb more strongly in the edge at higher densities. It is found that a majority of this edge-deposited power is promptly conducted to the divertor. This correlates with the loss of current drive efficiency at high density previously observed on Alcator C-Mod, and displaying characteristics that contrast with the local RF edge absorption seen on other tokamaks. Measurements of ionization in the active divertor show dramatic changes due to LHRF power, implying that divertor region can be key for the LHRF edge power deposition physics. These observations support the existence a loss mechanism near the edge for LHRF at high density (ne > 1 . 0 .1020 [m-3]). Results will be shown addressing the distribution of power within the SOL, including the toroidal symmetry and radial distribution. These characteristics are important for deducing the cause of the reduced LHCD efficiency at high density and motivates the tailoring of wave propagation to minimize SOL interaction, for example, through the use of high-field-side launch. This work was performed on the Alcator C-Mod tokamak, a DoE Office of Science user facility, and is supported by USDoE award DE-FC02-99ER54512.

Learning Hierarchical Feature Extractors for Image Recognition

DTIC Science & Technology

2012-09-01

space as a natural criterion for devising better pools. Finally, we propose ways to make coding faster and more powerful through fast convolutional...parameter is the set of pools over which the summary statistic is computed. We propose locality in feature configuration space as a natural criterion for...pooling (dotted lines) is consistently higher than average pooling (solid lines), but the gap is much less signif - icant with intersection kernel (closed

Subthreshold transpupillary thermotherapy reduces experimental choroidal neovascularization in the mouse without collateral damage to the neural retina.

PubMed

Ming, Yue; Algvere, Peep V; Odergren, Anne; Berglin, Lennart; van der Ploeg, Ingeborg; Seregard, Stefan; Kvanta, Anders

2004-06-01

Transpupillary thermotherapy (TTT) is currently being evaluated for treatment of choroidal neovascularization (CNV) in age-related macular degeneration. To optimize TTT for CNV, the effect was analyzed of invisible (subthreshold) or visible (threshold) doses of TTT on the normal mouse retina and on experimental CNV. TTT was delivered to the normal retina of 42 mice with a diode laser at increasing power settings (50, 60, 70, or 80 mW), to obtain thermal lesions ranging from invisible (subthreshold) to visible (threshold) burns. CNV was induced in 53 mice by krypton laser photocoagulation of the fundus, after which the CNV lesions were treated with TTT (50, 60, or 80 mW). Eyes were enucleated 7 days after TTT and prepared for histology, and the CNV complex was evaluated on hematoxylin-eosin stained serial sections by measuring the maximum height of the CNV lesions. Ultrastructural changes were examined by transmission electron microscopy. Increasing the TTT laser power yielded gradually more visible effects. At 50 mW, which induced subthreshold burns, no damage was seen in the neural retina, retinal pigment epithelium (RPE), or choroid at any time point. By contrast, eyes treated with higher power exhibited progressively more damage to the neural retina, including a complete disruption of the outer nuclear layer. When TTT was applied to the laser-induced CNV lesions, the height of lesions was significantly reduced (P < 0.001) in response to all three power settings at 7 days after treatment. The mean relative thickness of the CNV lesion was 3.29 +/- 0.89 in untreated mice, whereas in TTT-treated mice it was 1.69 +/- 0.35, 1.69 +/- 0.41 and 1.70 +/- 0.17 at power settings of 50, 60, and 80 mW, respectively. The overlying neural retina showed no apparent damage with the 50- or 60-mW settings, whereas outer nuclear layer disruption occurred with a power of 80 mW. Electron microscopy confirmed the presence of vascular occlusion at 1 day and a fibrotic scar at 7 days after TTT. Subthreshold TTT can effectively occlude newly formed vessels and cause regression of the experimental CNV complex without damaging the neural retina. The results demonstrate the importance of using subthreshold laser power in experimental and clinical evaluation of TTT.

Fuel-cell based power generating system having power conditioning apparatus

DOEpatents

Mazumder, Sudip K.; Pradhan, Sanjaya K.

2010-10-05

A power conditioner includes power converters for supplying power to a load, a set of selection switches corresponding to the power converters for selectively connecting the fuel-cell stack to the power converters, and another set of selection switches corresponding to the power converters for selectively connecting the battery to the power converters. The power conveners output combined power that substantially optimally meets a present demand of the load.

High-Energy Passive Mode-Locking of Fiber Lasers

PubMed Central

Ding, Edwin; Renninger, William H.; Wise, Frank W.; Grelu, Philippe; Shlizerman, Eli; Kutz, J. Nathan

2012-01-01

Mode-locking refers to the generation of ultrashort optical pulses in laser systems. A comprehensive study of achieving high-energy pulses in a ring cavity fiber laser that is passively mode-locked by a series of waveplates and a polarizer is presented in this paper. Specifically, it is shown that the multipulsing instability can be circumvented in favor of bifurcating to higher-energy single pulses by appropriately adjusting the group velocity dispersion in the fiber and the waveplate/polarizer settings in the saturable absorber. The findings may be used as practical guidelines for designing high-power lasers since the theoretical model relates directly to the experimental settings. PMID:22866059

Localization of genes involved in the metabolic syndrome using multivariate linkage analysis.

PubMed

Olswold, Curtis; de Andrade, Mariza

2003-12-31

There are no well accepted criteria for the diagnosis of the metabolic syndrome. However, the metabolic syndrome is identified clinically by the presence of three or more of these five variables: larger waist circumference, higher triglyceride levels, lower HDL-cholesterol concentrations, hypertension, and impaired fasting glucose. We use sets of two or three variables, which are available in the Framingham Heart Study data set, to localize genes responsible for this syndrome using multivariate quantitative linkage analysis. This analysis demonstrates the applicability of using multivariate linkage analysis and how its use increases the power to detect linkage when genes are involved in the same disease mechanism.

Thermal actuator improvements: tapering and folding

NASA Astrophysics Data System (ADS)

Sinclair, Michael J.; Wang, Kerwin

2003-04-01

Electrothermal actuation is not a popular technology for today"s MEMS transducers due to its relatively slow response and large appetite for power. The large displacement with high force and low voltage gives reason to try to improve thermal actuator"s operating characteristics. This paper describes some improvements to thermal actuators, mainly in increased output energy per actuator chip area and area utilization. The devices presented here are a variation of the chevron thermal actuator - one with two sets of thermally expanding beams pushing at a slight angle on either side of a suspended shuttle, causing it to be displaced parallel to the substrate. One improvement is to taper the thermal expansion beams so they exhibit a higher strain energy, allowing a larger thermal input power and hence more output mechanical power per beam. Another improvement is to move (fold) both sets of thermal beams to the same side of the shuttle so all are exerting force on the same side. The thermal expansion beams cause compression against the shuttle and work against one or two orthogonal cold beams in tension to produce an output force and displacement. This resembles a pseudo-bimorph array with the exception of having far fewer non-force-producing beams to bend.

Effect of Initiators on Thermal Changes in Soft Tissues Using a Diode Laser.

PubMed

Romanos, Georgios E; Sacks, Danielle; Montanaro, Nicholas; Delgado-Ruiz, Rafael; Calvo-Guirado, Jose Luis; Javed, Fawad

2018-06-15

The aim was to determine the effect of various initiators on the thermal changes that occur during incisions performed in soft tissues using a diode laser. There are no studies that have assessed the effect of various initiators on the thermal changes that occur during incisions performed in soft tissues using a diode laser. Thermal changes were observed during standardized incisions in chicken breast (without skin) via thermoelements over a 10-sec irradiation period. Incisions were created using a 975 nm diode laser with a 320 μ fiber tip diameter. Incisions (10 in each group) were performed with and without an initiator (control group). Red/blue articulating paper, cork, and SureStep ® were used as initiators. The tissue was irradiated in a continuous wave mode at 3 and 6 W in room temperature (21°C). At 3 and 6 W without any initiator, the mean temperature increased by 5.7°C versus 12.4°C, respectively. Cork initiator at 3 and 6 W resulted in temperature increase by 4.88°C versus 6.21°C, respectively. Incisions made using the blue/red articulating paper-initiated tip resulted in temperature increase by 2.9/5.8°C versus 8.2/7.6°C at 3 and 6 W power settings, respectively. Initiation with SureStep resulted in temperature increase by 2.3°C and at 6 W by 4.1°C. No significant differences were recorded between the different groups, but higher temperatures were associated with higher power settings. The power settings of the diode laser and type of initiator used, both effect the degree to which the temperature of the soft tissue increases during incisions and have to be considered for the safety in soft tissue applications.

Active and Inactive Leg Hemodynamics during Sequential Single-Leg Interval Cycling.

PubMed

Gordon, Nicole; Abbiss, Chris R; Ihsan, Mohammed; Maiorana, Andrew J; Peiffer, Jeremiah J

2018-06-01

Leg order during sequential single-leg cycling (i.e., exercising both legs independently within a single session) may affect local muscular responses potentially influencing adaptations. This study examined the cardiovascular and skeletal muscle hemodynamic responses during double-leg and sequential single-leg cycling. Ten young healthy adults (28 ± 6 yr) completed six 1-min double-leg intervals interspersed with 1 min of passive recovery and, on a separate occasion, 12 (six with one leg followed by six with the other leg) 1-min single-leg intervals interspersed with 1 min of passive recovery. Oxygen consumption, heart rate, blood pressure, muscle oxygenation, muscle blood volume, and power output were measured throughout each session. Oxygen consumption, heart rate, and power output were not different between sets of single-leg intervals, but the average of both sets was lower than the double-leg intervals. Mean arterial pressure was higher during double-leg compared with sequential single-leg intervals (115 ± 9 vs 104 ± 9 mm Hg, P < 0.05) and higher during the initial compared with second set of single-leg intervals (108 ± 10 vs 101 ± 10 mm Hg, P < 0.05). The increase in muscle blood volume from baseline was similar between the active single leg and the double leg (267 ± 150 vs 214 ± 169 μM·cm, P = 0.26). The pattern of change in muscle blood volume from the initial to second set of intervals was significantly different (P < 0.05) when the leg was active in the initial (-52.3% ± 111.6%) compared with second set (65.1% ± 152.9%). These data indicate that the order in which each leg performs sequential single-leg cycling influences the local hemodynamic responses, with the inactive muscle influencing the stimulus experienced by the contralateral leg.

A kinetic model for the synthesis of high-molecular-weight alcohols over a sulfided Co-K-Mo/C catalyst

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

Gunturu, A.K.; Kugler, E.L.; Cropley, J.B.

A statistically designed set of experiments was run in a recycle reactor to evaluate the kinetics of the formation of higher-molecular-weight alcohols (higher alcohols) and total hydrocarbon byproducts from synthesis gas (hydrogen and carbon monoxide) in a range of experimental conditions that mirrors the limits of commercial production. The alkali-promoted, C-supported Co-Mo sulfide catalyst that was employed in this study is well known for its sulfur resistance. The reaction was carried out in a gradientless Berty-type recycle reactor. A two-level fractional-factorial set consisting of 16 experiments was performed. Five independent variables were selected for this study, namely, temperature, partial pressuremore » of carbon monoxide, partial pressure of hydrogen, partial pressure of inerts, and methanol concentration in the feed. The major oxygenated products were linear alcohols up to n-butanol, but alcohols of higher carbon number were also detected, and analysis of the liquid product revealed the presence of trace amounts of ethers also. Yields of hydrocarbons were non-negligible. The alcohol product followed an Anderson-Schultz-Flory distribution. From the results of the factorial experiments, a preliminary power-law model was developed, and the statistically significant variables in the rate expression for the production of each alcohol were found. Based on the results of the power-law models, rate expressions of the Langmuir-Hinshelwood type were fitted. The observed kinetics are consistent with the rate-limiting step for the production of each higher alcohol being a surface reaction of the alcohol of next-lower carbon number. All other steps, including CO-insertion, H{sub 2}-cleavage, and hydrogenation steps, do not appear to affect the rate correlations.« less

Using a higher criticism statistic to detect modest effects in a genome-wide study of rheumatoid arthritis

PubMed Central

2009-01-01

In high-dimensional studies such as genome-wide association studies, the correction for multiple testing in order to control total type I error results in decreased power to detect modest effects. We present a new analytical approach based on the higher criticism statistic that allows identification of the presence of modest effects. We apply our method to the genome-wide study of rheumatoid arthritis provided in the Genetic Analysis Workshop 16 Problem 1 data set. There is evidence for unknown bias in this study that could be explained by the presence of undetected modest effects. We compared the asymptotic and empirical thresholds for the higher criticism statistic. Using the asymptotic threshold we detected the presence of modest effects genome-wide. We also detected modest effects using 90th percentile of the empirical null distribution as a threshold; however, there is no such evidence when the 95th and 99th percentiles were used. While the higher criticism method suggests that there is some evidence for modest effects, interpreting individual single-nucleotide polymorphisms with significant higher criticism statistics is of undermined value. The goal of higher criticism is to alert the researcher that genetic effects remain to be discovered and to promote the use of more targeted and powerful studies to detect the remaining effects. PMID:20018032

The effects of a customized over-the-counter mouth guard on neuromuscular force and power production in trained men and women.

PubMed

Dunn-Lewis, Courtenay; Luk, Hui-Ying; Comstock, Brett A; Szivak, Tunde K; Hooper, David R; Kupchak, Brian R; Watts, Ashley M; Putney, Brendan J; Hydren, Jay R; Volek, Jeff S; Denegar, Craig R; Kraemer, William J

2012-04-01

Although mouth guards were originally designed for injury prevention, even elite athletes are now using performance mouth guards to improve athletic success. Both expensive custom models and over-the-counter models are available, but the efficacy is not well known. Some athletes remain wary of the perceived potential for detriments using a mouth guard to their performance. Thus, the purpose of this study was to examine various physical performance tests when using a mouth guard including a customized over-the-counter mouth guard. Twenty-six trained men (25 ± 4 years; 1.78 ± 0.07 m; 83.3 ± 11.4 kg) and 24 trained women (23 ± 3 years; 1.65 ± 0.08 m; 62.6 ± 7.8 kg) volunteered for the investigation. The subjects completed a familiarization period and then balanced and randomized treatment conditions that included: (a) a customized Power Balance performance mouth guard (PB MG); (b) a regular over the counter boil-and-bite mouth guard (Reg MG); and (c) a no mouth guard (No MG) treatment condition. At each visit, the subjects completed a testing protocol that was sequenced in the following order: sit-and-reach flexibility, medial-lateral balance, visual reaction time, vertical jump, 10-m sprint, bench throw, and plyo press power quotient (3PQ). Heart rate and rating of perceived exertion (RPE) were recorded around the 3PQ. Significance was set at p ≤ 0.05. Expected significant sex differences existed for all power, strength, and speed variables. Bench throw power (watts) and force (newtons) were significantly higher under PB MG than either Reg MG or No MG or in both men and women. The 3PQ power and force production were higher than that for the other 2 treatments for the PB MG for men only. There were no significant differences for treatment conditions in the heart rate or RPE after the 3PQ test. Men were better able to maintain significantly higher 3PQ power production under PB MG treatment condition compared with the other 2 treatment conditions. Rate of power development was significantly higher in men for the vertical jump when using the PB MG compared with that for other treatment conditions in men only. No differences were observed in flexibility, balance, visual reaction time, or sprint time. The PB MG performance mouth guard improves performance of upper-body loaded power exercises in both men and women and lower body power exercise in men without compromising performance on any other performance parameters.

Definition of a Robust Supervisory Control Scheme for Sodium-Cooled Fast Reactors

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

Ponciroli, R.; Passerini, S.; Vilim, R. B.

In this work, an innovative control approach for metal-fueled Sodium-cooled Fast Reactors is proposed. With respect to the classical approach adopted for base-load Nuclear Power Plants, an alternative control strategy for operating the reactor at different power levels by respecting the system physical constraints is presented. In order to achieve a higher operational flexibility along with ensuring that the implemented control loops do not influence the system inherent passive safety features, a dedicated supervisory control scheme for the dynamic definition of the corresponding set-points to be supplied to the PID controllers is designed. In particular, the traditional approach based onmore » the adoption of tabulated lookup tables for the set-point definition is found not to be robust enough when failures of the implemented SISO (Single Input Single Output) actuators occur. Therefore, a feedback algorithm based on the Reference Governor approach, which allows for the optimization of reference signals according to the system operating conditions, is proposed.« less

Solder doped polycaprolactone scaffold enables reproducible laser tissue soldering.

PubMed

Bregy, Amadé; Bogni, Serge; Bernau, Vianney J P; Vajtai, Istvan; Vollbach, Felix; Petri-Fink, Alke; Constantinescu, Mihai; Hofmann, Heinrich; Frenz, Martin; Reinert, Michael

2008-12-01

In this in vitro feasibility study we analyzed tissue fusion using bovine serum albumin (BSA) and Indocyanine green (ICG) doped polycaprolactone (PCL) scaffolds in combination with a diode laser as energy source while focusing on the influence of irradiation power and albumin concentration on the resulting tensile strength and induced tissue damage. A porous PCL scaffold doped with either 25% or 40% (w/w) of BSA in combination with 0.1% (w/w) ICG was used to fuse rabbit aortas. Soldering energy was delivered through the vessel from the endoluminal side using a continuous wave diode laser at 808 nm via a 400 microm core fiber. Scaffold surface temperatures were analyzed with an infrared camera. Optimum parameters such as irradiation time, radiation power and temperature were determined in view of maximum tensile strength but simultaneously minimum thermally induced tissue damage. Differential scanning calorimetry (DSC) was performed to measure the influence of PCL on the denaturation temperature of BSA. Optimum parameter settings were found to be 60 seconds irradiation time and 1.5 W irradiation power resulting in tensile strengths of around 2,000 mN. Corresponding scaffold surface temperature was 117.4+/- 12 degrees C. Comparison of the two BSA concentration revealed that 40% BSA scaffold resulted in significant higher tensile strength compared to the 25%. At optimum parameter settings, thermal damage was restricted to the adventitia and its interface with the outermost layer of the tunica media. The DSC showed two endothermic peaks in BSA containing samples, both strongly depending on the water content and the presence of PCL and/or ICG. Diode laser soldering of vascular tissue using BSA-ICG-PCL-scaffolds leads to strong and reproducible tissue bonds, with vessel damage limited to the adventitia. Higher BSA content results in higher tensile strengths. The DSC-measurements showed that BSA denaturation temperature is lowered by addition of water and/or ICG-PCL. (c) 2008 Wiley-Liss, Inc.

Three dimensional thermal pollution models. Volume 3: Free surface models. [waste heat discharge from power plants and effects on ecosystems

NASA Technical Reports Server (NTRS)

Lee, S. S.; Sengupta, S.

1978-01-01

Two sets of programs, named Nasum 2 and Nasum 3 are presented in detail. Nasum 2 is a far field formulation and is used without including the plant thermal discharge. Nasum 3 uses horizontal stretching to provide higher resolution at thermal discharge joints; and includes far field influences such as varying tides and ambient currents far from point of discharge.

The Post-9/11 American Serviceman

DTIC Science & Technology

2010-01-01

their own unique ways. A clear majority in the military adhere to a decidedly Judeo- Christian worldview, which holds a belief in a higher power...military have with the Republican Party is a marked example of a Judeo- Christian worldview set to politics. It is an affiliation that crosses the...Battles (Princeton: Princeton University Press, 2004). 5 Sean Alfano , “Rangel Will Push to Bring Back the Draft,” November 20, 2006, available at

Methods and apparatus of analyzing electrical power grid data

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

Hafen, Ryan P.; Critchlow, Terence J.; Gibson, Tara D.

Apparatus and methods of processing large-scale data regarding an electrical power grid are described. According to one aspect, a method of processing large-scale data regarding an electrical power grid includes accessing a large-scale data set comprising information regarding an electrical power grid; processing data of the large-scale data set to identify a filter which is configured to remove erroneous data from the large-scale data set; using the filter, removing erroneous data from the large-scale data set; and after the removing, processing data of the large-scale data set to identify an event detector which is configured to identify events of interestmore » in the large-scale data set.« less

Sound Shell Model for Acoustic Gravitational Wave Production at a First-Order Phase Transition in the Early Universe.

PubMed

Hindmarsh, Mark

2018-02-16

A model for the acoustic production of gravitational waves at a first-order phase transition is presented. The source of gravitational radiation is the sound waves generated by the explosive growth of bubbles of the stable phase. The model assumes that the sound waves are linear and that their power spectrum is determined by the characteristic form of the sound shell around the expanding bubble. The predicted power spectrum has two length scales, the average bubble separation and the sound shell width when the bubbles collide. The peak of the power spectrum is at wave numbers set by the sound shell width. For a higher wave number k, the power spectrum decreases to k^{-3}. At wave numbers below the inverse bubble separation, the power spectrum goes to k^{5}. For bubble wall speeds near the speed of sound where these two length scales are distinguished, there is an intermediate k^{1} power law. The detailed dependence of the power spectrum on the wall speed and the other parameters of the phase transition raises the possibility of their constraint or measurement at a future space-based gravitational wave observatory such as LISA.

Sound Shell Model for Acoustic Gravitational Wave Production at a First-Order Phase Transition in the Early Universe

NASA Astrophysics Data System (ADS)

Hindmarsh, Mark

2018-02-01

A model for the acoustic production of gravitational waves at a first-order phase transition is presented. The source of gravitational radiation is the sound waves generated by the explosive growth of bubbles of the stable phase. The model assumes that the sound waves are linear and that their power spectrum is determined by the characteristic form of the sound shell around the expanding bubble. The predicted power spectrum has two length scales, the average bubble separation and the sound shell width when the bubbles collide. The peak of the power spectrum is at wave numbers set by the sound shell width. For a higher wave number k , the power spectrum decreases to k-3. At wave numbers below the inverse bubble separation, the power spectrum goes to k5. For bubble wall speeds near the speed of sound where these two length scales are distinguished, there is an intermediate k1 power law. The detailed dependence of the power spectrum on the wall speed and the other parameters of the phase transition raises the possibility of their constraint or measurement at a future space-based gravitational wave observatory such as LISA.

Bioaccumulation, oxidative stress and genotoxicity in fish (Channa punctatus) exposed to a thermal power plant effluent.

PubMed

Javed, Mehjbeen; Ahmad, Irshad; Usmani, Nazura; Ahmad, Masood

2016-05-01

Metal bioaccumulation and induction of biomarkers such as lipid peroxidation (LPO), superoxide dismutase (SOD), catalase (CAT), glutathione S transferase (GST), reduced glutathione (GSH) and DNA damage are potential indicators of stress in Channa punctatus exposed to effluents. In canal water, receiving thermal power plant discharges, Fe and Ni concentrations exceeded the recommended guidelines set by the United Nations Environment Programme Global Environment Monitoring System (UNEPGEMS). Fe was highly bioavailable and accumulated in all organs (liver, kidney, muscle and integument). The highest metal pollution index (MPI) value of 41.2 was observed in kidney and the lowest 13.5 in muscle tissue. LPO, SOD, CAT and GST levels were significantly higher in liver and kidney, whereas GSH levels declined significantly compared to fish from the reference site. Concomitant damage to DNA was observed with significantly higher mean tail length in the exposed fish gill cells (26.5µm) and in liver (20.8µm) compared to reference fish. Therefore, it can be concluded that the thermal power plant effluent had the potential to cause oxidative stress and DNA damage in C. punctatus. Copyright © 2016 Elsevier Inc. All rights reserved.

Thermal Response to High-Power Holmium Laser Lithotripsy.

PubMed

Aldoukhi, Ali H; Ghani, Khurshid R; Hall, Timothy L; Roberts, William W

2017-12-01

The aim of this study was to investigate "caliceal" fluid temperature changes during holmium laser activation/lithotripsy using settings up to 40 W power output with different irrigation flow rates. The experimental system consisted of a glass test tube (diameter 10 mm/length 75 mm) filled with deionized water, to mimic a calix. Real-time temperature was recorded using a thermocouple (Physitemp, NJ) positioned 5 mm from the bottom of the tube. A 200 μm laser fiber (Flexiva; Boston Scientific, MA) was introduced through the working channel of a disposable ureteroscope (LithoVue; Boston Scientific) and the laser fiber tip was positioned 15 mm above the bottom of the test tube. Deionized water irrigation (room temperature) through the working channel of the ureteroscope was delivered at flow rates of 0, 7-8, 14-15, and 38-40 mL/minute. A 120-W holmium laser (pulse 120; Lumenis, CA) was used. The following settings were explored: 0.5 J × 10 Hz, 1.0 J × 10 Hz, 0.5 J × 20 Hz, 1.0 J × 20 Hz, 0.5 J × 40 Hz, 1.0 J × 40 Hz, and 0.5 J × 80 Hz. During each experiment, the laser was activated continuously for 60 seconds. Temperature increased with increasing laser power output and decreasing irrigation flow rate. The highest temperature, 70.3°C (standard deviation 2.7), occurred with laser setting of 1.0 J × 40 Hz and no irrigation after 60 seconds of continuous laser firing. None of the tested laser settings and irrigation parameters produced temperature exceeding 51°C when activated for only 10 seconds of continuous laser firing. High-power holmium settings fired in long bursts with low irrigation flow rates can generate high fluid temperatures in a laboratory "caliceal" model. Awareness of this risk allows urologist to implement a variety of techniques (higher irrigation flow rates, intermittent laser activation, and potentially cooled irrigation fluid) to control and mitigate thermal effects during holmium laser lithotripsy.

A Power Conditioning Stage Based on Analog-Circuit MPPT Control and a Superbuck Converter for Thermoelectric Generators in Spacecraft Power Systems

NASA Astrophysics Data System (ADS)

Sun, Kai; Wu, Hongfei; Cai, Yan; Xing, Yan

2014-06-01

A thermoelectric generator (TEG) is a very important kind of power supply for spacecraft, especially for deep-space missions, due to its long lifetime and high reliability. To develop a practical TEG power supply for spacecraft, a power conditioning stage is indispensable, being employed to convert the varying output voltage of the TEG modules to a definite voltage for feeding batteries or loads. To enhance the system reliability, a power conditioning stage based on analog-circuit maximum-power-point tracking (MPPT) control and a superbuck converter is proposed in this paper. The input of this power conditioning stage is connected to the output of the TEG modules, and the output of this stage is connected to the battery and loads. The superbuck converter is employed as the main circuit, featuring low input current ripples and high conversion efficiency. Since for spacecraft power systems reliable operation is the key target for control circuits, a reset-set flip-flop-based analog circuit is used as the basic control circuit to implement MPPT, being much simpler than digital control circuits and offering higher reliability. Experiments have verified the feasibility and effectiveness of the proposed power conditioning stage. The results show the advantages of the proposed stage, such as maximum utilization of TEG power, small input ripples, and good stability.

Power Versus Affiliation in Political Ideology: Robust Linguistic Evidence for Distinct Motivation-Related Signatures.

PubMed

Fetterman, Adam K; Boyd, Ryan L; Robinson, Michael D

2015-09-01

Posited motivational differences between liberals and conservatives have historically been controversial. This motivational interface has recently been bridged, but the vast majority of studies have used self-reports of values or motivation. Instead, the present four studies investigated whether two classic social motive themes--power and affiliation--vary by political ideology in objective linguistic analysis terms. Study 1 found that posts to liberal chat rooms scored higher in standardized affiliation than power, whereas the reverse was true of posts to conservative chat rooms. Study 2 replicated this pattern in the context of materials posted to liberal versus conservative political news websites. Studies 3 and 4, finally, replicated a similar interactive (ideology by motive type) pattern in State of the State and State of the Union addresses. Differences in political ideology, these results suggest, are marked by, and likely reflective of, mind-sets favoring affiliation (liberal) or power (conservative). © 2015 by the Society for Personality and Social Psychology, Inc.

Photovoltaics for high capacity space power systems

NASA Technical Reports Server (NTRS)

Flood, Dennis J.

1988-01-01

The anticipated energy requirements of future space missions will grow by factors approaching 100 or more, particularly as a permanent manned presence is established in space. The advances that can be expected in solar array performance and lifetime, when coupled with advanced, high energy density storage batteries and/or fuel cells, will continue to make photovoltaic energy conversion a viable power generating option for the large systems of the future. The specific technologies required to satisfy any particular set of power requirements will vary from mission to mission. Nonetheless, in almost all cases the technology push will be toward lighter weight and higher efficiency, whether of solar arrays of storage devices. This paper will describe the content and direction of the current NASA program in space photovoltaic technology. The paper will also discuss projected system level capabilities of photovoltaic power systems in the context of some of the new mission opportunities under study by NASA, such as a manned lunar base, and a manned visit to Mars.

Photovoltaics for high capacity space power systems

NASA Technical Reports Server (NTRS)

Flood, Dennis J.

1988-01-01

The anticipated energy requirements of future space missions will grow by factors approaching 100 or more, particularly as a permanent manned presence is established in space. The advances that can be expected in solar array performance and lifetime, when coupled with advanced, high energy density storage batteries and/or fuel cells, will continue to make photovoltaic energy conversion a viable power generating option for the large systems of the future. The specific technologies required to satisfy any particular set of power requirements will vary from mission to mission. Nonetheless, in almost all cases the technology push will be toward lighter weight and higher efficiency, whether of solar arrays or storage devices. This paper will describe the content and direction of the current NASA program in space photovoltaic technology. The paper will also discuss projected system level capabilities of photovoltaic power systems in the context of some of the new mission opportunities under study by NASA, such as a manned lunar base, and a manned visit to Mars.

Eastern and Western Data Sets | Grid Modernization | NREL

Science.gov Websites

and Western Data Sets Eastern and Western Data Sets The Eastern Wind Integration Data Set and Western Wind Integration Data Set were designed to perform wind integration studies and estimate power production from hypothetical wind power plants in the United States. These data sets can help energy

Exploring empowerment in settings: mapping distributions of network power.

PubMed

Neal, Jennifer Watling

2014-06-01

This paper brings together two trends in the empowerment literature-understanding empowerment in settings and understanding empowerment as relational-by examining what makes settings empowering from a social network perspective. Specifically, extending Neal and Neal's (Am J Community Psychol 48(3/4):157-167, 2011) conception of network power, an empowering setting is defined as one in which (1) actors have existing relationships that allow for the exchange of resources and (2) the distribution of network power among actors in the setting is roughly equal. The paper includes a description of how researchers can examine distributions of network power in settings. Next, this process is illustrated in both an abstract example and using empirical data on early adolescents' peer relationships in urban classrooms. Finally, implications for theory, methods, and intervention related to understanding empowering settings are explored.

[Implementation results of emission standards of air pollutants for thermal power plants: a numerical simulation].

PubMed

Wang, Zhan-Shan; Pan, Li-Bo

2014-03-01

The emission inventory of air pollutants from the thermal power plants in the year of 2010 was set up. Based on the inventory, the air quality of the prediction scenarios by implementation of both 2003-version emission standard and the new emission standard were simulated using Models-3/CMAQ. The concentrations of NO2, SO2, and PM2.5, and the deposition of nitrogen and sulfur in the year of 2015 and 2020 were predicted to investigate the regional air quality improvement by the new emission standard. The results showed that the new emission standard could effectively improve the air quality in China. Compared with the implementation results of the 2003-version emission standard, by 2015 and 2020, the area with NO2 concentration higher than the emission standard would be reduced by 53.9% and 55.2%, the area with SO2 concentration higher than the emission standard would be reduced by 40.0%, the area with nitrogen deposition higher than 1.0 t x km(-2) would be reduced by 75.4% and 77.9%, and the area with sulfur deposition higher than 1.6 t x km(-2) would be reduced by 37.1% and 34.3%, respectively.

News

NASA Astrophysics Data System (ADS)

2001-05-01

LINKS WITH PRIMARY SCIENCE SAD Physics; PHYSICS RESEARCH In a hurry...; PHYSICS COMMUNITY Scottish Stirling Meeting; PHYSICS AT CONGRESS Global warming forecasts rise in skin cancer; EVENTS 2001 SET week; E-MAIL DISCUSSIONS Learning in science; STUDENT ACTIVITY Paperclip Physics; CURRICULUM DEVELOPMENT Perspectives on Science; AWARDS Award for causing chaos; PHYSICS AT CONGRESS Physics and public heath: Do electrical power lines cause cancer? HIGHER EDUCATION First-year course development; INTERSCHOOL COLLABORATION Monitoring geomagnetic storms; CURRICULUM DEVELOPMENT UK course goes international; PHYSICS IN SCIENCE YEAR Website launched

Digital Waveguide Architectures for Virtual Musical Instruments

NASA Astrophysics Data System (ADS)

Smith, Julius O.

Digital sound synthesis has become a standard staple of modern music studios, videogames, personal computers, and hand-held devices. As processing power has increased over the years, sound synthesis implementations have evolved from dedicated chip sets, to single-chip solutions, and ultimately to software implementations within processors used primarily for other tasks (such as for graphics or general purpose computing). With the cost of implementation dropping closer and closer to zero, there is increasing room for higher quality algorithms.

Develop Measures of Effectiveness and Deployment Optimization Rules for Networked Ground Micro-Sensors

DTIC Science & Technology

2001-05-01

types and total #) Ø Control of Sensors ( Scheduling ) Ø Coverage (Time & Area) Uncontrollable Inputs ØWeather Ø Atmospheric Effects Ø Equipment...are widely scattered and used to cue or wakeup other higher-level sensors. Trip line sensors consist of some combination of acoustic, seismic and...Employ a mix if different sensor types in order to increase detection probability 4.4.4.2 Minimize Battery Power • Set schedule turn on and off

Atrial fibrillation ablation: "perpetual motion" of open irrigated tip catheters at 50 W is safe and improves outcomes.

PubMed

Winkle, Roger A; Mead, R Hardwin; Engel, Gregory; Patrawala, Rob A

2011-05-01

Point-by-point use of open irrigated tip catheters (OITCs) at 50 W increases atrial fibrillation (AF) ablation cure rates but also increases complications. We determined if constantly moving the OITC (perpetual motion) when using 50 W increases ablation cure rates without increasing complications. We evaluated procedural data, complications, and individual procedure cure rates (IPCRs) for AF ablation using closed tip catheters (CTC) versus OITC at 40, 45, and 50 W in 1,122 ablations. We used "perpetual motion" to move the OITC at 50 W every 3-10 seconds. The OITC showed higher IPCR than CTC at 45 W (P = 0.012) and 50 W (P < 0.0005). For the OITC, IPCR increased from 44.6% to 60.7% as power increased from 40 to 50 W (P = 0.008). The OITC appeared superior to the CTC for all types of AF. For paroxysmal AF, increasing OITC power from 40 to 50 W provided no increase in IPCR (70.6% vs 71.2%, P = 0.827). For persistent AF, increasing power from 40 to 50 W increased IPCR from 34.5% to 59.5% (P = 0.001). Complications were similar for the CTC and the OITC at any power. The OITC at 50 W had shorter procedure, left atrial, and fluoroscopy times (P < 0.0005). Increasing OITC power from 40 to 50 W increases IPCR with no increase in complications as long as the 50 W setting is done using "perpetual motion." The OITC 50 W power setting results in shorter procedure and fluoroscopy times and should be considered for AF ablations. ©2010, The Authors. Journal compilation ©2010 Wiley Periodicals, Inc.

Improved Heat Dissipation of High-Power LED Lighting by a Lens Plate with Thermally-Conductive Plastics.

PubMed

Lee, Dong Kyu; Park, Hyun Jung; Cha, Yu-Jung; Kim, Hyeong Jin; Kwak, Joon Seop

2018-03-01

The junction temperature of high-power LED lighting was reduced effectively using a lens plate made from a thermally-conductive plastics (TCP). TCP has an excellent thermal conductivity, approximately 5 times that of polymethylmethacrylate (PMMA). Two sets of high-power LED lighting were designed using a multi array LED package with a lens plate for thermal simulation. The difference between two models was the materials of the lens plate. The lens plates of first and second models were fabricated by PMMA (PMMA lighting) and TCP (TCP lighting), respectively. At the lens plate, the simulated temperature of the TCP lighting was higher than that of the PMMA lighting. Near the LED package, the temperature of the TCP lighting was 2 °C lower than that of the PMMA lighting. This was well matched with the measured temperature of the fabricated lighting with TCP and PMMA.

Socially Isolated Mice Exhibit a Blunted Homeostatic Sleep Response to Acute Sleep Deprivation Compared to Socially Paired Mice

PubMed Central

Kaushal, Navita; Nair, Deepti; Gozal, David; Ramesh, Vijay

2012-01-01

Sleep is an important physiological process underlying maintenance of physical, mental and emotional health. Consequently, sleep deprivation (SD) is associated with adverse consequences and increases the risk for anxiety, immune, and cognitive disorders. SD is characterized by increased energy expenditure responses and sleep rebound upon recovery that are regulated by homeostatic processes, which in turn are influenced by stress. Since all previous studies on SD were conducted in a setting of social isolation, the impact of the social contextual setting is unknown. Therefore, we used a relatively stress-free SD paradigm in mice to assess the impact of social isolation on sleep, wakefulness and delta electroencephalogram (EEG) power during non-rapid eye movement (NREM) sleep. Paired or isolated C57BL/6J adult chronically-implanted male mice were exposed to SD for 6 hours and telemetric polygraphic recordings were conducted, including 18 hours recovery. Recovery from SD in the paired group showed a significant decrease in wake and significant increase in NREM sleep and rapid eye movement (REM), and a similar, albeit less robust response occurred in the isolated mice. Delta power during NREM sleep was increased in both groups immediately following SD, but paired mice exhibited significantly higher delta power throughout the dark period. The increase in body temperature and gross motor activity observed during the SD procedure was decreased during the dark period. In both open field and elevated plus maze tests, socially isolated mice showed significantly higher anxiety than paired mice. The homeostatic processes altered by SD are differentially affected in paired and isolated mice, suggesting that the social context of isolation stress may adversely affect the quantity and quality of sleep in mice. PMID:22498175

Stone Retropulsion with Ho: YAG and Tm: YAG Lasers: A Clinical Practice-Oriented Experimental Study.

PubMed

Kamal, Wissam; Kallidonis, Panagiotis; Koukiou, Georgia; Amanatides, Lefteris; Panagopoulos, Vasileios; Ntasiotis, Pantelis; Liatsikos, Evangelos

2016-11-01

To compare the retropulsion of stones with the use of holmium: yttrium aluminum garnet (Ho: YAG) laser and thulium: yttrium aluminum garnet (Tm: YAG) laser in settings that could be used in clinical practice. The experimental configuration included a glass tube set in a water bath filled with physiologic saline. Plaster of Paris stones were inserted in the tube. Tm: YAG and Ho: YAG laser systems were used along with a high-speed slow-motion camera. The lasers were activated with different settings. The displacement of the stone was measured according to a custom-made algorithm. Ho: YAG: the retropulsion of stones was the lowest with the energy setting of 0.5 J and the frequency of 20 Hz with long pulse duration. The highest retropulsion was observed in the case of 3 J, 5 Hz, and short pulse. Tm: YAG: the retropulsion of stones was the lowest with the energy setting of 1 J and the frequency of 10 Hz with either long or short pulse duration. Practically, there was no retropulsion at all. The highest retropulsion was observed in the case of 8 J, 5 Hz, and short pulse. Ho: YAG laser has a linear increase in stone retropulsion with increased pulse energy. On the other hand, the retropulsion rate was kept to the minimum with Tm: YAG as much as the energy level of 8 J. The activation of lasers with short pulse resulted in further displacement of the stone. Lower frequency with the same power setting seemed to result in further stone retropulsion. Higher power with the same frequency setting resulted in further displacement of the stone.

Change in power output across a high-repetition set of bench throws and jump squats in highly trained athletes.

PubMed

Baker, Daniel G; Newton, Robert U

2007-11-01

Athletes experienced in maximal-power and power-endurance training performed 1 set of 2 common power training exercises in an effort to determine the effects of moderately high repetitions upon power output levels throughout the set. Twenty-four and 15 athletes, respectively, performed a set of 10 repetitions in both the bench throw (BT P60) and jump squat exercise (JS P60) with a resistance of 60 kg. For both exercises, power output was highest on either the second (JS P60) or the third repetition (BT P60) and was then maintained until the fifth repetition. Significant declines in power output occurred from the sixth repetition onwards until the 10th repetition (11.2% for BT P60 and 5% for JS P60 by the 10th repetition). These findings suggest that athletes attempting to increase maximal power limit their repetitions to 2 to 5 when using resistances of 35 to 45% 1RM in these exercises.

Rolling resistance and propulsion efficiency of manual and power-assisted wheelchairs.

PubMed

Pavlidou, Efthymia; Kloosterman, Marieke G M; Buurke, Jaap H; Rietman, Johan S; Janssen, Thomas W J

2015-11-01

Rolling resistance is one of the main forces resisting wheelchair propulsion and thus affecting stress exerted on the upper limbs. The present study investigates the differences in rolling resistance, propulsion efficiency and energy expenditure required by the user during power-assisted and manual propulsion. Different tire pressures (50%, 75%, 100%) and two different levels of motor assistance were tested. Drag force, energy expenditure and propulsion efficiency were measured in 10 able-bodied individuals under different experimental settings on a treadmill. Results showed that drag force levels were significantly higher in the 50%, compared to the 75% and 100% inflation conditions. In terms of wheelchair type, the manual wheelchair displayed significantly lower drag force values than the power-assisted one. The use of extra-power-assisted wheelchair appeared to be significantly superior to conventional power-assisted and manual wheelchairs concerning both propulsion efficiency and energy expenditure required by the user. Overall, the results of the study suggest that the use of power-assisted wheelchair was more efficient and required less energy input by the user, depending on the motor assistance provided. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

Maintenance of Velocity and Power With Cluster Sets During High-Volume Back Squats.

PubMed

Tufano, James J; Conlon, Jenny A; Nimphius, Sophia; Brown, Lee E; Seitz, Laurent B; Williamson, Bryce D; Haff, G Gregory

2016-10-01

To compare the effects of a traditional set structure and 2 cluster set structures on force, velocity, and power during back squats in strength-trained men. Twelve men (25.8 ± 5.1 y, 1.74 ± 0.07 m, 79.3 ± 8.2 kg) performed 3 sets of 12 repetitions at 60% of 1-repetition maximum using 3 different set structures: traditional sets (TS), cluster sets of 4 (CS4), and cluster sets of 2 (CS2). When averaged across all repetitions, peak velocity (PV), mean velocity (MV), peak power (PP), and mean power (MP) were greater in CS2 and CS4 than in TS (P < .01), with CS2 also resulting in greater values than CS4 (P < .02). When examining individual sets within each set structure, PV, MV, PP, and MP decreased during the course of TS (effect sizes 0.28-0.99), whereas no decreases were noted during CS2 (effect sizes 0.00-0.13) or CS4 (effect sizes 0.00-0.29). These results demonstrate that CS structures maintain velocity and power, whereas TS structures do not. Furthermore, increasing the frequency of intraset rest intervals in CS structures maximizes this effect and should be used if maximal velocity is to be maintained during training.

Self-compression of spatially limited laser pulses in a system of coupled light-guides

NASA Astrophysics Data System (ADS)

Balakin, A. A.; Litvak, A. G.; Mironov, V. A.; Skobelev, S. A.

2018-04-01

The self-action features of wave packets propagating in a 2D system of equidistantly arranged fibers are studied analytically and numerically on the basis of the discrete nonlinear Schrödinger equation. Self-consistent equations for the characteristic scales of a Gaussian wave packet are derived on the basis of the variational approach, which are proved numerically for powers P < 10 P_cr , slightly exceeding the critical one for self-focusing. At higher powers, the wave beams become filamented, and their amplitude is limited due to the nonlinear breaking of the interaction between neighboring light-guides. This makes it impossible to collect a powerful wave beam in a single light-guide. Variational analysis shows the possibility of the adiabatic self-compression of soliton-like laser pulses in the process of 3D self-focusing on the central light-guide. However, further increase of the field amplitude during self-compression leads to the development of longitudinal modulation instability and the formation of a set of light bullets in the central fiber. In the regime of hollow wave beams, filamentation instability becomes predominant. As a result, it becomes possible to form a set of light bullets in optical fibers located on the ring.

A new dose of maximal-intensity interval training in hypoxia to improve body composition and hemoglobin and hematocrit levels: a pilot study.

PubMed

Camacho-Cardenosa, Marta; Camacho-Cardenosa, Alba; Martínez Guardado, Ismael; Marcos-Serrano, Marta; Timon, Rafael; Olcina, Guillermo

2017-01-01

This pilot study had the aim to determine the effects of a new dose of maximal-intensity interval training in hypoxia in active adults. Twenty-four university student volunteers were randomly assigned to three groups: hypoxia group, normoxia group or control group. The eight training sessions consisted of 2 sets of 5 repeated sprints of 10 seconds with a recovery of 20 seconds between sprints and a recovery period of 10 minutes between sets. Body composition was measured following standard procedures. A blood sample was taken for an immediate hematocrit (HCT) and hemoglobin (Hb) concentration assessment. An all-out 3-ute test was performed to evaluate ventilation parameters and power. HCT and Hb were significantly higher for the hypoxia group in Post- and Det- (P=0.01; P=0.03). Fat mass percentage was significantly lower for the hypoxia group in both assessments (P=0.05; P=0.05). The hypoxia group underwent a significant increase in mean power after the recovery period. A new dose of 8 sessions of maximal-intensity interval training in hypoxia is enough to decrease the percentage of fat mass and to improve HCT and Hb parameters and mean muscle power in healthy and active adults.

W-band PELDOR with 1 kW microwave power: molecular geometry, flexibility and exchange coupling.

PubMed

Reginsson, Gunnar W; Hunter, Robert I; Cruickshank, Paul A S; Bolton, David R; Sigurdsson, Snorri Th; Smith, Graham M; Schiemann, Olav

2012-03-01

A technique that is increasingly being used to determine the structure and conformational flexibility of biomacromolecules is Pulsed Electron-Electron Double Resonance (PELDOR or DEER), an Electron Paramagnetic Resonance (EPR) based technique. At X-band frequencies (9.5 GHz), PELDOR is capable of precisely measuring distances in the range of 1.5-8 nm between paramagnetic centres but the orientation selectivity is weak. In contrast, working at higher frequencies increases the orientation selection but usually at the expense of decreased microwave power and PELDOR modulation depth. Here it is shown that a home-built high-power pulsed W-band EPR spectrometer (HiPER) with a large instantaneous bandwidth enables one to achieve PELDOR data with a high degree of orientation selectivity and large modulation depths. We demonstrate a measurement methodology that gives a set of PELDOR time traces that yield highly constrained data sets. Simulating the resulting time traces provides a deeper insight into the conformational flexibility and exchange coupling of three bisnitroxide model systems. These measurements provide strong evidence that W-band PELDOR may prove to be an accurate and quantitative tool in assessing the relative orientations of nitroxide spin labels and to correlate those orientations to the underlying biological structure and dynamics. Copyright © 2012 Elsevier Inc. All rights reserved.

Heel and toe driving on fuel cell vehicle

DOEpatents

Choi, Tayoung; Chen, Dongmei

2012-12-11

A system and method for providing nearly instantaneous power in a fuel cell vehicle. The method includes monitoring the brake pedal angle and the accelerator pedal angle of the vehicle, and if the vehicle driver is pressing both the brake pedal and the accelerator pedal at the same time and the vehicle is in a drive gear, activating a heel and toe mode. When the heel and toe mode is activated, the speed of a cathode compressor is increased to a predetermined speed set-point, which is higher than the normal compressor speed for the pedal position. Thus, when the vehicle brake is removed, the compressor speed is high enough to provide enough air to the cathode, so that the stack can generate nearly immediate power.

Cleaning mechanism of particle contaminants on large aperture optical components by using air knife sweeping technology

NASA Astrophysics Data System (ADS)

Niu, Longfei; Liu, Hao; Miao, Xinxiang; Lv, Haibing; Yuan, Xiaodong; Zhou, Hai; Yao, Caizhen; Zhou, Guorui; Li, Qin

2017-05-01

The cleaning mechanism of optical surface particle contaminants in the light pneumatic tube was simulated based on the static equations and JKR model. Cleaning verification experiment based on air knife sweeping system and on-line monitoring system in high power laser facility was set up in order to verify the simulated results. Results showed that the removal ratio is significantly influenced by sweeping velocity and angle. The removal ratio can reach to 94.3% by using higher input pressure of the air knife, demonstrating that the air knife sweeping technology is useful for maintaining the surface cleanliness of optical elements, and thus guaranteeing the long-term stable running of the high power laser facility.

A reduced number of mtSNPs saturates mitochondrial DNA haplotype diversity of worldwide population groups.

PubMed

Salas, Antonio; Amigo, Jorge

2010-05-03

The high levels of variation characterising the mitochondrial DNA (mtDNA) molecule are due ultimately to its high average mutation rate; moreover, mtDNA variation is deeply structured in different populations and ethnic groups. There is growing interest in selecting a reduced number of mtDNA single nucleotide polymorphisms (mtSNPs) that account for the maximum level of discrimination power in a given population. Applications of the selected mtSNP panel range from anthropologic and medical studies to forensic genetic casework. This study proposes a new simulation-based method that explores the ability of different mtSNP panels to yield the maximum levels of discrimination power. The method explores subsets of mtSNPs of different sizes randomly chosen from a preselected panel of mtSNPs based on frequency. More than 2,000 complete genomes representing three main continental human population groups (Africa, Europe, and Asia) and two admixed populations ("African-Americans" and "Hispanics") were collected from GenBank and the literature, and were used as training sets. Haplotype diversity was measured for each combination of mtSNP and compared with existing mtSNP panels available in the literature. The data indicates that only a reduced number of mtSNPs ranging from six to 22 are needed to account for 95% of the maximum haplotype diversity of a given population sample. However, only a small proportion of the best mtSNPs are shared between populations, indicating that there is not a perfect set of "universal" mtSNPs suitable for all population contexts. The discrimination power provided by these mtSNPs is much higher than the power of the mtSNP panels proposed in the literature to date. Some mtSNP combinations also yield high diversity values in admixed populations. The proposed computational approach for exploring combinations of mtSNPs that optimise the discrimination power of a given set of mtSNPs is more efficient than previous empirical approaches. In contrast to precedent findings, the results seem to indicate that only few mtSNPs are needed to reach high levels of discrimination power in a population, independently of its ancestral background.

A Reduced Number of mtSNPs Saturates Mitochondrial DNA Haplotype Diversity of Worldwide Population Groups

PubMed Central

Salas, Antonio; Amigo, Jorge

2010-01-01

Background The high levels of variation characterising the mitochondrial DNA (mtDNA) molecule are due ultimately to its high average mutation rate; moreover, mtDNA variation is deeply structured in different populations and ethnic groups. There is growing interest in selecting a reduced number of mtDNA single nucleotide polymorphisms (mtSNPs) that account for the maximum level of discrimination power in a given population. Applications of the selected mtSNP panel range from anthropologic and medical studies to forensic genetic casework. Methodology/Principal Findings This study proposes a new simulation-based method that explores the ability of different mtSNP panels to yield the maximum levels of discrimination power. The method explores subsets of mtSNPs of different sizes randomly chosen from a preselected panel of mtSNPs based on frequency. More than 2,000 complete genomes representing three main continental human population groups (Africa, Europe, and Asia) and two admixed populations (“African-Americans” and “Hispanics”) were collected from GenBank and the literature, and were used as training sets. Haplotype diversity was measured for each combination of mtSNP and compared with existing mtSNP panels available in the literature. The data indicates that only a reduced number of mtSNPs ranging from six to 22 are needed to account for 95% of the maximum haplotype diversity of a given population sample. However, only a small proportion of the best mtSNPs are shared between populations, indicating that there is not a perfect set of “universal” mtSNPs suitable for all population contexts. The discrimination power provided by these mtSNPs is much higher than the power of the mtSNP panels proposed in the literature to date. Some mtSNP combinations also yield high diversity values in admixed populations. Conclusions/Significance The proposed computational approach for exploring combinations of mtSNPs that optimise the discrimination power of a given set of mtSNPs is more efficient than previous empirical approaches. In contrast to precedent findings, the results seem to indicate that only few mtSNPs are needed to reach high levels of discrimination power in a population, independently of its ancestral background. PMID:20454657

Computation and application of tissue-specific gene set weights.

PubMed

Frost, H Robert

2018-04-06

Gene set testing, or pathway analysis, has become a critical tool for the analysis of highdimensional genomic data. Although the function and activity of many genes and higher-level processes is tissue-specific, gene set testing is typically performed in a tissue agnostic fashion, which impacts statistical power and the interpretation and replication of results. To address this challenge, we have developed a bioinformatics approach to compute tissuespecific weights for individual gene sets using information on tissue-specific gene activity from the Human Protein Atlas (HPA). We used this approach to create a public repository of tissue-specific gene set weights for 37 different human tissue types from the HPA and all collections in the Molecular Signatures Database (MSigDB). To demonstrate the validity and utility of these weights, we explored three different applications: the functional characterization of human tissues, multi-tissue analysis for systemic diseases and tissue-specific gene set testing. All data used in the reported analyses is publicly available. An R implementation of the method and tissue-specific weights for MSigDB gene set collections can be downloaded at http://www.dartmouth.edu/∼hrfrost/TissueSpecificGeneSets. rob.frost@dartmouth.edu.

Traveling Wave Tube (TVT) RF Power Combining Demonstration for use in the Jupiter Icy Moons Orbiter (JIMO)

NASA Technical Reports Server (NTRS)

Downey, Joseph A.

2004-01-01

The Jupiter Icy Moons Orbiter (JIMO) is set to launch between the years 2012 and 2015. It will possibly utilize a nuclear reactor power source and ion engines as it travels to the moons of Jupiter. The nuclear reactor will produce hundreds of kilowatts of power for propulsion, communication and various scientific instruments. Hence, the RF amplification devices aboard will be able to operate at a higher power level and data rate. The initial plan for the communications system is for an output of 1000 watts of RF power, a data rate of at least 10 megabits a second, and a frequency of 32 GHz. A higher data rate would be ideal to fully utilize the instruments aboard JIMO. At NASA Glenn, one of our roles in the JIMO project is to demonstrate RF power combining using multiple traveling wave tubes (TWT). In order for the power of separate TWT s to be combined, the RF output waves from each must be in-phase and have the same amplitude. Since different tubes act differently, we had to characterize each tube using a Network Analyzer. We took frequency sweeps and power sweeps to characterize each tube to ensure that they will behave similarly under the same conditions. The 200 watt Dornier tubes had been optimized to run at a lower power level (120 watts) for their extensive use in the ACTS program, so we also had to experiment with adjusting the voltage settings on several internal components (helix, anode, collector) of the tubes to reach the full 200 watt potential. from the ACTS program. Phase shifters and power attenuators were placed in the waveguide circuit at the inputs to the tubes so that adjustments could be made individually to match them exactly. A magic tee was used to route and combine the amplified electromagnetic RF waves on the tube output side. The demonstration of 200 watts of combined power was successful with efficiencies greater than 90% over a 500 MHz bandwidth. The next step will be to demonstrate the use of three amplifiers using two magic tees by adding a 200 watt Dornier tube to the Varian and Logimetrics combined setup for a total of 400 watts. After that we will use two 200 watt Dorniers for 400 watts and eventually four 200 watt Dornier tubes to demonstrate 800 watts. After demonstrating the success of power combining, we will need to verify the integrity of a modulated signal sent through the combined tubes. The purpose will be to see what effects separating and recombining will have on the modulated signal and also what effect it will have on combining efficiency. A Bit Error Rate (BER) will be determined by a Bit Error Rate Tester (BERT) by comparing the random information it transmits to what it receives back. The process began with two 100 watt tubes, a Varian and a Logimetrics, salvaged

Intensity limits of the PSI Injector II cyclotron

NASA Astrophysics Data System (ADS)

Kolano, A.; Adelmann, A.; Barlow, R.; Baumgarten, C.

2018-03-01

We investigate limits on the current of the PSI Injector II high intensity separate-sector isochronous cyclotron, in its present configuration and after a proposed upgrade. Accelerator Driven Subcritical Reactors, neutron and neutrino experiments, and medical isotope production all benefit from increases in current, even at the ∼ 10% level: the PSI cyclotrons provide relevant experience. As space charge dominates at low beam energy, the injector is critical. Understanding space charge effects and halo formation through detailed numerical modelling gives clues on how to maximise the extracted current. Simulation of a space-charge dominated low energy high intensity (9.5 mA DC) machine, with a complex collimator set up in the central region shaping the bunch, is not trivial. We use the OPAL code, a tool for charged-particle optics calculations in large accelerator structures and beam lines, including 3D space charge. We have a precise model of the present (production) Injector II, operating at 2.2 mA current. A simple model of the proposed future (upgraded) configuration of the cyclotron is also investigated. We estimate intensity limits based on the developed models, supported by fitted scaling laws and measurements. We have been able to perform more detailed analysis of the bunch parameters and halo development than any previous study. Optimisation techniques enable better matching of the simulation set-up with Injector II parameters and measurements. We show that in the production configuration the beam current scales to the power of three with the beam size. However, at higher intensities, 4th power scaling is a better fit, setting the limit of approximately 3 mA. Currents of over 5 mA, higher than have been achieved to date, can be produced if the collimation scheme is adjusted.

Estimating initial contaminant mass based on fitting mass-depletion functions to contaminant mass discharge data: Testing method efficacy with SVE operations data

NASA Astrophysics Data System (ADS)

Mainhagu, J.; Brusseau, M. L.

2016-09-01

The mass of contaminant present at a site, particularly in the source zones, is one of the key parameters for assessing the risk posed by contaminated sites, and for setting and evaluating remediation goals and objectives. This quantity is rarely known and is challenging to estimate accurately. This work investigated the efficacy of fitting mass-depletion functions to temporal contaminant mass discharge (CMD) data as a means of estimating initial mass. Two common mass-depletion functions, exponential and power functions, were applied to historic soil vapor extraction (SVE) CMD data collected from 11 contaminated sites for which the SVE operations are considered to be at or close to essentially complete mass removal. The functions were applied to the entire available data set for each site, as well as to the early-time data (the initial 1/3 of the data available). Additionally, a complete differential-time analysis was conducted. The latter two analyses were conducted to investigate the impact of limited data on method performance, given that the primary mode of application would be to use the method during the early stages of a remediation effort. The estimated initial masses were compared to the total masses removed for the SVE operations. The mass estimates obtained from application to the full data sets were reasonably similar to the measured masses removed for both functions (13 and 15% mean error). The use of the early-time data resulted in a minimally higher variation for the exponential function (17%) but a much higher error (51%) for the power function. These results suggest that the method can produce reasonable estimates of initial mass useful for planning and assessing remediation efforts.

Mechanical Alterations Associated with Repeated Treadmill Sprinting under Heat Stress

PubMed Central

Brocherie, Franck; Morin, Jean-Benoit; Racinais, Sébastien; Millet, Grégoire P.; Périard, Julien D.

2017-01-01

Purpose Examine the mechanical alterations associated with repeated treadmill sprinting performed in HOT (38°C) and CON (25°C) conditions. Methods Eleven recreationally active males performed a 30-min warm-up followed by three sets of five 5-s sprints with 25-s recovery and 3-min between sets in each environment. Constant-velocity running for 1-min at 10 and 20 km.h-1 was also performed prior to and following sprinting. Results Mean skin (37.2±0.7 vs. 32.7±0.8°C; P<0.001) and core (38.9±0.2 vs. 38.8±0.3°C; P<0.05) temperatures, together with thermal comfort (P<0.001) were higher following repeated sprinting in HOT vs. CON. Step frequency and vertical stiffness were lower (-2.6±1.6% and -5.5±5.5%; both P<0.001) and contact time (+3.2±2.4%; P<0.01) higher in HOT for the mean of sets 1–3 compared to CON. Running distance per sprint decreased from set 1 to 3 (-7.0±6.4%; P<0.001), with a tendency for shorter distance covered in HOT vs. CON (-2.7±3.4%; P = 0.06). Mean vertical (-2.6±5.5%; P<0.01), horizontal (-9.1±4.4%; P<0.001) and resultant ground reaction forces (-3.0±2.8%; P<0.01) along with vertical stiffness (-12.9±2.3%; P<0.001) and leg stiffness (-8.4±2.7%; P<0.01) decreased from set 1 to 3, independently of conditions. Propulsive power decreased from set 1 to 3 (-16.9±2.4%; P<0.001), with lower propulsive power values in set 2 (-6.6%; P<0.05) in HOT vs. CON. No changes in constant-velocity running patterns occurred between conditions, or from pre-to-post repeated-sprint exercise. Conclusions Thermal strain alters step frequency and vertical stiffness during repeated sprinting; however without exacerbating mechanical alterations. The absence of changes in constant-velocity running patterns suggests a strong link between fatigue-induced velocity decrements during sprinting and mechanical alterations. PMID:28146582

Crouch gait can be an effective form of forced-use/no constraint exercise for the paretic lower limb in stroke.

PubMed

Tesio, Luigi; Rota, Viviana; Malloggi, Chiara; Brugliera, Luigia; Catino, Luigi

2017-09-01

In hemiplegic gait the paretic lower limb provides less muscle power and shows a briefer stance compared with the unaffected limb. Yet, a longer stance and a higher power can be obtained from the paretic lower limb if gait speed is increased. This supports the existence of a 'learned non-use' phenomenon, similar to that underlying some asymmetric impairments of the motion of the eyes and of the upper limbs. Crouch gait (CG) (bent-hip bent-knee, about 30° minimum knee flexion) might be an effective form of 'forced-use' treatment of the paretic lower limb. It is not known whether it also stimulates a more symmetric muscle power output. Gait analysis on a force treadmill was carried out in 12 healthy adults and seven hemiplegic patients (1-127 months after stroke, median: 1.6). Speed was imposed at 0.3 m/s. Step length and single and double stance times, sagittal joint rotations, peak positive power, and work in extension of the hip, knee, and ankle (plantar flexion), and surface electromyography (sEMG) area from extensor muscles during the generation of power were measured on either side during both erect and crouch walking. Significance was set at P less than 0.05; corrections for multiplicity were applied. Patients, compared with healthy controls, adopted in both gait modalities and on both sides a shorter step length (61-84%) as well as a shorter stance (76-90%) and swing (63-83%) time. As a rule, they also provided a higher muscular work (median: 137%, range: 77-250%) paralleled by a greater sEMG area (median: 174%, range: 75-185%). In erect gait, the generation of peak extensor power across hip, knee, and ankle joints was in general lower (83-90%) from the paretic limb and higher (98-165%) from the unaffected limb compared with control values. In CG, peak power generation across the three lower limb joints was invariably higher in hemiparetic patients: 107-177% from the paretic limb and 114-231% from the unaffected limb. When gait shifted from erect to crouch, only for hemiplegic patients, at the hip, the paretic/unaffected ratio increased significantly. For peak power, work, sEMG area, and joint rotation, the paretic/unaffected ratio increased from 55 to 85%, 56 to 72%, 68 to 91%, and 67 to 93%, respectively. CG appears to be an effective form of forced-use exercise eliciting more power and work from the paretic lower limb muscles sustained by a greater neural drive. It also seems effective in forcing a more symmetric power and work from the hip extensor muscles, but neither from the knee nor the ankle.

Demonstrating the Viability and Affordability of Nuclear Surface Power Systems

NASA Technical Reports Server (NTRS)

Vandyke, Melissa K.

2006-01-01

A set of tasks have been identified to help demonstrate the viability, performance, and affordability of surface fission systems. Completion of these tasks will move surface fission systems closer to reality by demonstrating affordability and performance potential. Tasks include fabrication and test of a 19-pin section of a Surface Power Unit Demonstrator (SPUD); design, fabrication, and utilization of thermal simulators optimized for surface fission' applications; design, fabrication, and utilization of GPHS module thermal simulators; design, fabrication, and test of a fission surface power system shield; and work related to potential fission surface power fuel/clad systems. Work on the SPUD will feed directly into joint NASA MSFC/NASA GRC fabrication and test of a surface power plant Engineering Development Unit (EDU). The goal of the EDU will be to perform highly realistic thermal, structural, and electrical testing on an integrated fission surface power system. Fission thermal simulator work will help enable high fidelity non-nuclear testing of pumped NaK surface fission power systems. Radioisotope thermal simulator work will help enable design and development of higher power radioisotope systems (power ultimately limited by Pu-238 availability). Shield work is designed to assess the potential of using a water neutron shield on the surface of the moon. Fuels work is geared toward assessing the current potential of using fuels that have already flown in space.

Simulation studies on Tube End Expansion of AA2014 Alloy Tubes

NASA Astrophysics Data System (ADS)

Venugopal, L.; Prasad, N. E. C.; Geeta Krishna, P.; Praveen, L.

2018-03-01

End forming is defined as forming the end of tubular forms either by inverting the tube or by expanding it. It finds application in many fields such as in automotive and aerospace sectors as power transmission elements, fuel lines, exhaust pipes etc. The main aim of the present work is to expand the AA2014 alloy tubes with different die sets without any fracture. Deform 2D software was used for performing simulations on expanding the tubes with different die set (punch) values having differed forming angles (α = 15°, 30° and 45°) and expansion ratios (rp/r0 = 1.39, 1.53 and 1.67). Experiments were also conducted and the results correlate with the simulation results. The results shows that for the punch having less cone angle (α) values the linear displacement is more rather than higher cone angles. But in the case of higher cone angles the radial displacement is more than the linear displacement.

The Effect of the Number of Sets on Power Output for Different Loads

PubMed Central

Morales-Artacho, Antonio J.; Padial, Paulino; García-Ramos, Amador; Feriche, Belén

2015-01-01

There is much debate concerning the optimal load (OL) for power training. The purpose of this study was to investigate the effect of the number of sets performed for a given load on mean power output (Pmean). Fourteen physically active men performed 3 sets of 3 bench-press repetitions with 30, 40 and 50 kg. The highest mean power value (Pmax) across all loads and Pmean were compared when data were taken from the first set at each absolute load vs. from the best of three sets performed. Pmean increased from the first to the third set (from 5.99 ± 0.81 to 6.16 ± 0.96 W·kg−1, p = 0.017), resulting in a main effect of the set number (p < 0.05). At the 30 kg load Pmean increased from the first to the third set (from 6.01 ± 0.75 to 6.35 ± 0.85 W·kg−1; p < 0.01). No significant effect was observed at 40 and 50 kg loads (p > 0.05). Pmax and velocity were significantly affected by the method employed to determine Pmean at each load (p < 0.05). These results show a positive effect of the number of sets per load on Pmean, affecting Pmax, OL and potentially power training prescription. PMID:26240658

Reliability and validity of a novel tool to comprehensively assess food and beverage marketing in recreational sport settings.

PubMed

Prowse, Rachel J L; Naylor, Patti-Jean; Olstad, Dana Lee; Carson, Valerie; Mâsse, Louise C; Storey, Kate; Kirk, Sara F L; Raine, Kim D

2018-05-31

Current methods for evaluating food marketing to children often study a single marketing channel or approach. As the World Health Organization urges the removal of unhealthy food marketing in children's settings, methods that comprehensively explore the exposure and power of food marketing within a setting from multiple marketing channels and approaches are needed. The purpose of this study was to test the inter-rater reliability and the validity of a novel settings-based food marketing audit tool. The Food and beverage Marketing Assessment Tool for Settings (FoodMATS) was developed and its psychometric properties evaluated in five public recreation and sport facilities (sites) and subsequently used in 51 sites across Canada for a cross-sectional analysis of food marketing. Raters recorded the count of food marketing occasions, presence of child-targeted and sports-related marketing techniques, and the physical size of marketing occasions. Marketing occasions were classified by healthfulness. Inter-rater reliability was tested using Cohen's kappa (κ) and intra-class correlations (ICC). FoodMATS scores for each site were calculated using an algorithm that represented the theoretical impact of the marketing environment on food preferences, purchases, and consumption. Higher FoodMATS scores represented sites with higher exposure to, and more powerful (unhealthy, child-targeted, sports-related, large) food marketing. Validity of the scoring algorithm was tested through (1) Pearson's correlations between FoodMATS scores and facility sponsorship dollars, and (2) sequential multiple regression for predicting "Least Healthy" food sales from FoodMATS scores. Inter-rater reliability was very good to excellent (κ = 0.88-1.00, p < 0.001; ICC = 0.97, p < 0.001). There was a strong positive correlation between FoodMATS scores and food sponsorship dollars, after controlling for facility size (r = 0.86, p < 0.001). The FoodMATS score explained 14% of the variability in "Least Healthy" concession sales (p = 0.012) and 24% of the variability total concession and vending "Least Healthy" food sales (p = 0.003). FoodMATS has high inter-rater reliability and good validity. As the first validated tool to evaluate the exposure and power of food marketing in recreation facilities, the FoodMATS provides a novel means to comprehensively track changes in food marketing environments that can assist in developing and monitoring the impact of policies and interventions.

Report of the x ray and gamma ray sensors panel

NASA Technical Reports Server (NTRS)

Szymkowiak, Andrew; Collins, S.; Kurfess, J.; Mahoney, W.; Mccammon, D.; Pehl, R.; Ricker, G.

1991-01-01

Overall five major areas of technology are recommended for development in order to meet the science requirements of the Astrotech 21 mission set. These are: detectors for high resolution gamma ray spectroscopy, cryogenic detectors for improved x ray spectral and spatial resolution, advanced x ray charge coupled devices (CCDs) for higher energy resolution and larger format, extension to higher energies, liquid and solid position sensitive detectors for improving stopping power in the energy range 5 to 500 keV and 0.2 to 2 MeV. Development plans designed to achieve the desired capabilities on the time scales required by the technology freeze dates have been recommended in each of these areas.

Optimal Parameter Selection for Support Vector Machine Based on Artificial Bee Colony Algorithm: A Case Study of Grid-Connected PV System Power Prediction.

PubMed

Gao, Xiang-Ming; Yang, Shi-Feng; Pan, San-Bo

2017-01-01

Predicting the output power of photovoltaic system with nonstationarity and randomness, an output power prediction model for grid-connected PV systems is proposed based on empirical mode decomposition (EMD) and support vector machine (SVM) optimized with an artificial bee colony (ABC) algorithm. First, according to the weather forecast data sets on the prediction date, the time series data of output power on a similar day with 15-minute intervals are built. Second, the time series data of the output power are decomposed into a series of components, including some intrinsic mode components IMFn and a trend component Res, at different scales using EMD. The corresponding SVM prediction model is established for each IMF component and trend component, and the SVM model parameters are optimized with the artificial bee colony algorithm. Finally, the prediction results of each model are reconstructed, and the predicted values of the output power of the grid-connected PV system can be obtained. The prediction model is tested with actual data, and the results show that the power prediction model based on the EMD and ABC-SVM has a faster calculation speed and higher prediction accuracy than do the single SVM prediction model and the EMD-SVM prediction model without optimization.

Optimal Parameter Selection for Support Vector Machine Based on Artificial Bee Colony Algorithm: A Case Study of Grid-Connected PV System Power Prediction

PubMed Central

2017-01-01

Predicting the output power of photovoltaic system with nonstationarity and randomness, an output power prediction model for grid-connected PV systems is proposed based on empirical mode decomposition (EMD) and support vector machine (SVM) optimized with an artificial bee colony (ABC) algorithm. First, according to the weather forecast data sets on the prediction date, the time series data of output power on a similar day with 15-minute intervals are built. Second, the time series data of the output power are decomposed into a series of components, including some intrinsic mode components IMFn and a trend component Res, at different scales using EMD. The corresponding SVM prediction model is established for each IMF component and trend component, and the SVM model parameters are optimized with the artificial bee colony algorithm. Finally, the prediction results of each model are reconstructed, and the predicted values of the output power of the grid-connected PV system can be obtained. The prediction model is tested with actual data, and the results show that the power prediction model based on the EMD and ABC-SVM has a faster calculation speed and higher prediction accuracy than do the single SVM prediction model and the EMD-SVM prediction model without optimization. PMID:28912803

Assessment of Gravity Wave Momentum Flux Measurement Capabilities by Meteor Radars Having Different Transmitter Power and Antenna Configurations

NASA Technical Reports Server (NTRS)

Fritts, D. C.; Janches, D.; Hocking, W. K.; Mitchell, N. J.; Taylor, M. J.

2011-01-01

Measurement capabilities of five meteor radars are assessed and compared to determine how well radars having different transmitted power and antenna configurations perform in defining mean winds, tidal amplitudes, and gravity wave (GW) momentum fluxes. The five radars include two new-generation meteor radars on Tierra del Fuego, Argentina (53.8 deg S) and on King George Island in the Antarctic (62.1 deg S) and conventional meteor radars at Socorro, New Mexico (34.1 deg N, 106.9 deg W), Bear Lake Observatory, Utah (approx 41.9 deg N, 111.4 deg W), and Yellowknife, Canada (62.5 deg N, 114.3 deg W). Our assessment employs observed meteor distributions for June of 2009, 2010, or 2011 for each radar and a set of seven test motion fields including various superpositions of mean winds, constant diurnal tides, constant and variable semidiurnal tides, and superposed GWs having various amplitudes, scales, periods, directions of propagation, momentum fluxes, and intermittencies. Radars having higher power and/or antenna patterns yielding higher meteor counts at small zenith angles perform well in defining monthly and daily mean winds, tidal amplitudes, and GW momentum fluxes, though with expected larger uncertainties in the daily estimates. Conventional radars having lower power and a single transmitting antenna are able to describe monthly mean winds and tidal amplitudes reasonably well, especially at altitudes having the highest meteor counts. They also provide qualitative estimates of GW momentum fluxes at the altitudes having the highest meteor counts; however, these estimates are subject to uncertainties of approx 20 to 50% and uncertainties rapidly become excessive at higher and lower altitudes. Estimates of all quantities degrade somewhat for more complex motion fields.

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.

Defining Simple nD Operations Based on Prosmatic nD Objects

NASA Astrophysics Data System (ADS)

Arroyo Ohori, K.; Ledoux, H.; Stoter, J.

2016-10-01

An alternative to the traditional approaches to model separately 2D/3D space, time, scale and other parametrisable characteristics in GIS lies in the higher-dimensional modelling of geographic information, in which a chosen set of non-spatial characteristics, e.g. time and scale, are modelled as extra geometric dimensions perpendicular to the spatial ones, thus creating a higher-dimensional model. While higher-dimensional models are undoubtedly powerful, they are also hard to create and manipulate due to our lack of an intuitive understanding in dimensions higher than three. As a solution to this problem, this paper proposes a methodology that makes nD object generation easier by splitting the creation and manipulation process into three steps: (i) constructing simple nD objects based on nD prismatic polytopes - analogous to prisms in 3D -, (ii) defining simple modification operations at the vertex level, and (iii) simple postprocessing to fix errors introduced in the model. As a use case, we show how two sets of operations can be defined and implemented in a dimension-independent manner using this methodology: the most common transformations (i.e. translation, scaling and rotation) and the collapse of objects. The nD objects generated in this manner can then be used as a basis for an nD GIS.

POWER Web Access Data

Atmospheric Science Data Center

2018-05-27

Description:  Obtain Prediction of Worldwide Energy Resource (POWER) data The Prediction of Worldwide Energy ... (POWER) project was initiated to improve upon the current renewable energy data set and to create new data sets from new satellite ...

The implementation and evaluation of therapeutic touch in burn patients: an instructive experience of conducting a scientific study within a non-academic nursing setting.

PubMed

Busch, Martine; Visser, Adriaan; Eybrechts, Maggie; van Komen, Rob; Oen, Irma; Olff, Miranda; Dokter, Jan; Boxma, Han

2012-12-01

Evaluation of therapeutic touch (TT) in the nursing of burn patients; post hoc evaluation of the research process in a non-academic nursing setting. 38 burn patients received either TT or nursing presence. On admission, days 2, 5 and 10 of hospitalization, data were collected on anxiety for pain, salivary cortisol, and pain medication. Interviews with nurses were held concerning research in a non-academic setting. Anxiety for pain was more reduced on day 10 in the TT-group. The TT-group was prescribed less morphine on day 1 and 2. On day 2 cortisol level before dressing changes was higher in the TT-group. The situational challenges of this study led to inconsistencies in data collection and a high patient attrition rate, weakening its statistical power. Conducting an effect study within daily nursing practice should not be done with a nursing staff inexperienced in research. Analysis of the remaining data justifies further research on TT for burn patients with pain, anxiety for pain, and cortisol levels as outcomes. Administering and evaluating TT during daily care requires nurses experienced both in TT and research, thus leading to less attrition and missing data, increasing the power of future studies. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Electric power monthly, June 1988

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

Not Available

1988-09-15

Total net generation by electric utilities in the United States for the month of June 1988 was 232,183 gigawatthours, 3 percent higher than the amount reported a year ago. Although temperatures (measured by cooling degree days) for June 1988 were 9 percent warmer than normal, they were 3 percent cooler than for June 1987. A large portion of that higher demand for electricity was met by nuclear-powered generation. Net generation from nuclear power during June 1988 (44,079 gigawatthours) was only 1 percent below the record set in January of this year, and 21 percent above that reported in June 1987more » (36,560 gigawatthours). The only energy source other than nuclear that reported higher levels of net generation during June 1988 was coal, up 2 percent over the same period last year. Warmer-than-normal temperatures did, however, have an affect on various parts of the country. For example, on Wednesday, June 22, 1988, unseasonably high temperatures forced the Pennsylvania, New Jersey, and Maryland Interconnection (PJM) into a system-wide 5-percent voltage reduction for 2 hours. Contributing to that reduction in voltage was the shutdown of the Three Mile Island, Unit 1, for refueling and the closing of the Peach Bottom Units 2 and 3 by the Nuclear Regulatory Commission. Three Mile Island, Unit 1, normally provides the PJM system with about 800 megawatts while the two Peach Bottom units, combined, provide approximately 2100 megawatts. 10 refs., 1 fig., 27 tabs.« less

Wind Integration Data Sets | Grid Modernization | NREL

Science.gov Websites

Wind Integration Data Sets Wind Integration Data Sets NREL's wind integration data sets provide the Integration Data Sets Ten-minute time-series wind data for 2004, 2005, and 2006 to help energy professionals perform wind integration studies and estimate power production from hypothetical wind power plants. Access

Quantitative structure-activity relationship modeling of rat acute toxicity by oral exposure.

PubMed

Zhu, Hao; Martin, Todd M; Ye, Lin; Sedykh, Alexander; Young, Douglas M; Tropsha, Alexander

2009-12-01

Few quantitative structure-activity relationship (QSAR) studies have successfully modeled large, diverse rodent toxicity end points. In this study, a comprehensive data set of 7385 compounds with their most conservative lethal dose (LD(50)) values has been compiled. A combinatorial QSAR approach has been employed to develop robust and predictive models of acute toxicity in rats caused by oral exposure to chemicals. To enable fair comparison between the predictive power of models generated in this study versus a commercial toxicity predictor, TOPKAT (Toxicity Prediction by Komputer Assisted Technology), a modeling subset of the entire data set was selected that included all 3472 compounds used in TOPKAT's training set. The remaining 3913 compounds, which were not present in the TOPKAT training set, were used as the external validation set. QSAR models of five different types were developed for the modeling set. The prediction accuracy for the external validation set was estimated by determination coefficient R(2) of linear regression between actual and predicted LD(50) values. The use of the applicability domain threshold implemented in most models generally improved the external prediction accuracy but expectedly led to the decrease in chemical space coverage; depending on the applicability domain threshold, R(2) ranged from 0.24 to 0.70. Ultimately, several consensus models were developed by averaging the predicted LD(50) for every compound using all five models. The consensus models afforded higher prediction accuracy for the external validation data set with the higher coverage as compared to individual constituent models. The validated consensus LD(50) models developed in this study can be used as reliable computational predictors of in vivo acute toxicity.

Optimum design on refrigeration system of high-repetition-frequency laser

NASA Astrophysics Data System (ADS)

Li, Gang; Li, Li; Jin, Yezhou; Sun, Xinhua; Mao, Shaojuan; Wang, Yuanbo

2014-12-01

A refrigeration system with fluid cycle, semiconductor cooler and air cooler is designed to solve the problems of thermal lensing effect and unstable output of high-repetition-frequency solid-state lasers. Utilizing a circulating water pump, water recycling system carries the water into laser cavity to absorb the heat then get to water cooling head. The water cooling head compacts cold spot of semiconductor cooling chips, so the heat is carried to hot spot which contacts the radiating fins, then is expelled through cooling fan. Finally, the cooled water return to tank. The above processes circulate to achieve the purposes of highly effective refrigeration in miniative solid-state lasers.The refrigeration and temperature control components are designed strictly to ensure refrigeration effect and practicability. we also set up a experiment to test the performances of this refrigeration system, the results show that the relationship between water temperature and cooling power of semiconductor cooling chip is linear at 20°C-30°C (operating temperature range of Nd:YAG), the higher of the water temperature, the higher of cooling power. According to the results, cooling power of single semiconductor cooling chip is above 60W, and the total cooling power of three semiconductor cooling chips achieves 200W that will satisfy the refrigeration require of the miniative solid-state lasers.The performance parameters of laser pulse are also tested, include pulse waveform, spectrogram and laser spot. All of that indicate that this refrigeration system can ensure the output of high-repetition-frequency pulse whit high power and stability.

Respiratory Cycle-Related Electroencephalographic Changes during Sleep in Healthy Children and in Children with Sleep Disordered Breathing

PubMed Central

Immanuel, Sarah A.; Pamula, Yvonne; Kohler, Mark; Martin, James; Kennedy, Declan; Saint, David A.; Baumert, Mathias

2014-01-01

Study Objective: To investigate respiratory cycle-related electroencephalographic changes (RCREC) in healthy children and in children with sleep disordered breathing (SDB) during scored event-free (SEF) breathing periods of sleep. Design: Interventional case-control repeated measurements design. Setting: Paediatric sleep laboratory in a hospital setting. Participants: Forty children with SDB and 40 healthy, age- and sex-matched children. Interventions: Adenotonsillectomy in children with SDB and no intervention in controls. Measurements and Results: Overnight polysomnography; electroencephalography (EEG) power variations within SEF respiratory cycles in the overall and frequency band-specific EEG within stage 2 nonrapid eye movement (NREM) sleep, slow wave sleep (SWS), and rapid eye movement (REM) sleep. Within both groups there was a decrease in EEG power during inspiration compared to expiration across all sleep stages. Compared to controls, RCREC in children with SDB in the overall EEG were significantly higher during REM and frequency band specific RCRECs were higher in the theta band of stage 2 and REM sleep, alpha band of SWS and REM sleep, and sigma band of REM sleep. This between-group difference was not significant postadenotonsillectomy. Conclusion: The presence of nonrandom respiratory cycle-related electroencephalographic changes (RCREC) in both healthy children and in children with sleep disordered breathing (SDB) during NREM and REM sleep has been demonstrated. The RCREC values were higher in children with SDB, predominantly in REM sleep and this difference reduced after adenotonsillectomy. Citation: Immanuel SA, Pamula Y, Kohler M, Martin J, Kennedy D, Saint DA, Baumert M. Respiratory cycle-related electroencephalographic changes during sleep in healthy children and in children with sleep disordered breathing. SLEEP 2014;37(8):1353-1361. PMID:25083016

POWER/SSE Web Access Data

Atmospheric Science Data Center

2018-06-25

Description:  Obtain Prediction of Worldwide Energy Resource (POWER) data The Prediction of Worldwide Energy ... (POWER) project was initiated to improve upon the current renewable energy data set and to create new data sets from new satellite ...

Association between expression of random gene sets and survival is evident in multiple cancer types and may be explained by sub-classification.

PubMed

Shimoni, Yishai

2018-02-01

One of the goals of cancer research is to identify a set of genes that cause or control disease progression. However, although multiple such gene sets were published, these are usually in very poor agreement with each other, and very few of the genes proved to be functional therapeutic targets. Furthermore, recent findings from a breast cancer gene-expression cohort showed that sets of genes selected randomly can be used to predict survival with a much higher probability than expected. These results imply that many of the genes identified in breast cancer gene expression analysis may not be causal of cancer progression, even though they can still be highly predictive of prognosis. We performed a similar analysis on all the cancer types available in the cancer genome atlas (TCGA), namely, estimating the predictive power of random gene sets for survival. Our work shows that most cancer types exhibit the property that random selections of genes are more predictive of survival than expected. In contrast to previous work, this property is not removed by using a proliferation signature, which implies that proliferation may not always be the confounder that drives this property. We suggest one possible solution in the form of data-driven sub-classification to reduce this property significantly. Our results suggest that the predictive power of random gene sets may be used to identify the existence of sub-classes in the data, and thus may allow better understanding of patient stratification. Furthermore, by reducing the observed bias this may allow more direct identification of biologically relevant, and potentially causal, genes.

Association between expression of random gene sets and survival is evident in multiple cancer types and may be explained by sub-classification

PubMed Central

2018-01-01

One of the goals of cancer research is to identify a set of genes that cause or control disease progression. However, although multiple such gene sets were published, these are usually in very poor agreement with each other, and very few of the genes proved to be functional therapeutic targets. Furthermore, recent findings from a breast cancer gene-expression cohort showed that sets of genes selected randomly can be used to predict survival with a much higher probability than expected. These results imply that many of the genes identified in breast cancer gene expression analysis may not be causal of cancer progression, even though they can still be highly predictive of prognosis. We performed a similar analysis on all the cancer types available in the cancer genome atlas (TCGA), namely, estimating the predictive power of random gene sets for survival. Our work shows that most cancer types exhibit the property that random selections of genes are more predictive of survival than expected. In contrast to previous work, this property is not removed by using a proliferation signature, which implies that proliferation may not always be the confounder that drives this property. We suggest one possible solution in the form of data-driven sub-classification to reduce this property significantly. Our results suggest that the predictive power of random gene sets may be used to identify the existence of sub-classes in the data, and thus may allow better understanding of patient stratification. Furthermore, by reducing the observed bias this may allow more direct identification of biologically relevant, and potentially causal, genes. PMID:29470520

Effects of forward motion on jet and core noise

NASA Technical Reports Server (NTRS)

Low, J. K. C.

1977-01-01

A study was conducted to investigate the effects of forward motion on both jet and core noise. Measured low-frequency noise from static-engine and from flyover tests with a DC-9-30 powered by JT8D-109 turbofan engines and with a DC-10-40 powered by JT9D-59A turbofan engines was separated into jet- and core noise components. Comparisons of the static and the corresponding in-flight jet- and core-noise components are presented. The results indicate that for the DC-9 airplane at low power settings, where core noise is predominant, the effect of convective amplification on core-noise levels is responsible for the higher in-flight low-frequency noise levels in the inlet quadrant. Similarly, it was found that for the DC-10 airplane with engines mounted under the wings and flaps and flap deflection greater than 30 degrees, the contribution from jet-flap-interaction noise is as much as 5 dB in the inlet quadrant and is responsible for higher in-flight low-frequency noise levels during approach conditions. Those results indicate that to properly investigate flight effects, it is important to consider the noise contributions from other low-frequency sources, such as the core and the jet-flap interaction.

Performance analysis and optimization of power plants with gas turbines

NASA Astrophysics Data System (ADS)

Besharati-Givi, Maryam

The gas turbine is one of the most important applications for power generation. The purpose of this research is performance analysis and optimization of power plants by using different design systems at different operation conditions. In this research, accurate efficiency calculation and finding optimum values of efficiency for design of chiller inlet cooling and blade cooled gas turbine are investigated. This research shows how it is possible to find the optimum design for different operation conditions, like ambient temperature, relative humidity, turbine inlet temperature, and compressor pressure ratio. The simulated designs include the chiller, with varied COP and fogging cooling for a compressor. In addition, the overall thermal efficiency is improved by adding some design systems like reheat and regenerative heating. The other goal of this research focuses on the blade-cooled gas turbine for higher turbine inlet temperature, and consequently, higher efficiency. New film cooling equations, along with changing film cooling effectiveness for optimum cooling air requirement at the first-stage blades, and an internal and trailing edge cooling for the second stage, are innovated for optimal efficiency calculation. This research sets the groundwork for using the optimum value of efficiency calculation, while using inlet cooling and blade cooling designs. In the final step, the designed systems in the gas cycles are combined with a steam cycle for performance improvement.

Simulation of VSPT Experimental Cascade Under High and Low Free-Stream Turbulence Conditions

NASA Technical Reports Server (NTRS)

Ameri, Ali A.; Giel, Paul W.; Flegel, Ashlie

2014-01-01

Variable-Speed Power Turbines (VSPT) for rotorcraft applications operate in conditions of low Reynolds number and a wide range in incidence resulting from rotational speed variation. A comprehensive data set obtained in a linear cascade which includes the effects of Reynolds number, free-stream turbulence and incidence is now available and this paper concerns itself with the post-diction of boundary layer transitionseparation, blade pressure loading and total pressure loss pertaining to the conditions set for measurements in that data set. The distinction between the state of the measured data presented here and the earlier publications is the addition of high free-stream turbulence intensity. We will, for the purposes of the numerical post-diction, present some of the higher free stream turbulence data in this paper but defer a comprehensive presentation and treatment of the measured data will be done elsewhere.

Solar power generation system for reducing leakage current

NASA Astrophysics Data System (ADS)

Wu, Jinn-Chang; Jou, Hurng-Liahng; Hung, Chih-Yi

2018-04-01

This paper proposes a transformer-less multi-level solar power generation system. This solar power generation system is composed of a solar cell array, a boost power converter, an isolation switch set and a full-bridge inverter. A unipolar pulse-width modulation (PWM) strategy is used in the full-bridge inverter to attenuate the output ripple current. Circuit isolation is accomplished by integrating the isolation switch set between the solar cell array and the utility, to suppress the leakage current. The isolation switch set also determines the DC bus voltage for the full-bridge inverter connecting to the solar cell array or the output of the boost power converter. Accordingly, the proposed transformer-less multi-level solar power generation system generates a five-level voltage, and the partial power of the solar cell array is also converted to AC power using only the full-bridge inverter, so the power efficiency is increased. A prototype is developed to validate the performance of the proposed transformer-less multi-level solar power generation system.

Calcium signalling indicates bilateral power balancing in the Drosophila flight muscle during manoeuvring flight

PubMed Central

Lehmann, Fritz-Olaf; Skandalis, Dimitri A.; Berthé, Ruben

2013-01-01

Manoeuvring flight in animals requires precise adjustments of mechanical power output produced by the flight musculature. In many insects such as fruit flies, power generation is most likely varied by altering stretch-activated tension, that is set by sarcoplasmic calcium levels. The muscles reside in a thoracic shell that simultaneously drives both wings during wing flapping. Using a genetically expressed muscle calcium indicator, we here demonstrate in vivo the ability of this animal to bilaterally adjust its calcium activation to the mechanical power output required to sustain aerodynamic costs during flight. Motoneuron-specific comparisons of calcium activation during lift modulation and yaw turning behaviour suggest slightly higher calcium activation for dorso-longitudinal than for dorsoventral muscle fibres, which corroborates the elevated need for muscle mechanical power during the wings’ downstroke. During turning flight, calcium activation explains only up to 54 per cent of the required changes in mechanical power, suggesting substantial power transmission between both sides of the thoracic shell. The bilateral control of muscle calcium runs counter to the hypothesis that the thorax of flies acts as a single, equally proportional source for mechanical power production for both flapping wings. Collectively, power balancing highlights the precision with which insects adjust their flight motor to changing energetic requirements during aerial steering. This potentially enhances flight efficiency and is thus of interest for the development of technical vehicles that employ bioinspired strategies of power delivery to flapping wings. PMID:23486171

Creating of structure of facts for the knowledge base of an expert system for wind power plant's equipment diagnosis

NASA Astrophysics Data System (ADS)

Duer, Stanisław; Wrzesień, Paweł; Duer, Radosław

2017-10-01

This article describes rules and conditions for making a structure (a set) of facts for an expert knowledge base of the intelligent system to diagnose Wind Power Plants' equipment. Considering particular operational conditions of a technical object, that is a set of Wind Power Plant's equipment, this is a significant issue. A structural model of Wind Power Plant's equipment is developed. Based on that, a functional - diagnostic model of Wind Power Plant's equipment is elaborated. That model is a basis for determining primary elements of the object structure, as well as for interpreting a set of diagnostic signals and their reference signals. The key content of this paper is a description of rules for building of facts on the basis of developed analytical dependence. According to facts, their dependence is described by rules for transferring of a set of pieces of diagnostic information into a specific set of facts. The article consists of four chapters that concern particular issues on the subject.

Performance and properties of the first plasmas of Wendelstein 7-X

NASA Astrophysics Data System (ADS)

Klinger, T.; Alonso, A.; Bozhenkov, S.; Burhenn, R.; Dinklage, A.; Fuchert, G.; Geiger, J.; Grulke, O.; Langenberg, A.; Hirsch, M.; Kocsis, G.; Knauer, J.; Krämer-Flecken, A.; Laqua, H.; Lazerson, S.; Landreman, M.; Maaßberg, H.; Marsen, S.; Otte, M.; Pablant, N.; Pasch, E.; Rahbarnia, K.; Stange, T.; Szepesi, T.; Thomsen, H.; Traverso, P.; Velasco, J. L.; Wauters, T.; Weir, G.; Windisch, T.; The Wendelstein 7-X Team

2017-01-01

The optimized, superconducting stellarator Wendelstein 7-X went into operation and delivered first measurement data after 15 years of construction and one year commissioning. Errors in the magnet assembly were confirmend to be small. Plasma operation was started with 5 MW electron cyclotron resonance heating (ECRH) power and five inboard limiters. Core plasma values of {{T}\\text{e}}>8 keV, {{T}\\text{i}}>2 keV at line-integrated densities n≈ 3\\centerdot {{10}19}~{{\\text{m}}-2} were achieved, exceeding the original expectations by about a factor of two. Indications for a core-electron-root were found. The energy confinement times are in line with the international stellarator scaling, despite unfavourable wall conditions, i.e. large areas of metal surfaces and particle sources from the limiter close to the plasma volume. Well controlled shorter hydrogen discharges at higher power (4 MW ECRH power for 1 s) and longer discharges at lower power (0.7 MW ECRH power for 6 s) could be routinely established after proper wall conditioning. The fairly large set of diagnostic systems running in the end of the 10 weeks operation campaign provided first insights into expected and unexpected physics of optimized stellarators.

Improved transistorized AC motor controller for battery powered urban electric passenger vehicles

NASA Technical Reports Server (NTRS)

Peak, S. C.

1982-01-01

An ac motor controller for an induction motor electric vehicle drive system was designed, fabricated, tested, evaluated, and cost analyzed. A vehicle performance analysis was done to establish the vehicle tractive effort-speed requirements. These requirements were then converted into a set of ac motor and ac controller requirements. The power inverter is a three-phase bridge using power Darlington transistors. The induction motor was optimized for use with an inverter power source. The drive system has a constant torque output to base motor speed and a constant horsepower output to maximum speed. A gear shifting transmission is not required. The ac controller was scaled from the base 20 hp (41 hp peak) at 108 volts dec to an expanded horsepower and battery voltage range. Motor reversal was accomplished by electronic reversal of the inverter phase sequence. The ac controller can also be used as a boost chopper battery charger. The drive system was tested on a dynamometer and results are presented. The current-controlled pulse width modulation control scheme yielded improved motor current waveforms. The ac controller favors a higher system voltage.

SequenceLDhot: detecting recombination hotspots.

PubMed

Fearnhead, Paul

2006-12-15

There is much local variation in recombination rates across the human genome--with the majority of recombination occurring in recombination hotspots--short regions of around approximately 2 kb in length that have much higher recombination rates than neighbouring regions. Knowledge of this local variation is important, e.g. in the design and analysis of association studies for disease genes. Population genetic data, such as that generated by the HapMap project, can be used to infer the location of these hotspots. We present a new, efficient and powerful method for detecting recombination hotspots from population data. We compare our method with four current methods for detecting hotspots. It is orders of magnitude quicker, and has greater power, than two related approaches. It appears to be more powerful than HotspotFisher, though less accurate at inferring the precise positions of the hotspot. It was also more powerful than LDhot in some situations: particularly for weaker hotspots (10-40 times the background rate) when SNP density is lower (< 1/kb). Program, data sets, and full details of results are available at: http://www.maths.lancs.ac.uk/~fearnhea/Hotspot.

Photovoltaic Hosting Capacity of Feeders with Reactive Power Control and Tap Changers

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

Ceylan, Oğuzhan; Paudyal, Sumit; Bhattarai, Bishnu P.

This paper proposes an algorithm to determine photovoltaic (PV) hosting capacity of power distribution networks as a function of number of PV injection nodes, reactive power support from the PVs, and the sub-station load tap changers (LTCs). In the proposed method, several minute by minute simulations are run based on randomly chosen PV injection nodes, daily PV output profiles, and daily load profiles from a pool of high-resolution realistic data set. The simulation setup is built using OpenDSS and MATLAB. The performance of the proposed method is investigated in the IEEE 123-node distribution feeder for multiple scenarios. The case studiesmore » are performed particularly for one, two, five and ten PV injection nodes, and looking at the maximum voltage deviations. Case studies show that the PV hosting capacity of the 123-node feeder greatly differs with the number of PV injection nodes. We have also observed that the PV hosting capacity increases with reactive power support and higher tap position of sub-station LTC.« less

Proximal fiber tip damage during Holmium:YAG and thulium fiber laser ablation of kidney stones

NASA Astrophysics Data System (ADS)

Wilson, Christopher R.; Hardy, Luke A.; Irby, Pierce B.; Fried, Nathaniel M.

2016-02-01

The Thulium fiber laser (TFL) is being studied as an alternative to Holmium:YAG laser for lithotripsy. TFL beam originates within an 18-μm-core thulium doped silica fiber, and its near single mode, Gaussian beam profile enables transmission of higher laser power through smaller fibers than possible during Holmium laser lithotripsy. This study examines whether TFL beam profile also reduces proximal fiber tip damage compared to Holmium laser multimodal beam. TFL beam at wavelength of 1908 nm was coupled into 105-μm-core silica fibers, with 35-mJ energy, 500-μs pulse duration, and pulse rates of 50-500 Hz. For each pulse rate, 500,000 pulses were delivered. Magnified images of proximal fiber surfaces were taken before and after each trial. For comparison, 20 single-use, 270-μm-core fibers were collected after clinical Holmium laser lithotripsy procedures using standard settings (600 mJ, 350 μs, 6 Hz). Total laser energy, number of laser pulses, and laser irradiation time were recorded, and fibers were rated for damage. For TFL studies, output power was stable, and no proximal fiber damage was observed after delivery of 500,000 pulses at settings up to 35 mJ, 500 Hz, and 17.5 W average power. In contrast, confocal microscopy images of fiber tips after Holmium lithotripsy showed proximal fiber tip degradation in all 20 fibers. The proximal fiber tip of a 105-μm-core fiber transmitted 17.5 W of TFL power without degradation, compared to degradation of 270-μm-core fibers after transmission of 3.6 W of Holmium laser power. The smaller and more uniform TFL beam profile may improve fiber lifetime, and potentially reduce costs for the surgical disposables as well.

Analysis of Power Laws, Shape Collapses, and Neural Complexity: New Techniques and MATLAB Support via the NCC Toolbox

PubMed Central

Marshall, Najja; Timme, Nicholas M.; Bennett, Nicholas; Ripp, Monica; Lautzenhiser, Edward; Beggs, John M.

2016-01-01

Neural systems include interactions that occur across many scales. Two divergent methods for characterizing such interactions have drawn on the physical analysis of critical phenomena and the mathematical study of information. Inferring criticality in neural systems has traditionally rested on fitting power laws to the property distributions of “neural avalanches” (contiguous bursts of activity), but the fractal nature of avalanche shapes has recently emerged as another signature of criticality. On the other hand, neural complexity, an information theoretic measure, has been used to capture the interplay between the functional localization of brain regions and their integration for higher cognitive functions. Unfortunately, treatments of all three methods—power-law fitting, avalanche shape collapse, and neural complexity—have suffered from shortcomings. Empirical data often contain biases that introduce deviations from true power law in the tail and head of the distribution, but deviations in the tail have often been unconsidered; avalanche shape collapse has required manual parameter tuning; and the estimation of neural complexity has relied on small data sets or statistical assumptions for the sake of computational efficiency. In this paper we present technical advancements in the analysis of criticality and complexity in neural systems. We use maximum-likelihood estimation to automatically fit power laws with left and right cutoffs, present the first automated shape collapse algorithm, and describe new techniques to account for large numbers of neural variables and small data sets in the calculation of neural complexity. In order to facilitate future research in criticality and complexity, we have made the software utilized in this analysis freely available online in the MATLAB NCC (Neural Complexity and Criticality) Toolbox. PMID:27445842

Analysis of Power Laws, Shape Collapses, and Neural Complexity: New Techniques and MATLAB Support via the NCC Toolbox.

PubMed

Marshall, Najja; Timme, Nicholas M; Bennett, Nicholas; Ripp, Monica; Lautzenhiser, Edward; Beggs, John M

2016-01-01

Neural systems include interactions that occur across many scales. Two divergent methods for characterizing such interactions have drawn on the physical analysis of critical phenomena and the mathematical study of information. Inferring criticality in neural systems has traditionally rested on fitting power laws to the property distributions of "neural avalanches" (contiguous bursts of activity), but the fractal nature of avalanche shapes has recently emerged as another signature of criticality. On the other hand, neural complexity, an information theoretic measure, has been used to capture the interplay between the functional localization of brain regions and their integration for higher cognitive functions. Unfortunately, treatments of all three methods-power-law fitting, avalanche shape collapse, and neural complexity-have suffered from shortcomings. Empirical data often contain biases that introduce deviations from true power law in the tail and head of the distribution, but deviations in the tail have often been unconsidered; avalanche shape collapse has required manual parameter tuning; and the estimation of neural complexity has relied on small data sets or statistical assumptions for the sake of computational efficiency. In this paper we present technical advancements in the analysis of criticality and complexity in neural systems. We use maximum-likelihood estimation to automatically fit power laws with left and right cutoffs, present the first automated shape collapse algorithm, and describe new techniques to account for large numbers of neural variables and small data sets in the calculation of neural complexity. In order to facilitate future research in criticality and complexity, we have made the software utilized in this analysis freely available online in the MATLAB NCC (Neural Complexity and Criticality) Toolbox.

Spacecraft computer technology at Southwest Research Institute

NASA Technical Reports Server (NTRS)

Shirley, D. J.

1993-01-01

Southwest Research Institute (SwRI) has developed and delivered spacecraft computers for a number of different near-Earth-orbit spacecraft including shuttle experiments and SDIO free-flyer experiments. We describe the evolution of the basic SwRI spacecraft computer design from those weighing in at 20 to 25 lb and using 20 to 30 W to newer models weighing less than 5 lb and using only about 5 W, yet delivering twice the processing throughput. Because of their reduced size, weight, and power, these newer designs are especially applicable to planetary instrument requirements. The basis of our design evolution has been the availability of more powerful processor chip sets and the development of higher density packaging technology, coupled with more aggressive design strategies in incorporating high-density FPGA technology and use of high-density memory chips. In addition to reductions in size, weight, and power, the newer designs also address the necessity of survival in the harsh radiation environment of space. Spurred by participation in such programs as MSTI, LACE, RME, Delta 181, Delta Star, and RADARSAT, our designs have evolved in response to program demands to be small, low-powered units, radiation tolerant enough to be suitable for both Earth-orbit microsats and for planetary instruments. Present designs already include MIL-STD-1750 and Multi-Chip Module (MCM) technology with near-term plans to include RISC processors and higher-density MCM's. Long term plans include development of whole-core processors on one or two MCM's.

Histologic evaluation of laser lipolysis: pulsed 1064-nm Nd:YAG laser versus cw 980-nm diode laser.

PubMed

Mordon, Serge; Eymard-Maurin, Anne Françoise; Wassmer, Benjamin; Ringot, Jean

2007-01-01

The use of the laser as an auxiliary tool has refined the traditional technique for lipoplasty. During laser lipolysis, the interaction between the laser and the fat produced direct cellular destruction before the suction, reduced bleeding, and promoted skin tightening. This study sought to perform a comparative histologic evaluation of laser lipolysis with the pulsed 1064-nm Nd:YAG laser versus a continuous 980-nm diode laser. A pulsed 1064-nm Nd:YAG (Smart-Lipo; Deka, Italy) and a CW 980-nm diode laser (Pharaon, Osyris, France) were evaluated at different energy settings for lipolysis on the thighs of a fresh cadaver. The lasers were coupled to a 600-microm optical fiber inserted in a 1-mm diameter cannula. Biopsy specimens were taken on irradiated and non-irradiated areas. Hematoxylin-erythrosin-safran staining and immunostaining (anti-PS100 polyclonal antibody) were performed to identify fat tissue damage. In the absence of laser exposures (control specimens), cavities created by cannulation were seen; adipocytes were round in appearance and not deflated. At low energy settings, tumescent adipocytes were observed. At higher energy settings, cytoplasmic retraction, disruption of membranes, and heat-coagulated collagen fibers were noted; coagulated blood cells were also present. For the highest energy settings, carbonization of fat tissue involving fibers and membranes was clearly seen. For equivalent energy settings, 1064-nm and 980-nm wavelengths gave similar histologic results. Laser lipolysis is a relatively new technique that is still under development. Our histologic findings suggest several positive benefits of the laser, including skin retraction and a reduction in intraoperative bleeding. The interaction of the laser with the tissue is similar at 980 nm and 1064 nm with the same energy settings. Because higher volumes of fat are removed with higher total energy, a high-power 980-nm diode laser could offer an interesting alternative to the 1064-nm Nd:YAG laser.

Largest Ever Wind Power Commitments Sets Clean Energy Example for Nation

Science.gov Websites

'Largest Ever' Wind Power Commitments Sets Clean Energy Example for Nation NEWS MEDIA CONTACTS ;Federal agencies in Colorado are setting an example for the rest of the nation and the leaders of business

Microwave-enhanced persulfate oxidation to treat mature landfill leachate.

PubMed

Chou, Yu-Chieh; Lo, Shang-Lien; Kuo, Jeff; Yeh, Chih-Jung

2015-03-02

Microwave oxidation process (MOP) was evaluated for treatment of landfill leachate. Kinetics of persulfate oxidation in MOP, effects of pH and persulfate doses on fates of derivative organic acids, and the energy cost of MOP were evaluated. The results showed that total organic carbon (TOC) removal of 79.4%, color removal of 88.4%, and UV254 removal of 77.1% were reached at MOP 550 W/85 °C within 30 min. The kinetics of oxidation by MOP followed the first-order reaction. For a given persulfate dose, the reaction rate increased with the microwave power setting (775 W>550 W>325 W>128 W) with reaction rate constants ranging from 10(-5) to 10(-2) min(-1). The adverse effects on reaction rates under higher microwave power settings and high persulfate doses are plausibly caused by excessive persulfate oxidation and self-scavenging termination of free radicals. During the MOP treatment, TOC/COD ratio dropped with time and an 86.7% reduction in TOC/COD ratio after 120 min at pH 7. Oxalic acid was the major derivative and its concentrations were higher under acidic conditions. Malic, lactic, and acetic acids were formed and soon degraded, and the solution pH has an insignificant effect on their fates. The energy cost of MOP (USD$6.03/m(3)) is essentially similar to that of conventional heating oxidation (CHO) (USD$6.10/m(3)). Published by Elsevier B.V.

Flow structure in continuous flow electrophoresis chambers

NASA Technical Reports Server (NTRS)

Deiber, J. A.; Saville, D. A.

1982-01-01

There are at least two ways that hydrodynamic processes can limit continiuous flow electrophoresis. One arises from the sensitivity of the flow to small temerature gradients, especially at low flow rates and power levels. This sensitivity can be suppressed, at least in principle, by providing a carefully tailored, stabilizing temperature gradient in the cooling system that surrounds the flow channel. At higher power levels another limitation arises due to a restructuring of the main flow. This restructuring is caused by buoyancy, which is in turn affected by the electro-osmotic crossflow. Approximate solutions to appropriate partial differential equations have been computed by finite difference methods. One set of results is described here to illustrate the strong coupling between the structure of the main (axial) flow and the electro-osmotic flow.

Energy characterisation of ultrasonic systems for industrial processes.

PubMed

Al-Juboori, Raed A; Yusaf, Talal; Bowtell, Leslie; Aravinthan, Vasantha

2015-03-01

Obtaining accurate power characteristics of ultrasonic treatment systems is an important step towards their industrial scalability. Calorimetric measurements are most commonly used for quantifying the dissipated ultrasonic power. However, accuracy of these measurements is affected by various heat losses, especially when working at high power densities. In this work, electrical power measurements were conducted at all locations in the piezoelectric ultrasonic system equipped with ½″ and ¾″ probes. A set of heat transfer calculations were developed to estimate the convection heat losses from the reaction solution. Chemical dosimeters represented by the oxidation of potassium iodide, Fricke solution and 4-nitrophenol were used to chemically correlate the effect of various electrical amplitudes and treatment regimes. This allowed estimation of sonochemical-efficiency (SE) and energy conversion (XUS) of the ultrasonic system. Results of this study showed overall conversion efficiencies of 60-70%. This correlated well with the chemical dosimeter yield curves of both organic and inorganic aqueous solutions. All dosimeters showed bubble shielding and coalescence effects at higher ultrasonic power levels, less pronounced for the ½″ probe case. SE and XUS values in the range of 10(-10) mol/J and 10(-3) J/J respectively confirmed that conversion of ultrasonic power to chemical yield declined with amplitude. Copyright © 2014 Elsevier B.V. All rights reserved.

Epidemiology of Medicare Abuse: The Example of Power Wheelchairs R2

PubMed Central

Goodwin, James S.; Nguyen-Oghalai, Tracy U.; Kuo, Yong-Fang; Ottenbacher, Kenneth J.

2007-01-01

Background Press reports and government investigations have uncovered widespread abuse in power wheelchair prescriptions reimbursed by Medicare, with specific targeting of minority neighborhoods for aggressive marketing. Objective We sought to determine the impact of neighborhood ethnic composition on power wheelchair prescriptions. Design The 5% non-cancer sample of Medicare recipients in the Surveillance, Epidemiology and End Results (SEER)-Medicare linked database, from 1994–2001 Setting SEER regions Participants Individuals covered by Medicare living in SEER regions without a cancer diagnosis Measurements Individual characteristics (age, gender, ethnicity, justifying diagnosis, and comorbidity), primary diagnoses, neighborhood characteristics (% black, % Hispanic, % with <12 years education and median income) and SEER region Results The rate of power wheelchair prescriptions increased 33 fold from 1994 to 2001, with a shift over time from justifying diagnoses more closely tied to mobility impairment, such as strokes, to less specific medical diagnoses, such as osteoarthritis. In multilevel, multivariate analyses, individuals living in neighborhoods with higher percentages of blacks or Hispanics were more likely to receive power wheelchairs (OR= 1.09 for each 10% increase in black residents and 1.23 for each 10% increase in Hispanic residents), after controlling for ethnicity and other characteristics at the individual level. Conclusion These results support allegations that minority neighborhoods have been specifically targeted by marketers promoting power wheelchairs. PMID:17302658

High Efficiency Microwave Power Amplifier: From the Lab to Industry

NASA Technical Reports Server (NTRS)

Sims, William Herbert, III; Bell, Joseph L. (Technical Monitor)

2001-01-01

Since the beginnings of space travel, various microwave power amplifier designs have been employed. These included Class-A, -B, and -C bias arrangements. However, shared limitation of these topologies is the inherent high total consumption of input power associated with the generation of radio frequency (RF)/microwave power. The power amplifier has always been the largest drain for the limited available power on the spacecraft. Typically, the conversion efficiency of a microwave power amplifier is 10 to 20%. For a typical microwave power amplifier of 20 watts, input DC power of at least 100 watts is required. Such a large demand for input power suggests that a better method of RF/microwave power generation is required. The price paid for using a linear amplifier where high linearity is unnecessary includes higher initial and operating costs, lower DC-to-RF conversion efficiency, high power consumption, higher power dissipation and the accompanying need for higher capacity heat removal means, and an amplifier that is more prone to parasitic oscillation. The first use of a higher efficiency mode of power generation was described by Baxandall in 1959. This higher efficiency mode, Class-D, is achieved through distinct switching techniques to reduce the power losses associated with switching, conduction, and gate drive losses of a given transistor.

Optimization of the generator settings for endobiliary radiofrequency ablation.

PubMed

Barret, Maximilien; Leblanc, Sarah; Vienne, Ariane; Rouquette, Alexandre; Beuvon, Frederic; Chaussade, Stanislas; Prat, Frederic

2015-11-10

To determine the optimal generator settings for endobiliary radiofrequency ablation. Endobiliary radiofrequency ablation was performed in live swine on the ampulla of Vater, the common bile duct and in the hepatic parenchyma. Radiofrequency ablation time, "effect", and power were allowed to vary. The animals were sacrificed two hours after the procedure. Histopathological assessment of the depth of the thermal lesions was performed. Twenty-five radiofrequency bursts were applied in three swine. In the ampulla of Vater (n = 3), necrosis of the duodenal wall was observed starting with an effect set at 8, power output set at 10 W, and a 30 s shot duration, whereas superficial mucosal damage of up to 350 μm in depth was recorded for an effect set at 8, power output set at 6 W and a 30 s shot duration. In the common bile duct (n = 4), a 1070 μm, safe and efficient ablation was obtained for an effect set at 8, a power output of 8 W, and an ablation time of 30 s. Within the hepatic parenchyma (n = 18), the depth of tissue damage varied from 1620 μm (effect = 8, power = 10 W, ablation time = 15 s) to 4480 μm (effect = 8, power = 8 W, ablation time = 90 s). The duration of the catheter application appeared to be the most important parameter influencing the depth of the thermal injury during endobiliary radiofrequency ablation. In healthy swine, the currently recommended settings of the generator may induce severe, supratherapeutic tissue damage in the biliary tree, especially in the high-risk area of the ampulla of Vater.

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

Potts, C.; Faber, M.; Gunderson, G.

The as-built lattice of the Rapid-Cycling Synchrotron (RCS) had two sets of correction sextupoles and two sets of quadrupoles energized by dc power supplies to control the tune and the tune tilt. With this method of powering these magnets, adjustment of tune conditions during the accelerating cycle as needed was not possible. A set of dynamically programmable power supplies has been built and operated to provide the required chromaticity adjustment. The short accelerating time (16.7 ms) of the RCS and the inductance of the magnets dictated large transistor amplifier power supplies. The required time resolution and waveform flexibility indicated themore » desirability of computer control. Both the amplifiers and controls are described, along with resulting improvements in the beam performance. A set of octupole magnets and programmable power supplies with similar dynamic qualities have been constructed and installed to control the anticipated high-intensity transverse instability. This system will be operational in the spring of 1981.« less

Multicore Programming Challenges

NASA Astrophysics Data System (ADS)

Perrone, Michael

The computer industry is facing fundamental challenges that are driving a major change in the design of computer processors. Due to restrictions imposed by quantum physics, one historical path to higher computer processor performance - by increased clock frequency - has come to an end. Increasing clock frequency now leads to power consumption costs that are too high to justify. As a result, we have seen in recent years that the processor frequencies have peaked and are receding from their high point. At the same time, competitive market conditions are giving business advantage to those companies that can field new streaming applications, handle larger data sets, and update their models to market conditions faster. The desire for newer, faster and larger is driving continued demand for higher computer performance.

Development and validation of a shared decision-making instrument for health-related quality of life one year after total hip replacement based on quality registries data.

PubMed

Nemes, Szilard; Rolfson, Ola; Garellick, Göran

2018-02-01

Clinicians considering improvements in health-related quality of life (HRQoL) after total hip replacement (THR) must account for multiple pieces of information. Evidence-based decisions are important to best assess the effect of THR on HRQoL. This work aims at constructing a shared decision-making tool that helps clinicians assessing the future benefits of THR by offering predictions of 1-year postoperative HRQoL of THR patients. We used data from the Swedish Hip Arthroplasty Register. Data from 2008 were used as training set and data from 2009 to 2012 as validation set. We adopted two approaches. First, we assumed a continuous distribution for the EQ-5D index and modelled the postoperative EQ-5D index with regression models. Second, we modelled the five dimensions of the EQ-5D and weighted together the predictions using the UK Time Trade-Off value set. As predictors, we used preoperative EQ-5D dimensions and the EQ-5D index, EQ visual analogue scale, visual analogue scale pain, Charnley classification, age, gender, body mass index, American Society of Anesthesiologists, surgical approach and prosthesis type. Additionally, the tested algorithms were combined in a single predictive tool by stacking. Best predictive power was obtained by the multivariate adaptive regression splines (R 2  = 0.158). However, this was not significantly better than the predictive power of linear regressions (R 2  = 0.157). The stacked model had a predictive power of 17%. Successful implementation of a shared decision-making tool that can aid clinicians and patients in understanding expected improvement in HRQoL following THR would require higher predictive power than we achieved. For a shared decision-making tool to succeed, further variables, such as socioeconomics, need to be considered. © 2016 John Wiley & Sons, Ltd.

Reduced model simulations of the scrape-off-layer heat-flux width and comparison with experiment

DOE PAGES

Myra, J. R.; Russell, D. A.; D’Ippolito, D. A.; ...

2011-01-01

Reduced model simulations of turbulence in the edge and scrape-off-layer (SOL) region of a spherical torus or tokamak plasma are employed to address the physics of the scrape-off-layer heat flux width. The simulation model is an electrostatic two-dimensional fluid turbulence model, applied in the plane perpendicular to the magnetic field at the outboard midplane of the torus. The model contains curvature-driven-interchange modes, sheath losses, and both perpendicular turbulent diffusive and convective (blob) transport. These transport processes compete with classical parallel transport to set the SOL width. Midplane SOL profiles of density, temperature and parallel heat flux are obtained from themore » simulation and compared with experimental results from the National Spherical Torus Experiment (NSTX) to study the scaling of the heat flux width with power and plasma current. It is concluded that midplane turbulence is the main contributor to the SOL heat flux width for the low power H-mode discharges studied, while additional physics is required to explain the plasma current scaling of the SOL heat flux width observed experimentally in higher power discharges. Intermittent separatrix spanning convective cells are found to be the main mechanism that sets the near-SOL width in the simulations. The roles of sheared flows and blob trapping vs. emission are discussed.« less

On the Performance Evaluation of a MIMO-WCDMA Transmission Architecture for Building Management Systems.

PubMed

Tsampasis, Eleftherios; Gkonis, Panagiotis K; Trakadas, Panagiotis; Zahariadis, Theodοre

2018-01-08

The goal of this study was to investigate the performance of a realistic wireless sensor nodes deployment in order to support modern building management systems (BMSs). A three-floor building orientation is taken into account, where each node is equipped with a multi-antenna system while a central base station (BS) collects and processes all received information. The BS is also equipped with multiple antennas; hence, a multiple input-multiple output (MIMO) system is formulated. Due to the multiple reflections during transmission in the inner of the building, a wideband code division multiple access (WCDMA) physical layer protocol has been considered, which has already been adopted for third-generation (3G) mobile networks. Results are presented for various MIMO orientations, where the mean transmission power per node is considered as an output metric for a specific signal-to-noise ratio (SNR) requirement and number of resolvable multipath components. In the first set of presented results, the effects of multiple access interference on overall transmission power are highlighted. As the number of mobile nodes per floor or the requested transmission rate increases, MIMO systems of a higher order should be deployed in order to maintain transmission power at adequate levels. In the second set of results, a comparison is performed among transmission in diversity combining and spatial multiplexing mode, which clearly indicate that the first case is the most appropriate solution for indoor communications.

Improving accuracy and power with transfer learning using a meta-analytic database.

PubMed

Schwartz, Yannick; Varoquaux, Gaël; Pallier, Christophe; Pinel, Philippe; Poline, Jean-Baptiste; Thirion, Bertrand

2012-01-01

Typical cohorts in brain imaging studies are not large enough for systematic testing of all the information contained in the images. To build testable working hypotheses, investigators thus rely on analysis of previous work, sometimes formalized in a so-called meta-analysis. In brain imaging, this approach underlies the specification of regions of interest (ROIs) that are usually selected on the basis of the coordinates of previously detected effects. In this paper, we propose to use a database of images, rather than coordinates, and frame the problem as transfer learning: learning a discriminant model on a reference task to apply it to a different but related new task. To facilitate statistical analysis of small cohorts, we use a sparse discriminant model that selects predictive voxels on the reference task and thus provides a principled procedure to define ROIs. The benefits of our approach are twofold. First it uses the reference database for prediction, i.e., to provide potential biomarkers in a clinical setting. Second it increases statistical power on the new task. We demonstrate on a set of 18 pairs of functional MRI experimental conditions that our approach gives good prediction. In addition, on a specific transfer situation involving different scanners at different locations, we show that voxel selection based on transfer learning leads to higher detection power on small cohorts.

Remote hybrid power systems

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

Barley, C.D.; Winn, C.B.

1997-12-31

This paper provides an overview of the emerging technology of remote, stand-alone electrical power systems featuring a renewable source (wind or photovoltaics [PV]) as well as a diesel generator, with or without an energy storage device. Other stand-alone power systems are discussed briefly, mainly to emphasize the domain of hybrid systems. The history of hybrid systems is reviewed, beginning with the first wind/diesel system in the late 1970s. Other topics include issues arising from the characteristics of diesel engine/generator sets; simple vs. complex systems; the various energy storage technologies that have been used or proposed; control strategies; modeling; optimization; andmore » some {open_quotes}nuts & bolts{close_quotes} details. The bibliography includes over 130 references which are cited throughout the topical discussions. It is concluded that the technical feasibility of hybrid systems has been demonstrated through many prototype installations, and that areas for further improvements include higher reliability and more economical energy storage devices. 139 refs., 7 figs., 1 tab.« less

Power laws in citation distributions: evidence from Scopus.

PubMed

Brzezinski, Michal

Modeling distributions of citations to scientific papers is crucial for understanding how science develops. However, there is a considerable empirical controversy on which statistical model fits the citation distributions best. This paper is concerned with rigorous empirical detection of power-law behaviour in the distribution of citations received by the most highly cited scientific papers. We have used a large, novel data set on citations to scientific papers published between 1998 and 2002 drawn from Scopus. The power-law model is compared with a number of alternative models using a likelihood ratio test. We have found that the power-law hypothesis is rejected for around half of the Scopus fields of science. For these fields of science, the Yule, power-law with exponential cut-off and log-normal distributions seem to fit the data better than the pure power-law model. On the other hand, when the power-law hypothesis is not rejected, it is usually empirically indistinguishable from most of the alternative models. The pure power-law model seems to be the best model only for the most highly cited papers in "Physics and Astronomy". Overall, our results seem to support theories implying that the most highly cited scientific papers follow the Yule, power-law with exponential cut-off or log-normal distribution. Our findings suggest also that power laws in citation distributions, when present, account only for a very small fraction of the published papers (less than 1 % for most of science fields) and that the power-law scaling parameter (exponent) is substantially higher (from around 3.2 to around 4.7) than found in the older literature.

Persistence in the WFC3 IR Detector: Intrinsic Variability

NASA Astrophysics Data System (ADS)

Long, Knox S.; Baggett, Sylvia M.

2018-03-01

When the WFC3 IR detector is exposed to a bright source or sources, the sources can appear as afterimages in subsequent exposures, a phenomenon known as persistence. This can affect the science obtained with the IR channel. We have been involved in an effort to predict the brightness of the afterimages so that users can (at a minimum) flag the affected pixels and remove them from their analysis or (even better) subtract the afterimages from their science images to salvage the data. The ability of any model to remove afterimages depends on the degree to which persistence is the same for identical sets of exposures. We investigate possible time variability of persistence in the WFC3 detector using sets of (almost) identical visits comprised of single exposures of Omega Cen followed by a series of darks in which persistence is measured. We analyze 8 data sets, each consisting of two or three identical visits, with stimulus exposures between 49 and 1199 s, and find clear evidence of variability in several of the datasets in darks taken within 1000 s of the stimulus exposure. In most of the datasets, the difference in persistence for saturated pixels in the stimulus exposure is < 0.01 e-/s for darks taken 1000 s after the initial exposure. One of three 274-second visits has significantly more persistence than its two identical visits. Persistence in this visit was higher in all 4 detector quadrants. The persistence in all three visits is well modeled as a power law decay; the visit with higher persistence has a higher power law amplitude. There was nothing unusual about the observing conditions preceding and during each of these visits that can explain the discrepancy in persistence levels. Variation in persistence implies that: (1) Unless and until the source of the variability is understood, any persistence model for the WFC3 array will be limited in its ability to predict persistence in a single observation, and, (2) as a consequence, users should always carefully inspect the results of any attempt to subtract persistence from WFC3 IR data based on a model prediction.

Crouch gait can be an effective form of forced-use/no constraint exercise for the paretic lower limb in stroke

PubMed Central

Rota, Viviana; Malloggi, Chiara; Brugliera, Luigia; Catino, Luigi

2017-01-01

In hemiplegic gait the paretic lower limb provides less muscle power and shows a briefer stance compared with the unaffected limb. Yet, a longer stance and a higher power can be obtained from the paretic lower limb if gait speed is increased. This supports the existence of a ‘learned non-use’ phenomenon, similar to that underlying some asymmetric impairments of the motion of the eyes and of the upper limbs. Crouch gait (CG) (bent-hip bent-knee, about 30° minimum knee flexion) might be an effective form of ‘forced-use’ treatment of the paretic lower limb. It is not known whether it also stimulates a more symmetric muscle power output. Gait analysis on a force treadmill was carried out in 12 healthy adults and seven hemiplegic patients (1–127 months after stroke, median: 1.6). Speed was imposed at 0.3 m/s. Step length and single and double stance times, sagittal joint rotations, peak positive power, and work in extension of the hip, knee, and ankle (plantar flexion), and surface electromyography (sEMG) area from extensor muscles during the generation of power were measured on either side during both erect and crouch walking. Significance was set at P less than 0.05; corrections for multiplicity were applied. Patients, compared with healthy controls, adopted in both gait modalities and on both sides a shorter step length (61–84%) as well as a shorter stance (76–90%) and swing (63–83%) time. As a rule, they also provided a higher muscular work (median: 137%, range: 77–250%) paralleled by a greater sEMG area (median: 174%, range: 75–185%). In erect gait, the generation of peak extensor power across hip, knee, and ankle joints was in general lower (83–90%) from the paretic limb and higher (98–165%) from the unaffected limb compared with control values. In CG, peak power generation across the three lower limb joints was invariably higher in hemiparetic patients: 107–177% from the paretic limb and 114–231% from the unaffected limb. When gait shifted from erect to crouch, only for hemiplegic patients, at the hip, the paretic/unaffected ratio increased significantly. For peak power, work, sEMG area, and joint rotation, the paretic/unaffected ratio increased from 55 to 85%, 56 to 72%, 68 to 91%, and 67 to 93%, respectively. CG appears to be an effective form of forced-use exercise eliciting more power and work from the paretic lower limb muscles sustained by a greater neural drive. It also seems effective in forcing a more symmetric power and work from the hip extensor muscles, but neither from the knee nor the ankle. PMID:28574860

Open-systems Architecture of a Standardized Command Interface Chip-set for Switching and Control of a Spacecraft Power Bus

NASA Technical Reports Server (NTRS)

Ruiz, B. Ian; Burke, Gary R.; Lung, Gerald; Whitaker, William D.; Nowicki, Robert M.

2004-01-01

This viewgraph presentation reviews the architecture of the The CIA-AlA chip-set is a set of mixed-signal ASICs that provide a flexible high level interface between the spacecraft's command and data handling (C&DH) electronics and lower level functions in other spacecraft subsystems. Due to the open-systems architecture of the chip-set including an embedded micro-controller a variety of applications are possible. The chip-set was developed for the missions to the outer planets. The chips were developed to provide a single solution for both the switching and regulation of a spacecraft power bus. The Open-Systems Architecture allows for other powerful applications.

Somatotype is More Interactive with Strength than Fat Mass and Physical Activity in Peripubertal Children

PubMed Central

Marta, Carlos; Marinho, Daniel A.; Costa, Aldo M.; Barbosa, Tiago M.; Marques, Mário C.

2011-01-01

The purpose of this study was to analyse the interaction between somatotype, body fat and physical activity in prepubescent children. This was a cross-sectional study design involving 312 children (160 girls, 152 boys) aged between 10 and 11.5 years old (10.8 ± 0.4 years old). Evaluation of body composition was done determining body mass index and body fat by means of skin-fold measurements, using the method described by Slaughter. Somatotype was computed according to the Carter’s method. Physical activity was assessed with the Baecke questionnaire. The physical activity assessment employed sets of curl-ups, push-ups, standing broad jump, medicine ball throw, handgrip strength and Margaria-Kalamen power stair. There were negative associations for body fat, endomorphy and mesomorphy with curl-ups, push-ups and broad jump tests and positive associations with ball throw, handgrip strength and Margaria-Kalamen power tests. The associations for ectomorphy were the inverse of those for endomorphy and mesomorphy. Non obese children presented higher values for curl-ups, push-ups and standing broad jump. In medicine ball throw, handgrip strength and Margaria-Kalamen power test obese children presented higher scores, followed by children who were overweight. The mesoectomorphic boys and ectomesomorphic girls performed higher in all tests. The morphological typology presented more interactions with strength than % of body fat and physical activity. These data seem to suggest that the presence/absence of certain physical characteristics is crucial in the levels of motor provision in prepubescent children. PMID:23486278

A Repeated Power Training Enhances Fatigue Resistance While Reducing Intraset Fluctuations.

PubMed

Gonzalo-Skok, Oliver; Tous-Fajardo, Julio; Moras, Gerard; Arjol-Serrano, José Luis; Mendez-Villanueva, Alberto

2018-04-04

Oliver, GS, Julio, TF, Moras, G, José Luis, AS, and Alberto, MV. A repeated power training enhances fatigue resistance while reducing intraset fluctuations. J Strength Cond Res XX(X): 000-000, 2018-The present study analyzed the effects of adding an upper-body repeated power ability (RPA) training to habitual strength training sessions. Twenty young elite male basketball players were randomly allocated into a control group (CON, n = 10) or repeated power group (RPG, n = 10) and evaluated by 1 repetition maximum (1RM), incremental load, and RPA tests in the bench press exercise before and after a 7-week period and a 4-week cessation period. Repeated power group performed 1-3 blocks of 5 sets of 5 repetitions using the load that maximized power output with 30 seconds and 3 minute of passive recovery between sets and blocks, respectively. Between-group analysis showed substantial greater improvements in RPG compared with CON in: best set (APB), last set (APL), mean power over 5 sets (APM), percentage of decrement, fluctuation decrease during APL and RPA index (APLpost/APBpre) during the RPA test (effect size [ES] = 0.64-1.86), and 1RM (ES = 0.48) and average power at 80% of 1RM (ES = 1.11) in the incremental load test. The improvements of APB and APM were almost perfectly correlated. In conclusion, RPA training represents an effective method to mainly improve fatigue resistance together with the novel finding of a better consistency in performance (measured as reduced intraset power fluctuations) at the end of a dynamic repeated effort.

The effects of unilateral and bilateral eccentric overload training on hypertrophy, muscle power and COD performance, and its determinants, in team sport players.

PubMed

Núñez, Francisco Javier; Santalla, Alfredo; Carrasquila, Irene; Asian, Jose Antonio; Reina, Jose Ignacio; Suarez-Arrones, Luis Jesús

2018-01-01

The study aimed to compare the chronic eccentric-overload training effects of unilateral (lateral lunge) vs bilateral (half-squat) using an inertial device, on hypertrophy and physical performance. Twenty-seven young team sports male players performed a 4 sets of 7 repetitions of inertial eccentric overload training, biweekly for 6 weeks, distributed in unilateral lunge group (UG: age: 22.8 ± 2.9 years; body mass: 75.3 ± 8.8 kg; height: 177.3 ± 3.7 cm) and bilateral squat group (BG: age: 22.6 ± 2.7 years; body mass: 79.5 ± 12.8 kg; height: 164.2 ± 7 cm). Lower limb muscle volume, counter movement jump (CMJ), power with both (POWER), dominant (POWERd) and no-dominant leg (POWERnd), change of direction turn of 90° with dominant (COD90d) and no-dominant leg (COD90nd) and 180° (COD180d and COD180nd), and 10m sprint time (T-10m) were measured pre and post-intervention. The UG obtained an increase of adductor major (+11.1%) and vastus medialis (+12.6%) higher than BG. The BG obtained an increase of vastus lateralis (+9.9%) and lateral gastrocnemius (+9.1%) higher than UG. Both groups improved CMJ, POWER, POWERd, POWERnd, COD90 and DEC-COD90, without changes in T-10m. The UG decrease DEC-COD90nd (-21.1%) and BG increase POWER (+38.6%) substantially more than the other group. Six-weeks of unilateral / bilateral EO training induce substantial improvements in lower limbs muscle volume and functional performance, although unilateral training seems to be more effective in improving COD90 performance.

The effects of unilateral and bilateral eccentric overload training on hypertrophy, muscle power and COD performance, and its determinants, in team sport players

PubMed Central

Carrasquila, Irene; Asian, Jose Antonio; Reina, Jose Ignacio

2018-01-01

The study aimed to compare the chronic eccentric-overload training effects of unilateral (lateral lunge) vs bilateral (half-squat) using an inertial device, on hypertrophy and physical performance. Twenty-seven young team sports male players performed a 4 sets of 7 repetitions of inertial eccentric overload training, biweekly for 6 weeks, distributed in unilateral lunge group (UG: age: 22.8 ± 2.9 years; body mass: 75.3 ± 8.8 kg; height: 177.3 ± 3.7 cm) and bilateral squat group (BG: age: 22.6 ± 2.7 years; body mass: 79.5 ± 12.8 kg; height: 164.2 ± 7 cm). Lower limb muscle volume, counter movement jump (CMJ), power with both (POWER), dominant (POWERd) and no-dominant leg (POWERnd), change of direction turn of 90° with dominant (COD90d) and no-dominant leg (COD90nd) and 180° (COD180d and COD180nd), and 10m sprint time (T-10m) were measured pre and post-intervention. The UG obtained an increase of adductor major (+11.1%) and vastus medialis (+12.6%) higher than BG. The BG obtained an increase of vastus lateralis (+9.9%) and lateral gastrocnemius (+9.1%) higher than UG. Both groups improved CMJ, POWER, POWERd, POWERnd, COD90 and DEC-COD90, without changes in T-10m. The UG decrease DEC-COD90nd (-21.1%) and BG increase POWER (+38.6%) substantially more than the other group. Six-weeks of unilateral / bilateral EO training induce substantial improvements in lower limbs muscle volume and functional performance, although unilateral training seems to be more effective in improving COD90 performance. PMID:29590139

Scaling of Yb-Fiber Frequency Combs

NASA Astrophysics Data System (ADS)

Ruehl, Axel; Marcinkevicius, Andrius; Fermann, Martin E.; Hartl, Ingmar

2010-06-01

Immediately after their introduction in 1999, femtosecond laser frequency combs revolutionized the field of precision optical frequency metrology and are key elements in many experiments. Frequency combs based on femtosecond Er-fiber lasers based were demonstrated in 2005, allowing additionally rugged, compact set-ups and reliable unattended long-term operation. The introduction of Yb-fiber technology led to an dramatic improvement in fiber-comb performance in various aspects. Low-noise Yb-fiber femtosecond oscillators enabled a reduction of relative comb tooth linewidth to the sub-Hz level as well as scaling of the fundamental comb spacings up to 1 GHz. This is beneficial for any frequency-domain comb application due to the higher power per comb-mode. Many spectroscopic applications require, however, frequency combs way beyond the wavelength range accessible with broad band laser materials, so nonlinear conversion and hence higher peak intensity is required. We demonstrated power scaling of Yb-fiber frequency combs up to 80 W average power in a strictly linear chirped-pulse amplification schemes compatible with low-noise phase control. These high-power Yb-fiber-frequency combs facilitated not only the extension to the mid-IR spectral region. When coupled to a passive enhancement cavity, the average power can be further scaled to the kW-level opening new capabilities for XUV frequency combs via high-harmonic generation. All these advances of fiber-based frequency combs will trigger many novel applications both in fundamental and applied sciences. Schibli et al., Nature Photonics 2 355 (2008). Hartl et al., MF9 in Advanced Solid-State Photonics. 2009, Optical Society of America. Ruehl et al., AWC7 in Advanced Solid-State Photonics. 2010, Optical Society of America. Adler et al., Optics Letters 34 1330 (2009). Yost et al., Nature Physics 5 815 (2009).

Effects of microwave radiation on house dust mites, Dermatophagoides pteronyssinus and Dermatophagoides farinae (Astigmata: Pyroglyphidae).

PubMed

Ernieenor, F C L; Ho, T M

2010-11-01

Dermatophagoides pteronyssinus and Dermatophagoides farinae mites are commonly found in house dust, and are important sources of allergens affecting humans. Various approaches to killing the mites have been examined. This study investigated the mortalities of adult mites exposed to 2,450 MHz microwave radiation produced by 3 ovens at various exposure times and power settings. The ovens all had 3 power settings. The average maximum water temperatures generated at high, medium and low power settings were 99.4 +/- 0.2, 84.1 +/- 0.4 and 44.8 +/- 0.9 degrees C, respectively. At high and medium settings, there was 100.0% mortality in both species when exposed for 300 seconds. The mean mortality rates at low power were 10.8 +/- 0.7% for D. pteronyssinus and 9.7 +/- 2.6% for D. farinae. When mites were exposed in the presence of culture media, the mortality rates decreased with increasing weight of media. The mean mortality with the largest amount of media tested at high power setting was 61.4%.

Giving behavior of millionaires

PubMed Central

Smeets, Paul; Bauer, Rob; Gneezy, Uri

2015-01-01

This paper studies conditions influencing the generosity of wealthy people. We conduct incentivized experiments with individuals who have at least €1 million in their bank account. The results show that millionaires are more generous toward low-income individuals in a giving situation when the other participant has no power, than in a strategic setting, where the other participant can punish unfair behavior. Moreover, the level of giving by millionaires is higher than in any other previous study. Our findings have important implications for charities and financial institutions that deal with wealthy individuals. PMID:26261327

Giving behavior of millionaires.

PubMed

Smeets, Paul; Bauer, Rob; Gneezy, Uri

2015-08-25

This paper studies conditions influencing the generosity of wealthy people. We conduct incentivized experiments with individuals who have at least €1 million in their bank account. The results show that millionaires are more generous toward low-income individuals in a giving situation when the other participant has no power, than in a strategic setting, where the other participant can punish unfair behavior. Moreover, the level of giving by millionaires is higher than in any other previous study. Our findings have important implications for charities and financial institutions that deal with wealthy individuals.

Application of a flexible CO(2) laser fiber for neurosurgery: laser-tissue interactions.

PubMed

Ryan, Robert W; Wolf, Tamir; Spetzler, Robert F; Coons, Stephen W; Fink, Yoel; Preul, Mark C

2010-02-01

The CO(2) laser has an excellent profile for use in neurosurgery. Its high absorption in water results in low thermal spread, sparing adjacent tissue. Use of this laser has been limited to line-of-sight applications because no solid fiber optic cables could transmit its wavelength. Flexible photonic bandgap fiber technology enables delivery of CO(2) laser energy through a flexible fiber easily manipulated in a handheld device. The authors examined and compared the first use of this CO(2) laser fiber to conventional methods for incising neural tissue. Carbon dioxide laser energy was delivered in pulsed or continuous wave settings for different power settings, exposure times, and distances to cortical tissue of 6 anesthetized swine. Effects of CO(2) energy on the tissue were compared with bipolar cautery using a standard pial incision technique, and with scalpel incisions without cautery. Tissue was processed for histological analysis (using H & E, silver staining, and glial fibrillary acidic protein immunohistochemistry) and scanning electron microscopy, and lesion measurements were made. Light microscopy and scanning electron microscopy revealed laser incisions of consistent shape, with central craters surrounded by limited zones of desiccated and edematous tissue. Increased laser power resulted in deeper but not significantly wider incisions. Bipolar cautery lesions showed desiccated and edematous zones but did not incise the pia, and width increased more than depth with higher power. Incisions made without using cautery produced hemorrhage but minimal adjacent tissue damage. The photonic bandgap fiber CO(2) laser produced reliable cortical incisions, adjustable over a range of settings, with minimal adjacent thermal tissue damage. Ease of application under the microscope suggests this laser system has reached true practicality for neurosurgery.

An analysis of strategic price setting in retail gasoline markets

NASA Astrophysics Data System (ADS)

Jaureguiberry, Florencia

This dissertation studies price-setting behavior in the retail gasoline industry. The main questions addressed are: How important is a retail station's brand and proximity to competitors when retail stations set price? How do retailers adjust their pricing when they cater to consumers who are less aware of competing options or have less discretion over where they purchase gasoline? These questions are explored in two separate analyses using a unique datasets containing retail pricing behavior of stations in California and in 24 different metropolitan areas. The evidence suggests that brand and location generate local market power for gasoline stations. After controlling for market and station characteristics, the analysis finds a spread of 11 cents per gallon between the highest and the lowest priced retail gasoline brands. The analysis also indicates that when the nearest competitor is located over 2 miles away as opposed to next door, consumers will pay an additional 1 cent per gallon of gasoline. In order to quantify the significance of local market power, data for stations located near major airport rental car locations are utilized. The presumption here is that rental car users are less aware or less sensitive to fueling options near the rental car return location and are to some extent "captured consumers". Retailers located near rental car locations have incentives to adjust their pricing strategies to exploit this. The analysis of pricing near rental car locations indicates that retailers charge prices that are 4 cent per gallon higher than other stations in the same metropolitan area. This analysis is of interest to regulators who are concerned with issues of consolidation, market power, and pricing in the retail gasoline industry. This dissertation concludes with a discussion of the policy implications of the empirical analysis.

Applying reliability analysis to design electric power systems for More-electric aircraft

NASA Astrophysics Data System (ADS)

Zhang, Baozhu

The More-Electric Aircraft (MEA) is a type of aircraft that replaces conventional hydraulic and pneumatic systems with electrically powered components. These changes have significantly challenged the aircraft electric power system design. This thesis investigates how reliability analysis can be applied to automatically generate system topologies for the MEA electric power system. We first use a traditional method of reliability block diagrams to analyze the reliability level on different system topologies. We next propose a new methodology in which system topologies, constrained by a set reliability level, are automatically generated. The path-set method is used for analysis. Finally, we interface these sets of system topologies with control synthesis tools to automatically create correct-by-construction control logic for the electric power system.

Direct power comparisons between simple LOD scores and NPL scores for linkage analysis in complex diseases.

PubMed

Abreu, P C; Greenberg, D A; Hodge, S E

1999-09-01

Several methods have been proposed for linkage analysis of complex traits with unknown mode of inheritance. These methods include the LOD score maximized over disease models (MMLS) and the "nonparametric" linkage (NPL) statistic. In previous work, we evaluated the increase of type I error when maximizing over two or more genetic models, and we compared the power of MMLS to detect linkage, in a number of complex modes of inheritance, with analysis assuming the true model. In the present study, we compare MMLS and NPL directly. We simulated 100 data sets with 20 families each, using 26 generating models: (1) 4 intermediate models (penetrance of heterozygote between that of the two homozygotes); (2) 6 two-locus additive models; and (3) 16 two-locus heterogeneity models (admixture alpha = 1.0,.7,.5, and.3; alpha = 1.0 replicates simple Mendelian models). For LOD scores, we assumed dominant and recessive inheritance with 50% penetrance. We took the higher of the two maximum LOD scores and subtracted 0.3 to correct for multiple tests (MMLS-C). We compared expected maximum LOD scores and power, using MMLS-C and NPL as well as the true model. Since NPL uses only the affected family members, we also performed an affecteds-only analysis using MMLS-C. The MMLS-C was both uniformly more powerful than NPL for most cases we examined, except when linkage information was low, and close to the results for the true model under locus heterogeneity. We still found better power for the MMLS-C compared with NPL in affecteds-only analysis. The results show that use of two simple modes of inheritance at a fixed penetrance can have more power than NPL when the trait mode of inheritance is complex and when there is heterogeneity in the data set.

Socioeconomic context and the association between marriage and Mexico-U.S. migration.

PubMed

Riosmena, Fernando

2009-06-01

In this paper, I analyze how the association between Mexico-U.S. migration and marriage varies across socioeconomic settings in origins. Using Mexican Migration Project data and employing bilevel survival analysis with controls for socioeconomic, migrant network, and marriage market characteristics and family size, I find that single people are most likely to migrate relative to those married in areas of recent industrialization, where the Mexican patriarchal system is weaker and economic opportunities for both men and women make post-marital migration less attractive. Marital status is not significant in agriculture-dependent areas, where the bargaining power of husbands might be higher relative to other settings; their age-profiles of earnings flatter; and remunerated female work scarcer, making migration attractive later in the life course.

Socioeconomic context and the association between marriage and Mexico–U.S. migration

PubMed Central

Riosmena, Fernando

2009-01-01

In this paper, I analyze how the association between Mexico–U.S. migration and marriage varies across socioeconomic settings in origins. Using Mexican Migration Project data and employing bilevel survival analysis with controls for socioeconomic, migrant network, and marriage market characteristics and family size, I find that single people are most likely to migrate relative to those married in areas of recent industrialization, where the Mexican patriarchal system is weaker and economic opportunities for both men and women make post-marital migration less attractive. Marital status is not significant in agriculture-dependent areas, where the bargaining power of husbands might be higher relative to other settings; their age-profiles of earnings flatter; and remunerated female work scarcer, making migration attractive later in the life course. PMID:19756216

Single-pass beam measurements for the verification of the LHC magnetic model

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

Calaga, R.; Giovannozzi, M.; Redaelli, S.

2010-05-23

During the 2009 LHC injection tests, the polarities and effects of specific quadrupole and higher-order magnetic circuits were investigated. A set of magnet circuits had been selected for detailed investigation based on a number of criteria. On or off-momentum difference trajectories launched via appropriate orbit correctors for varying strength settings of the magnet circuits under study - e.g. main, trim and skew quadrupoles; sextupole families and spool piece correctors; skew sextupoles, octupoles - were compared with predictions from various optics models. These comparisons allowed confirming or updating the relative polarity conventions used in the optics model and the accelerator controlmore » system, as well as verifying the correct powering and assignment of magnet families. Results from measurements in several LHC sectors are presented.« less

Development of microheaters for gas sensor with an AT-Mega 8535 temperature controller using a PWM (pulse width modulation) method

NASA Astrophysics Data System (ADS)

Megayanti, Meti; Panatarani, Camellia; Joni, I. Made

2016-03-01

Microheater is the main component in gas sensor characterized by their sensitivity, selectivity, and time response of gas sensor which is depend on the microheater temperature stability. A Cu microheater was developed and utilized AT-Mega 8535 controller using a PWM (pulse width modulation) method. This control system is interfaced to the PC to observe the real time temperature response of the microheater. Three initial resistance (R0) variations of microheater were developed in an open loop control system. The power characteristic of designed microheater depends on the specified microheater initial resistance. The smaller R0, the less power required to reach a temperature setting value. The developed microheater was designed to reach a temperature setting value of 250°C having resistance 0.531 Ω for 1.979 Watt and 0.265 Ω for 1.072 Watt respectively. The results of the investigation on the control performances shows microheater-control system achieved operating temperature up to 250°C. The response of the temperature control shows smallest R0 resulted in a high stability with short settling time, short delay time and small ripple for temperature setting values higher than 150°C. The obtained error of microheater temperature with R0 = 0.265 is 8.596 %. It is concluded that the developed microheater can be utilized as a component of a gas sensor.

Predicting Increased Blood Pressure Using Machine Learning

PubMed Central

Golino, Hudson Fernandes; Amaral, Liliany Souza de Brito; Duarte, Stenio Fernando Pimentel; Soares, Telma de Jesus; dos Reis, Luciana Araujo

2014-01-01

The present study investigates the prediction of increased blood pressure by body mass index (BMI), waist (WC) and hip circumference (HC), and waist hip ratio (WHR) using a machine learning technique named classification tree. Data were collected from 400 college students (56.3% women) from 16 to 63 years old. Fifteen trees were calculated in the training group for each sex, using different numbers and combinations of predictors. The result shows that for women BMI, WC, and WHR are the combination that produces the best prediction, since it has the lowest deviance (87.42), misclassification (.19), and the higher pseudo R 2 (.43). This model presented a sensitivity of 80.86% and specificity of 81.22% in the training set and, respectively, 45.65% and 65.15% in the test sample. For men BMI, WC, HC, and WHC showed the best prediction with the lowest deviance (57.25), misclassification (.16), and the higher pseudo R 2 (.46). This model had a sensitivity of 72% and specificity of 86.25% in the training set and, respectively, 58.38% and 69.70% in the test set. Finally, the result from the classification tree analysis was compared with traditional logistic regression, indicating that the former outperformed the latter in terms of predictive power. PMID:24669313

Predicting increased blood pressure using machine learning.

PubMed

Golino, Hudson Fernandes; Amaral, Liliany Souza de Brito; Duarte, Stenio Fernando Pimentel; Gomes, Cristiano Mauro Assis; Soares, Telma de Jesus; Dos Reis, Luciana Araujo; Santos, Joselito

2014-01-01

The present study investigates the prediction of increased blood pressure by body mass index (BMI), waist (WC) and hip circumference (HC), and waist hip ratio (WHR) using a machine learning technique named classification tree. Data were collected from 400 college students (56.3% women) from 16 to 63 years old. Fifteen trees were calculated in the training group for each sex, using different numbers and combinations of predictors. The result shows that for women BMI, WC, and WHR are the combination that produces the best prediction, since it has the lowest deviance (87.42), misclassification (.19), and the higher pseudo R (2) (.43). This model presented a sensitivity of 80.86% and specificity of 81.22% in the training set and, respectively, 45.65% and 65.15% in the test sample. For men BMI, WC, HC, and WHC showed the best prediction with the lowest deviance (57.25), misclassification (.16), and the higher pseudo R (2) (.46). This model had a sensitivity of 72% and specificity of 86.25% in the training set and, respectively, 58.38% and 69.70% in the test set. Finally, the result from the classification tree analysis was compared with traditional logistic regression, indicating that the former outperformed the latter in terms of predictive power.

Optimization of the generator settings for endobiliary radiofrequency ablation

PubMed Central

Barret, Maximilien; Leblanc, Sarah; Vienne, Ariane; Rouquette, Alexandre; Beuvon, Frederic; Chaussade, Stanislas; Prat, Frederic

2015-01-01

AIM: To determine the optimal generator settings for endobiliary radiofrequency ablation. METHODS: Endobiliary radiofrequency ablation was performed in live swine on the ampulla of Vater, the common bile duct and in the hepatic parenchyma. Radiofrequency ablation time, “effect”, and power were allowed to vary. The animals were sacrificed two hours after the procedure. Histopathological assessment of the depth of the thermal lesions was performed. RESULTS: Twenty-five radiofrequency bursts were applied in three swine. In the ampulla of Vater (n = 3), necrosis of the duodenal wall was observed starting with an effect set at 8, power output set at 10 W, and a 30 s shot duration, whereas superficial mucosal damage of up to 350 μm in depth was recorded for an effect set at 8, power output set at 6 W and a 30 s shot duration. In the common bile duct (n = 4), a 1070 μm, safe and efficient ablation was obtained for an effect set at 8, a power output of 8 W, and an ablation time of 30 s. Within the hepatic parenchyma (n = 18), the depth of tissue damage varied from 1620 μm (effect = 8, power = 10 W, ablation time = 15 s) to 4480 μm (effect = 8, power = 8 W, ablation time = 90 s). CONCLUSION: The duration of the catheter application appeared to be the most important parameter influencing the depth of the thermal injury during endobiliary radiofrequency ablation. In healthy swine, the currently recommended settings of the generator may induce severe, supratherapeutic tissue damage in the biliary tree, especially in the high-risk area of the ampulla of Vater. PMID:26566429

Effects of ultrasonic root-end cavity preparation with different surgical-tips and at different power-settings on glucose-leakage of root-end filling material.

PubMed

Gunes, Betul; Aydinbelge, Hale Ali

2014-09-01

The aim of this in vitro study was to evaluate the effects of different ultrasonic surgical-tips and power-settings on micro-leakage of root-end filling material. The root canals were instrumented using rotary-files and were filled with tapered gutta-percha and root canal sealer using a single-cone technique. The apical 3 mm of each root was resected and the roots were divided into six experimental groups; negative and positive control groups. Root-end cavities were prepared with diamond-coated, zirconum-nitride-coated and stainless-steel ultrasonic retro-tips at half-power and high-power settings. The time required to prepare the root-end cavities for each group was recorded. Root-end cavities were filled with Super-EBA. Leakage values of all samples evaluated with glucose penetration method on 7, 14, 21 and 28(th) days. The results were statistically analyzed with Kruskal-Wallis and Hollander-Wolfe tests. The mean time required to prepare retro cavities using diamond-coated surgical tip at high-power setting was significantly less than other groups (P < 0.01). There were no statistically significant differences in the glucose penetration between the groups at first and second weeks (P > 0.01). Diamond-coated surgical tip showed the least leakage at high-power setting at 3(rd) and 4(th) weeks (P < 0.01). Under the conditions of this study, cavity preparation time was the shortest and the leakage of the root-end filling was the least when diamond-coated retro-tip used at high-power setting.

A Hermeneutic Phenomenology of Graduate Education Students' Understandings of Instructor Power in a Higher Education Classroom

ERIC Educational Resources Information Center

Delgado, Antonio

2012-01-01

Higher education is a distribution center of knowledge and economic, social, and cultural power (Cervero & Wilson, 2001). A critical approach to understanding a higher education classroom begins with recognizing the instructor's position of power and authority (Tisdell, Hanley, & Taylor, 2000). The power instructors wield exists…

Visual Communication in PowerPoint Presentations in Applied Linguistics

ERIC Educational Resources Information Center

Kmalvand, Ayad

2014-01-01

PowerPoint knowledge presentation as a digital genre has established itself as the main software by which the findings of theses are disseminated in the academic settings. Although the importance of PowerPoint presentations is typically realized in academic settings like lectures, conferences, and seminars, the study of the visual features of…

Results of the deepest all-sky survey for continuous gravitational waves on LIGO S6 data running on the Einstein@Home volunteer distributed computing project

NASA Astrophysics Data System (ADS)

Abbott, B. P.; Abbott, R.; Abbott, T. D.; Abernathy, M. R.; Acernese, F.; Ackley, K.; Adams, C.; Adams, T.; Addesso, P.; Adhikari, R. X.; Adya, V. B.; Affeldt, C.; Agathos, M.; Agatsuma, K.; Aggarwal, N.; Aguiar, O. D.; Aiello, L.; Ain, A.; Allen, B.; Allocca, A.; Altin, P. A.; Anderson, S. B.; Anderson, W. G.; Arai, K.; Araya, M. C.; Arceneaux, C. C.; Areeda, J. S.; Arnaud, N.; Arun, K. G.; Ascenzi, S.; Ashton, G.; Ast, M.; Aston, S. M.; Astone, P.; Aufmuth, P.; Aulbert, C.; Babak, S.; Bacon, P.; Bader, M. K. M.; Baker, P. T.; Baldaccini, F.; Ballardin, G.; Ballmer, S. W.; Barayoga, J. C.; Barclay, S. E.; Barish, B. C.; Barker, D.; Barone, F.; Barr, B.; Barsotti, L.; Barsuglia, M.; Barta, D.; Bartlett, J.; Bartos, I.; Bassiri, R.; Basti, A.; Batch, J. C.; Baune, C.; Bavigadda, V.; Bazzan, M.; Bejger, M.; Bell, A. S.; Berger, B. K.; Bergmann, G.; Berry, C. P. L.; Bersanetti, D.; Bertolini, A.; Betzwieser, J.; Bhagwat, S.; Bhandare, R.; Bilenko, I. A.; Billingsley, G.; Birch, J.; Birney, R.; Biscans, S.; Bisht, A.; Bitossi, M.; Biwer, C.; Bizouard, M. A.; Blackburn, J. K.; Blair, C. D.; Blair, D. G.; Blair, R. M.; Bloemen, S.; Bock, O.; Boer, M.; Bogaert, G.; Bogan, C.; Bohe, A.; Bond, C.; Bondu, F.; Bonnand, R.; Boom, B. A.; Bork, R.; Boschi, V.; Bose, S.; Bouffanais, Y.; Bozzi, A.; Bradaschia, C.; Brady, P. R.; Braginsky, V. B.; Branchesi, M.; Brau, J. E.; Briant, T.; Brillet, A.; Brinkmann, M.; Brisson, V.; Brockill, P.; Broida, J. E.; Brooks, A. F.; Brown, D. A.; Brown, D. D.; Brown, N. M.; Brunett, S.; Buchanan, C. C.; Buikema, A.; Bulik, T.; Bulten, H. J.; Buonanno, A.; Buskulic, D.; Buy, C.; Byer, R. L.; Cabero, M.; Cadonati, L.; Cagnoli, G.; Cahillane, C.; Calderón Bustillo, J.; Callister, T.; Calloni, E.; Camp, J. B.; Cannon, K. C.; Cao, J.; Capano, C. D.; Capocasa, E.; Carbognani, F.; Caride, S.; Casanueva Diaz, J.; Casentini, C.; Caudill, S.; Cavaglià, M.; Cavalier, F.; Cavalieri, R.; Cella, G.; Cepeda, C. B.; Cerboni Baiardi, L.; Cerretani, G.; Cesarini, E.; Chamberlin, S. J.; Chan, M.; Chao, S.; Charlton, P.; Chassande-Mottin, E.; Cheeseboro, B. D.; Chen, H. Y.; Chen, Y.; Cheng, C.; Chincarini, A.; Chiummo, A.; Cho, H. S.; Cho, M.; Chow, J. H.; Christensen, N.; Chu, Q.; Chua, S.; Chung, S.; Ciani, G.; Clara, F.; Clark, J. A.; Cleva, F.; Coccia, E.; Cohadon, P.-F.; Colla, A.; Collette, C. G.; Cominsky, L.; Constancio, M.; Conte, A.; Conti, L.; Cook, D.; Corbitt, T. R.; Cornish, N.; Corsi, A.; Cortese, S.; Costa, C. A.; Coughlin, M. W.; Coughlin, S. B.; Coulon, J.-P.; Countryman, S. T.; Couvares, P.; Cowan, E. E.; Coward, D. M.; Cowart, M. J.; Coyne, D. C.; Coyne, R.; Craig, K.; Creighton, J. D. E.; Creighton, T. D.; Cripe, J.; Crowder, S. G.; Cumming, A.; Cunningham, L.; Cuoco, E.; Dal Canton, T.; Danilishin, S. L.; D'Antonio, S.; Danzmann, K.; Darman, N. S.; Dasgupta, A.; Da Silva Costa, C. F.; Dattilo, V.; Dave, I.; Davier, M.; Davies, G. S.; Daw, E. J.; Day, R.; De, S.; DeBra, D.; Debreczeni, G.; Degallaix, J.; De Laurentis, M.; Deléglise, S.; Del Pozzo, W.; Denker, T.; Dent, T.; Dergachev, V.; De Rosa, R.; DeRosa, R. T.; DeSalvo, R.; Devine, R. C.; Dhurandhar, S.; Díaz, M. C.; Di Fiore, L.; Di Giovanni, M.; Di Girolamo, T.; Di Lieto, A.; Di Pace, S.; Di Palma, I.; Di Virgilio, A.; Dolique, V.; Donovan, F.; Dooley, K. L.; Doravari, S.; Douglas, R.; Downes, T. P.; Drago, M.; Drever, R. W. P.; Driggers, J. C.; Ducrot, M.; Dwyer, S. E.; Edo, T. B.; Edwards, M. C.; Effler, A.; Eggenstein, H.-B.; Ehrens, P.; Eichholz, J.; Eikenberry, S. S.; Engels, W.; Essick, R. C.; Etzel, T.; Evans, M.; Evans, T. M.; Everett, R.; Factourovich, M.; Fafone, V.; Fair, H.; Fairhurst, S.; Fan, X.; Fang, Q.; Farinon, S.; Farr, B.; Farr, W. M.; Favata, M.; Fays, M.; Fehrmann, H.; Fejer, M. M.; Fenyvesi, E.; Ferrante, I.; Ferreira, E. C.; Ferrini, F.; Fidecaro, F.; Fiori, I.; Fiorucci, D.; Fisher, R. P.; Flaminio, R.; Fletcher, M.; Fournier, J.-D.; Frasca, S.; Frasconi, F.; Frei, Z.; Freise, A.; Frey, R.; Frey, V.; Fritschel, P.; Frolov, V. V.; Fulda, P.; Fyffe, M.; Gabbard, H. A. G.; Gair, J. R.; Gammaitoni, L.; Gaonkar, S. G.; Garufi, F.; Gaur, G.; Gehrels, N.; Gemme, G.; Geng, P.; Genin, E.; Gennai, A.; George, J.; Gergely, L.; Germain, V.; Ghosh, Abhirup; Ghosh, Archisman; Ghosh, S.; Giaime, J. A.; Giardina, K. D.; Giazotto, A.; Gill, K.; Glaefke, A.; Goetz, E.; Goetz, R.; Gondan, L.; González, G.; Gonzalez Castro, J. M.; Gopakumar, A.; Gordon, N. A.; Gorodetsky, M. L.; Gossan, S. E.; Gosselin, M.; Gouaty, R.; Grado, A.; Graef, C.; Graff, P. B.; Granata, M.; Grant, A.; Gras, S.; Gray, C.; Greco, G.; Green, A. C.; Groot, P.; Grote, H.; Grunewald, S.; Guidi, G. M.; Guo, X.; Gupta, A.; Gupta, M. K.; Gushwa, K. E.; Gustafson, E. K.; Gustafson, R.; Hacker, J. J.; Hall, B. R.; Hall, E. D.; Hammond, G.; Haney, M.; Hanke, M. M.; Hanks, J.; Hanna, C.; Hanson, J.; Hardwick, T.; Harms, J.; Harry, G. M.; Harry, I. W.; Hart, M. J.; Hartman, M. T.; Haster, C.-J.; Haughian, K.; Heidmann, A.; Heintze, M. C.; Heitmann, H.; Hello, P.; Hemming, G.; Hendry, M.; Heng, I. S.; Hennig, J.; Henry, J.; Heptonstall, A. W.; Heurs, M.; Hild, S.; Hoak, D.; Hofman, D.; Holt, K.; Holz, D. E.; Hopkins, P.; Hough, J.; Houston, E. A.; Howell, E. J.; Hu, Y. M.; Huang, S.; Huerta, E. A.; Huet, D.; Hughey, B.; Husa, S.; Huttner, S. H.; Huynh-Dinh, T.; Indik, N.; Ingram, D. R.; Inta, R.; Isa, H. N.; Isac, J.-M.; Isi, M.; Isogai, T.; Iyer, B. R.; Izumi, K.; Jacqmin, T.; Jang, H.; Jani, K.; Jaranowski, P.; Jawahar, S.; Jian, L.; Jiménez-Forteza, F.; Johnson, W. W.; Jones, D. I.; Jones, R.; Jonker, R. J. G.; Ju, L.; K, Haris; Kalaghatgi, C. V.; Kalogera, V.; Kandhasamy, S.; Kang, G.; Kanner, J. B.; Kapadia, S. J.; Karki, S.; Karvinen, K. S.; Kasprzack, M.; Katsavounidis, E.; Katzman, W.; Kaufer, S.; Kaur, T.; Kawabe, K.; Kéfélian, F.; Kehl, M. S.; Keitel, D.; Kelley, D. B.; Kells, W.; Kennedy, R.; Key, J. S.; Khalili, F. Y.; Khan, I.; Khan, S.; Khan, Z.; Khazanov, E. A.; Kijbunchoo, N.; Kim, Chi-Woong; Kim, Chunglee; Kim, J.; Kim, K.; Kim, N.; Kim, W.; Kim, Y.-M.; Kimbrell, S. J.; King, E. J.; King, P. J.; Kissel, J. S.; Klein, B.; Kleybolte, L.; Klimenko, S.; Koehlenbeck, S. M.; Koley, S.; Kondrashov, V.; Kontos, A.; Korobko, M.; Korth, W. Z.; Kowalska, I.; Kozak, D. B.; Kringel, V.; Krishnan, B.; Królak, A.; Krueger, C.; Kuehn, G.; Kumar, P.; Kumar, R.; Kuo, L.; Kutynia, A.; Lackey, B. D.; Landry, M.; Lange, J.; Lantz, B.; Lasky, P. D.; Laxen, M.; Lazzaro, C.; Leaci, P.; Leavey, S.; Lebigot, E. O.; Lee, C. H.; Lee, H. K.; Lee, H. M.; Lee, K.; Lenon, A.; Leonardi, M.; Leong, J. R.; Leroy, N.; Letendre, N.; Levin, Y.; Lewis, J. B.; Li, T. G. F.; Libson, A.; Littenberg, T. B.; Lockerbie, N. A.; Lombardi, A. L.; London, L. T.; Lord, J. E.; Lorenzini, M.; Loriette, V.; Lormand, M.; Losurdo, G.; Lough, J. D.; Lück, H.; Lundgren, A. P.; Lynch, R.; Ma, Y.; Machenschalk, B.; MacInnis, M.; Macleod, D. M.; Magaña-Sandoval, F.; Magaña Zertuche, L.; Magee, R. M.; Majorana, E.; Maksimovic, I.; Malvezzi, V.; Man, N.; Mandic, V.; Mangano, V.; Mansell, G. L.; Manske, M.; Mantovani, M.; Marchesoni, F.; Marion, F.; Márka, S.; Márka, Z.; Markosyan, A. S.; Maros, E.; Martelli, F.; Martellini, L.; Martin, I. W.; Martynov, D. V.; Marx, J. N.; Mason, K.; Masserot, A.; Massinger, T. J.; Masso-Reid, M.; Mastrogiovanni, S.; Matichard, F.; Matone, L.; Mavalvala, N.; Mazumder, N.; McCarthy, R.; McClelland, D. E.; McCormick, S.; McGuire, S. C.; McIntyre, G.; McIver, J.; McManus, D. J.; McRae, T.; McWilliams, S. T.; Meacher, D.; Meadors, G. D.; Meidam, J.; Melatos, A.; Mendell, G.; Mercer, R. A.; Merilh, E. L.; Merzougui, M.; Meshkov, S.; Messenger, C.; Messick, C.; Metzdorff, R.; Meyers, P. M.; Mezzani, F.; Miao, H.; Michel, C.; Middleton, H.; Mikhailov, E. E.; Milano, L.; Miller, A. L.; Miller, A.; Miller, B. B.; Miller, J.; Millhouse, M.; Minenkov, Y.; Ming, J.; Mirshekari, S.; Mishra, C.; Mitra, S.; Mitrofanov, V. P.; Mitselmakher, G.; Mittleman, R.; Moggi, A.; Mohan, M.; Mohapatra, S. R. P.; Montani, M.; Moore, B. C.; Moore, C. J.; Moraru, D.; Moreno, G.; Morriss, S. R.; Mossavi, K.; Mours, B.; Mow-Lowry, C. M.; Mueller, G.; Muir, A. W.; Mukherjee, Arunava; Mukherjee, D.; Mukherjee, S.; Mukund, N.; Mullavey, A.; Munch, J.; Murphy, D. J.; Murray, P. G.; Mytidis, A.; Nardecchia, I.; Naticchioni, L.; Nayak, R. K.; Nedkova, K.; Nelemans, G.; Nelson, T. J. N.; Neri, M.; Neunzert, A.; Newton, G.; Nguyen, T. T.; Nielsen, A. B.; Nissanke, S.; Nitz, A.; Nocera, F.; Nolting, D.; Normandin, M. E. N.; Nuttall, L. K.; Oberling, J.; Ochsner, E.; O'Dell, J.; Oelker, E.; Ogin, G. H.; Oh, J. J.; Oh, S. H.; Ohme, F.; Oliver, M.; Oppermann, P.; Oram, Richard J.; O'Reilly, B.; O'Shaughnessy, R.; Ottaway, D. J.; Overmier, H.; Owen, B. J.; Pai, A.; Pai, S. A.; Palamos, J. R.; Palashov, O.; Palomba, C.; Pal-Singh, A.; Pan, H.; Pankow, C.; Pannarale, F.; Pant, B. C.; Paoletti, F.; Paoli, A.; Papa, M. A.; Paris, H. R.; Parker, W.; Pascucci, D.; Pasqualetti, A.; Passaquieti, R.; Passuello, D.; Patricelli, B.; Patrick, Z.; Pearlstone, B. L.; Pedraza, M.; Pedurand, R.; Pekowsky, L.; Pele, A.; Penn, S.; Perreca, A.; Perri, L. M.; Phelps, M.; Piccinni, O. J.; Pichot, M.; Piergiovanni, F.; Pierro, V.; Pillant, G.; Pinard, L.; Pinto, I. M.; Pitkin, M.; Poe, M.; Poggiani, R.; Popolizio, P.; Post, A.; Powell, J.; Prasad, J.; Predoi, V.; Prestegard, T.; Price, L. R.; Prijatelj, M.; Principe, M.; Privitera, S.; Prix, R.; Prodi, G. A.; Prokhorov, L.; Puncken, O.; Punturo, M.; Puppo, P.; Pürrer, M.; Qi, H.; Qin, J.; Qiu, S.; Quetschke, V.; Quintero, E. A.; Quitzow-James, R.; Raab, F. J.; Rabeling, D. S.; Radkins, H.; Raffai, P.; Raja, S.; Rajan, C.; Rakhmanov, M.; Rapagnani, P.; Raymond, V.; Razzano, M.; Re, V.; Read, J.; Reed, C. M.; Regimbau, T.; Rei, L.; Reid, S.; Reitze, D. H.; Rew, H.; Reyes, S. D.; Ricci, F.; Riles, K.; Rizzo, M.; Robertson, N. A.; Robie, R.; Robinet, F.; Rocchi, A.; Rolland, L.; Rollins, J. G.; Roma, V. J.; Romano, R.; Romanov, G.; Romie, J. H.; Rosińska, D.; Rowan, S.; Rüdiger, A.; Ruggi, P.; Ryan, K.; Sachdev, S.; Sadecki, T.; Sadeghian, L.; Sakellariadou, M.; Salconi, L.; Saleem, M.; Salemi, F.; Samajdar, A.; Sammut, L.; Sanchez, E. J.; Sandberg, V.; Sandeen, B.; Sanders, J. R.; Sassolas, B.; Saulson, P. R.; Sauter, O. E. S.; Savage, R. L.; Sawadsky, A.; Schale, P.; Schilling, R.; Schmidt, J.; Schmidt, P.; Schnabel, R.; Schofield, R. M. S.; Schönbeck, A.; Schreiber, E.; Schuette, D.; Schutz, B. F.; Scott, J.; Scott, S. M.; Sellers, D.; Sengupta, A. S.; Sentenac, D.; Sequino, V.; Sergeev, A.; Setyawati, Y.; Shaddock, D. A.; Shaffer, T.; Shahriar, M. S.; Shaltev, M.; Shapiro, B.; Shawhan, P.; Sheperd, A.; Shoemaker, D. H.; Shoemaker, D. M.; Siellez, K.; Siemens, X.; Sieniawska, M.; Sigg, D.; Silva, A. D.; Singer, A.; Singer, L. P.; Singh, A.; Singh, R.; Singhal, A.; Sintes, A. M.; Slagmolen, B. J. J.; Smith, J. R.; Smith, N. D.; Smith, R. J. E.; Son, E. J.; Sorazu, B.; Sorrentino, F.; Souradeep, T.; Srivastava, A. K.; Staley, A.; Steinke, M.; Steinlechner, J.; Steinlechner, S.; Steinmeyer, D.; Stephens, B. C.; Stone, R.; Strain, K. A.; Straniero, N.; Stratta, G.; Strauss, N. A.; Strigin, S.; Sturani, R.; Stuver, A. L.; Summerscales, T. Z.; Sun, L.; Sunil, S.; Sutton, P. J.; Swinkels, B. L.; Szczepańczyk, M. J.; Tacca, M.; Talukder, D.; Tanner, D. B.; Tápai, M.; Tarabrin, S. P.; Taracchini, A.; Taylor, R.; Theeg, T.; Thirugnanasambandam, M. P.; Thomas, E. G.; Thomas, M.; Thomas, P.; Thorne, K. A.; Thrane, E.; Tiwari, S.; Tiwari, V.; Tokmakov, K. V.; Toland, K.; Tomlinson, C.; Tonelli, M.; Tornasi, Z.; Torres, C. V.; Torrie, C. I.; Töyrä, D.; Travasso, F.; Traylor, G.; Trifirò, D.; Tringali, M. C.; Trozzo, L.; Tse, M.; Turconi, M.; Tuyenbayev, D.; Ugolini, D.; Unnikrishnan, C. S.; Urban, A. L.; Usman, S. A.; Vahlbruch, H.; Vajente, G.; Valdes, G.; van Bakel, N.; van Beuzekom, M.; van den Brand, J. F. J.; Van Den Broeck, C.; Vander-Hyde, D. C.; van der Schaaf, L.; van Heijningen, J. V.; van Veggel, A. A.; Vardaro, M.; Vass, S.; Vasúth, M.; Vaulin, R.; Vecchio, A.; Vedovato, G.; Veitch, J.; Veitch, P. J.; Venkateswara, K.; Verkindt, D.; Vetrano, F.; Viceré, A.; Vinciguerra, S.; Vine, D. J.; Vinet, J.-Y.; Vitale, S.; Vo, T.; Vocca, H.; Vorvick, C.; Voss, D. V.; Vousden, W. D.; Vyatchanin, S. P.; Wade, A. R.; Wade, L. E.; Wade, M.; Walker, M.; Wallace, L.; Walsh, S.; Wang, G.; Wang, H.; Wang, M.; Wang, X.; Wang, Y.; Ward, R. L.; Warner, J.; Was, M.; Weaver, B.; Wei, L.-W.; Weinert, M.; Weinstein, A. J.; Weiss, R.; Wen, L.; Weßels, P.; Westphal, T.; Wette, K.; Whelan, J. T.; Whiting, B. F.; Williams, R. D.; Williamson, A. R.; Willis, J. L.; Willke, B.; Wimmer, M. H.; Winkler, W.; Wipf, C. C.; Wittel, H.; Woan, G.; Woehler, J.; Worden, J.; Wright, J. L.; Wu, D. S.; Wu, G.; Yablon, J.; Yam, W.; Yamamoto, H.; Yancey, C. C.; Yu, H.; Yvert, M.; ZadroŻny, A.; Zangrando, L.; Zanolin, M.; Zendri, J.-P.; Zevin, M.; Zhang, L.; Zhang, M.; Zhang, Y.; Zhao, C.; Zhou, M.; Zhou, Z.; Zhu, S. J.; Zhu, X.; Zucker, M. E.; Zuraw, S. E.; Zweizig, J.; LIGO Scientific Collaboration; Virgo Collaboration

2016-11-01

We report results of a deep all-sky search for periodic gravitational waves from isolated neutron stars in data from the S6 LIGO science run. The search was possible thanks to the computing power provided by the volunteers of the Einstein@Home distributed computing project. We find no significant signal candidate and set the most stringent upper limits to date on the amplitude of gravitational wave signals from the target population. At the frequency of best strain sensitivity, between 170.5 and 171 Hz we set a 90% confidence upper limit of 5.5 ×10-25 , while at the high end of our frequency range, around 505 Hz, we achieve upper limits ≃10-24 . At 230 Hz we can exclude sources with ellipticities greater than 10-6 within 100 pc of Earth with fiducial value of the principal moment of inertia of 1038 kg m2 . If we assume a higher (lower) gravitational wave spin-down we constrain farther (closer) objects to higher (lower) ellipticities.

Exploring the general motor ability construct.

PubMed

Ibrahim, Halijah; Heard, N Paul; Blanksby, Brian

2011-10-01

Malaysian students ages 12 to 15 years (N = 330; 165 girls, 165 boys) took the Australian Institute of Sport Talent Identification Test (AIST) and the Balance and Movement Coordination Test (BMC), developed specifically to identify sport talent in Malaysian adolescents. To investigate evidence for general aptitude ("g") in motor ability, a higher-order factor analysis was applied to the motor skills subtests from the AIST and BMC. First-order principal components analysis indicated that scores for the adolescent boys and girls could be described by similar sets of specific motor abilities. In particular, sets of skills identified as Movement Coordination and Postural Control were found, with Balancing Ability also emerging. For the girls, a factor labeled Static Balance was indicated. However, for the boys a more general balance ability labeled Kinesthetic Integration was found, along with an ability labeled Explosive Power. These first-order analyses accounted for 45% to 60% of the variance in the scores on the motor skills tests for the boys and girls, respectively. Separate second-order factor analyses for the boys and girls extracted a single higher-order factor, which was consistent with the existence of a motoric "g".

An Independent Filter for Gene Set Testing Based on Spectral Enrichment.

PubMed

Frost, H Robert; Li, Zhigang; Asselbergs, Folkert W; Moore, Jason H

2015-01-01

Gene set testing has become an indispensable tool for the analysis of high-dimensional genomic data. An important motivation for testing gene sets, rather than individual genomic variables, is to improve statistical power by reducing the number of tested hypotheses. Given the dramatic growth in common gene set collections, however, testing is often performed with nearly as many gene sets as underlying genomic variables. To address the challenge to statistical power posed by large gene set collections, we have developed spectral gene set filtering (SGSF), a novel technique for independent filtering of gene set collections prior to gene set testing. The SGSF method uses as a filter statistic the p-value measuring the statistical significance of the association between each gene set and the sample principal components (PCs), taking into account the significance of the associated eigenvalues. Because this filter statistic is independent of standard gene set test statistics under the null hypothesis but dependent under the alternative, the proportion of enriched gene sets is increased without impacting the type I error rate. As shown using simulated and real gene expression data, the SGSF algorithm accurately filters gene sets unrelated to the experimental outcome resulting in significantly increased gene set testing power.

Observations of Children’s Interactions with Teachers, Peers, and Tasks across Preschool Classroom Activity Settings

PubMed Central

Booren, Leslie M.; Downer, Jason T.; Vitiello, Virginia E.

2014-01-01

This descriptive study examined classroom activity settings in relation to children’s observed behavior during classroom interactions, child gender, and basic teacher behavior within the preschool classroom. 145 children were observed for an average of 80 minutes during 8 occasions across 2 days using the inCLASS, an observational measure that conceptualizes behavior into teacher, peer, task, and conflict interactions. Findings indicated that on average children’s interactions with teachers were higher in teacher-structured settings, such as large group. On average, children’s interactions with peers and tasks were more positive in child-directed settings, such as free choice. Children experienced more conflict during recess and routines/transitions. Finally, gender differences were observed within small group and meals. The implications of these findings might encourage teachers to be thoughtful and intentional about what types of support and resources are provided so children can successfully navigate the demands of particular settings. These findings are not meant to discourage certain teacher behaviors or imply value of certain classroom settings; instead, by providing an evidenced-based picture of the conditions under which children display the most positive interactions, teachers can be more aware of choices within these settings and have a powerful way to assist in professional development and interventions. PMID:25717282

Observations of Children's Interactions with Teachers, Peers, and Tasks across Preschool Classroom Activity Settings.

PubMed

Booren, Leslie M; Downer, Jason T; Vitiello, Virginia E

2012-07-01

This descriptive study examined classroom activity settings in relation to children's observed behavior during classroom interactions, child gender, and basic teacher behavior within the preschool classroom. 145 children were observed for an average of 80 minutes during 8 occasions across 2 days using the inCLASS, an observational measure that conceptualizes behavior into teacher, peer, task, and conflict interactions. Findings indicated that on average children's interactions with teachers were higher in teacher-structured settings, such as large group. On average, children's interactions with peers and tasks were more positive in child-directed settings, such as free choice. Children experienced more conflict during recess and routines/transitions. Finally, gender differences were observed within small group and meals. The implications of these findings might encourage teachers to be thoughtful and intentional about what types of support and resources are provided so children can successfully navigate the demands of particular settings. These findings are not meant to discourage certain teacher behaviors or imply value of certain classroom settings; instead, by providing an evidenced-based picture of the conditions under which children display the most positive interactions, teachers can be more aware of choices within these settings and have a powerful way to assist in professional development and interventions.

Power Beaming Leakage Radiation as A SETI Observable

NASA Technical Reports Server (NTRS)

Benford, James N.; Benford, Dominic J.

2016-01-01

The most observable leakage radiation from an advanced civilization may well be from the use of power beam-ing to transfer energy and accelerate spacecraft. Applications suggested for power beaming involve launching spacecraft to orbit, raising satellites to a higher orbit, and interplanetary concepts involving space-to-space transfers of cargo or passengers. We also quantify beam-driven launch to the outer solar system, interstellar precursors and ultimately starships. We estimate the principal observable parameters of power beaming leak-age. Extraterrestrial civilizations would know their power beams could be observed, and so could put a message on the power beam and broadcast it for our receipt at little additional energy or cost. By observing leakage from power beams we may find a message embedded on the beam. Recent observations of the anomalous star KIC8462852 by the Allen Telescope Array (ATA) set some limits on extraterrestrial power beaming in that system.We show that most power beaming applications commensurate with those suggested for our solar system would be detectable if using the frequency range monitored by the ATA, and so the lack of detection is a meaningful,if modest, constraint on extraterrestrial power beaming in that system. Until more extensive observations are made, the limited observation time and frequency coverage are not sufficiently broad in frequency and duration to produce firm conclusions. Such beams would be visible over large interstellar distances. This implies a new approach to the SETI search: Instead of focusing on narrowband beacon transmissions generated by another civilization, look for more powerful beams with much wider bandwidth. This requires a new approach for their discovery by telescopes on Earth. Further studies of power beaming applications should be done, which could broaden the parameter space of observable features we have discussed here.

Power Beaming Leakage Radiation as a SETI Observable

NASA Astrophysics Data System (ADS)

Benford, James N.; Benford, Dominic J.

2016-07-01

The most observable leakage radiation from an advanced civilization may well be from the use of power beaming to transfer energy and accelerate spacecraft. Applications suggested for power beaming involve launching spacecraft to orbit, raising satellites to a higher orbit, and interplanetary concepts involving space-to-space transfers of cargo or passengers. We also quantify beam-driven launch to the outer solar system, interstellar precursors, and ultimately starships. We estimate the principal observable parameters of power beaming leakage. Extraterrestrial civilizations would know their power beams could be observed, and so could put a message on the power beam and broadcast it for our receipt at little additional energy or cost. By observing leakage from power beams we may find a message embedded on the beam. Recent observations of the anomalous star KIC 8462852 by the Allen Telescope Array (ATA) set some limits on extraterrestrial power beaming in that system. We show that most power beaming applications commensurate with those suggested for our solar system would be detectable if using the frequency range monitored by the ATA, and so the lack of detection is a meaningful, if modest, constraint on extraterrestrial power beaming in that system. Until more extensive observations are made, the limited observation time and frequency coverage are not sufficiently broad in frequency and duration to produce firm conclusions. Such beams would be visible over large interstellar distances. This implies a new approach to the SETI search: instead of focusing on narrowband beacon transmissions generated by another civilization, look for more powerful beams with much wider bandwidth. This requires a new approach for their discovery by telescopes on Earth. Further studies of power beaming applications should be performed, potentially broadening the parameter space of the observable features that we have discussed here.

Integrated flight/propulsion control - Adaptive engine control system mode

NASA Technical Reports Server (NTRS)

Yonke, W. A.; Terrell, L. A.; Meyers, L. P.

1985-01-01

The adaptive engine control system mode (ADECS) which is developed and tested on an F-15 aircraft with PW1128 engines, using the NASA sponsored highly integrated digital electronic control program, is examined. The operation of the ADECS mode, as well as the basic control logic, the avionic architecture, and the airframe/engine interface are described. By increasing engine pressure ratio (EPR) additional thrust is obtained at intermediate power and above. To modulate the amount of EPR uptrim and to prevent engine stall, information from the flight control system is used. The performance benefits, anticipated from control integration are shown for a range of flight conditions and power settings. It is found that at higher altitudes, the ADECS mode can increase thrust as much as 12 percent, which is used for improved acceleration, improved turn rate, or sustained turn angle.

Ultra-low-frequency wave power in the magnetotail lobes. I - Relation to substorm onsets and the auroral electrojet index

NASA Technical Reports Server (NTRS)

Smith, R. A.; Goertz, C. K.; Harrold, B. G.; Goldstein, M. L.; Lepping, R. P.; Fitch, C. A.; Sands, M. R.

1990-01-01

Time-series observations of the magnetotail-lobe magnetic field have been Fourier analyzed to compute the frequency-weighted energy density Pfz in the range 1-30 mHz. Pfz is generally observed in the range 0.0001-0.01 gamma-squared Hz with a mean value of 0.0012 during substorm growth phases and 0.001 in the comparison intervals. No strong correlation of Pfz is found with the auroral electrojet index in either set of intervals, but during substorm growth phases Pfz may vary by an order of magnitude over time scales of 30 min, with a tendency for higher power levels to occur later in the growth phase. Increases in Pfz precede by about 10 min localized expansive phase activity observed in individual magnetograms.

A case study demonstration of the soil temperature extrema recovery rates after precipitation cooling at 10-cm soil depth

NASA Technical Reports Server (NTRS)

Welker, Jean Edward

1991-01-01

Since the invention of maximum and minimum thermometers in the 18th century, diurnal temperature extrema have been taken for air worldwide. At some stations, these extrema temperatures were collected at various soil depths also, and the behavior of these temperatures at a 10-cm depth at the Tifton Experimental Station in Georgia is presented. After a precipitation cooling event, the diurnal temperature maxima drop to a minimum value and then start a recovery to higher values (similar to thermal inertia). This recovery represents a measure of response to heating as a function of soil moisture and soil property. Eight different curves were fitted to a wide variety of data sets for different stations and years, and both power and exponential curves were fitted to a wide variety of data sets for different stations and years. Both power and exponential curve fits were consistently found to be statistically accurate least-square fit representations of the raw data recovery values. The predictive procedures used here were multivariate regression analyses, which are applicable to soils at a variety of depths besides the 10-cm depth presented.

Unknown loads affect force production capacity in early phases of bench press throws.

PubMed

Hernández Davó, J L; Sabido Solana, R; Sarabia Marínm, J M; Sánchez Martos, Á; Moya Ramón, M

2015-10-01

Explosive strength training aims to improve force generation in early phases of movement due to its importance in sport performance. The present study examined the influence of lack of knowledge about the load lifted in explosive parameters during bench press throws. Thirteen healthy young men (22.8±2.0 years) participated in the study. Participants performed bench press throws with three different loads (30, 50 and 70% of 1 repetition maximum) in two different conditions (known and unknown loads). In unknown condition, loads were changed within sets in each repetition and participants did not know the load, whereas in known condition the load did not change within sets and participants had knowledge about the load lifted. Results of repeated-measures ANOVA revealed that unknown conditions involves higher power in the first 30, 50, 100 and 150 ms with the three loads, higher values of ratio of force development in those first instants, and differences in time to reach maximal rate of force development with 50 and 70% of 1 repetition maximum. This study showed that unknown conditions elicit higher values of explosive parameters in early phases of bench press throws, thereby this kind of methodology could be considered in explosive strength training.

Reconceptualising the "Child": Power and Resistance within Early Childhood Settings

ERIC Educational Resources Information Center

Tesar, Marek

2014-01-01

This article reconceptualises the postmodern "Child" through the lens of Havel's work on ideology, power and subject formations. Set in an any ideologically charged early childhood setting, it analyses Havel's claim that all citizens, including children, are instrumental in maintaining the ideology of the establishment, and…

Ranking Specific Sets of Objects.

PubMed

Maly, Jan; Woltran, Stefan

2017-01-01

Ranking sets of objects based on an order between the single elements has been thoroughly studied in the literature. In particular, it has been shown that it is in general impossible to find a total ranking - jointly satisfying properties as dominance and independence - on the whole power set of objects. However, in many applications certain elements from the entire power set might not be required and can be neglected in the ranking process. For instance, certain sets might be ruled out due to hard constraints or are not satisfying some background theory. In this paper, we treat the computational problem whether an order on a given subset of the power set of elements satisfying different variants of dominance and independence can be found, given a ranking on the elements. We show that this problem is tractable for partial rankings and NP-complete for total rankings.

Policies to keep and expand the option of concentrating solar power for dispatchable renewable electricity

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

Lilliestam, Johan; Barradi, Touria; Caldes, Natalia

Concentrating solar power (CSP) is one of the few renewable electricity technologies that can offer dispatchable electricity at large scale. Thus, it may play an important role in the future, especially to balance fluctuating sources in increasingly renewables-based power systems. Today, its costs are higher than those of PV and wind power and, as most countries do not support CSP, deployment is slow. Unless the expansion gains pace and costs decrease, the industry may stagnate or collapse, and an important technology for climate change mitigation has been lost. Keeping CSP as a maturing technology for dispatchable renewable power thus requiresmore » measures to improve its short-term economic attractiveness and to continue reducing costs in the longer term. We suggest a set of three policy instruments - feed-in tariffs or auctions reflecting the value of dispatchable CSP, and not merely its cost; risk coverage support for innovative designs; and demonstration projects - to be deployed, in regions where CSP has a potentially large role to play. This could provide the CSP industry with a balance of attractive profits and competitive pressure, the incentive to expand CSP while also reducing its costs, making it ready for broad-scale deployment when it is needed.« less

Policies to keep and expand the option of concentrating solar power for dispatchable renewable electricity

DOE PAGES

Lilliestam, Johan; Barradi, Touria; Caldes, Natalia; ...

2018-02-16

Concentrating solar power (CSP) is one of the few renewable electricity technologies that can offer dispatchable electricity at large scale. Thus, it may play an important role in the future, especially to balance fluctuating sources in increasingly renewables-based power systems. Today, its costs are higher than those of PV and wind power and, as most countries do not support CSP, deployment is slow. Unless the expansion gains pace and costs decrease, the industry may stagnate or collapse, and an important technology for climate change mitigation has been lost. Keeping CSP as a maturing technology for dispatchable renewable power thus requiresmore » measures to improve its short-term economic attractiveness and to continue reducing costs in the longer term. We suggest a set of three policy instruments - feed-in tariffs or auctions reflecting the value of dispatchable CSP, and not merely its cost; risk coverage support for innovative designs; and demonstration projects - to be deployed, in regions where CSP has a potentially large role to play. This could provide the CSP industry with a balance of attractive profits and competitive pressure, the incentive to expand CSP while also reducing its costs, making it ready for broad-scale deployment when it is needed.« less

Evaluation of dissociated and steam-reformed methanol as automotive engine fuels

NASA Technical Reports Server (NTRS)

Lalk, T. R.; Mccall, D. M.; Mccanlies, J. M.

1984-01-01

Dissociated and steam reformed methanol were evaluated as automotive engine fuels. Advantages and disadvantages in using methanol in the reformed rather than liquid state were discussed. Engine dynamometer tests were conducted with a four cylinder, 2.3 liter, spark ignition automotive engine to determine performance and emission characteristics operating on simulated dissociated and steam reformed methanol (2H2 + CO and 3H2 + CO2 respectively), and liquid methanol. Results are presented for engine performance and emissions as functions of equivalence ratio, at various throttle settings and engine speeds. Operation on dissociated and steam reformed methanol was characterized by flashback (violent propagation of a flame into the intake manifold) which limited operation to lower power output than was obtainable using liquid methanol. It was concluded that: an automobile could not be operated solely on dissociated or steam reformed methanol over the entire required power range - a supplementary fuel system or power source would be necessary to attain higher powers; the use of reformed mechanol, compared to liquid methanol, may result in a small improvement in thermal efficiency in the low power range; dissociated methanol is a better fuel than steam reformed methanol for use in a spark ignition engine; and use of dissociated or steam reformed methanol may result in lower exhaust emissions compared to liquid methanol.

Dependence of Edge Profiles and Stability on Neutral Beam Power in NSTX

NASA Astrophysics Data System (ADS)

Travis, P.; Canal, G. P.; Osborne, T. H.; Maingi, R.; Sabbagh, S. A.; NSTX-U Team

2016-10-01

Studying the effect of neutral beam injected (NBI) power on edge plasma profiles and magnetohydrodynamic (MHD) stability is central to the understanding of edge-localized modes (ELMs). Higher heating power should quicken the development of pressure and current-driven peeling-ballooning modes. NSTX ELMy H-mode discharges with NBI power of 4, 5 and 6 MW were analyzed with a python-based set of analysis tools that fit plasma profiles, compute kinetic equilibria, and evaluate the MHD stability with the code ELITE. Electron density and temperature from Thomson scattering measurements, and ion density, temperature, and rotation from Charge Exchange Recombination Spectroscopy were inputs to the kinetic equilibrium fits. The power scan provides an opportunity to compare the stability calculations from the ELITE (ideal) and M3D-C1 (resistive) codes. Preliminary analysis shows that edge pressure profiles for the 5 and 6 MW discharges are comparable, suggesting they both reach a stability boundary. The 4 MW case shows lower edge pressure, which is likely limited by edge transport below the edge stability boundary. This work was supported in part by the U.S. Department of Energy, Office of Science, Office of Workforce Development for Teachers and Scientists (WDTS) under the Science Undergraduate Laboratory Internship (SULI) program.

Performance and properties of the first plasmas of Wendelstein 7-X

DOE PAGES

Klinger, Thomas; Alonso, A.; Bozhenkov, S.; ...

2016-10-18

The optimized, superconducting stellarator Wendelstein 7-X went into operation and delivered first measurement data after 15 years of construction and one year commissioning. Errors in the magnet assembly were confirmend to be small. Plasma operation was started with 5 MW electron cyclotron resonance heating (ECRH) power and five inboard limiters. Core plasma values ofmore » $${{T}_{\\text{e}}}>8$$ keV, $${{T}_{\\text{i}}}>2$$ keV at line-integrated densities $$n\\approx 3\\centerdot {{10}^{19}}~{{\\text{m}}^{-2}}$$ were achieved, exceeding the original expectations by about a factor of two. Indications for a core-electron-root were found. The energy confinement times are in line with the international stellarator scaling, despite unfavourable wall conditions, i.e. large areas of metal surfaces and particle sources from the limiter close to the plasma volume. Well controlled shorter hydrogen discharges at higher power (4 MW ECRH power for 1 s) and longer discharges at lower power (0.7 MW ECRH power for 6 s) could be routinely established after proper wall conditioning. Lastly, the fairly large set of diagnostic systems running in the end of the 10 weeks operation campaign provided first insights into expected and unexpected physics of optimized stellarators.« less

46 CFR 129.315 - Power sources for OSVs of 100 or more gross tons.

Code of Federal Regulations, 2010 CFR

2010-10-01

... VESSELS ELECTRICAL INSTALLATIONS Power Sources and Distribution Systems § 129.315 Power sources for OSVs... one set must be independent of the main propulsion plant. A generator not independent of the main propulsion plant must comply with § 111.10-4(d) of this chapter. With any one generating set stopped, the...

Electrical system for pulse-width modulated control of a power inverter using phase-shifted carrier signals and related operating methods

DOEpatents

Welchko, Brian A [Torrance, CA

2012-02-14

Systems and methods are provided for pulse-width modulated control of power inverter using phase-shifted carrier signals. An electrical system comprises an energy source and a motor. The motor has a first set of windings and a second set of windings, which are electrically isolated from each other. An inverter module is coupled between the energy source and the motor and comprises a first set of phase legs coupled to the first set of windings and a second set of phase legs coupled to the second set of windings. A controller is coupled to the inverter module and is configured to achieve a desired power flow between the energy source and the motor by modulating the first set of phase legs using a first carrier signal and modulating the second set of phase legs using a second carrier signal. The second carrier signal is phase-shifted relative to the first carrier signal.

Influence of standing position on mechanical and energy costs in uphill cycling.

PubMed

Bouillod, Anthony; Pinot, Julien; Valade, Aurélien; Cassirame, Johan; Soto-Romero, Georges; Grappe, Frédéric

2018-04-27

This study was designed to examine the influence of standing position (vs. seated) during uphill cycling on both mechanical cost (MC) and energy cost (EC) in elite cyclists. For the study, thirteen elite cyclists (VO 2max : 71.4 ± 8.0 ml·min -1 ·kg -1 ) performed, in a randomised order, three sets of exercises. Each set comprised 2 min of exercise, alternating every 30 s between seated and standing postures, using different slopes and intensity levels on a motorised treadmill. MC was calculated from the measurement of power output and speed, whereas EC was calculated from the measurement of oxygen consumption and speed. MC was significantly higher (+4.3%, p < 0.001) in standing position compared to seated position when all slopes and intensities were considered. However, EC was not significantly affected by the change in position. The standing position also induced a significant increase in rolling resistance power (p < 0.001), rolling resistance coefficient (p < 0.001) and lateral sways (p < 0.001). The significant increase in MC observed in standing position was due to a higher rolling resistance induced by bicycle sways and a shift forward of the centre of mass compared to seated position. This result should lead bicycle tire manufacturers to reduce the increase in rolling resistance between the two positions. Considering the relationship observed between the MC and bicycle sways, cyclists would be well advised to decrease the bicycle sways in order to reduce the MC of locomotion. Copyright © 2018 Elsevier Ltd. All rights reserved.

Neighborhood × Serotonin Transporter Linked Polymorphic Region (5-HTTLPR) interactions for substance use from ages 10 to 24 years using a harmonized data set of African American children.

PubMed

Windle, Michael; Kogan, Steven M; Lee, Sunbok; Chen, Yi-Fu; Lei, Karlo Mankit; Brody, Gene H; Beach, Steven R H; Yu, Tianyi

2016-05-01

This study investigated the influences of neighborhood factors (residential stability and neighborhood disadvantage) and variants of the serotonin transporter linked polymorphic region (5-HTTLPR) genotype on the development of substance use among African American children aged 10-24 years. To accomplish this, a harmonized data set of five longitudinal studies was created via pooling overlapping age cohorts to establish a database with 2,689 children and 12,474 data points to span ages 10-24 years. A description of steps used in the development of the harmonized data set is provided, including how issues such as the measurement equivalence of constructs were addressed. A sequence of multilevel models was specified to evaluate Gene × Environment effects on growth of substance use across time. Findings indicated that residential instability was associated with higher levels and a steeper gradient of growth in substance use across time. The inclusion of the 5-HTTLPR genotype provided greater precision to the relationships in that higher residential instability, in conjunction with the risk variant of 5-HTTLPR (i.e., the short allele), was associated with the highest level and steepest gradient of growth in substance use across ages 10-24 years. The findings demonstrated how the creation of a harmonized data set increased statistical power to test Gene × Environment interactions for an under studied sample.

High Performance Power Module for Hall Effect Thrusters

NASA Technical Reports Server (NTRS)

Pinero, Luis R.; Peterson, Peter Y.; Bowers, Glen E.

2002-01-01

Previous efforts to develop power electronics for Hall thruster systems have targeted the 1 to 5 kW power range and an output voltage of approximately 300 V. New Hall thrusters are being developed for higher power, higher specific impulse, and multi-mode operation. These thrusters require up to 50 kW of power and a discharge voltage in excess of 600 V. Modular power supplies can process more power with higher efficiency at the expense of complexity. A 1 kW discharge power module was designed, built and integrated with a Hall thruster. The breadboard module has a power conversion efficiency in excess of 96 percent and weighs only 0.765 kg. This module will be used to develop a kW, multi-kW, and high voltage power processors.

How and where clinicians exercise power: interprofessional relations in health care.

PubMed

Nugus, Peter; Greenfield, David; Travaglia, Joanne; Westbrook, Johanna; Braithwaite, Jeffrey

2010-09-01

This study aims to contribute to the limited set of interactional studies of health occupational relations. A "negotiated order" perspective was applied to a multi-site setting to articulate the ways in which clinicians' roles, accountabilities and contributions to patient care are shaped by the care setting and are influenced by the management of patient pathways. The study responds to the polarized debate between a critical perspective that calls for collaboration as the re-distribution of occupational power, and a functionalist view that argues for better coordination of health care teams. The study draws on data from 63 interviews, 68 focus groups and 209 h of observation across acute and non-acute health services within a state/territory in Australia. The paper reveals the exercise of both "competitive power" and "collaborative power" in the negotiated order of health services. Both forms of power are exercised in all settings. Relationships among clinicians in various occupations are mediated by the expectation that doctors assume responsibility for patient management and coordinating roles in health care teams, and the degree of acuity of particular health care settings. The combination of a negotiated order perspective and its unique application across a whole health system shows the continuation of a broad pattern of power by doctors over those in other roles. The paper also reveals novel criteria for evaluating the extent of power-sharing in interprofessional interaction in case conferences, and a unique quantification of such interaction. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Effects of carbon brush anode size and loading on microbial fuel cell performance in batch and continuous mode

NASA Astrophysics Data System (ADS)

Lanas, Vanessa; Ahn, Yongtae; Logan, Bruce E.

2014-02-01

Larger scale microbial fuel cells (MFCs) require compact architectures to efficiently treat wastewater. We examined how anode-brush diameter, number of anodes, and electrode spacing affected the performance of the MFCs operated in fed-batch and continuous flow mode. All anodes were initially tested with the brush core set at the same distance from the cathode. In fed-batch mode, the configuration with three larger brushes (25 mm diameter) produced 80% more power (1240 mW m-2) than reactors with eight smaller brushes (8 mm) (690 mW m-2). The higher power production by the larger brushes was due to more negative and stable anode potentials than the smaller brushes. The same general result was obtained in continuous flow operation, although power densities were reduced. However, by moving the center of the smaller brushes closer to the cathode (from 16.5 to 8 mm), power substantially increased from 690 to 1030 mW m-2 in fed batch mode. In continuous flow mode, power increased from 280 to 1020 mW m-2, resulting in more power production from the smaller brushes than the larger brushes (540 mW m-2). These results show that multi-electrode MFCs can be optimized by selecting smaller anodes, placed as close as possible to the cathode.

Performance of a Permanent-Magnet Cylindrical Hall-Effect Thruster

NASA Technical Reports Server (NTRS)

Polzin, K. A.; Sooby, E. S.; Kimberlin, A. C.; Raites, Y.; Merino, E.; Fisch, N. J.

2009-01-01

The performance of a low-power cylindrical Hall thruster, which more readily lends itself to miniaturization and low-power operation than a conventional (annular) Hall thruster, was measured using a planar plasma probe and a thrust stand. The field in the cylindrical thruster was produced using permanent magnets, promising a power reduction over previous cylindrical thruster iterations that employed electromagnets to generate the required magnetic field topology. Two sets of ring-shaped permanent magnets are used, and two different field configurations can be produced by reorienting the poles of one magnet relative to the other. A plasma probe measuring ion flux in the plume is used to estimate the current utilization for the two magnetic topologies. The measurements indicate that electron transport is impeded much more effectively in one configuration, implying higher thrust efficiency. Thruster performance measurements on this configuration were obtained over a power range of 70-350 W and with the cathode orifice located at three different axial positions relative to the thruster exit plane. The thrust levels over this power range were 1.25-6.5 mN, with anode efficiencies and specific impulses spanning 4-21% and 400-1950 s, respectively. The anode efficiency of the permanent-magnet thruster compares favorable with the efficiency of the electromagnet thruster when the power consumed by the electromagnets is taken into account.

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

Benford, James N.; Benford, Dominic J., E-mail: jimbenford@gmail.com

The most observable leakage radiation from an advanced civilization may well be from the use of power beaming to transfer energy and accelerate spacecraft. Applications suggested for power beaming involve launching spacecraft to orbit, raising satellites to a higher orbit, and interplanetary concepts involving space-to-space transfers of cargo or passengers. We also quantify beam-driven launch to the outer solar system, interstellar precursors, and ultimately starships. We estimate the principal observable parameters of power beaming leakage. Extraterrestrial civilizations would know their power beams could be observed, and so could put a message on the power beam and broadcast it for ourmore » receipt at little additional energy or cost. By observing leakage from power beams we may find a message embedded on the beam. Recent observations of the anomalous star KIC 8462852 by the Allen Telescope Array (ATA) set some limits on extraterrestrial power beaming in that system. We show that most power beaming applications commensurate with those suggested for our solar system would be detectable if using the frequency range monitored by the ATA, and so the lack of detection is a meaningful, if modest, constraint on extraterrestrial power beaming in that system. Until more extensive observations are made, the limited observation time and frequency coverage are not sufficiently broad in frequency and duration to produce firm conclusions. Such beams would be visible over large interstellar distances. This implies a new approach to the SETI search: instead of focusing on narrowband beacon transmissions generated by another civilization, look for more powerful beams with much wider bandwidth. This requires a new approach for their discovery by telescopes on Earth. Further studies of power beaming applications should be performed, potentially broadening the parameter space of the observable features that we have discussed here.« less

Climate change impacts on thermoelectric-power generation in the United States

NASA Astrophysics Data System (ADS)

Liu, L.

2015-12-01

Thermoelectric-power generation accounts for more than 70% of the total electricity generation in the United States, which requires large amounts of water for cooling purposes. Water withdrawals for thermoelectric-power generation accounted for 45% of total water use in the United States in 2010. Across the country, water demand from power plants is increasing due to pressures from growing populations and other needs, and is straining existing water resources. Moreover, temperature exceedance in receiving waters has increasingly caused power plants shut downs across parts of the country. Thermoelectric power is vulnerable to climate change owing to the combined effects of lower summer river flows and higher receiving water temperatures. In addition, the efficiency of production is reduced as air temperature rises, which propagates to more unfulfilled power demand during peak seasons. Therefore, a holistic modeling framework of water-energy-climate for the contiguous U.S. is presented here to quantify thermal output from power plants and estimate water use and energy production fluctuations due to ambient climate as well as environmental regulations. The model is calibrated on a plant-by-plant basis for year 2010 and 2011 using the available power plant inventory from the Energy Information Administration (EIA). Simulations were carried out for years 2012 and 2013, and results show moderate improvements in capturing thermal output variabilities after calibration. Future power plant operations under scenarios featuring different climate and regulatory settings were investigated. Results demonstrate the interplay among water, energy and climate, and that future changes in climate and socioeconomics significantly affect power plant operations, which may provide insights to climate change mitigation considerations and energy decisions.

50. VIEW LOOKING SOUTHEAST AT A MOTORGENERATOR SET LOCATED UNDER ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

50. VIEW LOOKING SOUTHEAST AT A MOTOR-GENERATOR SET LOCATED UNDER CONTROL ROOM. THREE 450 kva., 2500 VOLT, 60 CYCLE MOTOR-GENERATOR UNITS PROVIDED POWER FOR THE RAILROAD SIGNAL SYSTEM. 25 CYCLE POWER WAS PROVIDED TO THE MOTOR (LEFT BACKGROUND). THE MOTOR TURNED THE GENERATOR (CENTER FOREGROUND) WHICH PRODUCED 60 CYCLE POWER TO OPERATE LIGHTS AND SIGNALING DEVICES. - New York, New Haven & Hartford Railroad, Cos Cob Power Plant, Sound Shore Drive, Greenwich, Fairfield County, CT

Full-custom design of split-set data weighted averaging with output register for jitter suppression

NASA Astrophysics Data System (ADS)

Jubay, M. C.; Gerasta, O. J.

2015-06-01

A full-custom design of an element selection algorithm, named as Split-set Data Weighted Averaging (SDWA) is implemented in 90nm CMOS Technology Synopsys Library. SDWA is applied in seven unit elements (3-bit) using a thermometer-coded input. Split-set DWA is an improved DWA algorithm which caters the requirement for randomization along with long-term equal element usage. Randomization and equal element-usage improve the spectral response of the unit elements due to higher Spurious-free dynamic range (SFDR) and without significantly degrading signal-to-noise ratio (SNR). Since a full-custom, the design is brought to transistor-level and the chip custom layout is also provided, having a total area of 0.3mm2, a power consumption of 0.566 mW, and simulated at 50MHz clock frequency. On this implementation, SDWA is successfully derived and improved by introducing a register at the output that suppresses the jitter introduced at the final stage due to switching loops and successive delays.

Sustainable Data Evolution Technology for Power Grid Optimization

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

The SDET Tool is used to create open-access power grid data sets and facilitate updates of these data sets by the community. Pacific Northwest National Laboratory (PNNL) and its power industry and software vendor partners are developing an innovative sustainable data evolution technology (SDET) to create open-access power grid datasets and facilitate updates to these datasets by the power grid community. The objective is to make this a sustained effort within and beyond the ARPA-E GRID DATA program so that the datasets can evolve over time and meet the current and future needs for power grid optimization and potentially othermore » applications in power grid operation and planning.« less

Intensity modulation of HF heater-induced plasma lines

NASA Technical Reports Server (NTRS)

Kuo, S. P.; Lee, M. C.

1990-01-01

The Arecibo HF heater is normally composed of two separate sets of antenna array, transmitting waves vertically at the same frequency and polarization. However, when these two sets of antenna array radiate at slightly different frequencies, the intensities of HF heater-induced plasma lines (HFPLs) can be drastically modulated. In recent Duncan et al.'s (1989) experiments the 100 percent intensity modulation of HFPLs was seen to persist even when the secondary set of antenna array radiated at a few percent of the power transmitted by the primary set of antenna array. An explanation is offered, and it is shown that there exists a minimum power, Pmin, and if the secondary set of antenna array radiates at a power lower than Pmin, the 100-percent intensity modulation of HFPLs will not be observed. The functional dependence of Pmin on the difference frequency of the two sets of antenna array is also predicted for future experiments to corroborate.

Using Analysis of Governance to Unpack Community-Based Conservation: A Case Study from Tanzania.

PubMed

Robinson, Lance W; Makupa, Enock

2015-11-01

Community-based conservation policies and programs are often hollow with little real devolution. But to pass a judgment of community-based or not community-based on such initiatives and programs obscures what is actually a suite of attributes. In this paper, we analyze governance around a specific case of what is nominally community-based conservation-Ikona Wildlife Management Area (WMA) in Tanzania-using two complementary sets of criteria. The first relates to governance "powers": planning powers, regulatory powers, spending powers, revenue-generating powers, and the power to enter into agreements. The second set of criteria derive from the understanding of governance as a set of social functions: social coordination, shaping power, setting direction, and building community. The analysis helps to detail ways in which the Tanzanian state through policy and regulations has constrained the potential for Ikona WMA to empower communities and community actors. Although it has some features of community-based conservation, community input into how the governance social functions would be carried out in the WMA was constrained from the start and is now largely out of community hands. The two governance powers that have any significant community-based flavor-spending powers and revenue-generating powers-relate to the WMA's tourism activities, but even here the picture is equivocal at best. The unpacking of governance that we have done, however, reveals that community empowerment through the processes associated with creating and recognizing indigenous and community-conserved areas is something that can be pursued through multiple channels, some of which might be more strategic than others.

Active Power Control of Wind Turbines for Ancillary Services: A Comparison of Pitch and Torque Control Methodologies

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

Aho, Jacob; Fleming, Paul; Pao, Lucy Y.

As wind energy generation becomes more prevalent in some regions, there is increased demand for wind power plants to provide ancillary services, which are essential for grid reliability. This paper compares two different wind turbine control methodologies to provide active power control (APC) ancillary services, which include derating or curtailing power generation, providing automatic generation control (AGC), and providing primary frequency control (PFC). The torque APC controller provides all power control through the power electronics whereas the pitch APC controller uses the blade pitch actuators as the primary means of power control. These controllers are simulated under various wind conditionsmore » with different derating set points and AGC participation levels. The metrics used to compare their performance are the damage equivalent loads (DELs) induced on the structural components and AGC performance metrics, which are used to determine the payments for AGC services by system operators in the United States. The simulation results show that derating the turbine reduces structural loads for both control methods, with the APC pitch control providing larger reductions in DELs, lower AGC performance scores, and higher root-mean-square pitch rates. Providing AGC increases the structural loads when compared to only derating the turbine, but even the AGC DELs are generally lower than those of the baseline control system. The torque APC control methodology also allows for more sustained PFC responses under certain derating conditions.« less

Advanced power generation systems for the 21st Century: Market survey and recommendations for a design philosophy

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

Andriulli, J.B.; Gates, A.E.; Haynes, H.D.

1999-11-01

The purpose of this report is to document the results of a study designed to enhance the performance of future military generator sets (gen-sets) in the medium power range. The study includes a market survey of the state of the art in several key component areas and recommendations comprising a design philosophy for future military gen-sets. The market survey revealed that the commercial market is in a state of flux, but it is currently or will soon be capable of providing the technologies recommended here in a cost-effective manner. The recommendations, if implemented, should result in future power generation systemsmore » that are much more functional than today's gen-sets. The number of differing units necessary (both family sizes and frequency modes) to cover the medium power range would be decreased significantly, while the weight and volume of each unit would decrease, improving the transportability of the power source. Improved fuel economy and overall performance would result from more effective utilization of the prime mover in the generator. The units would allow for more flexibility and control, improved reliability, and more effective power management in the field.« less

Transient stability enhancement of electric power generating systems by 120-degree phase rotation

DOEpatents

Cresap, Richard L.; Taylor, Carson W.; Kreipe, Michael J.

1982-01-01

A method and system for enhancing the transient stability of an intertied three-phase electric power generating system. A set of power exporting generators (10) is connected to a set of power importing generators (20). When a transient cannot be controlled by conventional stability controls, and imminent loss of synchronism is detected (such as when the equivalent rotor angle difference between the two generator sets exceeds a predetermined value, such as 150 degrees), the intertie is disconnected by circuit breakers. Then a switch (30) having a 120-degree phase rotation, or a circuit breaker having a 120-degree phase rotation is placed in the intertie. The intertie is then reconnected. This results in a 120-degree reduction in the equivalent rotor angle difference between the two generator sets, making the system more stable and allowing more time for the conventional controls to stabilize the transient.

Systems and methods for optimal power flow on a radial network

DOEpatents

Low, Steven H.; Peng, Qiuyu

2018-04-24

Node controllers and power distribution networks in accordance with embodiments of the invention enable distributed power control. One embodiment includes a node controller including a distributed power control application; a plurality of node operating parameters describing the operating parameter of a node and a set of at least one node selected from the group consisting of an ancestor node and at least one child node; wherein send node operating parameters to nodes in the set of at least one node; receive operating parameters from the nodes in the set of at least one node; calculate a plurality of updated node operating parameters using an iterative process to determine the updated node operating parameters using the node operating parameters that describe the operating parameters of the node and the set of at least one node, where the iterative process involves evaluation of a closed form solution; and adjust node operating parameters.

Keep it simple? Predicting primary health care costs with clinical morbidity measures

PubMed Central

Brilleman, Samuel L.; Gravelle, Hugh; Hollinghurst, Sandra; Purdy, Sarah; Salisbury, Chris; Windmeijer, Frank

2014-01-01

Models of the determinants of individuals’ primary care costs can be used to set capitation payments to providers and to test for horizontal equity. We compare the ability of eight measures of patient morbidity and multimorbidity to predict future primary care costs and examine capitation payments based on them. The measures were derived from four morbidity descriptive systems: 17 chronic diseases in the Quality and Outcomes Framework (QOF); 17 chronic diseases in the Charlson scheme; 114 Expanded Diagnosis Clusters (EDCs); and 68 Adjusted Clinical Groups (ACGs). These were applied to patient records of 86,100 individuals in 174 English practices. For a given disease description system, counts of diseases and sets of disease dummy variables had similar explanatory power. The EDC measures performed best followed by the QOF and ACG measures. The Charlson measures had the worst performance but still improved markedly on models containing only age, gender, deprivation and practice effects. Comparisons of predictive power for different morbidity measures were similar for linear and exponential models, but the relative predictive power of the models varied with the morbidity measure. Capitation payments for an individual patient vary considerably with the different morbidity measures included in the cost model. Even for the best fitting model large differences between expected cost and capitation for some types of patient suggest incentives for patient selection. Models with any of the morbidity measures show higher cost for more deprived patients but the positive effect of deprivation on cost was smaller in better fitting models. PMID:24657375

On the Performance Evaluation of a MIMO–WCDMA Transmission Architecture for Building Management Systems

PubMed Central

Tsampasis, Eleftherios; Gkonis, Panagiotis K.; Trakadas, Panagiotis; Zahariadis, Theodοre

2018-01-01

The goal of this study was to investigate the performance of a realistic wireless sensor nodes deployment in order to support modern building management systems (BMSs). A three-floor building orientation is taken into account, where each node is equipped with a multi-antenna system while a central base station (BS) collects and processes all received information. The BS is also equipped with multiple antennas; hence, a multiple input–multiple output (MIMO) system is formulated. Due to the multiple reflections during transmission in the inner of the building, a wideband code division multiple access (WCDMA) physical layer protocol has been considered, which has already been adopted for third-generation (3G) mobile networks. Results are presented for various MIMO orientations, where the mean transmission power per node is considered as an output metric for a specific signal-to-noise ratio (SNR) requirement and number of resolvable multipath components. In the first set of presented results, the effects of multiple access interference on overall transmission power are highlighted. As the number of mobile nodes per floor or the requested transmission rate increases, MIMO systems of a higher order should be deployed in order to maintain transmission power at adequate levels. In the second set of results, a comparison is performed among transmission in diversity combining and spatial multiplexing mode, which clearly indicate that the first case is the most appropriate solution for indoor communications. PMID:29316720

Ultraviolet divergences in non-renormalizable supersymmetric theories

NASA Astrophysics Data System (ADS)

Smilga, A.

2017-03-01

We present a pedagogical review of our current understanding of the ultraviolet structure of N = (1,1) 6D supersymmetric Yang-Mills theory and of N = 8 4 D supergravity. These theories are not renormalizable, they involve power ultraviolet divergences and, in all probability, an infinite set of higherdimensional counterterms that contribute to on-mass-shell scattering amplitudes. A specific feature of supersymmetric theories (especially, of extended supersymmetric theories) is that these counterterms may not be invariant off shell under the full set of supersymmetry transformations. The lowest-dimensional nontrivial counterterm is supersymmetric on shell. Still higher counterterms may lose even the on-shell invariance. On the other hand, the full effective Lagrangian, generating the amplitudes and representing an infinite sum of counterterms, still enjoys the complete symmetry of original theory. We also discuss simple supersymmetric quantum-mechanical models that exhibit the same behaviour.

High-quality weather data for grid integration studies

NASA Astrophysics Data System (ADS)

Draxl, C.

2016-12-01

As variable renewable power penetration levels increase in power systems worldwide, renewable integration studies are crucial to ensure continued economic and reliable operation of the power grid. In this talk we will shed light on requirements for grid integration studies as far as wind and solar energy are concerned. Because wind and solar plants are strongly impacted by weather, high-resolution and high-quality weather data are required to drive power system simulations. Future data sets will have to push limits of numerical weather prediction to yield these high-resolution data sets, and wind data will have to be time-synchronized with solar data. Current wind and solar integration data sets will be presented. The Wind Integration National Dataset (WIND) Toolkit is the largest and most complete grid integration data set publicly available to date. A meteorological data set, wind power production time series, and simulated forecasts created using the Weather Research and Forecasting Model run on a 2-km grid over the continental United States at a 5-min resolution is now publicly available for more than 126,000 land-based and offshore wind power production sites. The Solar Integration National Dataset (SIND) is available as time synchronized with the WIND Toolkit, and will allow for combined wind-solar grid integration studies. The National Solar Radiation Database (NSRDB) is a similar high temporal- and spatial resolution database of 18 years of solar resource data for North America and India. Grid integration studies are also carried out in various countries, which aim at increasing their wind and solar penetration through combined wind and solar integration data sets. We will present a multi-year effort to directly support India's 24x7 energy access goal through a suite of activities aimed at enabling large-scale deployment of clean energy and energy efficiency. Another current effort is the North-American-Renewable-Integration-Study, with the aim of providing a seamless data set across borders for a whole continent, to simulate and analyze the impacts of potential future large wind and solar power penetrations on bulk power system operations.

A new insight into the oscillation characteristics of endosonic files used in dentistry.

PubMed

Lea, S C; Walmsley, A D; Lumley, P J; Landini, G

2004-05-21

The aim of this study was to assess the oscillation characteristics of unconstrained endosonic files using a scanning laser vibrometer (SLV). Factors investigated included file vibration frequency and node/antinode location as well as the variation in file displacement amplitude due to increasing generator power setting. A 30 kHz Mini Piezon generator (Electro-Medical Systems, Switzerland) was used in conjunction with a #15 and #35 K-file. Each file was fixed in position with the long axis of the file perpendicular to the SLV camera head. The laser from the SLV was scanned over the length of the oscillating file for generator power settings 1 to 5 (minimum to half power). Measurements were repeated ten times. The fundamental vibration frequency for both files was 27.50 kHz. Scans of each file showed the positions of nodes/anti-nodes along the file length. The #15 file demonstrated no significant variation in its mean maximum displacement amplitude with increasing generator power, except at power setting 5, where a decrease in displacement amplitude was observed. The #35 file showed a general increase in mean maximum displacement amplitude with increasing power setting, except at power setting 4 where a 65% decrease in displacement amplitude occurred. In conclusion, scanning laser vibrometry is an effective method for assessing endosonic file vibration characteristics. The SLV was able to demonstrate that (unloaded) file vibration displacement amplitude does not increase linearly with increasing generator power. Further work is being performed on a greater variety of files and generators. Vibration characteristics of files under various loads and varying degrees of constraint should also be investigated.

Systems and methods for controlling energy use in a building management system using energy budgets

DOEpatents

Wenzel, Michael J.

2012-06-17

Systems and methods for limiting power consumption by a heating, ventilation, and air conditioning (HVAC) subsystem of a building are shown and described. A mathematical linear operator is found that transforms the unused or deferred cooling power usage of the HVAC system based on pre-determined temperature settings to a target cooling power usage. The mathematical operator is applied to the temperature settings to create a temperature setpoint trajectory expected to provide the target cooling power usage.

A time-varying effect model for examining group differences in trajectories of zero-inflated count outcomes with applications in substance abuse research.

PubMed

Yang, Songshan; Cranford, James A; Jester, Jennifer M; Li, Runze; Zucker, Robert A; Buu, Anne

2017-02-28

This study proposes a time-varying effect model for examining group differences in trajectories of zero-inflated count outcomes. The motivating example demonstrates that this zero-inflated Poisson model allows investigators to study group differences in different aspects of substance use (e.g., the probability of abstinence and the quantity of alcohol use) simultaneously. The simulation study shows that the accuracy of estimation of trajectory functions improves as the sample size increases; the accuracy under equal group sizes is only higher when the sample size is small (100). In terms of the performance of the hypothesis testing, the type I error rates are close to their corresponding significance levels under all settings. Furthermore, the power increases as the alternative hypothesis deviates more from the null hypothesis, and the rate of this increasing trend is higher when the sample size is larger. Moreover, the hypothesis test for the group difference in the zero component tends to be less powerful than the test for the group difference in the Poisson component. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

Normalization of Impact Energy by Laminate Thickness for Compression After Impact Testing

NASA Technical Reports Server (NTRS)

Nettles, A. T.; Hromisin, S. M.

2013-01-01

The amount of impact energy used to damage a composite laminate is a critical parameter when assessing residual strength properties. The compression after impact (CAI) strength of impacted laminates is dependent upon how thick the laminate is and this has traditionally been accounted for by normalizing (dividing) the impact energy by the laminate's thickness. However, when comparing CAI strength values for a given lay-up sequence and fiber/resin system, dividing the impact energy by the specimen thickness has been noted by the author to give higher CAI strength values for thicker laminates. A study was thus undertaken to assess the comparability of CAI strength data by normalizing the impact energy by the specimen thickness raised to a power to account for the higher strength of thicker laminates. One set of data from the literature and two generated in this study were analyzed by dividing the impact energy by the specimen thickness to the 1, 1.5, 2, and 2.5 powers. Results show that as laminate thickness and damage severity decreased, the value which the laminate thickness needs to be raised to in order to yield more comparable CAI data increases.

Statistical Properties of Ribbon Evolution and Reconnection Electric Fields in Eruptive and Confined Flares

NASA Astrophysics Data System (ADS)

Hinterreiter, J.; Veronig, A. M.; Thalmann, J. K.; Tschernitz, J.; Pötzi, W.

2018-03-01

A statistical study of the chromospheric ribbon evolution in Hα two-ribbon flares was performed. The data set consists of 50 confined (62%) and eruptive (38%) flares that occurred from June 2000 to June 2015. The flares were selected homogeneously over the Hα and Geostationary Operational Environmental Satellite (GOES) classes, with an emphasis on including powerful confined flares and weak eruptive flares. Hα filtergrams from the Kanzelhöhe Observatory in combination with Michelson Doppler Imager (MDI) and Helioseismic and Magnetic Imager (HMI) magnetograms were used to derive the ribbon separation, the ribbon-separation velocity, the magnetic-field strength, and the reconnection electric field. We find that eruptive flares reveal statistically larger ribbon separation and higher ribbon-separation velocities than confined flares. In addition, the ribbon separation of eruptive flares correlates with the GOES SXR flux, whereas no clear dependence was found for confined flares. The maximum ribbon-separation velocity is not correlated with the GOES flux, but eruptive flares reveal on average a higher ribbon-separation velocity (by ≈ 10 km s-1). The local reconnection electric field of confined (cc=0.50 ±0.02) and eruptive (cc=0.77 ±0.03) flares correlates with the GOES flux, indicating that more powerful flares involve stronger reconnection electric fields. In addition, eruptive flares with higher electric-field strengths tend to be accompanied by faster coronal mass ejections.

Silent strain of caregiving: exploring the best predictors of distress in family carers of geriatric patients.

PubMed

Bień-Barkowska, Katarzyna; Doroszkiewicz, Halina; Bień, Barbara

2017-01-01

The aim of this article was to identify the best predictors of distress suffered by family carers (FCs) of geriatric patients. A cross-sectional study of 100 FC-geriatric patient dyads was conducted. The negative impact of care (NIoC) subscale of the COPE index was dichotomized to identify lower stress (score of ≤15 on the scale) and higher stress (score of ≥16 on the scale) exerted on FCs by the process of providing care. The set of explanatory variables comprised a wide range of sociodemographic and care-related attributes, including patient-related results from comprehensive geriatric assessments and disease profiles. The best combination of explanatory variables that provided the highest predictive power for distress among FCs in the multiple logistic regression (LR) model was determined according to statistical information criteria. The statistical robustness of the observed relationships and the discriminative power of the model were verified with the cross-validation method. The mean age of FCs was 57.2 (±10.6) years, whereas that of geriatric patients was 81.7 (±6.4) years. Despite the broad initial set of potential explanatory variables, only five predictors were jointly selected for the best statistical model. A higher level of distress was independently predicted by lower self-evaluation of health; worse self-appraisal of coping well as a caregiver; lower sense of general support; more hours of care per week; and the motor retardation of the cared-for person measured with the speed of the Timed Up and Go (TUG) test. Worse performance on the TUG test was only the patient-related predictor of distress among the variables examined as contributors to the higher NIoC. Enhancing the mobility of geriatric patients through suitably tailored kinesitherapeutic methods during their hospital stay may mitigate the burden endured by FCs.

The optimization of nuclear power plants operation modes in emergency situations

NASA Astrophysics Data System (ADS)

Zagrebayev, A. M.; Trifonenkov, A. V.; Ramazanov, R. N.

2018-01-01

An emergency situations resulting in the necessity for temporary reactor trip may occur at the nuclear power plant while normal operating mode. The paper deals with some of the operation c aspects of nuclear power plant operation in emergency situations and during threatened period. The xenon poisoning causes limitations on the variety of statements of the problem of calculating characteristics of a set of optimal reactor power off controls. The article show a possibility and feasibility of new sets of optimization tasks for the operation of nuclear power plants under conditions of xenon poisoning in emergency circumstances.

Automatic Setting Procedure for Exoskeleton-Assisted Overground Gait: Proof of Concept on Stroke Population

PubMed Central

Gandolla, Marta; Guanziroli, Eleonora; D'Angelo, Andrea; Cannaviello, Giovanni; Molteni, Franco; Pedrocchi, Alessandra

2018-01-01

Stroke-related locomotor impairments are often associated with abnormal timing and intensity of recruitment of the affected and non-affected lower limb muscles. Restoring the proper lower limbs muscles activation is a key factor to facilitate recovery of gait capacity and performance, and to reduce maladaptive plasticity. Ekso is a wearable powered exoskeleton robot able to support over-ground gait training. The user controls the exoskeleton by triggering each single step during the gait cycle. The fine-tuning of the exoskeleton control system is crucial—it is set according to the residual functional abilities of the patient, and it needs to ensure lower limbs powered gait to be the most physiological as possible. This work focuses on the definition of an automatic calibration procedure able to detect the best Ekso setting for each patient. EMG activity has been recorded from Tibialis Anterior, Soleus, Rectus Femoris, and Semitendinosus muscles in a group of 7 healthy controls and 13 neurological patients. EMG signals have been processed so to obtain muscles activation patterns. The mean muscular activation pattern derived from the controls cohort has been set as reference. The developed automatic calibration procedure requires the patient to perform overground walking trials supported by the exoskeleton while changing parameters setting. The Gait Metric index is calculated for each trial, where the closer the performance is to the normative muscular activation pattern, in terms of both relative amplitude and timing, the higher the Gait Metric index is. The trial with the best Gait Metric index corresponds to the best parameters set. It has to be noted that the automatic computational calibration procedure is based on the same number of overground walking trials, and the same experimental set-up as in the current manual calibration procedure. The proposed approach allows supporting the rehabilitation team in the setting procedure. It has been demonstrated to be robust, and to be in agreement with the current gold standard (i.e., manual calibration performed by an expert engineer). The use of a graphical user interface is a promising tool for the effective use of an automatic procedure in a clinical context. PMID:29615890

Automatic Setting Procedure for Exoskeleton-Assisted Overground Gait: Proof of Concept on Stroke Population.

PubMed

Gandolla, Marta; Guanziroli, Eleonora; D'Angelo, Andrea; Cannaviello, Giovanni; Molteni, Franco; Pedrocchi, Alessandra

2018-01-01

Stroke-related locomotor impairments are often associated with abnormal timing and intensity of recruitment of the affected and non-affected lower limb muscles. Restoring the proper lower limbs muscles activation is a key factor to facilitate recovery of gait capacity and performance, and to reduce maladaptive plasticity. Ekso is a wearable powered exoskeleton robot able to support over-ground gait training. The user controls the exoskeleton by triggering each single step during the gait cycle. The fine-tuning of the exoskeleton control system is crucial-it is set according to the residual functional abilities of the patient, and it needs to ensure lower limbs powered gait to be the most physiological as possible. This work focuses on the definition of an automatic calibration procedure able to detect the best Ekso setting for each patient. EMG activity has been recorded from Tibialis Anterior, Soleus, Rectus Femoris, and Semitendinosus muscles in a group of 7 healthy controls and 13 neurological patients. EMG signals have been processed so to obtain muscles activation patterns. The mean muscular activation pattern derived from the controls cohort has been set as reference. The developed automatic calibration procedure requires the patient to perform overground walking trials supported by the exoskeleton while changing parameters setting. The Gait Metric index is calculated for each trial, where the closer the performance is to the normative muscular activation pattern, in terms of both relative amplitude and timing, the higher the Gait Metric index is. The trial with the best Gait Metric index corresponds to the best parameters set. It has to be noted that the automatic computational calibration procedure is based on the same number of overground walking trials, and the same experimental set-up as in the current manual calibration procedure. The proposed approach allows supporting the rehabilitation team in the setting procedure. It has been demonstrated to be robust, and to be in agreement with the current gold standard (i.e., manual calibration performed by an expert engineer). The use of a graphical user interface is a promising tool for the effective use of an automatic procedure in a clinical context.

A Test of the Agenda-Setting Power of the Black Periodical Press: 1974-1982.

ERIC Educational Resources Information Center

Cherry, Dianne Lynne

Defining agenda-setting as the ability of the mass media to influence the level of the public's awareness and perceptions of political issues, a study was conducted to examine the agenda-setting power of the black periodical press in the United States. Survey responses collected by the University of Michigan Center for Political Studies were…

Heuristic approaches for energy-efficient shared restoration in WDM networks

NASA Astrophysics Data System (ADS)

Alilou, Shahab

In recent years, there has been ongoing research on the design of energy-efficient Wavelength Division Multiplexing (WDM) networks. The explosive growth of Internet traffic has led to increased power consumption of network components. Network survivability has also been a relevant research topic, as it plays a crucial role in assuring continuity of service with no disruption, regardless of network component failure. Network survivability mechanisms tend to utilize considerable resources such as spare capacity in order to protect and restore information. This thesis investigates techniques for reducing energy demand and enhancing energy efficiency in the context of network survivability. We propose two novel heuristic energy-efficient shared protection approaches for WDM networks. These approaches intend to save energy by setting on sleep mode devices that are not being used while providing shared backup paths to satisfy network survivability. The first approach exploits properties of a math series in order to assign weight to the network links. It aims at reducing power consumption at the network indirectly by aggregating traffic on a set of nodes and links with high traffic load level. Routing traffic on links and nodes that are already under utilization makes it possible for the links and nodes with no load to be set on sleep mode. The second approach is intended to dynamically route traffic through nodes and links with high traffic load level. Similar to the first approach, this approach computes a pair of paths for every newly arrived demand. It computes these paths for every new demand by comparing the power consumption of nodes and links in the network before the demand arrives with their potential power consumption if they are chosen along the paths of this demand. Simulations of two different networks were used to compare the total network power consumption obtained using the proposed techniques against a standard shared-path restoration scheme. Shared-path restoration is a network survivability method in which a link-disjoint backup path and wavelength is reserved at the time of call setup for a working path. However, in order to reduce spare capacity consumption, this reserved backup path and wavelength may be shared with other backup paths. Pool Sharing Scheme (PSS) is employed to implement shared-path restoration scheme [1]. In an optical network, the failure of a single link leads to the failure of all the lightpaths that pass through that particular link. PSS ensures that the amount of backup bandwidth required on a link to restore the failed connections will not be more than the total amount of reserved backup bandwidth on that link. Simulation results indicate that the proposed approaches lead to up to 35% power savings in WDM networks when traffic load is low. However, power saving decreases to 14% at high traffic load level. Furthermore, in terms of the total capacity consumption for working paths, PSS outperforms the two proposed approaches, as expected. In terms of total capacity consumption all the approaches behave similarly. In general, at low traffic load level, the two proposed approaches behave similar to PSS in terms of average link load, and the ratio of block demands. Nevertheless, at high traffic load, the proposed approaches result in higher ratio of blocked demands than PSS. They also lead to higher average link load than PSS for the equal number of generated demands.

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

Potts, C.; Faber, M.; Gunderson, G.

The as-built lattice of the Rapid Cycling Synchrotron (RCS) had two sets of correction sextupoles and two sets of quadrupoles energized by dc power supplies to control the tune and the tune tilt. With this method of powering these magnets, adjustment of tune conditions during the accelerating cycle as needed was not possible. A set of dynamically programmable power supplies has been built and operated to provide the required chromaticity adjustment. The short accelerating time (16.7 ms) of the RCS and the inductance of the magnets dictated large transistor amplifier power supplies. The required time resolution and waveform flexibility indicatedmore » the desirability of computer control. Both the amplifiers and controls are described, along with resulting improvements in the beam performance. 5 refs.« less

Measurements and predictions of flyover and static noise of a TF30 afterburning turbofan engine

NASA Technical Reports Server (NTRS)

Burcham, F. W., Jr.; Lasagna, P. L.; Oas, S. C.

1978-01-01

The noise of the TF30 afterburning turbofan engine in an F-111 airplane was determined from static (ground) and flyover tests. A survey was made to measure the exhaust temperature and velocity profiles for a range of power settings. Comparisons were made between predicted and measured jet mixing, internal, and shock noise. It was found that the noise produced at static conditions was dominated by jet mixing noise, and was adequately predicted by current methods. The noise produced during flyovers exhibited large contributions from internally generated noise in the forward arc. For flyovers with the engine at nonafterburning power, the internal noise, shock noise, and jet mixing noise were accurately predicted. During flyovers with afterburning power settings, however, additional internal noise believed to be due to the afterburning process was evident; its level was as much as 8 decibels above the nonafterburning internal noise. Power settings that produced exhausts with inverted velocity profiles appeared to be slightly less noisy than power settings of equal thrust that produced uniform exhaust velocity profiles both in flight and in static testing.

Visual areas become less engaged in associative recall following memory stabilization.

PubMed

Nieuwenhuis, Ingrid L C; Takashima, Atsuko; Oostenveld, Robert; Fernández, Guillén; Jensen, Ole

2008-04-15

Numerous studies have focused on changes in the activity in the hippocampus and higher association areas with consolidation and memory stabilization. Even though perceptual areas are engaged in memory recall, little is known about how memory stabilization is reflected in those areas. Using magnetoencephalography (MEG) we investigated changes in visual areas with memory stabilization. Subjects were trained on associating a face to one of eight locations. The first set of associations ('stabilized') was learned in three sessions distributed over a week. The second set ('labile') was learned in one session just prior to the MEG measurement. In the recall session only the face was presented and subjects had to indicate the correct location using a joystick. The MEG data revealed robust gamma activity during recall, which started in early visual cortex and propagated to higher visual and parietal brain areas. The occipital gamma power was higher for the labile than the stabilized condition (time=0.65-0.9 s). Also the event-related field strength was higher during recall of labile than stabilized associations (time=0.59-1.5 s). We propose that recall of the spatial associations prior to memory stabilization involves a top-down process relying on reconstructing learned representations in visual areas. This process is reflected in gamma band activity consistent with the notion that neuronal synchronization in the gamma band is required for visual representations. More direct synaptic connections are formed with memory stabilization, thus decreasing the dependence on visual areas.

Multi-time Scale Joint Scheduling Method Considering the Grid of Renewable Energy

NASA Astrophysics Data System (ADS)

Zhijun, E.; Wang, Weichen; Cao, Jin; Wang, Xin; Kong, Xiangyu; Quan, Shuping

2018-01-01

Renewable new energy power generation prediction error like wind and light, brings difficulties to dispatch the power system. In this paper, a multi-time scale robust scheduling method is set to solve this problem. It reduces the impact of clean energy prediction bias to the power grid by using multi-time scale (day-ahead, intraday, real time) and coordinating the dispatching power output of various power supplies such as hydropower, thermal power, wind power, gas power and. The method adopts the robust scheduling method to ensure the robustness of the scheduling scheme. By calculating the cost of the abandon wind and the load, it transforms the robustness into the risk cost and optimizes the optimal uncertainty set for the smallest integrative costs. The validity of the method is verified by simulation.

Model-independent test for scale-dependent non-Gaussianities in the cosmic microwave background.

PubMed

Räth, C; Morfill, G E; Rossmanith, G; Banday, A J; Górski, K M

2009-04-03

We present a model-independent method to test for scale-dependent non-Gaussianities in combination with scaling indices as test statistics. Therefore, surrogate data sets are generated, in which the power spectrum of the original data is preserved, while the higher order correlations are partly randomized by applying a scale-dependent shuffling procedure to the Fourier phases. We apply this method to the Wilkinson Microwave Anisotropy Probe data of the cosmic microwave background and find signatures for non-Gaussianities on large scales. Further tests are required to elucidate the origin of the detected anomalies.

Power of the Poincaré group: elucidating the hidden symmetries in focal conic domains.

PubMed

Alexander, Gareth P; Chen, Bryan Gin-Ge; Matsumoto, Elisabetta A; Kamien, Randall D

2010-06-25

Focal conic domains are typically the "smoking gun" by which smectic liquid crystalline phases are identified. The geometry of the equally spaced smectic layers is highly generic but, at the same time, difficult to work with. In this Letter we develop an approach to the study of focal sets in smectics which exploits a hidden Poincaré symmetry revealed only by viewing the smectic layers as projections from one-higher dimension. We use this perspective to shed light upon several classic focal conic textures, including the concentric cyclides of Dupin, polygonal textures, and tilt-grain boundaries.

Research on the content framework of information disclosure mechanism in Shanxi power market

NASA Astrophysics Data System (ADS)

Sun, Yanzhang; Li, Tao; Hou, Zhehui; Cao, Xiaozhong

2018-06-01

With the further development of the power reform, establishing a sound power system with rich content and efficient operation has become an urgent need. Faced with the current circumstance of power market information disclosure in Shanxi province, this paper fully incorporates the actual situation and introduces the index into the power market information disclosure mechanism, and sets up the general information disclosure framework in Shanxi province power market on the basis of which A direct information disclosure mechanism and an indirect information disclosure mechanism were designed. Then we formulate comprehensive power index system, generation index system, transmission and distribution index system, and power utilization index system. In conclusion, the outcomes above will enrich power information disclosure mechanism in Shanxi province and will provide a platform for various market members as a guidance on setting right business decisions.

(De)Constructing Power in Higher Education Governance Structures: An Analysis of Representation and Roles in Governing Bodies

ERIC Educational Resources Information Center

Bótas, Paulo Charles Pimentel; Huisman, Jeroen

2012-01-01

This article explores how power relations are constructed in the governance of higher education institutions. It examines and deconstructs, from a Foucauldian perspective, power relations and mechanisms in the relationship between the state and higher education institutions, and between academic and management staff. This research article…

A comparison of per sample global scaling and per gene normalization methods for differential expression analysis of RNA-seq data.

PubMed

Li, Xiaohong; Brock, Guy N; Rouchka, Eric C; Cooper, Nigel G F; Wu, Dongfeng; O'Toole, Timothy E; Gill, Ryan S; Eteleeb, Abdallah M; O'Brien, Liz; Rai, Shesh N

2017-01-01

Normalization is an essential step with considerable impact on high-throughput RNA sequencing (RNA-seq) data analysis. Although there are numerous methods for read count normalization, it remains a challenge to choose an optimal method due to multiple factors contributing to read count variability that affects the overall sensitivity and specificity. In order to properly determine the most appropriate normalization methods, it is critical to compare the performance and shortcomings of a representative set of normalization routines based on different dataset characteristics. Therefore, we set out to evaluate the performance of the commonly used methods (DESeq, TMM-edgeR, FPKM-CuffDiff, TC, Med UQ and FQ) and two new methods we propose: Med-pgQ2 and UQ-pgQ2 (per-gene normalization after per-sample median or upper-quartile global scaling). Our per-gene normalization approach allows for comparisons between conditions based on similar count levels. Using the benchmark Microarray Quality Control Project (MAQC) and simulated datasets, we performed differential gene expression analysis to evaluate these methods. When evaluating MAQC2 with two replicates, we observed that Med-pgQ2 and UQ-pgQ2 achieved a slightly higher area under the Receiver Operating Characteristic Curve (AUC), a specificity rate > 85%, the detection power > 92% and an actual false discovery rate (FDR) under 0.06 given the nominal FDR (≤0.05). Although the top commonly used methods (DESeq and TMM-edgeR) yield a higher power (>93%) for MAQC2 data, they trade off with a reduced specificity (<70%) and a slightly higher actual FDR than our proposed methods. In addition, the results from an analysis based on the qualitative characteristics of sample distribution for MAQC2 and human breast cancer datasets show that only our gene-wise normalization methods corrected data skewed towards lower read counts. However, when we evaluated MAQC3 with less variation in five replicates, all methods performed similarly. Thus, our proposed Med-pgQ2 and UQ-pgQ2 methods perform slightly better for differential gene analysis of RNA-seq data skewed towards lowly expressed read counts with high variation by improving specificity while maintaining a good detection power with a control of the nominal FDR level.

A comparison of per sample global scaling and per gene normalization methods for differential expression analysis of RNA-seq data

PubMed Central

Li, Xiaohong; Brock, Guy N.; Rouchka, Eric C.; Cooper, Nigel G. F.; Wu, Dongfeng; O’Toole, Timothy E.; Gill, Ryan S.; Eteleeb, Abdallah M.; O’Brien, Liz

2017-01-01

Normalization is an essential step with considerable impact on high-throughput RNA sequencing (RNA-seq) data analysis. Although there are numerous methods for read count normalization, it remains a challenge to choose an optimal method due to multiple factors contributing to read count variability that affects the overall sensitivity and specificity. In order to properly determine the most appropriate normalization methods, it is critical to compare the performance and shortcomings of a representative set of normalization routines based on different dataset characteristics. Therefore, we set out to evaluate the performance of the commonly used methods (DESeq, TMM-edgeR, FPKM-CuffDiff, TC, Med UQ and FQ) and two new methods we propose: Med-pgQ2 and UQ-pgQ2 (per-gene normalization after per-sample median or upper-quartile global scaling). Our per-gene normalization approach allows for comparisons between conditions based on similar count levels. Using the benchmark Microarray Quality Control Project (MAQC) and simulated datasets, we performed differential gene expression analysis to evaluate these methods. When evaluating MAQC2 with two replicates, we observed that Med-pgQ2 and UQ-pgQ2 achieved a slightly higher area under the Receiver Operating Characteristic Curve (AUC), a specificity rate > 85%, the detection power > 92% and an actual false discovery rate (FDR) under 0.06 given the nominal FDR (≤0.05). Although the top commonly used methods (DESeq and TMM-edgeR) yield a higher power (>93%) for MAQC2 data, they trade off with a reduced specificity (<70%) and a slightly higher actual FDR than our proposed methods. In addition, the results from an analysis based on the qualitative characteristics of sample distribution for MAQC2 and human breast cancer datasets show that only our gene-wise normalization methods corrected data skewed towards lower read counts. However, when we evaluated MAQC3 with less variation in five replicates, all methods performed similarly. Thus, our proposed Med-pgQ2 and UQ-pgQ2 methods perform slightly better for differential gene analysis of RNA-seq data skewed towards lowly expressed read counts with high variation by improving specificity while maintaining a good detection power with a control of the nominal FDR level. PMID:28459823

Thermoelectric power generator for variable thermal power source

DOEpatents

Bell, Lon E; Crane, Douglas Todd

2015-04-14

Traditional power generation systems using thermoelectric power generators are designed to operate most efficiently for a single operating condition. The present invention provides a power generation system in which the characteristics of the thermoelectrics, the flow of the thermal power, and the operational characteristics of the power generator are monitored and controlled such that higher operation efficiencies and/or higher output powers can be maintained with variably thermal power input. Such a system is particularly beneficial in variable thermal power source systems, such as recovering power from the waste heat generated in the exhaust of combustion engines.

Design of online monitoring and forecasting system for electrical equipment temperature of prefabricated substation based on WSN

NASA Astrophysics Data System (ADS)

Qi, Weiran; Miao, Hongxia; Miao, Xuejiao; Xiao, Xuanxuan; Yan, Kuo

2016-10-01

In order to ensure the safe and stable operation of the prefabricated substations, temperature sensing subsystem, temperature remote monitoring and management subsystem, forecast subsystem are designed in the paper. Wireless temperature sensing subsystem which consists of temperature sensor and MCU sends the electrical equipment temperature to the remote monitoring center by wireless sensor network. Remote monitoring center can realize the remote monitoring and prediction by monitoring and management subsystem and forecast subsystem. Real-time monitoring of power equipment temperature, history inquiry database, user management, password settings, etc., were achieved by monitoring and management subsystem. In temperature forecast subsystem, firstly, the chaos of the temperature data was verified and phase space is reconstructed. Then Support Vector Machine - Particle Swarm Optimization (SVM-PSO) was used to predict the temperature of the power equipment in prefabricated substations. The simulation results found that compared with the traditional methods SVM-PSO has higher prediction accuracy.

Analysis of the Intel 386 and i486 microprocessors for the Space Station Freedom Data Management System

NASA Technical Reports Server (NTRS)

Liu, Yuan-Kwei

1991-01-01

The feasibility is analyzed of upgrading the Intel 386 microprocessor, which has been proposed as the baseline processor for the Space Station Freedom (SSF) Data Management System (DMS), to the more advanced i486 microprocessors. The items compared between the two processors include the instruction set architecture, power consumption, the MIL-STD-883C Class S (Space) qualification schedule, and performance. The advantages of the i486 over the 386 are (1) lower power consumption; and (2) higher floating point performance. The i486 on-chip cache does not have parity check or error detection and correction circuitry. The i486 with on-chip cache disabled, however, has lower integer performance than the 386 without cache, which is the current DMS design choice. Adding cache to the 386/386 DX memory hierachy appears to be the most beneficial change to the current DMS design at this time.

Analysis of the Intel 386 and i486 microprocessors for the Space Station Freedom Data Management System

NASA Technical Reports Server (NTRS)

Liu, Yuan-Kwei

1991-01-01

The feasibility is analyzed of upgrading the Intel 386 microprocessor, which has been proposed as the baseline processor for the Space Station Freedom (SSF) Data Management System (DMS), to the more advanced i486 microprocessors. The items compared between the two processors include the instruction set architecture, power consumption, the MIL-STD-883C Class S (Space) qualification schedule, and performance. The advantages of the i486 over the 386 are (1) lower power consumption; and (2) higher floating point performance. The i486 on-chip cache does not have parity check or error detection and correction circuitry. The i486 with on-chip cache disabled, however, has lower integer performance than the 386 without cache, which is the current DMS design choice. Adding cache to the 386/387 DX memory hierarchy appears to be the most beneficial change to the current DMS design at this time.

Performance Testing of a High Temperature Linear Alternator for Stirling Convertors

NASA Technical Reports Server (NTRS)

Metscher, Jonathan F.; Geng, Steven M.

2016-01-01

The NASA Glenn Research Center has conducted performance testing of a high temperature linear alternator (HTLA) in support of Stirling power convertor development for potential future Radioisotope Power Systems (RPS). The high temperature linear alternator is a modified version of that used in Sunpower's Advanced Stirling Convertor (ASC), and is capable of operation at temperatures up to 200 deg. Increasing the temperature capability of the linear alternator could expand the mission set of future Stirling RPS designs. High temperature Neodymium-Iron-Boron (Nd-Fe-B) magnets were selected for the HTLA application, and were fully characterized and tested prior to use. Higher temperature epoxy for alternator assembly was also selected and tested for thermal stability and strength. A characterization test was performed on the HTLA to measure its performance at various amplitudes, loads, and temperatures. HTLA endurance testing at 200 deg is currently underway.

Note on Salter's energy absorber in random waves

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

Serman, D.D.; Mei, C.C.

1980-01-01

Salter's wave theory energy device has been the object of extensive theoretical and experimental studies during recent years. This paper describes the performance of the device in random waves by means of a numerical study. Different situations are considered. First, the cam is allowed to have one degree of freedom (the cam rolls about a rigid and fixed shaft) and is in a shallow sea where the waves are modeled by the JONSWAP spectrum. Power extraction, efficiency and dynamic response are presented in terms of wind characteristics for a cam radius of 3 m. In the open sea where typicalmore » waves are longer and higher, waves are represented by the P-M spectrum and the cam radius is taken to be 7 m. Finally, it is shown for a particular set of design parameters how the efficiency decays and the power extraction decreases with lack of rigidity in the support system.« less

Food marketing in recreational sport settings in Canada: a cross-sectional audit in different policy environments using the Food and beverage Marketing Assessment Tool for Settings (FoodMATS).

PubMed

Prowse, Rachel J L; Naylor, Patti-Jean; Olstad, Dana Lee; Carson, Valerie; Storey, Kate; Mâsse, Louise C; Kirk, Sara F L; Raine, Kim D

2018-05-31

Children's recreational sport settings typically sell energy dense, low nutrient products; however, it is unknown whether the same types of food and beverages are also marketed in these settings. Understanding food marketing in sports settings is important because the food industry often uses the promotion of physical activity to justify their products. This study aimed to document the 'exposure' and 'power' of food marketing present in public recreation facilities in Canada and assess differences between provinces with and without voluntary provincial nutrition guidelines for recreation facilities. Food marketing was measured in 51 sites using the Food and beverage Marketing Assessment Tool for Settings (FoodMATS). The frequency and repetition ('exposure') of food marketing and the presence of select marketing techniques, including child-targeted, sports-related, size, and healthfulness ('power'), were assessed. Differences in 'exposure' and 'power' characteristics between sites in three guideline provinces (n = 34) and a non-guideline province (n = 17) were assessed using Pearson's Chi squared tests of homogeneity and Mann-Whitney U tests. Ninety-eight percent of sites had food marketing present. The frequency of food marketing per site did not differ between guideline and non-guideline provinces (median = 29; p = 0.576). Sites from guideline provinces had a significantly lower proportion of food marketing occasions that were "Least Healthy" (47.9%) than sites from the non-guideline province (73.5%; p < 0.001). Use of child-targeted and sports-related food marketing techniques was significantly higher in sites from guideline provinces (9.5% and 10.9%, respectively), than in the non-guideline province (1.9% and 4.5% respectively; p values < 0.001). It was more common in the non-guideline province to use child-targeted and sports-related techniques to promote "Least Healthy" items (100.0% and 68.4%, respectively), compared to the guideline provinces (59.3% and 52.0%, respectively). Recreation facilities are a source of children's exposure to unhealthy food marketing. Having voluntary provincial nutrition guidelines that recommend provision of healthier foods was not related to the frequency of food marketing in recreation facilities but was associated with less frequent marketing of unhealthy foods. Policy makers should provide explicit food marketing regulations that complement provincial nutrition guidelines to fulfill their ethical responsibility to protect children and the settings where children spend time.

High current density sheet-like electron beam generator

NASA Astrophysics Data System (ADS)

Chow-Miller, Cora; Korevaar, Eric; Schuster, John

Sheet electron beams are very desirable for coupling to the evanescent waves in small millimeter wave slow-wave circuits to achieve higher powers. In particular, they are critical for operation of the free-electron-laser-like Orotron. The program was a systematic effort to establish a solid technology base for such a sheet-like electron emitter system that will facilitate the detailed studies of beam propagation stability. Specifically, the effort involved the design and test of a novel electron gun using Lanthanum hexaboride (LaB6) as the thermionic cathode material. Three sets of experiments were performed to measure beam propagation as a function of collector current, beam voltage, and heating power. The design demonstrated its reliability by delivering 386.5 hours of operation throughout the weeks of experimentation. In addition, the cathode survived two venting and pump down cycles without being poisoned or losing its emission characteristics. A current density of 10.7 A/sq cm. was measured while operating at 50 W of ohmic heating power. Preliminary results indicate that the nearby presence of a metal plate can stabilize the beam.

Differences in Physiological Responses to Interval Training in Cyclists With and Without Interval Training Experience

PubMed Central

Hebisz, Rafal; Borkowski, Jacek; Zatoń, Marek

2016-01-01

Abstract The aim of this study was to determine differences in glycolytic metabolite concentrations and work output in response to an all-out interval training session in 23 cyclists with at least 2 years of interval training experience (E) and those inexperienced (IE) in this form of training. The intervention involved subsequent sets of maximal intensity exercise on a cycle ergometer. Each set comprised four 30 s repetitions interspersed with 90 s recovery periods; sets were repeated when blood pH returned to 7.3. Measurements of post-exercise hydrogen (H+) and lactate ion (LA-) concentrations and work output were taken. The experienced cyclists performed significantly more sets of maximal efforts than the inexperienced athletes (5.8 ± 1.2 vs. 4.3 ± 0.9 sets, respectively). Work output decreased in each subsequent set in the IE group and only in the last set in the E group. Distribution of power output changed only in the E group; power decreased in the initial repetitions of set only to increase in the final repetitions. H+ concentration decreased in the third, penultimate, and last sets in the E group and in each subsequent set in the IE group. LA- decreased in the last set in both groups. In conclusion, the experienced cyclists were able to repeatedly induce elevated levels of lactic acidosis. Power output distribution changed with decreased acid–base imbalance. In this way, this group could compensate for a decreased anaerobic metabolism. The above factors allowed cyclists experienced in interval training to perform more sets of maximal exercise without a decrease in power output compared with inexperienced cyclists. PMID:28149346

A Multi-Band Uncertainty Set Based Robust SCUC With Spatial and Temporal Budget Constraints

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

Dai, Chenxi; Wu, Lei; Wu, Hongyu

2016-11-01

The dramatic increase of renewable energy resources in recent years, together with the long-existing load forecast errors and increasingly involved price sensitive demands, has introduced significant uncertainties into power systems operation. In order to guarantee the operational security of power systems with such uncertainties, robust optimization has been extensively studied in security-constrained unit commitment (SCUC) problems, for immunizing the system against worst uncertainty realizations. However, traditional robust SCUC models with single-band uncertainty sets may yield over-conservative solutions in most cases. This paper proposes a multi-band robust model to accurately formulate various uncertainties with higher resolution. By properly tuning band intervalsmore » and weight coefficients of individual bands, the proposed multi-band robust model can rigorously and realistically reflect spatial/temporal relationships and asymmetric characteristics of various uncertainties, and in turn could effectively leverage the tradeoff between robustness and economics of robust SCUC solutions. The proposed multi-band robust SCUC model is solved by Benders decomposition (BD) and outer approximation (OA), while taking the advantage of integral property of the proposed multi-band uncertainty set. In addition, several accelerating techniques are developed for enhancing the computational performance and the convergence speed. Numerical studies on a 6-bus system and the modified IEEE 118-bus system verify the effectiveness of the proposed robust SCUC approach for enhancing uncertainty modeling capabilities and mitigating conservativeness of the robust SCUC solution.« less

Development of microheaters for gas sensor with an AT-Mega 8535 temperature controller using a PWM (pulse width modulation) method

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

Megayanti, Meti; Panatarani, Camellia; Joni, I. Made, E-mail: imadejoni@phys.unpad.ac.id

Microheater is the main component in gas sensor characterized by their sensitivity, selectivity, and time response of gas sensor which is depend on the microheater temperature stability. A Cu microheater was developed and utilized AT-Mega 8535 controller using a PWM (pulse width modulation) method. This control system is interfaced to the PC to observe the real time temperature response of the microheater. Three initial resistance (R0) variations of microheater were developed in an open loop control system. The power characteristic of designed microheater depends on the specified microheater initial resistance. The smaller R0, the less power required to reach amore » temperature setting value. The developed microheater was designed to reach a temperature setting value of 250°C having resistance 0.531 Ω for 1.979 Watt and 0.265 Ω for 1.072 Watt respectively. The results of the investigation on the control performances shows microheater-control system achieved operating temperature up to 250°C. The response of the temperature control shows smallest R0 resulted in a high stability with short settling time, short delay time and small ripple for temperature setting values higher than 150°C. The obtained error of microheater temperature with R0 = 0.265 is 8.596 %. It is concluded that the developed microheater can be utilized as a component of a gas sensor.« less

Predictive regulatory models in Drosophila melanogaster by integrative inference of transcriptional networks

PubMed Central

Marbach, Daniel; Roy, Sushmita; Ay, Ferhat; Meyer, Patrick E.; Candeias, Rogerio; Kahveci, Tamer; Bristow, Christopher A.; Kellis, Manolis

2012-01-01

Gaining insights on gene regulation from large-scale functional data sets is a grand challenge in systems biology. In this article, we develop and apply methods for transcriptional regulatory network inference from diverse functional genomics data sets and demonstrate their value for gene function and gene expression prediction. We formulate the network inference problem in a machine-learning framework and use both supervised and unsupervised methods to predict regulatory edges by integrating transcription factor (TF) binding, evolutionarily conserved sequence motifs, gene expression, and chromatin modification data sets as input features. Applying these methods to Drosophila melanogaster, we predict ∼300,000 regulatory edges in a network of ∼600 TFs and 12,000 target genes. We validate our predictions using known regulatory interactions, gene functional annotations, tissue-specific expression, protein–protein interactions, and three-dimensional maps of chromosome conformation. We use the inferred network to identify putative functions for hundreds of previously uncharacterized genes, including many in nervous system development, which are independently confirmed based on their tissue-specific expression patterns. Last, we use the regulatory network to predict target gene expression levels as a function of TF expression, and find significantly higher predictive power for integrative networks than for motif or ChIP-based networks. Our work reveals the complementarity between physical evidence of regulatory interactions (TF binding, motif conservation) and functional evidence (coordinated expression or chromatin patterns) and demonstrates the power of data integration for network inference and studies of gene regulation at the systems level. PMID:22456606

Gamma power and cognition in patients with schizophrenia and their first-degree relatives.

PubMed

Díez, Álvaro; Suazo, Vanessa; Casado, Pilar; Martín-Loeches, Manuel; Molina, Vicente

2014-01-01

Gamma oscillations are essential for functional neural assembly formation underlying higher cerebral functions. Previous studies concerning gamma band power in schizophrenia have yielded diverse results. In this study, we assessed gamma band power in minimally treated patients with schizophrenia, their first-degree relatives and healthy controls during an oddball paradigm performance, as well as the relation between gamma power and cognitive performance. We found a higher gamma power in the patient group than in the healthy controls at the P3, P4, Fz, Pz and T5 sites. Compared with their relatives, gamma power in the patients was only marginally higher over P3 and P4. We found a nearly significant inverse association between gamma power at F4 and Tower of London performance in the patients, as well as a significant inverse association between gamma power at T5 and verbal memory and working memory scores in the relatives. These results support higher total gamma power in association with schizophrenia and its inverse association with cognitive performance in patients and their first-degree relatives.

Finite-size effects in transcript sequencing count distribution: its power-law correction necessarily precedes downstream normalization and comparative analysis.

PubMed

Wong, Wing-Cheong; Ng, Hong-Kiat; Tantoso, Erwin; Soong, Richie; Eisenhaber, Frank

2018-02-12

Though earlier works on modelling transcript abundance from vertebrates to lower eukaroytes have specifically singled out the Zip's law, the observed distributions often deviate from a single power-law slope. In hindsight, while power-laws of critical phenomena are derived asymptotically under the conditions of infinite observations, real world observations are finite where the finite-size effects will set in to force a power-law distribution into an exponential decay and consequently, manifests as a curvature (i.e., varying exponent values) in a log-log plot. If transcript abundance is truly power-law distributed, the varying exponent signifies changing mathematical moments (e.g., mean, variance) and creates heteroskedasticity which compromises statistical rigor in analysis. The impact of this deviation from the asymptotic power-law on sequencing count data has never truly been examined and quantified. The anecdotal description of transcript abundance being almost Zipf's law-like distributed can be conceptualized as the imperfect mathematical rendition of the Pareto power-law distribution when subjected to the finite-size effects in the real world; This is regardless of the advancement in sequencing technology since sampling is finite in practice. Our conceptualization agrees well with our empirical analysis of two modern day NGS (Next-generation sequencing) datasets: an in-house generated dilution miRNA study of two gastric cancer cell lines (NUGC3 and AGS) and a publicly available spike-in miRNA data; Firstly, the finite-size effects causes the deviations of sequencing count data from Zipf's law and issues of reproducibility in sequencing experiments. Secondly, it manifests as heteroskedasticity among experimental replicates to bring about statistical woes. Surprisingly, a straightforward power-law correction that restores the distribution distortion to a single exponent value can dramatically reduce data heteroskedasticity to invoke an instant increase in signal-to-noise ratio by 50% and the statistical/detection sensitivity by as high as 30% regardless of the downstream mapping and normalization methods. Most importantly, the power-law correction improves concordance in significant calls among different normalization methods of a data series averagely by 22%. When presented with a higher sequence depth (4 times difference), the improvement in concordance is asymmetrical (32% for the higher sequencing depth instance versus 13% for the lower instance) and demonstrates that the simple power-law correction can increase significant detection with higher sequencing depths. Finally, the correction dramatically enhances the statistical conclusions and eludes the metastasis potential of the NUGC3 cell line against AGS of our dilution analysis. The finite-size effects due to undersampling generally plagues transcript count data with reproducibility issues but can be minimized through a simple power-law correction of the count distribution. This distribution correction has direct implication on the biological interpretation of the study and the rigor of the scientific findings. This article was reviewed by Oliviero Carugo, Thomas Dandekar and Sandor Pongor.

A relational approach to durable poverty, inequality and power.

PubMed

Mosse, David

2010-01-01

The article argues for what can be called a 'relational' approach to poverty: one that first views persistent poverty as the consequence of historically developed economic and political relations, and second, that emphasises poverty and inequality as an effect of social categorisation and identity, drawing in particular on the experience of adivasis ("tribals") and dalits ("untouchables") subordinated in Indian society. The approach follows Charles Tilly's Durable Inequality in combining Marxian ideas of exploitation and dispossession with Weberian notions of social closure. The article then draws on the work of Steven Lukes, Pierre Bourdieu and Arjun Appadurai to argue for the need to incorporate a multidimensional conception of power; including not only power as the direct assertion of will but also 'agenda-setting power' that sets the terms in which poverty becomes (or fails to become) politicised, and closely related to power as political representation. This sets the basis for discussion of the politics of poverty and exclusion.

The Questionable Economic Case for Value-Based Drug Pricing in Market Health Systems.

PubMed

Pauly, Mark V

2017-02-01

This article investigates the economic theory and interpretation of the concept of "value-based pricing" for new breakthrough drugs with no close substitutes in a context (such as the United States) in which a drug firm with market power sells its product to various buyers. The interpretation is different from that in a country that evaluates medicines for a single public health insurance plan or a set of heavily regulated plans. It is shown that there will not ordinarily be a single value-based price but rather a schedule of prices with different volumes of buyers at each price. Hence, it is incorrect to term a particular price the value-based price, or to argue that the profit-maximizing monopoly price is too high relative to some hypothesized value-based price. When effectiveness of treatment or value of health is heterogeneous, the profit-maximizing price can be higher than that associated with assumed values of quality-adjusted life-years. If the firm sets a price higher than the value-based price for a set of potential buyers, the optimal strategy of the buyers is to decline to purchase that drug. The profit-maximizing price will come closer to a unique value-based price if demand is less heterogeneous. Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

QSAR Modeling of Rat Acute Toxicity by Oral Exposure

PubMed Central

Zhu, Hao; Martin, Todd M.; Ye, Lin; Sedykh, Alexander; Young, Douglas M.; Tropsha, Alexander

2009-01-01

Few Quantitative Structure-Activity Relationship (QSAR) studies have successfully modeled large, diverse rodent toxicity endpoints. In this study, a comprehensive dataset of 7,385 compounds with their most conservative lethal dose (LD50) values has been compiled. A combinatorial QSAR approach has been employed to develop robust and predictive models of acute toxicity in rats caused by oral exposure to chemicals. To enable fair comparison between the predictive power of models generated in this study versus a commercial toxicity predictor, TOPKAT (Toxicity Prediction by Komputer Assisted Technology), a modeling subset of the entire dataset was selected that included all 3,472 compounds used in the TOPKAT’s training set. The remaining 3,913 compounds, which were not present in the TOPKAT training set, were used as the external validation set. QSAR models of five different types were developed for the modeling set. The prediction accuracy for the external validation set was estimated by determination coefficient R2 of linear regression between actual and predicted LD50 values. The use of the applicability domain threshold implemented in most models generally improved the external prediction accuracy but expectedly led to the decrease in chemical space coverage; depending on the applicability domain threshold, R2 ranged from 0.24 to 0.70. Ultimately, several consensus models were developed by averaging the predicted LD50 for every compound using all 5 models. The consensus models afforded higher prediction accuracy for the external validation dataset with the higher coverage as compared to individual constituent models. The validated consensus LD50 models developed in this study can be used as reliable computational predictors of in vivo acute toxicity. PMID:19845371

The dependence of the sporicidal effects on the power and pressure of RF-generated plasma processes.

PubMed

Lassen, Klaus S; Nordby, Bolette; Grün, Reinar

2005-07-01

The sporicidal effect of 20 different radio-frequency plasma processes produced by combining five different gas mixtures [O(2), Ar/H(2) (50/50%), Ar/H(2) (5/95%), O(2)/H(2) (50/50%), O(2)/H(2) (95/5%)] with four power/pressure settings were tested. Sporicidal effects of oxygen-containing plasmas were dependent on power at low pressure settings but not at high pressure settings. In the absence of oxygen no power dependency was observed at either high or low pressure settings. Survivor curves obtained with the use of nonoxygen plasmas typically had a tailing tendency. Only a mixture-optimized Ar/H(2) (15/85%) plasma process was not encumbered by tailing, and produced a decimal reduction time (D value) below 2 min for Bacillus stearothermophilus spores. Scanning electron microscopy showed that a CF(4)/O(2) plasma did more damage to the substrate than the 15/85% Ar/H(2) plasma. The present results indicate that UV irradiation inactivation is swift and power and pressure independent. Additionally, it is produced at low energy. However, it is not complete. Inactivation through etching is highly power and pressure dependent; finally, inactivation by photodesorption is moderately power and pressure dependent. A sterilization process relying on this mechanism is very advantageous because it combines a highly sporicidal effect with low substrate damage. Copyright 2005 Wiley Periodicals, Inc.

Development of an Energy Harvesting Device using Piezoceramic Materials

NASA Astrophysics Data System (ADS)

Kulkarni, Vainatey

Piezoelectric energy harvesters are increasingly being pursued for their potential to replace finite-life batteries in wireless sensor modules and for their potential to create self-powered devices. This work presents the development of a novel piezoelectric harvester that attempts to improve upon the power output limitations of current piezoelectric harvesting technology. This novel harvester uses the concept of torsion on a tube to produce shear stresses and hence uses improved piezoelectric properties of the shear mode of piezoceramics to generate higher power outputs. This concept is first presented in this work and a proof-of-concept prototype is utilized to experimentally demonstrate the validity of this novel device. After this, the behaviour of the novel harvester is explored through an investigation into three cross-section geometries of the torsion tube and varying geometries of the eccentric mass using three different comparison metrics. Through this, it is observed that configurations with higher torsional compliance and high eccentric mass inertias have the potential for the highest power output and highest harvester effectiveness. However, the mechanical damping in the system is also found to significantly impact the harvester output resulting in prototypes of the various configurations not performing as expected. As a result of this discrepancy, the factors affecting the performance of the harvester are analyzed in greater detail through the development of a mathematical model that is then used to develop a set of guidelines to direct the design of a torsion harvester for a desired application. These guidelines are then used to develop an improved torsion harvester with a demonstrated ability to produce 1.2 mW of output power at its resonant frequency to power a wireless sensor module. Finally, the use of alternative materials such as single crystals of PMN-PT in the torsion harvester is also examined. Through finite element simulations and with material properties reported in the literature, the torsion harvester used with the sensor module is found to significantly benefit with the addition of the single crystal materials and ultimately generate 300% improvements in average output power while converting 11% of the input energy into usable electrical energy.

Endocrine and aggressive responses to competition are moderated by contest outcome, gender, individual versus team competition, and implicit motives

PubMed Central

Oxford, Jon K.; Tiedtke, Johanna M.; Ossmann, Anna; Özbe, Dominik

2017-01-01

This study examined hormonal responses to competition in relation to gender, social context, and implicit motives. Participants (N = 326) were randomly assigned to win or lose in a 10-round, virtual face-to-face competition, in same-sex individual- and team-competition contexts. Saliva samples, taken before and twice after the competition, were assayed for testosterone (T), estradiol (E), progesterone (P), and cortisol (C). Implicit needs for power (nPower) and affiliation (nAffiliation) were assessed with a picture-story exercise before the competition. Aggression was measured via the volume at which participants set noise blasts for their opponents. Men competing individually and women competing as teams showed similar T increases after winning. C was differentially associated with outcome in the team matches, with higher post-match cortisol for winning women, and an opposite effect for male teams. Analyses including implicit motives indicated that situational variables interacted with motivational needs in shaping hormonal responses to competition: in naturally cycling women, nPower predicted T increases after winning and T and E decreases after losing. In men, nPower predicted T increases after losing and decreases after winning. In male teams, nPower predicted C increases after losing, but not after winning, whereas in individual competitions, nPower was a general negative predictor of C changes in women. nAffiliation predicted P increases for women competing as teams, and P decreases for women competing individually. Aggression was higher in men, losers, and teams than in women, winners, and individuals. High aggression was associated with high baseline C in women competing individually and with low baseline C and C decreases in women competing as teams and in men generally. Our findings suggest that while situational and gender factors play a role in hormonal responses to competition, they also depend on their interplay with motivational factors. They also suggest that while aggression is strongly affected by situational factors in the context of a competition, it has no direct association with motivational and hormonal correlates of dominance (nPower, T, E) and instead is associated with (mostly) low levels of C. PMID:28750061

Intimate Partner Violence, Relationship Power Inequity and the Role of Sexual and Social Risk Factors in the Production of Violence among Young Women Who Have Multiple Sexual Partners in a Peri-Urban Setting in South Africa

PubMed Central

Zembe, Yanga Z.; Townsend, Loraine; Thorson, Anna; Silberschmidt, Margrethe; Ekstrom, Anna Mia

2015-01-01

Introduction This paper aims to assess the extent and correlates of intimate partner violence (IPV), explore relationship power inequity and the role of sexual and social risk factors in the production of violence among young women aged 16–24 reporting more than one partner in the past three months in a peri-urban setting in the Western Cape, South Africa. Recent estimates suggest that every six hours a woman is killed by an intimate partner in South Africa, making IPV a leading public health problem in the country. While there is mounting evidence that levels of IPV are high in peri-urban settings in South Africa, not much is known about how it manifests among women who engage in concomitantly high HIV risk behaviours such as multiple sexual partnering, transactional sex and age mixing. We know even less about how such women negotiate power and control if exposed to violence in such sexual networks. Methods Two hundred and fifty nine women with multiple sexual partners, residing in a predominantly Black peri-urban community in the Western Cape, South Africa, were recruited into a bio-behavioural survey using Respondent Driven Sampling (RDS). After the survey, focus group discussions and individual interviews were conducted among young women and men to understand the underlying factors informing their risk behaviours and experiences of violence. Findings 86% of the young women experienced IPV in the past 12 months. Sexual IPV was significantly correlated with sex with a man who was 5 years or older than the index female partner (OR 1.7, 95% CI 1.0–3.2) and transactional sex with most recent casual partner (OR 2.1, 95% CI 1.1–3.8). Predictably, women experienced high levels of relationship power inequity. However, they also identified areas in their controlling relationships where they shared decision making power. Discussion Levels of IPV among young women with multiple sexual partners were much higher than what is reported among women in the general population and shown to be associated with sexual risk taking. Interventions targeting IPV need to address sexual risk taking as it heightens vulnerability to violence. PMID:26599394

The influence of power and actor relations on priority setting and resource allocation practices at the hospital level in Kenya: a case study.

PubMed

Barasa, Edwine W; Cleary, Susan; English, Mike; Molyneux, Sassy

2016-09-30

Priority setting and resource allocation in healthcare organizations often involves the balancing of competing interests and values in the context of hierarchical and politically complex settings with multiple interacting actor relationships. Despite this, few studies have examined the influence of actor and power dynamics on priority setting practices in healthcare organizations. This paper examines the influence of power relations among different actors on the implementation of priority setting and resource allocation processes in public hospitals in Kenya. We used a qualitative case study approach to examine priority setting and resource allocation practices in two public hospitals in coastal Kenya. We collected data by a combination of in-depth interviews of national level policy makers, hospital managers, and frontline practitioners in the case study hospitals (n = 72), review of documents such as hospital plans and budgets, minutes of meetings and accounting records, and non-participant observations in case study hospitals over a period of 7 months. We applied a combination of two frameworks, Norman Long's actor interface analysis and VeneKlasen and Miller's expressions of power framework to examine and interpret our findings RESULTS: The interactions of actors in the case study hospitals resulted in socially constructed interfaces between: 1) senior managers and middle level managers 2) non-clinical managers and clinicians, and 3) hospital managers and the community. Power imbalances resulted in the exclusion of middle level managers (in one of the hospitals) and clinicians and the community (in both hospitals) from decision making processes. This resulted in, amongst others, perceptions of unfairness, and reduced motivation in hospital staff. It also puts to question the legitimacy of priority setting processes in these hospitals. Designing hospital decision making structures to strengthen participation and inclusion of relevant stakeholders could improve priority setting practices. This should however, be accompanied by measures to empower stakeholders to contribute to decision making. Strengthening soft leadership skills of hospital managers could also contribute to managing the power dynamics among actors in hospital priority setting processes.

Soft Power and Higher Education: An Examination of China's Confucius Institutes

ERIC Educational Resources Information Center

Yang, Rui

2010-01-01

China's global presence has become a significant subject. However, little attention has been directed to the role of higher education in projecting China's soft power, and little academic work has been done directly on it, despite the fact that there has been some work on related topics. Borrowing the theories of soft power and higher education…

What graph theory actually tells us about resting state interictal MEG epileptic activity.

PubMed

Niso, Guiomar; Carrasco, Sira; Gudín, María; Maestú, Fernando; Del-Pozo, Francisco; Pereda, Ernesto

2015-01-01

Graph theory provides a useful framework to study functional brain networks from neuroimaging data. In epilepsy research, recent findings suggest that it offers unique insight into the fingerprints of this pathology on brain dynamics. Most studies hitherto have focused on seizure activity during focal epilepsy, but less is known about functional epileptic brain networks during interictal activity in frontal focal and generalized epilepsy. Besides, it is not clear yet which measures are most suitable to characterize these networks. To address these issues, we recorded magnetoencephalographic (MEG) data using two orthogonal planar gradiometers from 45 subjects from three groups (15 healthy controls (7 males, 24 ± 6 years), 15 frontal focal (8 male, 32 ± 16 years) and 15 generalized epileptic (6 male, 27 ± 7 years) patients) during interictal resting state with closed eyes. Then, we estimated the total and relative spectral power of the largest principal component of the gradiometers, and the degree of phase synchronization between each sensor site in the frequency range [0.5-40 Hz]. We further calculated a comprehensive battery of 15 graph-theoretic measures and used the affinity propagation clustering algorithm to elucidate the minimum set of them that fully describe these functional brain networks. The results show that differences in spectral power between the control and the other two groups have a distinctive pattern: generalized epilepsy presents higher total power for all frequencies except the alpha band over a widespread set of sensors; frontal focal epilepsy shows higher relative power in the beta band bilaterally in the fronto-central sensors. Moreover, all network indices can be clustered into three groups, whose exemplars are the global network efficiency, the eccentricity and the synchronizability. Again, the patterns of differences were clear: the brain network of the generalized epilepsy patients presented greater efficiency and lower eccentricity than the control subjects for the high frequency bands, without a clear topography. Besides, the frontal focal epileptic patients showed only reduced eccentricity for the theta band over fronto-temporal and central sensors. These outcomes indicate that functional epileptic brain networks are different to those of healthy subjects during interictal stage at rest, with a unique pattern of dissimilarities for each type of epilepsy. Further, when properly selected, three network indices suffice to provide a comprehensive description of these differences. Yet, since such uniqueness in the pattern of differences is also evident in the power spectrum, we conclude that the added value of the graph theory approach in this context should not be overestimated.

Methods to Determine Recommended Feeder-Wide Advanced Inverter Settings for Improving Distribution System Performance

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

Rylander, Matthew; Reno, Matthew J.; Quiroz, Jimmy E.

This paper describes methods that a distribution engineer could use to determine advanced inverter settings to improve distribution system performance. These settings are for fixed power factor, volt-var, and volt-watt functionality. Depending on the level of detail that is desired, different methods are proposed to determine single settings applicable for all advanced inverters on a feeder or unique settings for each individual inverter. Seven distinctly different utility distribution feeders are analyzed to simulate the potential benefit in terms of hosting capacity, system losses, and reactive power attained with each method to determine the advanced inverter settings.

Age-Related Differences in Sleep Architecture and Electroencephalogram in Adolescents in the National Consortium on Alcohol and Neurodevelopment in Adolescence Sample.

PubMed

Baker, Fiona C; Willoughby, Adrian R; de Zambotti, Massimiliano; Franzen, Peter L; Prouty, Devin; Javitz, Harold; Hasler, Brant; Clark, Duncan B; Colrain, Ian M

2016-07-01

To investigate age-related differences in polysomnographic and sleep electroencephalographic (EEG) measures, considering sex, pubertal stage, ethnicity, and scalp topography in a large group of adolescents in the National Consortium on Alcohol and NeuroDevelopment in Adolescence (NCANDA). Following an adaptation/clinical screening night, 141 healthy adolescents (12-21 y, 64 girls) had polysomnographic recordings, from which sleep staging and EEG measures were derived. The setting was the SRI International Human Sleep Laboratory and University of Pittsburgh Pediatric Sleep Laboratory. Older age was associated with a lower percentage of N3 sleep, accompanied by higher percentages of N2, N1, and rapid eye movement (REM) sleep. Older boys compared with younger boys had more frequent awakenings and wakefulness after sleep onset, effects that were absent in girls. Delta (0.3-4 Hz) EEG power in nonrapid eye movement NREM sleep was lower in older than younger adolescents at all electrode sites, with steeper slopes of decline over the occipital scalp. EEG power in higher frequency bands was also lower in older adolescents than younger adolescents, with equal effects across electrodes. Percent delta power in the first NREM period was similar across age. African Americans had lower EEG power across frequency bands (delta to sigma) compared with Caucasians. Finally, replacing age with pubertal status in the models showed similar relationships. Substantial differences in sleep architecture and EEG were evident across adolescence in this large group, with sex modifying some relationships. Establishment and follow-up of this cohort allows the investigation of sleep EEG-brain structural relationships and the effect of behaviors, such as alcohol and substance use, on sleep EEG maturation. © 2016 Associated Professional Sleep Societies, LLC.

Multi-Dimensional Voice Program (MDVP) vs Praat for Assessing Euphonic Subjects: A Preliminary Study on the Gender-discriminating Power of Acoustic Analysis Software.

PubMed

Lovato, Andrea; De Colle, Wladimiro; Giacomelli, Luciano; Piacente, Alessandro; Righetto, Lara; Marioni, Gino; de Filippis, Cosimo

2016-11-01

The aim of this study was to compare the discriminatory power of the Multi-Dimensional Voice Program (MDVP) and Praat in distinguishing the gender of euphonic adults. This is a cross-sectional study. The recordings of 100 euphonic volunteers (50 males and 50 females) producing a sustained vowel /a/ were analyzed with MDVP and Praat software. Both computer programs identified significant differences between male and female volunteers in absolute jitter (MDVP P < 0.00001 and Praat P < 0.00001) and in shimmer in decibel (dB) (MDVP P = 0.006 and Praat P = 0.001). Using the scale proposed by Hosmer and Lemeshow, we found no gender discrimination for shimmer in dB with either the MDVP (area under the receiver operating characteristics curve [AUC] = 0.658) or Praat (AUC = 0.682). In our series, on the other hand, MDVP absolute jitter achieved an acceptable discrimination between males and females (AUC = 0.752), and Praat absolute jitter achieved an outstanding discrimination (AUC = 0.901). The discriminatory power of Praat absolute jitter was significantly higher than that of the MDVP (P = 0.003). Absolute jitter sensitivity and specificity were also higher for Praat (83% and 80%) than for the MDVP (74% and 49%). Differences attributable to a subject's gender and to the software used to measure acoustic parameters should be carefully considered in both research and clinical settings. Further studies are needed to test the discriminatory power of different voice analysis programs when differentiating between normal and dysphonic voices. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

Wireless powering for a self-propelled and steerable endoscopic capsule for stomach inspection.

PubMed

Carta, R; Tortora, G; Thoné, J; Lenaerts, B; Valdastri, P; Menciassi, A; Dario, P; Puers, R

2009-12-15

This paper describes the integration of an active locomotion module in a wirelessly powered endoscopic capsule. The device is a submersible capsule optimized to operate in a fluid environment in a liquid-distended stomach. A 3D inductive link is used to supply up to 400mW to the embedded electronics and a set of 4 radio-controlled motor propellers. The design takes advantage of a ferrite-core in the receiving coil-set. This approach significantly improves the coupling with the external field source with respect to earlier work by the group. It doubles the power that can be received with a coreless coil-set under identical external conditions. The upper limit of the received power was achieved complying with the strict regulations for safe exposure of biological tissue to variable magnetic fields. The wireless transferred power was proven to be sufficient to achieve the speed of 7cm/s in any directions. An optimized locomotion strategy was defined which limits the power consumption by running only 2 motors at a time. A user interface and a joystick controller allow to fully drive the capsule in an intuitive manner. The device functionalities were successfully tested in a dry and a wet environment in a laboratory set-up.

In vivo assessment of diet-induced rat hepatic steatosis development by percutaneous single-fiber spectroscopy detects scattering spectral changes due to fatty infiltration

NASA Astrophysics Data System (ADS)

Piao, Daqing; Sultana, Nigar; Holyoak, G. Reed; Ritchey, Jerry W.; Wall, Corey R.; Murray, Jill K.; Bartels, Kenneth E.

2015-11-01

This study explores percutaneous single-fiber spectroscopy (SfS) of rat livers undergoing fatty infiltration. Eight test rats were fed a methionine-choline-deficient (MCD) diet, and four control rats were fed a normal diet. Two test rats and one control rat were euthanized on days 12, 28, 49, and 77 following initiation of the diet, after percutaneous SfS of the liver under transabdominal ultrasound guidance. Histology of each set of the two euthanized test rats showed mild and mild hepatic lipid accumulations on day 12, moderate and severe on day 28, severe and mild on day 49, and moderate and mild on day 77. Livers with moderate or higher lipid accumulation generally presented higher spectral reflectance intensity when compared to lean livers. Livers of the eight test rats on day 12, two of which had mild lipid accumulation, revealed an average scattering power of 0.37±0.14 in comparison to 0.07±0.14 for the four control rats (p<0.01). When livers of the test rats with various levels of fatty infiltration were combined, the average scattering power was 0.36±0.15 in comparison to 0.14±0.24 of the control rats (0.05

The renormalization group method in statistical hydrodynamics

NASA Astrophysics Data System (ADS)

Eyink, Gregory L.

1994-09-01

This paper gives a first principles formulation of a renormalization group (RG) method appropriate to study of turbulence in incompressible fluids governed by Navier-Stokes equations. The present method is a momentum-shell RG of Kadanoff-Wilson type based upon the Martin-Siggia-Rose (MSR) field-theory formulation of stochastic dynamics. A simple set of diagrammatic rules are developed which are exact within perturbation theory (unlike the well-known Ma-Mazenko prescriptions). It is also shown that the claim of Yakhot and Orszag (1986) is false that higher-order terms are irrelevant in the ɛ expansion RG for randomly forced Navier-Stokes (RFNS) with power-law force spectrum F̂(k)=D0k-d+(4-ɛ). In fact, as a consequence of Galilei covariance, there are an infinite number of higher-order nonlinear terms marginal by power counting in the RG analysis of the power-law RFNS, even when ɛ≪4. The difficulty does not occur in the Forster-Nelson-Stephen (FNS) RG analysis of thermal fluctuations in an equilibrium NS fluid, which justifies a linear regression law for d≳2. On the other hand, the problem occurs also at the nontrivial fixed point in the FNS Model A, or its Burgers analog, when d<2. The marginal terms can still be present at the strong-coupling fixed point in true NS turbulence. If so, infinitely many fixed points may exist in turbulence and be associated to a somewhat surprising phenomenon: nonuniversality of the inertial-range scaling laws depending upon the dissipation-range dynamics.

The dispositions of things: the non-human dimension of power and ethics in patient-centred medicine.

PubMed

Gardner, John; Cribb, Alan

2016-09-01

This article explores power relations between clinicians, patients and families as clinicians engage in patient-centred ethical work. Specifically, we draw on actor-network theory to interrogate the role of non-human elements in distributing power relations in clinical settings, as clinicians attempt to manage the expectations of patients and families. Using the activities of a multidisciplinary team providing deep brain stimulation to children with severe movement disorders as an example, we illustrate how a patient-centred tool is implicated in establishing relations that constitute four modes of power: 'power over', 'power to', "power storage" and "power/discretion". We argue that understanding the role of non-human elements in structuring power relations can guide and inform bioethical discussions on the suitability of patient-centred approaches in clinical settings. © 2016 The Authors. Sociology of Health & Illness published by John Wiley & Sons Ltd on behalf of Foundation for SHIL.

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.

Cold-air performance of free-power turbine designed for 112-kilowatt automotive gas-turbine engine. 1: Design Stator-vane-chord setting angle of 35 deg

NASA Technical Reports Server (NTRS)

Kofskey, M. G.; Nusbaum, W. J.

1978-01-01

A cold air experimental investigation of a free power turbine designed for a 112-kW automotive gas-turbine was made over a range of speeds from 0 to 130 percent of design equivalent speeds and over a range of pressure ratio from 1.11 to 2.45. Results are presented in terms of equivalent power, torque, mass flow, and efficiency for the design power point setting of the variable stator.

HEMT Amplifiers and Equipment for their On-Wafer Testing

NASA Technical Reports Server (NTRS)

Fung, King man; Gaier, Todd; Samoska, Lorene; Deal, William; Radisic, Vesna; Mei, Xiaobing; Lai, Richard

2008-01-01

Power amplifiers comprising InP-based high-electron-mobility transistors (HEMTs) in coplanar-waveguide (CPW) circuits designed for operation at frequencies of hundreds of gigahertz, and a test set for onwafer measurement of their power levels have been developed. These amplifiers utilize an advanced 35-nm HEMT monolithic microwave integrated-circuit (MMIC) technology and have potential utility as local-oscillator drivers and power sources in future submillimeter-wavelength heterodyne receivers and imaging systems. The test set can reduce development time by enabling rapid output power characterization, not only of these and similar amplifiers, but also of other coplanar-waveguide power circuits, without the necessity of packaging the circuits.

Planning for Power.

ERIC Educational Resources Information Center

Failla, Victor A.; Birk, Thomas A.

1999-01-01

Discusses the electrical power problems that can arise when schools try to integrate educational technology components into an existing facility, and how to plan the electrical power design to avoid power failures. Examines setting objectives, evaluating current electrical conditions, and developing the technology power design. (GR)

Increasing the lensing figure of merit through higher order convergence moments

NASA Astrophysics Data System (ADS)

Vicinanza, Martina; Cardone, Vincenzo F.; Maoli, Roberto; Scaramella, Roberto; Er, Xinzhong

2018-01-01

The unprecedented quality, the increased data set, and the wide area of ongoing and near future weak lensing surveys allows one to move beyond the standard two points statistics, thus making it worthwhile to investigate higher order probes. As an interesting step toward this direction, we explore the use of higher order moments (HOM) of the convergence field as a way to increase the lensing figure of merit (FoM). To this end, we rely on simulated convergence to first show that HOM can be measured and calibrated so that it is indeed possible to predict them for a given cosmological model provided suitable nuisance parameters are introduced and then marginalized over. We then forecast the accuracy on cosmological parameters from the use of HOM alone and in combination with standard shear power spectra tomography. It turns out that HOM allow one to break some common degeneracies, thus significantly boosting the overall FoM. We also qualitatively discuss possible systematics and how they can be dealt with.

[Different configurations of violence in pedagogical relationships between teachers and students of higher education].

PubMed

Cruz, Gênesis Vivianne; Pereira, Wilza Rocha

2013-01-01

The aim of this study was to investigate the different settings of violence in pedagogical relations between teachers and students in a higher education from the theory of violence symbolic power. Twelve interviews were conducted with students from six courses of graduation from a higher educational institution; it was used the content analysis to interpret the data. It was found that violence is configured from the most subtle to the most noticeable way and that, although violence was present in the pedagogical processes of the context studied, this was not fully realized, probably because of the reproduction of the symbolic order, socially constructed and internalized by teachers and students. It is considered that the teaching practice needs to be improved in order to make the classroom democratic spaces and to make the students share responsibility for the pursuit of knowledge. We conclude that violence in relationships pedagogical produces certain effects, changes and consequences both, immediate and delayed, which can be minimized.

Hyper-polyhedron model applied to molecular screening of guanidines as Na/H exchange inhibitors.

PubMed

Bao, Xin-Hua; Lu, Wen-Cong; Liu, Liang; Chen, Nian-Yi

2003-05-01

To investigate structure-activity relationships of N-(3-Oxo-3,4-dihydro-2H-benzo[1,4]oxazine-6-carbonyl) guanidines in Na/H exchange inhibitory activities and probe into a new method of the computer-aided molecular screening. The hyper-polyhedron model (HPM) was proposed in our lab. The samples with probably higher activities could be determined in such a way that their representing points should be in the hyper-polyhedron region where all known samples with high activities were distributed. And the predictive ability of different methods available was tested by the cross-validation experiment. The accurate rate of molecular screening of N-(3-Oxo-3,4-dihydro-2H-benzo[1,4]oxazine-6-carbonyl) guanidines by HPM was much higher than that obtained by PCA (principal component analysis) and Fisher methods for the data set available here. Therefore, HPM could be used as a powerful tool for screening new compounds with probably higher activities.

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

O'Driscoll, M.

Power capacity additions in Asia will at least triple by 2010, and Arthur D. Little Inc. predicts natural gas can pick up a good 15 percent of that market. The study predicts Asia potentially will need 720 gigawatts of new power generation by 2010, of which 15 percent may be gas-based. This represents a market three times the size of the US market in the same period, and would require more than $1 trillion in investment to finance the power generation projects alone. Six forces are driving new market opportunities for natural gas in Asia, and have set the stagemore » for major investments in Asian gas-based power generation. They are: New technologies; growing environmental pressures; privatization; alternative energy pricing; gas availability; and continued economic growth. Japan, South Korea and Taiwan already have large, well-established markets for both gas and power that provide minimal opportunities for foreign investment. But the rest of Asia - specifically, India, Pakistan, the Philippines, Vietnam, Indonesia, Malaysia, the People's Republic of China, Thailand, Bangladesh and Myanmar - is still relatively undeveloped, the study said, and gas is emerging as an energy import substitute or export earner. The study found those countries will turn increased environmental awareness and concern into legislation as their economic prosperity grows, leading to a higher future value for natural gas relative to other fuels. Stricter emissions standards will favor gas over diesel, fuel oil and coal.« less

Effects of shade on physiological changes, oxidative stress, and total antioxidant power in Thai Brahman cattle.

PubMed

Aengwanich, Worapol; Kongbuntad, Watee; Boonsorn, Thongchai

2011-09-01

The purpose of this study was to assess the effects of artificial shade, tree shade, and no shade on physiological changes, oxidative stress, and total antioxidant power in Thai Brahman cattle. Twenty-one cattle were divided into three groups: cattle maintained under artificial shade, under tree shade, and without shade. On days 1, 7, 14, 21, and 28 of the experimental period, after the cattle were set in individual stalls for 2 h, physiological changes, thiobarbituric acid reactive substances (TBARS), and total antioxidant power were investigated. The results revealed that the respiratory rate, heart rate, sweat rate and the neutrophil/lymphocyte ratio of the no-shade cattle were significantly higher than those of cattle maintained under artificial shade and tree shade (P < 0.05). During the early period of heat exposure, the total antioxidant power of the no-shade cattle was lower than those of cattle maintained under artificial shade and tree shade, but the total antioxidant power of cattle maintained under artificial shade and tree shade were not different (P > 0.05). However, rectal temperature and packed cell volume of the cattle in all groups did not differ (P > 0.05). These results showed that artificial shade and tree shade can protect cattle from sunlight compared to no shade, and that the effectiveness of tree shade for sunlight protection is at an intermediate level.

Validity and reproducibility of the ErgomoPro power meter compared with the SRM and Powertap power meters.

PubMed

Duc, Sebastien; Villerius, Vincent; Bertucci, William; Grappe, Frederic

2007-09-01

The ErgomoPro (EP) is a power meter that measures power output (PO) during outdoor and indoor cycling via 2 optoelectronic sensors located in the bottom bracket axis. The aim of this study was to determine the validity and the reproducibility of the EP compared with the SRM crank set and Powertap hub (PT). The validity of the EP was tested in the laboratory during 8 submaximal incremental tests (PO: 100 to 400 W), eight 30-min submaximal constant-power tests (PO = 180 W), and 8 sprint tests (PO > 750 W) and in the field during 8 training sessions (time: 181 +/- 73 min; PO: approximately 140 to 160 W). The reproducibility was assessed by calculating the coefficient of PO variation (CV) during the submaximal incremental and constant tests. The EP provided a significantly higher PO than the SRM and PT during the submaximal incremental test: The mean PO differences were +6.3% +/- 2.5% and +11.1% +/- 2.1% respectively. The difference was greater during field training sessions (+12.0% +/- 5.7% and +16.5% +/- 5.9%) but lower during sprint tests (+1.6% +/- 2.5% and +3.2% +/- 2.7%). The reproducibility of the EP is lower than those of the SRM and PT (CV = 4.1% +/- 1.8%, 1.9% +/- 0.4%, and 2.1% +/- 0.8%, respectively). The EP power meter appears less valid and reliable than the SRM and PT systems.

High Quality Data for Grid Integration Studies

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

Clifton, Andrew; Draxl, Caroline; Sengupta, Manajit

As variable renewable power penetration levels increase in power systems worldwide, renewable integration studies are crucial to ensure continued economic and reliable operation of the power grid. The existing electric grid infrastructure in the US in particular poses significant limitations on wind power expansion. In this presentation we will shed light on requirements for grid integration studies as far as wind and solar energy are concerned. Because wind and solar plants are strongly impacted by weather, high-resolution and high-quality weather data are required to drive power system simulations. Future data sets will have to push limits of numerical weather predictionmore » to yield these high-resolution data sets, and wind data will have to be time-synchronized with solar data. Current wind and solar integration data sets are presented. The Wind Integration National Dataset (WIND) Toolkit is the largest and most complete grid integration data set publicly available to date. A meteorological data set, wind power production time series, and simulated forecasts created using the Weather Research and Forecasting Model run on a 2-km grid over the continental United States at a 5-min resolution is now publicly available for more than 126,000 land-based and offshore wind power production sites. The National Solar Radiation Database (NSRDB) is a similar high temporal- and spatial resolution database of 18 years of solar resource data for North America and India. The need for high-resolution weather data pushes modeling towards finer scales and closer synchronization. We also present how we anticipate such datasets developing in the future, their benefits, and the challenges with using and disseminating such large amounts of data.« less

Reversing Optical Damage In LiNbO3 Switches

NASA Technical Reports Server (NTRS)

Gee, C. M.; Thurmond, G. D.

1985-01-01

One symptom of optical damage in Ti-diffused LiNbO3 directional-coupler switch reversed by temporarily raising input illumination to higher-thannormal power level. Healing phenomenon used to restore normal operation, increase operating-power rating, and stabilize operating characteristics at lower powers. Higher operating power is tolerated after treatment.

Thermal effects of Ho: YAG laser lithotripsy: real-time evaluation in an in vitro model.

PubMed

Hein, Simon; Petzold, Ralf; Schoenthaler, Martin; Wetterauer, Ulrich; Miernik, Arkadiusz

2018-04-24

To evaluate the thermal effect of Ho:YAG laser lithotripsy in a standardized in vitro model via real-time temperature measurement. Our model comprised a 20 ml test tube simulating the renal pelvis that was immersed in a 37 °C water bath. Two different laser fibers [FlexiFib (15-45 W), RigiFib 1000 (45-100 W), LISA laser products OHG, Katlenburg-Lindau, Germany] were placed in the test tube. An Ho:YAG 100 W laser was used in all experiments (LISA). Each experiment involved 120 s of continuous laser application, and was repeated five times. Different laser settings (high vs. low frequency, high vs. low energy, and long vs. short pulse duration), irrigation rates (0 up to 100 ml/min, realized by several pumps), and human calcium oxalate stone samples were analyzed. Temperature data were acquired by a real-time data logger with thermocouples (PICO Technology, Cambridgeshire, UK). Real-time measurements were assessed using MatLab ® . Laser application with no irrigation results in a rapid increase in temperature up to ∆28 K, rising to 68 °C at 100 W. Low irrigation rates yield significantly higher temperature outcomes. Higher irrigation rates result immediately in a lower temperature rise. High irrigation rates of 100 ml/min result in a temperature rise of 5 K at the highest laser power setting (100 W). Ho:YAG laser lithotripsy might be safe provided that there is sufficient irrigation. However, high power and low irrigation resulted in potentially tissue-damaging temperatures. Laser devices should, therefore, always be applied in conjunction with continuous, closely monitored irrigation whenever performing Ho:YAG laser lithotripsy.

NASA's RPS Design Reference Mission Set for Solar System Exploration

NASA Technical Reports Server (NTRS)

Balint, Tibor S.

2007-01-01

NASA's 2006 Solar System Exploration (SSE) Strategic Roadmap identified a set of proposed large Flagship, medium New Frontiers and small Discovery class missions, addressing key exploration objectives. These objectives respond to the recommendations by the National Research Council (NRC), reported in the SSE Decadal Survey. The SSE Roadmap is down-selected from an over-subscribed set of missions, called the SSE Design Reference Mission (DRM) set. Missions in the Flagship and New Frontiers classes can consider Radioisotope Power Systems (RPSs), while small Discovery class missions are not permitted to use them, due to cost constraints. In line with the SSE DRM set and the SSE Roadmap missions, the RPS DRM set represents a set of missions, which can be enabled or enhanced by RPS technologies. At present, NASA has proposed the development of two new types of RPSs. These are the Multi-Mission Radioisotope Thermoelectric Generator (MMRTG), with static power conversion; and the Stirling Radioisotope Generator (SRG), with dynamic conversion. Advanced RPSs, under consideration for possible development, aim to increase specific power levels. In effect, this would either increase electric power generation for the same amount of fuel, or reduce fuel requirements for the same power output, compared to the proposed MMRTG or SRG. Operating environments could also influence the design, such that an RPS on the proposed Titan Explorer would use smaller fins to minimize heat rejection in the extreme cold environment; while the Venus Mobile Explorer long-lived in-situ mission would require the development of a new RPS, in order to tolerate the extreme hot environment, and to simultaneously provide active cooling to the payload and other electric components. This paper discusses NASA's SSE RPS DRM set, in line with the SSE DRM set. It gives a qualitative assessment regarding the impact of various RPS technology and configuration options on potential mission architectures, which could support NASA's RPS technology development planning, and provide an understanding of fuel need trades over the next three decades.

Edge compression techniques for visualization of dense directed graphs.

PubMed

Dwyer, Tim; Henry Riche, Nathalie; Marriott, Kim; Mears, Christopher

2013-12-01

We explore the effectiveness of visualizing dense directed graphs by replacing individual edges with edges connected to 'modules'-or groups of nodes-such that the new edges imply aggregate connectivity. We only consider techniques that offer a lossless compression: that is, where the entire graph can still be read from the compressed version. The techniques considered are: a simple grouping of nodes with identical neighbor sets; Modular Decomposition which permits internal structure in modules and allows them to be nested; and Power Graph Analysis which further allows edges to cross module boundaries. These techniques all have the same goal--to compress the set of edges that need to be rendered to fully convey connectivity--but each successive relaxation of the module definition permits fewer edges to be drawn in the rendered graph. Each successive technique also, we hypothesize, requires a higher degree of mental effort to interpret. We test this hypothetical trade-off with two studies involving human participants. For Power Graph Analysis we propose a novel optimal technique based on constraint programming. This enables us to explore the parameter space for the technique more precisely than could be achieved with a heuristic. Although applicable to many domains, we are motivated by--and discuss in particular--the application to software dependency analysis.

Pathfinder aircraft taking off - setting new solar powered altitude record

NASA Technical Reports Server (NTRS)

1995-01-01

The Pathfinder solar-powered remotely piloted aircraft climbs to a record-setting altitude of 50,567 feet during a flight Sept. 11, 1995, at NASA's Dryden Flight Research Center, Edwards, California. Pathfinder was a lightweight, solar-powered, remotely piloted flying wing aircraft used to demonstrate the use of solar power for long-duration, high-altitude flight. Its name denotes its mission as the 'Pathfinder' or first in a series of solar-powered aircraft that will be able to remain airborne for weeks or months on scientific sampling and imaging missions. Solar arrays covered most of the upper wing surface of the Pathfinder aircraft. These arrays provided up to 8,000 watts of power at high noon on a clear summer day. That power fed the aircraft's six electric motors as well as its avionics, communications, and other electrical systems. Pathfinder also had a backup battery system that could provide power for two to five hours, allowing for limited-duration flight after dark. Pathfinder flew at airspeeds of only 15 to 20 mph. Pitch control was maintained by using tiny elevators on the trailing edge of the wing while turns and yaw control were accomplished by slowing down or speeding up the motors on the outboard sections of the wing. On September 11, 1995, Pathfinder set a new altitude record for solar-powered aircraft of 50,567 feet above Edwards Air Force Base, California, on a 12-hour flight. On July 7, 1997, it set another, unofficial record of 71,500 feet at the Pacific Missile Range Facility, Kauai, Hawaii. In 1998, Pathfinder was modified into the longer-winged Pathfinder Plus configuration. (See the Pathfinder Plus photos and project description.)

New insights into old methods for identifying causal rare variants.

PubMed

Wang, Haitian; Huang, Chien-Hsun; Lo, Shaw-Hwa; Zheng, Tian; Hu, Inchi

2011-11-29

The advance of high-throughput next-generation sequencing technology makes possible the analysis of rare variants. However, the investigation of rare variants in unrelated-individuals data sets faces the challenge of low power, and most methods circumvent the difficulty by using various collapsing procedures based on genes, pathways, or gene clusters. We suggest a new way to identify causal rare variants using the F-statistic and sliced inverse regression. The procedure is tested on the data set provided by the Genetic Analysis Workshop 17 (GAW17). After preliminary data reduction, we ranked markers according to their F-statistic values. Top-ranked markers were then subjected to sliced inverse regression, and those with higher absolute coefficients in the most significant sliced inverse regression direction were selected. The procedure yields good false discovery rates for the GAW17 data and thus is a promising method for future study on rare variants.

Military Curricula for Vocational & Technical Education. Basic Electricity and Electronics. CANTRAC A-100-0010. Module 20: Solid State Power Supplies; 20T: Electron Tube Power Supplies. Study Booklet.

ERIC Educational Resources Information Center

Chief of Naval Education and Training Support, Pensacola, FL.

This set of individualized learning modules on power supplies is one in a series of modules for a course in basic electricity and electronics. The course is one of a number of military-developed curriculum packages selected for adaptation to vocational instructional and curriculum development in a civilian setting. Two modules are included in the…

Investigation of microstructural and electrical properties of composition dependent co-sputtered Hf1-x Ta x O2 thin films

NASA Astrophysics Data System (ADS)

Das, K. C.; Tripathy, N.; Ghosh, S. P.; Mohanta, S. K.; Nakamura, A.; Kar, J. P.

2017-11-01

Tantalum doped HfO2 gate dielectric thin films were deposited on silicon substrates using RF reactive co-sputtering by varying RF power of Ta target from 15 W to 90 W. The morphological, compositional and electrical properties of Hf1-x Ta x O2 films were systematically investigated. The Ta content was found to be increased up to 21% for a Ta target power of 90 W. The evolution of monoclinic phase of Hf1-x Ta x O2 was seen from XRD study upto RF power of 60 W and afterwards, the amorphous like behaviour is appeared. The featureless smooth surface with the decrease in granular morphology has been observed from FESEM micrographs of the doped films at higher RF powers of Ta. The flatband voltage is found to be shifted towards negative voltage in the capacitance-voltage plot, which was attributed to the enhancement in positive oxide charge density with rise in RF power. The interface charge density has a minimum value of 7.85  ×  1011 eV-1 cm-2 for the film deposited at Ta RF power of 75 W. The Hf1-x Ta x O2 films deposited at Ta target RF power of 90 W has shown lower leakage current. The high on/off ratio of the current during the set process in Hf1-x Ta x O2 based memristors is found suitable for bipolar resistive switching memory device applications.

The reduction in treatment efficiency at high acoustic powers during MR-guided transcranial focused ultrasound thalamotomy for Essential Tremor.

PubMed

Hughes, Alec; Huang, Yuexi; Schwartz, Michael L; Hynynen, Kullervo

2018-05-14

To analyze clinical data indicating a reduction in the induced energy-temperature efficiency relationship during transcranial focused ultrasound (FUS) Essential Tremor (ET) thalamotomy treatments at higher acoustic powers, establish its relationship with the spatial distribution of the focal temperature elevation, and explore its cause. A retrospective observational study of patients (n = 19) treated between July 2015 and August 2016 for (ET) by FUS thalamotomy was performed. These data were analyzed to compare the relationships between the applied power, the applied energy, the resultant peak temperature achieved in the brain, and the dispersion of the focal volume. Full ethics approval was received and all patients provided signed informed consent forms before the initiation of the study. Computer simulations, animal experiments, and clinical system tests were performed to determine the effects of skull heating, changes in brain properties and transducer acoustic output, respectively. All animal procedures were approved by the Animal Care and Use Committee and conformed to the guidelines set out by the Canadian Council on Animal Care. MATLAB was used to perform statistical analysis. The reduction in the energy efficiency relationship during treatment correlates with the increase in size of the focal volume at higher sonication powers. A linear relationship exists showing that a decrease in treatment efficiency correlates positively with an increase in the focal size over the course of treatment (P < 0.01), supporting the hypothesis of transient skull and tissue heating causing acoustic aberrations leading to a decrease in efficiency. Changes in thermal conductivity, perfusion, absorption rates in the brain, as well as ultrasound transducer acoustic output levels were found to have minimal effects on the observed reduction in efficiency. The reduction in energy-temperature efficiency during high-power FUS treatments correlated with observed increases in the size of the focal volume and is likely caused by transient changes in the tissue and skull during heating. © 2018 American Association of Physicists in Medicine.

Optimization of pressure settings during adaptive servo-ventilation support using real-time heart rate variability assessment: initial case report.

PubMed

Imamura, Teruhiko; Nitta, Daisuke; Kinugawa, Koichiro

2017-01-05

Adaptive servo-ventilation (ASV) therapy is a recent non-invasive positive pressure ventilation therapy that was developed for patients with heart failure (HF) refractory to optimal medical therapy. However, it is likely that ASV therapy at relatively higher pressure setting worsens some of the patients' prognosis compared with optimal medical therapy. Therefore, identification of optimal pressure settings of ASV therapy is warranted. We present the case of a 42-year-old male with HF, which was caused by dilated cardiomyopathy, who was admitted to our institution for evaluating his eligibility for heart transplantation. To identify the optimal pressure setting [peak end-expiratory pressure (PEEP) ramp test], we performed an ASV support test, during which the PEEP settings were set at levels ranging from 4 to 8 mmHg, and a heart rate variability (HRV) analysis using the MemCalc power spectral density method. Clinical parameters varied dramatically during the PEEP ramp test. Over incremental PEEP levels, pulmonary capillary wedge pressure, cardiac index and high-frequency level (reflecting parasympathetic activity) decreased; however, the low-frequency level increased along with increase in plasma noradrenaline concentrations. An inappropriately high PEEP setting may stimulate sympathetic nerve activity accompanied by decreased cardiac output. This was the first report on the PEEP ramp test during ASV therapy. Further research is warranted to determine whether use of optimal pressure settings using HRV analyses may improve the long-term prognosis of such patients.

Hyperventilation as a strategy for improved repeated sprint performance.

PubMed

Sakamoto, Akihiro; Naito, Hisashi; Chow, Chin-Moi

2014-04-01

Repeated high-intensity sprints incur substantial anaerobic metabolic challenges and create an acidic muscle milieu that is unfavorable for subsequent performance. Hyperventilation, resulting in respiratory alkalosis, acts as a compensatory mechanism for metabolic acidosis. This study tested the hypothesis that hyperventilation performed during recovery intervals would attenuate performance decrement in repeated sprint pedaling. Thirteen male university athletes performed 10 sets of 10-second maximal pedaling on a cycle ergometer with a 60-second recovery between sets under control (spontaneous breathing) and hyperventilation conditions in a crossover counter-balanced manner. Pedaling load was set at 0.075 × body mass. Peak and mean power outputs were documented for each set to compare performance decrements for 10 sets between conditions. Hyperventilation (60 breaths per minute and end-tidal partial pressure of CO2 maintained at 20-25 mm Hg) was performed 30 seconds before each sprint set. This intervention successfully increased blood pH by 0.03-0.07 but lowered P(CO2) by 1.2-8.4 mm Hg throughout exercise (p < 0.001). The peak and mean power outputs, and blood [La] accumulation were not significantly different between the conditions. However, a significant condition × time interaction existed for peak power (p = 0.035) and mean power (p = 0.023), demonstrating an attenuation in power decrement in later sprint sets with hyperventilation. In conclusion, hyperventilation implemented during recovery intervals of repeated sprint pedaling attenuated performance decrements in later exercise bouts that was associated with substantial metabolic acidosis. The practical implication is that hyperventilation may have a strategic role for enhancing training effectiveness and may give an edge in performance outcomes.

The Influence of Relationship Power Dynamics on HIV Testing in Rural Malawi

PubMed Central

Conroy, Amy A.

2014-01-01

Using the theory of gender and power (TGP) and data from the Tsogolo la Thanzi (TLT) study, we examined how relationship power shapes young people’s decisions to test for HIV in rural Malawi (N=932), a high-HIV prevalence setting undergoing rapid expansions in testing services. We used generalized estimating equations (GEE) to examine associations among five constructs of relationship power (socioeconomic inequalities, relationship dominance, relationship violence, relationship unity, and mistrust), perceived risk, and receiving an HIV test over a 16-month period. The results indicate that young Malawians are testing for HIV at relatively high rates, repeatedly, and not just during pregnancy. Over the study period, 47.3% of respondents received at least one HIV test outside of TLT (range: 0–4). The GEE analysis revealed that men and women with higher levels of relationship unity were less likely to test for HIV. For men, being a victim of sexual coercion was an additional barrier to testing. Women’s testing decisions were more strongly influenced by perceptions of a partner’s risk for HIV than their own, whereas men relied more on self-assessments. The results highlight that testing decisions are deeply embedded within the relationship context, which should be considered in future HIV testing interventions. PMID:24670263

A simulation investigation of the effects of engine-and thrust-response characteristics on helicopter handling qualities

NASA Technical Reports Server (NTRS)

Corless, L. D.; Blanken, C. L.

1983-01-01

A multi-phase program is being conducted to study, in a generic sense and through ground simulation, the effects of engine response, rotor inertia, rpm control, excess power, and vertical damping on specific maneuvers included in nap-of-the-Earth (NOE) operations. The helicopter configuration with an rpm-governed gas-turbine engine are considered. Handling-qualities-criteria data are considered in light of aspects peculiar to rotary-wing and NOE operations. The results of three moving-based piloted simulation studies are summarized and the frequency, characteristics of the helicopter thrust response which set it apart from other VTOL types are explained. Power-system response is affected by both the engine-governor response and the level of rotor inertia. However, results indicate that with unlimited power, variations in engine response can have a significant effect on pilot rating, whereas changes in rotor inertia, in general, do not. The results also show that any pilot interaction required to maintain proper control can significantly degrade handling qualities. Data for variations in vertical damping and collective sensitivity are compared with existing handling-qualities specifications, MIL-F-83300 and AGARD 577, and show a need for higher minimums for both damping and sensitivity for the bob-up task. Results for cases of limited power are also shown.

Nevada Renewable Energy Training Project: Geothermal Power Plant Operators

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

Jim, Nichols

2014-04-29

The purpose of this project was to develop and institute a training program for certified geothermal power plant operators (GPO). An advisory board consisting of subject matter experts from the geothermal energy industry and academia identified the critical skill sets required for this profession. A 34-credit Certificate of Achievement (COA), Geothermal Power Plant Operator, was developed using eight existing courses and developing five new courses. Approval from the Nevada System of Higher Education Board of Regents was obtained. A 2,400 sq. ft. geothermal/fluid mechanics laboratory and a 3,000 sq. ft. outdoor demonstration laboratory were constructed for hands-on training. Students alsomore » participated in field trips to geothermal power plants in the region. The majority of students were able to complete the program in 2-3 semesters, depending on their level of math proficiency. Additionally the COA allowed students to continue to an Associate of Applied Science (AAS), Energy Technologies with an emphasis in Geothermal Energy (26 additional credits), if they desired. The COA and AAS are stackable degrees, which provide students with an ongoing career pathway. Articulation agreements with other NSHE institutions provide students with additional opportunities to pursue a Bachelor of Applied Science in Management or Instrumentation. Job placement for COA graduates has been excellent.« less

Environmental and economic assessment of a cracked ammonia fuelled alkaline fuel cell for off-grid power applications

NASA Astrophysics Data System (ADS)

Cox, Brian; Treyer, Karin

2015-02-01

Global mobile telecommunication is possible due to millions of Base Transceiver Stations (BTS). Nearly 1 million of these are operating off-grid, typically powered by diesel generators and therefore leading to significant CO2 emissions and other environmental burdens. A novel type of Alkaline Fuel Cell (AFC) powered by cracked ammonia is being developed for replacement of these generators. This study compares the environmental and economic performance of the two systems by means of Life Cycle Assessment (LCA) and Levelised Cost of Electricity (LCOE), respectively. Results show that the production of ammonia dominates the LCA results, and that renewable ammonia production pathways greatly improve environmental performance. Sensitivity analyses reveal that the fuel cell parameters that most affect system cost and environmental burdens are cell power density and lifetime and system efficiency. Recycling of anode catalyst and electrode substrate materials is found to have large impacts on environmental performance, though without large cost incentives. For a set of target parameter values and fossil sourced ammonia, the AFC is calculated to produce electricity with life cycle CO2 eq emissions of 1.08 kg kWh-1, which is 23% lower than a diesel generator with electricity costs that are 14% higher in the same application.

Polyspectral signal analysis techniques for condition based maintenance of helicopter drive-train system

NASA Astrophysics Data System (ADS)

Hassan Mohammed, Mohammed Ahmed

For an efficient maintenance of a diverse fleet of air- and rotorcraft, effective condition based maintenance (CBM) must be established based on rotating components monitored vibration signals. In this dissertation, we present theory and applications of polyspectral signal processing techniques for condition monitoring of critical components in the AH-64D helicopter tail rotor drive train system. Currently available vibration-monitoring tools are mostly built around auto- and cross-power spectral analysis which have limited performance in detecting frequency correlations higher than second order. Studying higher order correlations and their Fourier transforms, higher order spectra, provides more information about the vibration signals which helps in building more accurate diagnostic models of the mechanical system. Based on higher order spectral analysis, different signal processing techniques are developed to assess health conditions of different critical rotating-components in the AH-64D helicopter drive-train. Based on cross-bispectrum, quadratic nonlinear transfer function is presented to model second order nonlinearity in a drive-shaft running between the two hanger bearings. Then, quadratic-nonlinearity coupling coefficient between frequency harmonics of the rotating shaft is used as condition metric to study different seeded shaft faults compared to baseline case, namely: shaft misalignment, shaft imbalance, and combination of shaft misalignment and imbalance. The proposed quadratic-nonlinearity metric shows better capabilities in distinguishing the four studied shaft settings than the conventional linear coupling based on cross-power spectrum. We also develop a new concept of Quadratic-Nonlinearity Power-Index spectrum, QNLPI(f), that can be used in signal detection and classification, based on bicoherence spectrum. The proposed QNLPI(f) is derived as a projection of the three-dimensional bicoherence spectrum into two-dimensional spectrum that quantitatively describes how much of the mean square power at certain frequency f is generated due to nonlinear quadratic interaction between different frequency components. The proposed index, QNLPI(f), can be used to simplify the study of bispectrum and bicoherence signal spectra. It also inherits useful characteristics from the bicoherence such as high immunity to additive Gaussian noise, high capability of nonlinear-systems identifications, and amplification invariance. The quadratic-nonlinear power spectral density PQNL(f) and percentage of quadratic nonlinear power PQNLP are also introduced based on the QNLPI(f). Concept of the proposed indices and their computational considerations are discussed first using computer generated data, and then applied to real-world vibration data to assess health conditions of different rotating components in the drive train including drive-shaft, gearbox, and hanger bearing faults. The QNLPI(f) spectrum enables us to gain more details about nonlinear harmonic generation patterns that can be used to distinguish between different cases of mechanical faults, which in turn helps to gaining more diagnostic/prognostic capabilities.

36. SITE BUILDING 004 ELECTRIC POWER STATION CLOSE ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

36. SITE BUILDING 004 - ELECTRIC POWER STATION - CLOSE UP VIEW OF 1200 HORSEPOWER STANDBY POWER DIESEL ENGINE/GENERATOR SETS. - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

37. SITE BUILDING 004 ELECTRIC POWER STATION ELEVATED ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

37. SITE BUILDING 004 - ELECTRIC POWER STATION - ELEVATED VIEW OF FIVE (5) 1200 HORSEPOWER STANDBY - POWER DIESEL ENGINE/GENERATOR SETS. - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

Computer program analyzes and monitors electrical power systems (POSIMO)

NASA Technical Reports Server (NTRS)

Jaeger, K.

1972-01-01

Requirements to monitor and/or simulate electric power distribution, power balance, and charge budget are discussed. Computer program to analyze power system and generate set of characteristic power system data is described. Application to status indicators to denote different exclusive conditions is presented.

Optimal Settings for the Noncontact Holmium:YAG Stone Fragmentation Popcorn Technique.

PubMed

Emiliani, Esteban; Talso, Michele; Cho, Sung-Yong; Baghdadi, Mohammed; Mahmoud, Sadam; Pinheiro, Hugo; Traxer, Olivier

2017-09-01

The purpose of this study was to evaluate the popcorn technique using a wide range of holmium laser settings and fiber sizes in a systematic in vitro assessment. Evaluations were done with 4 artificial stones in a collection tube. A fixed ureteroscope was inserted through a ureteral access sheath to provide constant irrigation flow and the laser was placed 1 mm from the bottom. Combinations of 0.5 to 1.5 J, 10 to 20 and 40 Hz, and long and short pulses were tested for 2 and 4 minutes. We used 273 and 365 μm laser fibers. All tests were repeated 3 times. The stones were weighed before and after the experiments to evaluate the setting efficiency. Significant predictors of a highly efficient technique were assessed. A total of 144 tests were performed. Mean starting weight of the stones was 0.23 gm, which was consistent among the groups. After the experiment the median weight difference was 0.07 gm (range 0.01 to 0.24). When designating a 50% reduction in stone volume as the threshold indicating high efficiency, the significant predictors of an efficient popcorn technique were a long pulse (OR 2.7, 95% CI 1.05-7.15), a longer duration (OR 11.4, 95% CI 3.88-33.29), a small (273 μm) laser fiber (OR 0.23, 95% CI 0.08-0.70) and higher power (W) (OR 1.14, 95% CI 1.09-1.20). Higher energy, a longer pulse, frequencies higher than 10 Hz, a longer duration and a smaller laser fiber predict a popcorn technique that is more efficient at reducing stone volume. Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Relationships between postural orientation and self reported function, hop performance and muscle power in subjects with anterior cruciate ligament injury.

PubMed

Trulsson, Anna; Roos, Ewa M; Ageberg, Eva; Garwicz, Martin

2010-07-01

Injury to the anterior cruciate ligament (ACL) is associated not only with knee instability and impaired neuromuscular control, but also with altered postural orientation manifested as observable "substitution patterns". However, tests currently used to evaluate knee function in subjects with ACL injury are not designed to assess postural orientation. Therefore, we are in the process of developing an observational test set that measures postural orientation in terms of the ability to stabilize body segments in relation to each other and to the environment. The aim of the present study was to characterise correlations between this novel test set, called the Test for Substitution Patterns (TSP) and commonly used tests of knee function. In a blinded set-up, 53 subjects (mean age 30 years, range 20-39, with 2-5 years since ACL injury) were assessed using the TSP, the Knee Injury and Osteoarthritis Outcome Score subscale sport/recreation (KOOS sport/rec), 3 hop tests and 3 muscle power tests. Correlations between the scores of the TSP and the other tests were determined. Moderate correlations were found between TSP scores and KOOS sport/rec (rs = -0.43; p = 0.001) and between TSP scores and hop test results (rs = -0.40 to -0.46; p < or = 0.003), indicating that altered postural orientation was associated with worse self-reported KOOS sport/rec function and worse hop performance. No significant correlations were found between TSP scores and muscle power results. Subjects had higher TSP scores on their injured side than on their uninjured side (median 4 and 1 points; interquartile range 2-6 and 0-1.5, respectively; p < 0.0001). We conclude that the Test for Substitution Patterns is of relevance to the patient and measures a specific aspect of neuromuscular control not quantified by the other tests investigated. We suggest that the TSP may be a valuable complement in the assessment of neuromuscular control in the rehabilitation of subjects with ACL injury.

The effects of rest interval length manipulation of the first upper-body resistance exercise in sequence on acute performance of subsequent exercises in men and women.

PubMed

Ratamess, Nicholas A; Chiarello, Christina M; Sacco, Anthony J; Hoffman, Jay R; Faigenbaum, Avery D; Ross, Ryan E; Kang, Jie

2012-11-01

The purpose of the present study was to investigate the effects of manipulating rest interval (RI) length of the first upper-body exercise in sequence on subsequent resistance exercise performance. Twenty-two men and women with at least 1 year of resistance training experience performed resistance exercise protocols on 3 occasions in random order. Each protocol consisted of performing 4 barbell upper-body exercises in the same sequence (bench press, incline bench press, shoulder press, and bent-over row) for 3 sets of up to 10 repetitions with 75% of 1 repetition maximum. Bench press RIs were 1, 2, or 3 minutes, whereas other exercises were performed with a standard 2-minute rest interval. The number of repetitions completed, average power, and velocity for each set of each exercise were recorded. Gender differences were observed during the bench press and incline press as women performed significantly (p ≤ 0.05) more repetitions than men during all RIs. The magnitude of decline in velocity and power over 3 sets of the bench press and incline press was significantly higher in men than women. Manipulation of RI length during the bench press did not affect performance of the remaining exercises in men. However, significantly more repetitions were performed by women during the first set of the incline press using 3-minute rest interval than 1-minute rest interval. In men and women, performance of the incline press and shoulder press was compromised compared with baseline performances. Manipulation of RI length of the first exercise affected performance of only the first set of 1 subsequent exercise in women. All RIs led to comparable levels of fatigue in men, indicating that reductions in load are necessary for subsequent exercises performed in sequence that stress similar agonist muscle groups when 10 repetitions are desired.

A Historical Analysis of the Contributions of the Black Power Movement to Higher Education: 1960 - 1980

ERIC Educational Resources Information Center

Sokoya, Kinaya

2014-01-01

The purpose of this research was to study the link between the Black Power Movement and changes that occurred in higher education between 1960 and 1980. The main research question study was, "What effect did the Black Power Movement have on changes in higher education from 1960-1980?" The intent of this historical research is to…

Mental skills comparison between elite sprint and endurance track and field runners according to their genetic polymorphism: a pilot study.

PubMed

Znazen, Hela; Slimani, Maamer; Miarka, Bianca; Butovskaya, Marina; Siala, Hajer; Messaoud, Taieb; Chamari, Karim; Souissi, Nizar

2017-09-01

Achieving excellence in track and field athletes requires specific mental skills. The aim of the present study was to compare the mental skills between elite sprint and endurance athletes. Forty elite athletes (age 20.55±2.22 years, body mass 74.8±7.9 kg, height 1.70±0.1 m) participated in the present study. The athletes were classified into two groups according to their genetic polymorphism to physical activity: Endurance group (allele I, N.=20) and power group (allele D, N.=20). The mental skills were assessed by means of Ottawa Mental Skill Assessment Tool-3 inventory (OMSAT-3: based in foundation mental skills, psychosomatic skills, and cognitive skills subscales) before the competition period. Furthermore, genetic data were also collected. Sprint and endurance runners were participating in Tunisian National championship. The results showed a significant difference between elite sprint and endurance runners in the foundation mental and psychosomatic skills subscales (all, P<0.05). Typically, the present study revealed that goal setting, commitment, stress reactions, fear control, imagery, competition planning and mental practice were significantly higher among the elite sprint runners compared to the endurance runners (all, P<0.05). Findings from this study could confirm the widely acclaimed research assumption that mental skills, such as goal setting, commitment and mental practice, are the predictor variables of power performances, while endurance performances are associated with different mental skills components. Finally, the results may inform applied practitioners regarding the differences in mental skill demands between power and endurance athletes and the genetic predisposition of practitioners.

Device for adapting continuously variable transmissions to infinitely variable transmissions with forward-neutral-reverse capabilities

DOEpatents

Wilkes, Donald F.; Purvis, James W.; Miller, A. Keith

1997-01-01

An infinitely variable transmission is capable of operating between a maximum speed in one direction and a minimum speed in an opposite direction, including a zero output angular velocity, while being supplied with energy at a constant angular velocity. Input energy is divided between a first power path carrying an orbital set of elements and a second path that includes a variable speed adjustment mechanism. The second power path also connects with the orbital set of elements in such a way as to vary the rate of angular rotation thereof. The combined effects of power from the first and second power paths are combined and delivered to an output element by the orbital element set. The transmission can be designed to operate over a preselected ratio of forward to reverse output speeds.

Space Environments Testbed

NASA Technical Reports Server (NTRS)

Leucht, David K.; Koslosky, Marie J.; Kobe, David L.; Wu, Jya-Chang C.; Vavra, David A.

2011-01-01

The Space Environments Testbed (SET) is a flight controller data system for the Common Carrier Assembly. The SET-1 flight software provides the command, telemetry, and experiment control to ground operators for the SET-1 mission. Modes of operation (see dia gram) include: a) Boot Mode that is initiated at application of power to the processor card, and runs memory diagnostics. It may be entered via ground command or autonomously based upon fault detection. b) Maintenance Mode that allows for limited carrier health monitoring, including power telemetry monitoring on a non-interference basis. c) Safe Mode is a predefined, minimum power safehold configuration with power to experiments removed and carrier functionality minimized. It is used to troubleshoot problems that occur during flight. d) Operations Mode is used for normal experiment carrier operations. It may be entered only via ground command from Safe Mode.

Public Data Set: A Power-Balance Model for Local Helicity Injection Startup in a Spherical Tokamak

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

Barr, Jayson L.; Bongard, Michael W.; Burke, Marcus G.

This public data set contains openly-documented, machine readable digital research data corresponding to figures published in J.L. Barr et. al, 'A Power-Balance Model for Local Helicity Injection Startup in a Spherical Tokamak,' Nuclear Fusion 58, 076011 (2018).

Robustness of Type I Error and Power in Set Correlation Analysis of Contingency Tables.

ERIC Educational Resources Information Center

Cohen, Jacob; Nee, John C. M.

1990-01-01

The analysis of contingency tables via set correlation allows the assessment of subhypotheses involving contrast functions of the categories of the nominal scales. The robustness of such methods with regard to Type I error and statistical power was studied via a Monte Carlo experiment. (TJH)

Power quality analysis based on spatial correlation

NASA Astrophysics Data System (ADS)

Li, Jiangtao; Zhao, Gang; Liu, Haibo; Li, Fenghou; Liu, Xiaoli

2018-03-01

With the industrialization and urbanization, the status of electricity in the production and life is getting higher and higher. So the prediction of power quality is the more potential significance. Traditional power quality analysis methods include: power quality data compression, disturbance event pattern classification, disturbance parameter calculation. Under certain conditions, these methods can predict power quality. This paper analyses the temporal variation of power quality of one provincial power grid in China from time angle. The distribution of power quality was analyzed based on spatial autocorrelation. This paper tries to prove that the research idea of geography is effective for mining the potential information of power quality.

More realistic power estimation for new user, active comparator studies: an empirical example.

PubMed

Gokhale, Mugdha; Buse, John B; Pate, Virginia; Marquis, M Alison; Stürmer, Til

2016-04-01

Pharmacoepidemiologic studies are often expected to be sufficiently powered to study rare outcomes, but there is sequential loss of power with implementation of study design options minimizing bias. We illustrate this using a study comparing pancreatic cancer incidence after initiating dipeptidyl-peptidase-4 inhibitors (DPP-4i) versus thiazolidinediones or sulfonylureas. We identified Medicare beneficiaries with at least one claim of DPP-4i or comparators during 2007-2009 and then applied the following steps: (i) exclude prevalent users, (ii) require a second prescription of same drug, (iii) exclude prevalent cancers, (iv) exclude patients age <66 years and (v) censor for treatment changes during follow-up. Power to detect hazard ratios (effect measure strongly driven by the number of events) ≥ 2.0 estimated after step 5 was compared with the naïve power estimated prior to step 1. There were 19,388 and 28,846 DPP-4i and thiazolidinedione initiators during 2007-2009. The number of drug initiators dropped most after requiring a second prescription, outcomes dropped most after excluding patients with prevalent cancer and person-time dropped most after requiring a second prescription and as-treated censoring. The naïve power (>99%) was considerably higher than the power obtained after the final step (~75%). In designing new-user active-comparator studies, one should be mindful how steps minimizing bias affect sample-size, number of outcomes and person-time. While actual numbers will depend on specific settings, application of generic losses in percentages will improve estimates of power compared with the naive approach mostly ignoring steps taken to increase validity. Copyright © 2015 John Wiley & Sons, Ltd.

Cutting efficiency of apical preparation using ultrasonic tips with microprojections: confocal laser scanning microscopy study.

PubMed

Kwak, Sang-Won; Moon, Young-Mi; Yoo, Yeon-Jee; Baek, Seung-Ho; Lee, WooCheol; Kim, Hyeon-Cheol

2014-11-01

The purpose of this study was to compare the cutting efficiency of a newly developed microprojection tip and a diamond-coated tip under two different engine powers. The apical 3-mm of each root was resected, and root-end preparation was performed with upward and downward pressure using one of the ultrasonic tips, KIS-1D (Obtura Spartan) or JT-5B (B&L Biotech Ltd.). The ultrasonic engine was set to power-1 or -4. Forty teeth were randomly divided into four groups: K1 (KIS-1D / Power-1), J1 (JT-5B / Power-1), K4 (KIS-1D / Power-4), and J4 (JT-5B / Power-4). The total time required for root-end preparation was recorded. All teeth were resected and the apical parts were evaluated for the number and length of cracks using a confocal scanning micrscope. The size of the root-end cavity and the width of the remaining dentin were recorded. The data were statistically analyzed using two-way analysis of variance and a Mann-Whitney test. There was no significant difference in the time required between the instrument groups, but the power-4 groups showed reduced preparation time for both instrument groups (p < 0.05). The K4 and J4 groups with a power-4 showed a significantly higher crack formation and a longer crack irrespective of the instruments. There was no significant difference in the remaining dentin thickness or any of the parameters after preparation. Ultrasonic tips with microprojections would be an option to substitute for the conventional ultrasonic tips with a diamond coating with the same clinical efficiency.

Cutting efficiency of apical preparation using ultrasonic tips with microprojections: confocal laser scanning microscopy study

PubMed Central

Kwak, Sang-Won; Moon, Young-Mi; Yoo, Yeon-Jee; Baek, Seung-Ho; Lee, WooCheol

2014-01-01

Objectives The purpose of this study was to compare the cutting efficiency of a newly developed microprojection tip and a diamond-coated tip under two different engine powers. Materials and Methods The apical 3-mm of each root was resected, and root-end preparation was performed with upward and downward pressure using one of the ultrasonic tips, KIS-1D (Obtura Spartan) or JT-5B (B&L Biotech Ltd.). The ultrasonic engine was set to power-1 or -4. Forty teeth were randomly divided into four groups: K1 (KIS-1D / Power-1), J1 (JT-5B / Power-1), K4 (KIS-1D / Power-4), and J4 (JT-5B / Power-4). The total time required for root-end preparation was recorded. All teeth were resected and the apical parts were evaluated for the number and length of cracks using a confocal scanning micrscope. The size of the root-end cavity and the width of the remaining dentin were recorded. The data were statistically analyzed using two-way analysis of variance and a Mann-Whitney test. Results There was no significant difference in the time required between the instrument groups, but the power-4 groups showed reduced preparation time for both instrument groups (p < 0.05). The K4 and J4 groups with a power-4 showed a significantly higher crack formation and a longer crack irrespective of the instruments. There was no significant difference in the remaining dentin thickness or any of the parameters after preparation. Conclusions Ultrasonic tips with microprojections would be an option to substitute for the conventional ultrasonic tips with a diamond coating with the same clinical efficiency. PMID:25383346

Green power: A renewable energy resources marketing plan

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

Barr, R.C.

Green power is electricity generated from renewable energy sources such as power generated from the sun, the wind, the heat of the earth, and biomass. Green pricing is the marketing strategy to sell green power to customers who voluntarily pay a premium for it. Green pricing is evolving from the deregulation of the electric industry, the need for clean air, reflected in part as concern over global warming, and technology advances. The goal of the renewable energy marketing plan is to generate enough revenues for a utility to fund power purchase agreements (PPAs) with renewable energy developers or construct itsmore » own renewable facilities. Long-term, fixed price PPAs enable developers to obtain financing to construct new facilities, sometimes taking technological risks which a utility might not take otherwise. The marketing plan is built around different rate premiums for different categories of ratepayers, volunteer customer participation, customer participation recognition, and budget allocations between project costs and power marketing costs. Green prices are higher than those for conventional sources, particularly prices from natural gas fired plants. Natural gas is abundant relative to oil in price per British thermal unit (Btu). Green pricing can help bridge the gap between the current oversupply of gas and the time, not far off, when all petroleum prices will exceed those for renewable energy. The rapid implementation of green pricing is important. New marketing programs will bolster the growing demand for renewable energy evidenced in many national surveys thus decreasing the consumption of power now generated by burning hydrocarbons. This paper sets forth a framework to implement a green power marketing plan for renewable energy developers and utilities working together.« less

Using Self-regulation to Successfully Overcome the Negotiation Disadvantage of Low Power

PubMed Central

Jäger, Andreas; Loschelder, David D.; Friese, Malte

2017-01-01

A plethora of studies has demonstrated that low-power negotiators attain lower outcomes compared to high-power negotiators. We argue that this low-power disadvantage can be conceptualized as impaired goal attainment and that self-regulation can help to overcome it. Three experiments tested this assertion. In Study 1, low-power negotiators attained lower profits compared to their high-power opponents in a face-to-face negotiation. Negotiators who set themselves goals and those who additionally formed if-then plans prior to the negotiation overcame the low-power disadvantage. Studies 2 and 3 replicated these effects in computer-mediated negotiations: Low-power negotiators conceded more than high-power negotiators. Again, setting goals and forming additional if-then plans helped to counter the power disadvantage. Process analyses revealed that negotiators’ concession-making at the start of the negotiation mediated both the low-power disadvantage and the beneficial effects of self-regulation. The present findings show how the low-power disadvantage unfolds in negotiations and how self-regulatory techniques can help to overcome it. PMID:28382005

Using Self-regulation to Successfully Overcome the Negotiation Disadvantage of Low Power.

PubMed

Jäger, Andreas; Loschelder, David D; Friese, Malte

2017-01-01

A plethora of studies has demonstrated that low-power negotiators attain lower outcomes compared to high-power negotiators. We argue that this low-power disadvantage can be conceptualized as impaired goal attainment and that self-regulation can help to overcome it. Three experiments tested this assertion. In Study 1, low-power negotiators attained lower profits compared to their high-power opponents in a face-to-face negotiation. Negotiators who set themselves goals and those who additionally formed if-then plans prior to the negotiation overcame the low-power disadvantage. Studies 2 and 3 replicated these effects in computer-mediated negotiations: Low-power negotiators conceded more than high-power negotiators. Again, setting goals and forming additional if-then plans helped to counter the power disadvantage. Process analyses revealed that negotiators' concession-making at the start of the negotiation mediated both the low-power disadvantage and the beneficial effects of self-regulation. The present findings show how the low-power disadvantage unfolds in negotiations and how self-regulatory techniques can help to overcome it.

Pathfinder aircraft taking off - setting new solar powered altitude record

NASA Image and Video Library

1995-09-11

The Pathfinder solar-powered remotely piloted aircraft climbs to a record-setting altitude of 50,567 feet during a flight Sept. 11, 1995, at NASA's Dryden Flight Research Center, Edwards, California. The flight was part of the NASA ERAST (Environmental Research Aircraft and Sensor Technology) program. The Pathfinder was designed and built by AeroVironment Inc., Monrovia, California. Solar arrays cover nearly all of the upper wing surface and produce electricity to power the aircraft's six motors.

A study of the selection of microcomputer architectures to automate planetary spacecraft power systems

NASA Technical Reports Server (NTRS)

Nauda, A.

1982-01-01

Performance and reliability models of alternate microcomputer architectures as a methodology for optimizing system design were examined. A methodology for selecting an optimum microcomputer architecture for autonomous operation of planetary spacecraft power systems was developed. Various microcomputer system architectures are analyzed to determine their application to spacecraft power systems. It is suggested that no standardization formula or common set of guidelines exists which provides an optimum configuration for a given set of specifications.

Development of a gridded meteorological dataset over Java island, Indonesia 1985-2014.

PubMed

Yanto; Livneh, Ben; Rajagopalan, Balaji

2017-05-23

We describe a gridded daily meteorology dataset consisting of precipitation, minimum and maximum temperature over Java Island, Indonesia at 0.125°×0.125° (~14 km) resolution spanning 30 years from 1985-2014. Importantly, this data set represents a marked improvement from existing gridded data sets over Java with higher spatial resolution, derived exclusively from ground-based observations unlike existing satellite or reanalysis-based products. Gap-infilling and gridding were performed via the Inverse Distance Weighting (IDW) interpolation method (radius, r, of 25 km and power of influence, α, of 3 as optimal parameters) restricted to only those stations including at least 3,650 days (~10 years) of valid data. We employed MSWEP and CHIRPS rainfall products in the cross-validation. It shows that the gridded rainfall presented here produces the most reasonable performance. Visual inspection reveals an increasing performance of gridded precipitation from grid, watershed to island scale. The data set, stored in a network common data form (NetCDF), is intended to support watershed-scale and island-scale studies of short-term and long-term climate, hydrology and ecology.

Comet brightness parameters: Definition, determination, and correlations

NASA Technical Reports Server (NTRS)

Meisel, D. D.; Morris, C. S.

1976-01-01

The power-law definition of comet brightness is reviewed and possible systematic influences are discussed that can affect the derivation of m sub o and n values from visual magnitude estimates. A rationale for the Bobrovnikoff aperture correction method is given and it is demonstrated that the Beyer extrafocal method leads to large systematic effects which if uncorrected by an instrumental relationship result in values significantly higher than those derived according to the Bobrovnikoff guidelines. A series of visual brightness parameter sets are presented which have been reduced to the same photometric system. Recommendations are given to insure that future observations are reduced to the same system.

Food marketing to children in Canada: a settings-based scoping review on exposure, power and impact.

PubMed

Prowse, Rachel

2017-09-01

Food marketing impacts children's food knowledge, behaviours and health. Current regulations in Canada focus on restricting promotional aspects of food marketing with little-to-no consideration of the places where children experience food. Understanding food marketing in children's everyday settings is necessary to protect children. This scoping review describes the current literature on food marketing to children in Canada by setting. The author searched databases for Canadian research on children's exposure to food marketing, and the power and impact of food marketing to children (2-17 years) across settings, and on how current regulations may mediate the effect of food marketing on children. Peer-reviewed studies in English, published between 2000 and 2016, were included. Twenty-five studies documented children's exposure to food marketing and its power and/or impact on them in homes (via television, or online) (n = 12), public schools (n = 1), grocery stores (n = 8), fast food restaurants (n = 2), and in general (n = 2). Research trends suggest that unhealthy foods are targeted at children using multiple promotional techniques that overlap across settings. Several research gaps exist in this area, leading to an incomplete, and potentially underestimated, picture of food marketing to children in Canada. Available evidence suggests that current Canadian approaches have not reduced children's exposure to or the power of food marketing in these settings, with the exception of some positive influences from Quebec's statutory regulations. The settings where children eat, buy or learn about food expose them to powerful, often unhealthy food marketing. The current evidence suggests that "place" may be an important marketing component to be included in public policy in order to broadly protect children from unhealthy food marketing. Organizations and communities can engage in settings-based health promotion interventions by developing their own marketing policies that address the promotion and place of unhealthy food and beverages.

Food marketing to children in Canada: a settings-based scoping review on exposure, power and impact

PubMed Central

Rachel, Prowse

2017-01-01

Abstract Introduction: Food marketing impacts children’s food knowledge, behaviours and health. Current regulations in Canada focus on restricting promotional aspects of food marketing with little-to-no consideration of the places where children experience food. Understanding food marketing in children’s everyday settings is necessary to protect children. This scoping review describes the current literature on food marketing to children in Canada by setting. Methods: The author searched databases for Canadian research on children’s exposure to food marketing, and the power and impact of food marketing to children (2-17 years) across settings, and on how current regulations may mediate the effect of food marketing on children. Peer-reviewed studies in English, published between 2000 and 2016, were included. Results: Twenty-five studies documented children’s exposure to food marketing and its power and/or impact on them in homes (via television, or online) (n = 12), public schools (n = 1), grocery stores (n = 8), fast food restaurants (n = 2), and in general (n = 2). Research trends suggest that unhealthy foods are targeted at children using multiple promotional techniques that overlap across settings. Several research gaps exist in this area, leading to an incomplete, and potentially underestimated, picture of food marketing to children in Canada. Available evidence suggests that current Canadian approaches have not reduced children’s exposure to or the power of food marketing in these settings, with the exception of some positive influences from Quebec’s statutory regulations. Conclusion: The settings where children eat, buy or learn about food expose them to powerful, often unhealthy food marketing. The current evidence suggests that “place” may be an important marketing component to be included in public policy in order to broadly protect children from unhealthy food marketing. Organizations and communities can engage in settings-based health promotion interventions by developing their own marketing policies that address the promotion and place of unhealthy food and beverages. PMID:28902477

Improving the Energy Market: Algorithms, Market Implications, and Transmission Switching

NASA Astrophysics Data System (ADS)

Lipka, Paula Ann

This dissertation aims to improve ISO operations through a better real-time market solution algorithm that directly considers both real and reactive power, finds a feasible Alternating Current Optimal Power Flow solution, and allows for solving transmission switching problems in an AC setting. Most of the IEEE systems do not contain any thermal limits on lines, and the ones that do are often not binding. Chapter 3 modifies the thermal limits for the IEEE systems to create new, interesting test cases. Algorithms created to better solve the power flow problem often solve the IEEE cases without line limits. However, one of the factors that makes the power flow problem hard is thermal limits on the lines. The transmission networks in practice often have transmission lines that become congested, and it is unrealistic to ignore line limits. Modifying the IEEE test cases makes it possible for other researchers to be able to test their algorithms on a setup that is closer to the actual ISO setup. This thesis also examines how to convert limits given on apparent power---as is in the case in the Polish test systems---to limits on current. The main consideration in setting line limits is temperature, which linearly relates to current. Setting limits on real or apparent power is actually a proxy for using the limits on current. Therefore, Chapter 3 shows how to convert back to the best physical representation of line limits. A sequential linearization of the current-voltage formulation of the Alternating Current Optimal Power Flow (ACOPF) problem is used to find an AC-feasible generator dispatch. In this sequential linearization, there are parameters that are set to the previous optimal solution. Additionally, to improve accuracy of the Taylor series approximations that are used, the movement of the voltage is restricted. The movement of the voltage is allowed to be very large at the first iteration and is restricted further on each subsequent iteration, with the restriction corresponding to the accuracy and AC-feasiblity of the solution. This linearization was tested on the IEEE and Polish systems, which range from 14 to 3375 buses and 20 to 4161 transmission lines. It had an accuracy of 0.5% or less for all but the 30-bus system. It also solved in linear time with CPLEX, while the non-linear version solved in O(n1.11) to O(n1.39). The sequential linearization is slower than the nonlinear formulation for smaller problems, but faster for larger problems, and its linear computational time means it would continue solving faster for larger problems. A major consideration to implementing algorithms to solve the optimal generator dispatch is ensuring that the resulting prices from the algorithm will support the market. Since the sequential linearization is linear, it is convex, its marginal values are well-defined, and there is no duality gap. The prices and settlements obtained from the sequential linearization therefore can be used to run a market. This market will include extra prices and settlements for reactive power and voltage, compared to the present-day market, which is based on real power. An advantage of this is that there is a very clear pool that can be used for reactive power/voltage support payments, while presently there is not a clear pool to take them out of. This method also reveals how valuable reactive power and voltage are at different locations, which can enable better planning of reactive resource construction. Transmission switching increases the feasible region of the generator dispatch, which means there may be a better solution than without transmission switching. Power flows on transmission lines are not directly controllable; rather, the power flows according to how it is injected and the physical characteristics of the lines. Changing the network topology changes the physical characteristics, which changes the flows. This means that sets of generator dispatch that may have previously been infeasible due to the flow exceeding line constraints may be feasible, since the flows will be different and may meet line constraints. However, transmission switching is a mixed integer problem, which may have a very slow solution time. For economic switching, we examine a series of heuristics. We examine the congestion rent heuristic in detail and then examine many other heuristics at a higher level. Post-contingency corrective switching aims to fix issues in the power network after a line or generator outage. In Chapter 7, we show that using the sequential linear program with corrective switching helps solve voltage and excessive flow issues. (Abstract shortened by UMI.).

Anisotropic power-law inflation for a conformal-violating Maxwell model

NASA Astrophysics Data System (ADS)

Do, Tuan Q.; Kao, W. F.

2018-05-01

A set of power-law solutions of a conformal-violating Maxwell model with a non-standard scalar-vector coupling will be shown in this paper. In particular, we are interested in a coupling term of the form X^{2n} F^{μ ν }F_{μ ν } with X denoting the kinetic term of the scalar field. Stability analysis indicates that the new set of anisotropic power-law solutions is unstable during the inflationary phase. The result is consistent with the cosmic no-hair conjecture. We show, however, that a set of stable slowly expanding solutions does exist for a small range of parameters λ and n. Hence a small anisotropy can survive during the slowly expanding phase.

Static internal performance including thrust vectoring and reversing of two-dimensional convergent-divergent nozzles

NASA Technical Reports Server (NTRS)

Re, R. J.; Leavitt, L. D.

1984-01-01

The effects of geometric design parameters on two dimensional convergent-divergent nozzles were investigated at nozzle pressure ratios up to 12 in the static test facility. Forward flight (dry and afterburning power settings), vectored-thrust (afterburning power setting), and reverse-thrust (dry power setting) nozzles were investigated. The nozzles had thrust vector angles from 0 deg to 20.26 deg, throat aspect ratios of 3.696 to 7.612, throat radii from sharp to 2.738 cm, expansion ratios from 1.089 to 1.797, and various sidewall lengths. The results indicate that unvectored two dimensional convergent-divergent nozzles have static internal performance comparable to axisymmetric nozzles with similar expansion ratios.

Standardized Modular Power Interfaces for Future Space Explorations Missions

NASA Technical Reports Server (NTRS)

Oeftering, Richard

2015-01-01

Earlier studies show that future human explorations missions are composed of multi-vehicle assemblies with interconnected electric power systems. Some vehicles are often intended to serve as flexible multi-purpose or multi-mission platforms. This drives the need for power architectures that can be reconfigured to support this level of flexibility. Power system developmental costs can be reduced, program wide, by utilizing a common set of modular building blocks. Further, there are mission operational and logistics cost benefits of using a common set of modular spares. These benefits are the goals of the Advanced Exploration Systems (AES) Modular Power System (AMPS) project. A common set of modular blocks requires a substantial level of standardization in terms of the Electrical, Data System, and Mechanical interfaces. The AMPS project is developing a set of proposed interface standards that will provide useful guidance for modular hardware developers but not needlessly constrain technology options, or limit future growth in capability. In 2015 the AMPS project focused on standardizing the interfaces between the elements of spacecraft power distribution and energy storage. The development of the modular power standard starts with establishing mission assumptions and ground rules to define design application space. The standards are defined in terms of AMPS objectives including Commonality, Reliability-Availability, Flexibility-Configurability and Supportability-Reusability. The proposed standards are aimed at assembly and sub-assembly level building blocks. AMPS plans to adopt existing standards for spacecraft command and data, software, network interfaces, and electrical power interfaces where applicable. Other standards including structural encapsulation, heat transfer, and fluid transfer, are governed by launch and spacecraft environments and bound by practical limitations of weight and volume. Developing these mechanical interface standards is more difficult but an essential part of defining physical building blocks of modular power. This presentation describes the AMPS projects progress towards standardized modular power interfaces.

Pathfinder aircraft taking off - setting new solar powered altitude record

NASA Technical Reports Server (NTRS)

1995-01-01

The Pathfinder solar-powered remotely piloted aircraft climbs to a record-setting altitude of 50,567 feet during a flight Sept. 11, 1995, at NASA's Dryden Flight Research Center, Edwards, California. The flight was part of the NASA ERAST (Environmental Research Aircraft and Sensor Technology) program. The Pathfinder was designed and built by AeroVironment Inc., Monrovia, California. Solar arrays cover nearly all of the upper wing surface and produce electricity to power the aircraft's six motors. Pathfinder was a lightweight, solar-powered, remotely piloted flying wing aircraft used to demonstrate the use of solar power for long-duration, high-altitude flight. Its name denotes its mission as the 'Pathfinder' or first in a series of solar-powered aircraft that will be able to remain airborne for weeks or months on scientific sampling and imaging missions. Solar arrays covered most of the upper wing surface of the Pathfinder aircraft. These arrays provided up to 8,000 watts of power at high noon on a clear summer day. That power fed the aircraft's six electric motors as well as its avionics, communications, and other electrical systems. Pathfinder also had a backup battery system that could provide power for two to five hours, allowing for limited-duration flight after dark. Pathfinder flew at airspeeds of only 15 to 20 mph. Pitch control was maintained by using tiny elevators on the trailing edge of the wing while turns and yaw control were accomplished by slowing down or speeding up the motors on the outboard sections of the wing. On September 11, 1995, Pathfinder set a new altitude record for solar-powered aircraft of 50,567 feet above Edwards Air Force Base, California, on a 12-hour flight. On July 7, 1997, it set another, unofficial record of 71,500 feet at the Pacific Missile Range Facility, Kauai, Hawaii. In 1998, Pathfinder was modified into the longer-winged Pathfinder Plus configuration. (See the Pathfinder Plus photos and project description.)

Baseline predictors of persistence to first disease-modifying treatment in multiple sclerosis.

PubMed

Zettl, U K; Schreiber, H; Bauer-Steinhusen, U; Glaser, T; Hechenbichler, K; Hecker, M

2017-08-01

Patients with multiple sclerosis (MS) require lifelong therapy. However, success of disease-modifying therapies is dependent on patients' persistence and adherence to treatment schedules. In the setting of a large multicenter observational study, we aimed at assessing multiple parameters for their predictive power with respect to discontinuation of therapy. We analyzed 13 parameters to predict discontinuation of interferon beta-1b treatment during a 2-year follow-up period based on data from 395 patients with MS who were treatment-naïve at study onset. Besides clinical characteristics, patient-related psychosocial outcomes were assessed as well. Among patients without clinically relevant fatigue, males showed a higher persistence rate than females (80.3% vs 64.7%). Clinically relevant fatigue scores decreased the persistence rate in men and especially in women (71.4% and 51.2%). Besides gender and fatigue, univariable and multivariable analyses revealed further factors associated with interferon beta-1b therapy discontinuation, namely lower quality of life, depressiveness, and higher relapse rate before therapy initiation, while higher education, living without a partner, and higher age improved persistence. Patients with higher grades of fatigue and depressiveness are at higher risk to prematurely discontinue MS treatment; especially, women suffering from fatigue have an increased discontinuation rate. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Parametric Cost Study of AC-DC Wayside Power Systems

DOT National Transportation Integrated Search

1975-09-01

The wayside power system provides all the power requirements of an electric vehicle operating on a fixed guideway. For a given set of specifications there are numerous wayside power supply configurations which will be satisfactory from a technical st...

Power, leadership and transformation: the doctor's potential for influence.

PubMed

Gabel, Stewart

2012-12-01

Power and leadership are concepts that are linked. Both are studied too infrequently in medical and health care settings, given the responsibilities and opportunities doctors and other health care personnel have to exert leadership and power appropriately to foster patient-centred and health care organisational goals. This paper reviews Raven's concept of power, clarifies the bases of power that are available to doctors in different roles and provides illustrations of the application of the bases of power in medical practice. The relationship between power and leadership is explored, with an emphasis on how power and leadership are linked through the personal characteristics and competencies of the leader.   Transformational leadership illustrates the incorporation and elaboration of power strategies into a principles-driven, relationship-oriented and empirically grounded form of leadership. Illustrations of the appropriate and inappropriate use of power and leadership in health care settings are provided. The study of power, the study of leadership and their linkage should be incorporated to a greater degree into medical education at all levels. Strategies to achieve this end are suggested. © Blackwell Publishing Ltd 2012.

Nonlinear Effects in Ultrasound Fields of Diagnostic-type Transducers Used for Kidney Stone Propulsion: Characterization in Water

PubMed Central

Karzova, M.; Cunitz, B.; Yuldashev, P.; Andriyakhina, Y.; Kreider, W.; Sapozhnikov, O.; Bailey, M.; Khokhlova, V.

2016-01-01

Newer imaging and therapeutic ultrasound technologies require higher in situ pressure levels compared to conventional diagnostic values. One example is the recently developed use of focused ultrasonic radiation force to move kidney stones and residual fragments out of the urinary collecting system. A commercial diagnostic 2.3 MHz C5-2 array probe is used to deliver the acoustic pushing pulses. The probe comprises 128 elements equally spaced at the 55 mm long convex cylindrical surface with 38 mm radius of curvature. The efficacy of the treatment can be increased by using higher transducer output to provide stronger pushing force; however, nonlinear acoustic saturation effect can be a limiting factor. In this work nonlinear propagation effects were analyzed for the C5-2 transducer using a combined measurement and modeling approach. Simulations were based on the 3D Westervelt equation; the boundary condition was set to match low power pressure beam scans. Focal waveforms simulated for increased output power levels were compared with the fiber-optic hydrophone measurements and were found in good agreement. It was shown that saturation effects do limit the acoustic pressure in the focal region of the transducer. This work has application to standard diagnostic probes and imaging. PMID:27087711

Nonlinear effects in ultrasound fields of diagnostic-type transducers used for kidney stone propulsion: Characterization in water

NASA Astrophysics Data System (ADS)

Karzova, M.; Cunitz, B.; Yuldashev, P.; Andriyakhina, Y.; Kreider, W.; Sapozhnikov, O.; Bailey, M.; Khokhlova, V.

2015-10-01

Newer imaging and therapeutic ultrasound technologies require higher in situ pressure levels compared to conventional diagnostic values. One example is the recently developed use of focused ultrasonic radiation force to move kidney stones and residual fragments out of the urinary collecting system. A commercial diagnostic 2.3 MHz C5-2 array probe is used to deliver the acoustic pushing pulses. The probe comprises 128 elements equally spaced at the 55 mm long convex cylindrical surface with 38 mm radius of curvature. The efficacy of the treatment can be increased by using higher intensity at the focus to provide stronger pushing force; however, nonlinear acoustic saturation can be a limiting factor. In this work nonlinear propagation effects were analyzed for the C5-2 transducer using a combined measurement and modeling approach. Simulations were based on the 3D Westervelt equation; the boundary condition was set to match the focal geometry of the beam as measured at a low power output. Focal waveforms simulated for increased output power levels were compared with the fiber-optic hydrophone measurements and were found in good agreement. It was shown that saturation effects do limit the acoustic pressure in the focal region of the transducer. This work has application to standard diagnostic probes and imaging.

Factors affecting the acceptance of expert advice.

PubMed

Van Swol, Lyn M; Sniezek, Janet A

2005-09-01

This paper expands research on the judge advisor system (JAS) by examining advice utilization and trust. Experiment 1 examined five factors that could increase utilization of expert advice: judge's trust in the advisor, advisor confidence, advisor accuracy, judge's prior relationship with the advisor, and judge's power to set payment to the advisor. While judge's trust and advisor confidence correlated with the judge matching the advisor's advice, a stepwise regression found that of the five variables, advisor confidence was the only significant predictor of the judge matching the advisor. Experiment 2 examined trust without the role assignment to judge or advisor. While trust expressed in partner was not higher for the judge than the advisor in Experiment 1, in Experiment 2 trust in partner expressed by the low-expertise dyad member was higher than trust expressed by the high-expertise dyad member. Results from the two experiments are discussed in the context of Sniezek and Van Swol (2001).

Harnessing the Power of Interactivity for Instruction.

ERIC Educational Resources Information Center

Borsook, Terry K.

Arguing that what sets the computer apart from all other teaching devices is its potential for interactivity, this paper examines the concept of interactivity and explores ways in which its power can be harnessed and put to work. A discussion of interactivity in human-to-human communication sets a context within which to view human/computer…

You Cannot Step Into the Same River Twice: When Power Analyses Are Optimistic.

PubMed

McShane, Blakeley B; Böckenholt, Ulf

2014-11-01

Statistical power depends on the size of the effect of interest. However, effect sizes are rarely fixed in psychological research: Study design choices, such as the operationalization of the dependent variable or the treatment manipulation, the social context, the subject pool, or the time of day, typically cause systematic variation in the effect size. Ignoring this between-study variation, as standard power formulae do, results in assessments of power that are too optimistic. Consequently, when researchers attempting replication set sample sizes using these formulae, their studies will be underpowered and will thus fail at a greater than expected rate. We illustrate this with both hypothetical examples and data on several well-studied phenomena in psychology. We provide formulae that account for between-study variation and suggest that researchers set sample sizes with respect to our generally more conservative formulae. Our formulae generalize to settings in which there are multiple effects of interest. We also introduce an easy-to-use website that implements our approach to setting sample sizes. Finally, we conclude with recommendations for quantifying between-study variation. © The Author(s) 2014.

Optimization of transversal phacoemulsification settings in peristaltic mode using a new transversal ultrasound machine.

PubMed

Wright, Dannen D; Wright, Alex J; Boulter, Tyler D; Bernhisel, Ashlie A; Stagg, Brian C; Zaugg, Brian; Pettey, Jeff H; Ha, Larry; Ta, Brian T; Olson, Randall J

2017-09-01

To determine the optimum bottle height, vacuum, aspiration rate, and power settings in the peristaltic mode of the Whitestar Signature Pro machine with Ellips FX tip action (transversal). John A. Moran Eye Center Laboratories, University of Utah, Salt Lake City, Utah, USA. Experimental study. Porcine lens nuclei were hardened with formalin and cut into 2.0 mm cubes. Lens cubes were emulsified using transversal and fragment removal time (efficiency), and fragment bounces off the tip (chatter) were measured to determine optimum aspiration rate, bottle height, vacuum, and power settings in the peristaltic mode. Efficiency increased in a linear fashion with increasing bottle height and vacuum. The most efficient aspiration rate was 50 mL/min, with 60 mL/min statistically similar. Increasing power increased efficiency up to 90% with increased chatter at 100%. The most efficient values for the settings tested were bottle height at 100 cm, vacuum at 600 mm Hg, aspiration rate of 50 or 60 mL/min, and power at 90%. Copyright © 2017 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Power in global health agenda-setting: the role of private funding Comment on "Knowledge, moral claims and the exercise of power in global health".

PubMed

Levine, Ruth E

2015-03-04

The editorial by Jeremy Shiffman, "Knowledge, moral claims and the exercise of power in global health", highlights the influence on global health priority-setting of individuals and organizations that do not have a formal political mandate. This sheds light on the way key functions in global health depend on private funding, particularly from the Bill & Melinda Gates Foundation. © 2015 by Kerman University of Medical Sciences.

Influence of geographic setting on thermal discharge from coastal power plants.

PubMed

Jia, Hou-Lei; Zheng, Shu; Xie, Jian; Ying, Xiao-Ming; Zhang, Cui-Ping

2016-10-15

Characteristics of thermal discharge from three coastal power plants were studied in China. The three plants, Zhuhai Power Plant, Chaozhou Power Plant and Huilai Power Plant, are located in estuary, bay and open sea, respectively. The water temperatures and ocean currents surrounding the outlet of the three power plants were monitored. The results show that the temperature rise became smaller as the spread of thermal discharge moved toward the open sea, which confirms the results of previous studies. The results also indicated that the influence range of thermal discharge from a coastal power plant is determined by geographic setting. The temperature rise range of the Chaozhou Plant, which is located in a bay, was the largest, followed by that of the Zhuhai Plant located in an estuary, and the temperature rise range of the Huilai Plant located in an open sea was the smallest. Copyright © 2016 Elsevier Ltd. All rights reserved.

Adaptive Set-Based Methods for Association Testing

PubMed Central

Su, Yu-Chen; Gauderman, W. James; Kiros, Berhane; Lewinger, Juan Pablo

2017-01-01

With a typical sample size of a few thousand subjects, a single genomewide association study (GWAS) using traditional one-SNP-at-a-time methods can only detect genetic variants conferring a sizable effect on disease risk. Set-based methods, which analyze sets of SNPs jointly, can detect variants with smaller effects acting within a gene, a pathway, or other biologically relevant sets. While self-contained set-based methods (those that test sets of variants without regard to variants not in the set) are generally more powerful than competitive set-based approaches (those that rely on comparison of variants in the set of interest with variants not in the set), there is no consensus as to which self-contained methods are best. In particular, several self-contained set tests have been proposed to directly or indirectly ‘adapt’ to the a priori unknown proportion and distribution of effects of the truly associated SNPs in the set, which is a major determinant of their power. A popular adaptive set-based test is the adaptive rank truncated product (ARTP), which seeks the set of SNPs that yields the best-combined evidence of association. We compared the standard ARTP, several ARTP variations we introduced, and other adaptive methods in a comprehensive simulation study to evaluate their performance. We used permutations to assess significance for all the methods and thus provide a level playing field for comparison. We found the standard ARTP test to have the highest power across our simulations followed closely by the global model of random effects (GMRE) and a LASSO based test. PMID:26707371

Three-phase receiving coil of wireless power transmission system for gastrointestinal robot

NASA Astrophysics Data System (ADS)

Jia, Z. W.; Jiang, T.; Liu, Y.

2017-11-01

Power shortage is the bottleneck for the wide application of gastrointestinal (GI) robot. Owing to the limited volume and free change of orientation of the receiving set in GI trace, the optimal of receiving set is the key point to promote the transmission efficiency of wireless power transmission system. A new type of receiving set, similar to the winding of three-phase asynchronous motor, is presented and compared with the original three-dimensional orthogonal coil. Considering the given volume and the space utilization ratio, the three-phase and the three-orthogonal ones are the parameters which are optimized and compared. Both the transmission efficiency and stability are analyzed and verified by in vitro experiments. Animal experiments show that the new one could provide at least 420 mW power in volume of Φ11 × 13mm with a uniformity of 78.3% for the GI robot.

Insecticide treated bednet strategy in rural settings: can we exploit women's decision making power?

PubMed

Tilak, Rina; Tilak, V W; Bhalwar, R

2007-01-01

Use of insecticide treated bednets in prevention of malaria is a widely propagated global strategy, however, its use has been reported to be influenced and limited by many variables especially gender bias. A cross sectional field epidemiological study was conducted in a rural setting with two outcome variables, 'Bednet use'(primary outcome variable) and 'Women's Decision Making Power' which were studied in reference to various predictor variables. Analysis reveals a significant effect on the primary outcome variable 'Bednet use' of the predictor variables- age, occupation, bednet purchase decision, women's decision making power, husband's education and knowledge about malaria and its prevention. The study recommends IEC on treated bednets to be disseminated through TV targeting the elderly women who have better decision making power and mobilizing younger women who were found to prefer bednets for prevention of mosquito bites for optimizing the use of treated bednets in similar settings.

Utility of Squeeze Flow in the Food Industry

NASA Astrophysics Data System (ADS)

Huang, T. A.

2008-07-01

Squeeze flow for obtaining shear viscosity on Newtonian and non-Newtonian fluids has long been established in the literature. Rotational shear flow using cone/plate, a set of parallel plates, or concentric cylinders all develop wall slip, shear fracture, or instability on food related materials such as peanut butter or mayonnaise. Viscosity data obtained using any one of the above mentioned set-ups is suspect or potentially results in significant error. They are unreliable to support or predict the textural differences perceived by consumer evaluation. RMS-800, from Rheometrics Inc., was employed to conduct the squeezing flow under constant speeds on a set of parallel plates. Viscosity data, over a broad range of shear rates, is compared between Hellmann's real (HRM) and light mayonnaise (HLM). The Consistency and shear-thinning indices, as defined in the Power-Law Model, were determined. HRM exhibits a more pronounced shear-thinning when compared to HLM yet the Consistency of HRM is significantly higher. Sensory evaluation by a trained expert panel ranked that adhesiveness and cohesiveness of HLM are significantly higher. It appears that the degree of shear thinning is one of the key rheological parameters in predicting the above mentioned difference in textural attributes. Error involved in determining viscosity from non-parallelism between two plates can be significant to affect the accuracy of the viscosity, in particular, shear-thinning index. Details are a subject for the next presentation. Nevertheless, the method is proven to be fast, rugged, simple, and reliable. It can be developed as a QC tool.

Stimulus Load and Oscillatory Activity in Higher Cortex

PubMed Central

Kornblith, Simon; Buschman, Timothy J.; Miller, Earl K.

2016-01-01

Exploring and exploiting a rich visual environment requires perceiving, attending, and remembering multiple objects simultaneously. Recent studies have suggested that this mental “juggling” of multiple objects may depend on oscillatory neural dynamics. We recorded local field potentials from the lateral intraparietal area, frontal eye fields, and lateral prefrontal cortex while monkeys maintained variable numbers of visual stimuli in working memory. Behavior suggested independent processing of stimuli in each hemifield. During stimulus presentation, higher-frequency power (50–100 Hz) increased with the number of stimuli (load) in the contralateral hemifield, whereas lower-frequency power (8–50 Hz) decreased with the total number of stimuli in both hemifields. During the memory delay, lower-frequency power increased with contralateral load. Load effects on higher frequencies during stimulus encoding and lower frequencies during the memory delay were stronger when neural activity also signaled the location of the stimuli. Like power, higher-frequency synchrony increased with load, but beta synchrony (16–30 Hz) showed the opposite effect, increasing when power decreased (stimulus presentation) and decreasing when power increased (memory delay). Our results suggest roles for lower-frequency oscillations in top-down processing and higher-frequency oscillations in bottom-up processing. PMID:26286916

The statistical power to detect cross-scale interactions at macroscales

USGS Publications Warehouse

Wagner, Tyler; Fergus, C. Emi; Stow, Craig A.; Cheruvelil, Kendra S.; Soranno, Patricia A.

2016-01-01

Macroscale studies of ecological phenomena are increasingly common because stressors such as climate and land-use change operate at large spatial and temporal scales. Cross-scale interactions (CSIs), where ecological processes operating at one spatial or temporal scale interact with processes operating at another scale, have been documented in a variety of ecosystems and contribute to complex system dynamics. However, studies investigating CSIs are often dependent on compiling multiple data sets from different sources to create multithematic, multiscaled data sets, which results in structurally complex, and sometimes incomplete data sets. The statistical power to detect CSIs needs to be evaluated because of their importance and the challenge of quantifying CSIs using data sets with complex structures and missing observations. We studied this problem using a spatially hierarchical model that measures CSIs between regional agriculture and its effects on the relationship between lake nutrients and lake productivity. We used an existing large multithematic, multiscaled database, LAke multiscaled GeOSpatial, and temporal database (LAGOS), to parameterize the power analysis simulations. We found that the power to detect CSIs was more strongly related to the number of regions in the study rather than the number of lakes nested within each region. CSI power analyses will not only help ecologists design large-scale studies aimed at detecting CSIs, but will also focus attention on CSI effect sizes and the degree to which they are ecologically relevant and detectable with large data sets.

Global Security Rule Sets An Analysis of the Current Global Security Environment and Rule Sets Governing Nuclear Weapons Release

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

Mollahan, K; Nattrass, L

America is in a unique position in its history. In maintaining its position as the world's only superpower, the US consistently finds itself taking on the role of a global cop, chief exporter of hard and soft power, and primary impetus for globalization. A view of the current global situation shows an America that can benefit greatly from the effects of globalization and soft power. Similarly, America's power can be reduced significantly if globalization and its soft power are not handled properly. At the same time, America has slowly come to realize that its next major adversary is not amore » near peer competitor but terrorism and disconnected nations that seek nuclear capabilities. In dealing with this new threat, America needs to come to terms with its own nuclear arsenal and build a security rule set that will establish for the world explicitly what actions will cause the US to consider nuclear weapons release. This rule set; however, needs to be established with sensitivity to the US's international interests in globalization and soft power. The US must find a way to establish its doctrine governing nuclear weapons release without threatening other peaceful nations in the process.« less

The effect of exercise repetition on the frequency characteristics of motor output force: implications for Achilles tendinopathy rehabilitation.

PubMed

Grigg, Nicole L; Wearing, Scott C; O'Toole, John M; Smeathers, James E

2014-01-01

To investigate the frequency characteristics of the ground reaction force (GRF) recorded throughout the eccentric Achilles tendon rehabilitation programme described by Alfredson. Controlled laboratory study, longitudinal. Nine healthy adult males performed six sets (15 repetitions per set) of eccentric ankle exercise. Ground reaction force was recorded throughout the exercise protocol. For each exercise repetition the frequency power spectrum of the resultant ground reaction force was calculated and normalised to total power. The magnitude of peak relative power within the 8-12 Hz bandwidth and the frequency at which this peak occurred was determined. The magnitude of peak relative power within the 8-12 Hz bandwidth increased with each successive exercise set and following the 4th set (60 repetitions) of exercise the frequency at which peak relative power occurred shifted from 9 to 10 Hz. The increase in magnitude and frequency of ground reaction force vibrations with an increasing number of exercise repetitions is likely connected to changes in muscle activation with fatigue and tendon conditioning. This research illustrates the potential for the number of exercise repetitions performed to influence the tendons' mechanical environment, with implications for tendon remodelling and the clinical efficacy of eccentric rehabilitation programmes for Achilles tendinopathy. Copyright © 2013 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Operation strategy for grid-tied DC-coupling power converter interface integrating wind/solar/battery

NASA Astrophysics Data System (ADS)

Jou, H. L.; Wu, J. C.; Lin, J. H.; Su, W. N.; Wu, T. S.; Lin, Y. T.

2017-11-01

The operation strategy for a small-capacity grid-tied DC-coupling power converter interface (GDPCI) integrating wind energy, solar energy and battery energy storage is proposed. The GDPCI is composed of a wind generator, a solar module set a battery bank, a boost DC-DC power converter (DDPC), a bidirectional DDPC power converter, an AC-DC power converter (ADPC) and a five-level DC-AC inverter (DAI). A solar module set, a wind generator and a battery bank are coupled to the common DC bus through the boost DDPC, the ADPC and the bidirectional DDPC, respectively. For verifying the performance of the GDPCI under different operation modes, computer simulation is carried out by PSIM.

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

Rosenkranz, Joshua-Benedict; Brancucci Martinez-Anido, Carlo; Hodge, Bri-Mathias

Solar power generation, unlike conventional forms of electricity generation, has higher variability and uncertainty in its output because solar plant output is strongly impacted by weather. As the penetration rate of solar capacity increases, grid operators are increasingly concerned about accommodating the increased variability and uncertainty that solar power provides. This paper illustrates the impacts of increasing solar power penetration on the ramping of conventional electricity generators by simulating the operation of the Independent System Operator -- New England power system. A production cost model was used to simulate the power system under five different scenarios, one without solar powermore » and four with increasing solar power penetrations up to 18%, in terms of annual energy. The impact of solar power is analyzed on six different temporal intervals, including hourly and multi-hourly (2- to 6-hour) ramping. The results show how the integration of solar power increases the 1- to 6-hour ramping events of the net load (electric load minus solar power). The study also analyzes the impact of solar power on the distribution of multi-hourly ramping events of fossil-fueled generators and shows increasing 1- to 6-hour ramping events for all different generators. Generators with higher ramp rates such as gas and oil turbine and internal combustion engine generators increased their ramping events by 200% to 280%. For other generator types--including gas combined-cycle generators, coal steam turbine generators, and gas and oil steam turbine generators--more and higher ramping events occurred as well for higher solar power penetration levels.« less

Microwave Ablation of Porcine Kidneys in vivo: Effect of two Different Ablation Modes ('Temperature Control' and 'Power Control') on Procedural Outcome

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

Sommer, C. M., E-mail: christof.sommer@med.uni-heidelberg.de; Arnegger, F.; Koch, V.

2012-06-15

Purpose: This study was designed to analyze the effect of two different ablation modes ('temperature control' and 'power control') of a microwave system on procedural outcome in porcine kidneys in vivo. Methods: A commercially available microwave system (Avecure Microwave Generator; MedWaves, San Diego, CA) was used. The system offers the possibility to ablate with two different ablation modes: temperature control and power control. Thirty-two microwave ablations were performed in 16 kidneys of 8 pigs. In each animal, one kidney was ablated twice by applying temperature control (ablation duration set point at 60 s, ablation temperature set point at 96 Degree-Signmore » C, automatic power set point; group I). The other kidney was ablated twice by applying power control (ablation duration set point at 60 s, ablation temperature set point at 96 Degree-Sign C, ablation power set point at 24 W; group II). Procedural outcome was analyzed: (1) technical success (e.g., system failures, duration of the ablation cycle), and (2) ablation geometry (e.g., long axis diameter, short axis diameter, and circularity). Results: System failures occurred in 0% in group I and 13% in group II. Duration of the ablation cycle was 60 {+-} 0 s in group I and 102 {+-} 21 s in group II. Long axis diameter was 20.3 {+-} 4.6 mm in group I and 19.8 {+-} 3.5 mm in group II (not significant (NS)). Short axis diameter was 10.3 {+-} 2 mm in group I and 10.5 {+-} 2.4 mm in group II (NS). Circularity was 0.5 {+-} 0.1 in group I and 0.5 {+-} 0.1 in group II (NS). Conclusions: Microwave ablations performed with temperature control showed fewer system failures and were finished faster. Both ablation modes demonstrated no significant differences with respect to ablation geometry.« less

A two-step hierarchical hypothesis set testing framework, with applications to gene expression data on ordered categories

PubMed Central

2014-01-01

Background In complex large-scale experiments, in addition to simultaneously considering a large number of features, multiple hypotheses are often being tested for each feature. This leads to a problem of multi-dimensional multiple testing. For example, in gene expression studies over ordered categories (such as time-course or dose-response experiments), interest is often in testing differential expression across several categories for each gene. In this paper, we consider a framework for testing multiple sets of hypothesis, which can be applied to a wide range of problems. Results We adopt the concept of the overall false discovery rate (OFDR) for controlling false discoveries on the hypothesis set level. Based on an existing procedure for identifying differentially expressed gene sets, we discuss a general two-step hierarchical hypothesis set testing procedure, which controls the overall false discovery rate under independence across hypothesis sets. In addition, we discuss the concept of the mixed-directional false discovery rate (mdFDR), and extend the general procedure to enable directional decisions for two-sided alternatives. We applied the framework to the case of microarray time-course/dose-response experiments, and proposed three procedures for testing differential expression and making multiple directional decisions for each gene. Simulation studies confirm the control of the OFDR and mdFDR by the proposed procedures under independence and positive correlations across genes. Simulation results also show that two of our new procedures achieve higher power than previous methods. Finally, the proposed methodology is applied to a microarray dose-response study, to identify 17 β-estradiol sensitive genes in breast cancer cells that are induced at low concentrations. Conclusions The framework we discuss provides a platform for multiple testing procedures covering situations involving two (or potentially more) sources of multiplicity. The framework is easy to use and adaptable to various practical settings that frequently occur in large-scale experiments. Procedures generated from the framework are shown to maintain control of the OFDR and mdFDR, quantities that are especially relevant in the case of multiple hypothesis set testing. The procedures work well in both simulations and real datasets, and are shown to have better power than existing methods. PMID:24731138

Design principles and optimal performance for molecular motors under realistic constraints

NASA Astrophysics Data System (ADS)

Tu, Yuhai; Cao, Yuansheng

2018-02-01

The performance of a molecular motor, characterized by its power output and energy efficiency, is investigated in the motor design space spanned by the stepping rate function and the motor-track interaction potential. Analytic results and simulations show that a gating mechanism that restricts forward stepping in a narrow window in configuration space is needed for generating high power at physiologically relevant loads. By deriving general thermodynamics laws for nonequilibrium motors, we find that the maximum torque (force) at stall is less than its theoretical limit for any realistic motor-track interactions due to speed fluctuations. Our study reveals a tradeoff for the motor-track interaction: while a strong interaction generates a high power output for forward steps, it also leads to a higher probability of wasteful spontaneous back steps. Our analysis and simulations show that this tradeoff sets a fundamental limit to the maximum motor efficiency in the presence of spontaneous back steps, i.e., loose-coupling. Balancing this tradeoff leads to an optimal design of the motor-track interaction for achieving a maximum efficiency close to 1 for realistic motors that are not perfectly coupled with the energy source. Comparison with existing data and suggestions for future experiments are discussed.

Dynamic equations for an isotropic spherical shell using the power series method and surface differential operators

NASA Astrophysics Data System (ADS)

Okhovat, Reza; Boström, Anders

2017-04-01

Dynamic equations for an isotropic spherical shell are derived by using a series expansion technique. The displacement field is split into a scalar (radial) part and a vector (tangential) part. Surface differential operators are introduced to decrease the length of all equations. The starting point is a power series expansion of the displacement components in the thickness coordinate relative to the mid-surface of the shell. By using the expansions of the displacement components, the three-dimensional elastodynamic equations yield a set of recursion relations among the expansion functions that can be used to eliminate all but the four of lowest order and to express higher order expansion functions in terms of those of lowest orders. Applying the boundary conditions on the surfaces of the spherical shell and eliminating all but the four lowest order expansion functions give the shell equations as a power series in the shell thickness. After lengthy manipulations, the final four shell equations are obtained in a relatively compact form which are given to second order in shell thickness explicitly. The eigenfrequencies are compared to exact three-dimensional theory with excellent agreement and to membrane theory.

Electron Acceleration by Beating of Two Intense Cross-Focused Hollow Gaussian Laser Beams in Plasma

NASA Astrophysics Data System (ADS)

Mahmoud, Saleh T.; Gauniyal, Rakhi; Ahmad, Nafis; Rawat, Priyanka; Purohit, Gunjan

2018-01-01

This paper presents propagation of two cross-focused intense hollow Gaussian laser beams (HGBs) in collisionless plasma and its effect on the generation of electron plasma wave (EPW) and electron acceleration process, when relativistic and ponderomotive nonlinearities are simultaneously operative. Nonlinear differential equations have been set up for beamwidth of laser beams, power of generated EPW, and energy gain by electrons using WKB and paraxial approximations. Numerical simulations have been carried out to investigate the effect of typical laser-plasma parameters on the focusing of laser beams in plasmas and further its effect on power of excited EPW and acceleration of electrons. It is observed that focusing of two laser beams in plasma increases for higher order of hollow Gaussian beams, which significantly enhanced the power of generated EPW and energy gain. The amplitude of EPW and energy gain by electrons is found to enhance with an increase in the intensity of laser beams and plasma density. This study will be useful to plasma beat wave accelerator and in other applications requiring multiple laser beams. Supported by United Arab Emirates University for Financial under Grant No. UPAR (2014)-31S164

On the impact of the magnitude of interstellar pressure on physical properties of molecular cloud

NASA Astrophysics Data System (ADS)

Anathpindika, S.; Burkert, A.; Kuiper, R.

2017-04-01

Recently reported variations in the typical physical properties of Galactic and extra-Galactic molecular clouds (MCs), and, in their star-forming ability, have been attributed to local variations in the magnitude of interstellar pressure. Inferences from these surveys have called into question two long-standing beliefs that: (1) MCs are virialized and (2) they obey the Larson's third law. Here we invoked the framework of cloud formation via collision between warm gas-flows to examine if these latest observational inferences can be reconciled. To this end, we traced the temporal evolution of the gas surface density, the fraction of dense gas, the distribution of gas column density (N-PDF) and the virial nature of the assembled clouds. We conclude that these physical properties exhibit temporal variation and their respective peak magnitude also increases in proportion with the magnitude of external pressure, Pext. The velocity dispersion in assembled clouds appears to follow the power law, σ _{gas}∝ P_{ext}^{0.23}. The power-law tail of the N-PDFs at higher densities becomes shallower with increasing magnitude of external pressure for Pext/kB ≲ 107 K cm-3; at higher magnitudes such as those typically found in the Galactic Central Molecular Zone (Pext/kB > 107 K cm-3), the power-law shows significant steepening. While our results are broadly consistent with inferences from various recent observational surveys, it appears that MCs do not exhibit a unique set of properties, but rather a wide variety that can be reconciled with a range of magnitudes of pressure between 104 and 108 K cm-3.

University Rankings in Critical Perspective

ERIC Educational Resources Information Center

Pusser, Brian; Marginson, Simon

2013-01-01

This article addresses global postsecondary ranking systems by using critical-theoretical perspectives on power. This research suggests rankings are at once a useful lens for studying power in higher education and an important instrument for the exercise of power in service of dominant norms in global higher education. (Contains 1 table and 1…

Physiological and psychological responses to outdoor vs. laboratory cycling.

PubMed

Mieras, Molly E; Heesch, Matthew W S; Slivka, Dustin R

2014-08-01

The purpose of this study was to determine the physiological and psychological responses to laboratory vs. outdoor cycling. Twelve recreationally trained male cyclists participated in an initial descriptive testing session and 2 experimental trials consisting of 1 laboratory and 1 outdoor session, in a randomized order. Participants were given a standardized statement instructing them to give the same perceived effort for both the laboratory and outdoor 40-km trials. Variables measured include power output, heart rate (HR), core temperature, skin temperature, body weight, urine specific gravity (USG), Rating of Perceived Exertion (RPE), attentional focus, and environmental conditions. Wind speed was higher in the outdoor trial than in the laboratory trial (2.5 ± 0.6 vs. 0.0 ± 0.0 m·s-1, p = 0.02) whereas all other environmental conditions were similar. Power output (208.1 ± 10.2 vs. 163.4 ± 11.8 W, respectively, p < 0.001) and HR (152 ± 4 and 143 ± 6 b·min-1, respectively, p = 0.04) were higher in the outdoor trial than in the laboratory trial. Core temperature was similar, whereas skin temperature was cooler during the outdoor trial than during the laboratory trial (31.4 ± 0.3 vs. 33.0 ± 0.2° C, respectively, p < 0.001), thus creating a larger thermal gradient between the core and skin outdoors. No significant differences in body weight, USG, RPE, or attentional focus were observed between trials. These data indicate that outdoor cycling allows cyclists to exercise at a higher intensity than in laboratory cycling, despite similar environmental conditions and perceived exertion. In light of this, cyclists may want to ride at a higher perceived exertion in indoor settings to acquire the same benefit as they would from an outdoor ride.

Advanced control of neutral beam injected power in DIII-D

DOE PAGES

Pawley, Carl J.; Crowley, Brendan J.; Pace, David C.; ...

2017-03-23

In the DIII-D tokamak, one of the most powerful techniques to control the density, temperature and plasma rotation is by eight independently modulated neutral beam sources with a total power of 20 MW. The rapid modulation requires a high degree of reproducibility and precise control of the ion source plasma and beam acceleration voltage. Recent changes have been made to the controls to provide a new capability to smoothly vary the beam current and beam voltage during a discharge, while maintaining the modulation capability. The ion source plasma inside the arc chamber is controlled through feedback from the Langmuir probesmore » measuring plasma density near the extraction end. To provide the new capability, the plasma control system (PCS) has been enabled to change the Langmuir probe set point and the beam voltage set point in real time. When the PCS varies the Langmuir set point, the plasma density is directly controlled in the arc chamber, thus changing the beam current (perveance) and power going into the tokamak. Alternately, the PCS can sweep the beam voltage set point by 20 kV or more and adjust the Langmuir probe setting to match, keeping the perveance constant and beam divergence at a minimum. This changes the beam power and average neutral particle energy, which changes deposition in the tokamak plasma. The ion separating magnetic field must accurately match the beam voltage to protect the beam line. To do this, the magnet current control accurately tracks the beam voltage set point. In conclusion, these new capabilities allow continuous in-shot variation of neutral beam ion energy to complement« less

Plasma-Based Tunable High Frequency Power Limiter

NASA Astrophysics Data System (ADS)

Semnani, Abbas; Macheret, Sergey; Peroulis, Dimitrios

2016-09-01

Power limiters are often employed to protect sensitive receivers from being damaged or saturated by high-power incoming waves. Although wideband low-power limiters based on semiconductor technology are widely available, the options for high-power frequency-selective ones are very few. In this work, we study the application of a gas discharge tube (GDT) integrated in an evanescent-mode (EVA) cavity resonator as a plasma-based power limiter. Plasmas can inherently handle higher power in comparison with semiconductor diodes. Also, using a resonant structure provides the ability of having both lower threshold power and frequency-selective limiting, which are important if only a narrowband high-power signal is targeted. Higher input RF power results in stronger discharge in the GDT and consequently higher electron density which results in larger reflection. It is also possible to tune the threshold power by pre-ionizing the GDT with a DC bias voltage. As a proof of concept, a 2-GHz EVA resonator loaded by a 90-V GDT was fabricated and measured. With reasonable amount of insertion loss, the limiting threshold power was successfully tuned from 8.3 W to 590 mW when the external DC bias was varied from 0 to 80 V. The limiter performed well up to 100 W of maximum available input power.

A Metric-Based Validation Process to Assess the Realism of Synthetic Power Grids

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

Birchfield, Adam; Schweitzer, Eran; Athari, Mir

Public power system test cases that are of high quality benefit the power systems research community with expanded resources for testing, demonstrating, and cross-validating new innovations. Building synthetic grid models for this purpose is a relatively new problem, for which a challenge is to show that created cases are sufficiently realistic. This paper puts forth a validation process based on a set of metrics observed from actual power system cases. These metrics follow the structure, proportions, and parameters of key power system elements, which can be used in assessing and validating the quality of synthetic power grids. Though wide diversitymore » exists in the characteristics of power systems, the paper focuses on an initial set of common quantitative metrics to capture the distribution of typical values from real power systems. The process is applied to two new public test cases, which are shown to meet the criteria specified in the metrics of this paper.« less

A Metric-Based Validation Process to Assess the Realism of Synthetic Power Grids

DOE PAGES

Birchfield, Adam; Schweitzer, Eran; Athari, Mir; ...

2017-08-19

Public power system test cases that are of high quality benefit the power systems research community with expanded resources for testing, demonstrating, and cross-validating new innovations. Building synthetic grid models for this purpose is a relatively new problem, for which a challenge is to show that created cases are sufficiently realistic. This paper puts forth a validation process based on a set of metrics observed from actual power system cases. These metrics follow the structure, proportions, and parameters of key power system elements, which can be used in assessing and validating the quality of synthetic power grids. Though wide diversitymore » exists in the characteristics of power systems, the paper focuses on an initial set of common quantitative metrics to capture the distribution of typical values from real power systems. The process is applied to two new public test cases, which are shown to meet the criteria specified in the metrics of this paper.« less

Correlates of unmet need for contraception in Bangladesh: does couples' concordance in household decision making matter?

PubMed

Uddin, Jalal; Pulok, Mohammad Habibullah; Sabah, Md Nasim-Us

2016-07-01

A large body of literature has highlighted that women's household decision-making power is associated with better reproductive health outcomes, while most of the studies tend to measure such power from only women's point of view. Using both husband's and wife's matched responses to decision-making questions, this study examined the association between couples' concordant and discordant decision makings, and wife's unmet need for contraception in Bangladesh. This study used couple's data set (n=3336) from Bangladesh Demographic and Health Survey of 2007. Multivariate logistic regression was used to examine the likelihood of unmet need for contraception among married women of reproductive age. Study results suggested that couples who support the equalitarian power structure seemed to be more powerful in meeting the unmet demand for contraception. Logistic regression analysis revealed that compared to couple's concordant joint decision making, concordance in husband-only or other's involvement in decision making was associated with higher odds of unmet need for contraception. Wives exposed to family planning information discussed family planning more often with husbands, and those from richest households were less likely to have unmet need for contraception. Couple's concordant joint decision making, reflecting the concept of equalitarian power structure, appeared to be a significant analytic category. Policy makers in the field of family planning may promote community-based outreach programs and communication campaigns for family planning focusing on egalitarian gender roles in the household. Copyright © 2016 Elsevier Inc. All rights reserved.

Controls on morphological variability and role of stream power distribution pattern, Yamuna River, western India

NASA Astrophysics Data System (ADS)

Bawa, Nupur; Jain, Vikrant; Shekhar, Shashank; Kumar, Niraj; Jyani, Vikas

2014-12-01

Understanding the controls on the morphological variability of river systems constitutes one of the fundamental questions in geomorphic investigation. Channel morphology is an important indicator of river processes and is of significance for mapping the hydrology-ecologic connectivity in a river system and for predicting the future trajectory of river health in response to external forcings. This paper documents the spatial morphological variability and its natural and anthropogenic controls for the Yamuna River, a major tributary of the Ganga River, India. The Yamuna River runs through a major urban centre i.e. Delhi National Capital Region. The Yamuna River was divided into eight geomorphically distinct reaches on the basis of the assemblages of geomorphic units and the association of landscape, valley and floodplain settings. The morphological variability was analysed through stream power distribution and sediment load data at various stations. Stream power distribution of the Yamuna River basin is characterised by a non-linear pattern that was used to distinguish (a) high energy ‘natural' upstream reaches, (b) ‘anthropogenically altered', low energy middle stream reaches, and (c) ‘rejuvenated' downstream reaches again with higher stream power. The relationship between stream power and channel morphology in these reaches was integrated with sediment load data to define the maximum flow efficiency (MFE) as the threshold for geomorphic transition. This analysis supports the continuity of river processes and the significance of a holistic, basin-scale approach rather than isolated local scale analysis in river studies.

Improved accuracy of intraocular lens power calculation with the Zeiss IOLMaster.

PubMed

Olsen, Thomas

2007-02-01

This study aimed to demonstrate how the level of accuracy in intraocular lens (IOL) power calculation can be improved with optical biometry using partial optical coherence interferometry (PCI) (Zeiss IOLMaster) and current anterior chamber depth (ACD) prediction algorithms. Intraocular lens power in 461 consecutive cataract operations was calculated using both PCI and ultrasound and the accuracy of the results of each technique were compared. To illustrate the importance of ACD prediction per se, predictions were calculated using both a recently published 5-variable method and the Haigis 2-variable method and the results compared. All calculations were optimized in retrospect to account for systematic errors, including IOL constants and other off-set errors. The average absolute IOL prediction error (observed minus expected refraction) was 0.65 dioptres with ultrasound and 0.43 D with PCI using the 5-variable ACD prediction method (p < 0.00001). The number of predictions within +/- 0.5 D, +/- 1.0 D and +/- 2.0 D of the expected outcome was 62.5%, 92.4% and 99.9% with PCI, compared with 45.5%, 77.3% and 98.4% with ultrasound, respectively (p < 0.00001). The 2-variable ACD method resulted in an average error in PCI predictions of 0.46 D, which was significantly higher than the error in the 5-variable method (p < 0.001). The accuracy of IOL power calculation can be significantly improved using calibrated axial length readings obtained with PCI and modern IOL power calculation formulas incorporating the latest generation ACD prediction algorithms.

Preliminary Results of Performance Measurements on a Cylindrical Hall-Effect Thruster with Magnetic Field Generated by Permanent Magnets

NASA Technical Reports Server (NTRS)

Polzin, K. A.; Raitses, Y.; Merino, E.; Fisch, N. J.

2008-01-01

The performance of a low-power cylindrical Hall thruster, which more readily lends itself to miniaturization and low-power operation than a conventional (annular) Hall thruster, was measured using a planar plasma probe and a thrust stand. The field in the cylindrical thruster was produced using permanent magnets, promising a power reduction over previous cylindrical thruster iterations that employed electromagnets to generate the required magnetic field topology. Two sets of ring-shaped permanent magnets are used, and two different field configurations can be produced by reorienting the poles of one magnet relative to the other. A plasma probe measuring ion flux in the plume is used to estimate the current utilization for the two magnetic configurations. The measurements indicate that electron transport is impeded much more effectively in one configuration, implying a higher thrust efficiency. Preliminary thruster performance measurements on this configuration were obtained over a power range of 100-250 W. The thrust levels over this power range were 3.5-6.5 mN, with anode efficiencies and specific impulses spanning 14-19% and 875- 1425 s, respectively. The magnetic field in the thruster was lower for the thrust measurements than the plasma probe measurements due to heating and weakening of the permanent magnets, reducing the maximum field strength from 2 kG to roughly 750-800 G. The discharge current levels observed during thrust stand testing were anomalously high compared to those levels measured in previous experiments with this thruster.

Changes in skill and physical fitness following training in talent-identified volleyball players.

PubMed

Gabbett, Tim; Georgieff, Boris; Anderson, Steve; Cotton, Brad; Savovic, Darko; Nicholson, Lee

2006-02-01

This study investigated the effect of a skill-based training program on measurements of skill and physical fitness in talent-identified volleyball players. Twenty-six talented junior volleyball players (mean +/- SE age, 15.5 +/- 0.2 years) participated in an 8-week skill-based training program that included 3 skill-based court sessions per week. Skills sessions were designed to develop passing, setting, serving, spiking, and blocking technique and accuracy as well as game tactics and positioning skills. Coaches used a combination of technical and instructional coaching, coupled with skill-based games to facilitate learning. Subjects performed measurements of skill (passing, setting, serving, and spiking technique and accuracy), standard anthropometry (height, standing-reach height, body mass, and sum of 7 skinfolds), lower-body muscular power (vertical jump, spike jump), upper-body muscular power (overhead medicine-ball throw), speed (5- and 10-m sprint), agility (T-test), and maximal aerobic power (multistage fitness test) before and after training. Training induced significant (p < 0.05) improvements in spiking, setting, and passing accuracy and spiking and passing technique. Compared with pretraining, there were significant (p < 0.05) improvements in 5- and 10-m speed and agility. There were no significant differences between pretraining and posttraining for body mass, skinfold thickness, lower-body muscular power, upper-body muscular power, and maximal aerobic power. These findings demonstrate that skill-based volleyball training improves spiking, setting, and passing accuracy and spiking and passing technique, but has little effect on the physiological and anthropometric characteristics of players.

Power Calculations to Select Instruments for Clinical Trial Secondary Endpoints. A Case Study of Instrument Selection for Post-Traumatic Stress Symptoms in Subjects with Acute Respiratory Distress Syndrome.

PubMed

Sjoding, Michael W; Schoenfeld, David A; Brown, Samuel M; Hough, Catherine L; Yealy, Donald M; Moss, Marc; Angus, Derek C; Iwashyna, Theodore J

2017-01-01

After the sample size of a randomized clinical trial (RCT) is set by the power requirement of its primary endpoint, investigators select secondary endpoints while unable to further adjust sample size. How the sensitivity and specificity of an instrument used to measure these outcomes, together with their expected underlying event rates, affect an RCT's power to measure significant differences in these outcomes is poorly understood. Motivated by the design of an RCT of neuromuscular blockade in acute respiratory distress syndrome, we examined how power to detect a difference in secondary endpoints varies with the sensitivity and specificity of the instrument used to measure such outcomes. We derived a general formula and Stata code for calculating an RCT's power to detect differences in binary outcomes when such outcomes are measured with imperfect sensitivity and specificity. The formula informed the choice of instrument for measuring post-traumatic stress-like symptoms in the Reevaluation of Systemic Early Neuromuscular Blockade RCT ( www.clinicaltrials.gov identifier NCT02509078). On the basis of published sensitivities and specificities, the Impact of Events Scale-Revised was predicted to measure a 36% symptom rate, whereas the Post-Traumatic Stress Symptoms instrument was predicted to measure a 23% rate, if the true underlying rate of post-traumatic stress symptoms were 25%. Despite its lower sensitivity, the briefer Post-Traumatic Stress Symptoms instrument provided superior power to detect a difference in rates between trial arms, owing to its higher specificity. Examining instruments' power to detect differences in outcomes may guide their selection when multiple instruments exist, each with different sensitivities and specificities.

Power Calculations to Select Instruments for Clinical Trial Secondary Endpoints. A Case Study of Instrument Selection for Post-Traumatic Stress Symptoms in Subjects with Acute Respiratory Distress Syndrome

PubMed Central

Schoenfeld, David A.; Brown, Samuel M.; Hough, Catherine L.; Yealy, Donald M.; Moss, Marc; Angus, Derek C.; Iwashyna, Theodore J.

2017-01-01

Rationale: After the sample size of a randomized clinical trial (RCT) is set by the power requirement of its primary endpoint, investigators select secondary endpoints while unable to further adjust sample size. How the sensitivity and specificity of an instrument used to measure these outcomes, together with their expected underlying event rates, affect an RCT’s power to measure significant differences in these outcomes is poorly understood. Objectives: Motivated by the design of an RCT of neuromuscular blockade in acute respiratory distress syndrome, we examined how power to detect a difference in secondary endpoints varies with the sensitivity and specificity of the instrument used to measure such outcomes. Methods: We derived a general formula and Stata code for calculating an RCT’s power to detect differences in binary outcomes when such outcomes are measured with imperfect sensitivity and specificity. The formula informed the choice of instrument for measuring post-traumatic stress–like symptoms in the Reevaluation of Systemic Early Neuromuscular Blockade RCT (www.clinicaltrials.gov identifier NCT02509078). Measurements and Main Results: On the basis of published sensitivities and specificities, the Impact of Events Scale-Revised was predicted to measure a 36% symptom rate, whereas the Post-Traumatic Stress Symptoms instrument was predicted to measure a 23% rate, if the true underlying rate of post-traumatic stress symptoms were 25%. Despite its lower sensitivity, the briefer Post-Traumatic Stress Symptoms instrument provided superior power to detect a difference in rates between trial arms, owing to its higher specificity. Conclusions: Examining instruments’ power to detect differences in outcomes may guide their selection when multiple instruments exist, each with different sensitivities and specificities. PMID:27788018

Solid oxide fuel cell steam reforming power system

DOEpatents

Chick, Lawrence A.; Sprenkle, Vincent L.; Powell, Michael R.; Meinhardt, Kerry D.; Whyatt, Greg A.

2013-03-12

The present invention is a Solid Oxide Fuel Cell Reforming Power System that utilizes adiabatic reforming of reformate within this system. By utilizing adiabatic reforming of reformate within the system the system operates at a significantly higher efficiency than other Solid Oxide Reforming Power Systems that exist in the prior art. This is because energy is not lost while materials are cooled and reheated, instead the device operates at a higher temperature. This allows efficiencies higher than 65%.

The Effects of Gender Variety and Power Disparity on Group Cognitive Complexity in Collaborative Learning Groups

ERIC Educational Resources Information Center

Curseu, Petru Lucian; Sari, Kimzana

2015-01-01

This study sets up to test the extent to which gender variety moderates the impact of power disparity on group cognitive complexity (GCC) and satisfaction with the group in a collaborative learning setting. Using insights from gender differences in perceptions, orientations and conflict handling behavior in negotiation, as well as gender…

Salivary hormone and immune responses to three resistance exercise schemes in elite female athletes.

PubMed

Nunes, João A; Crewther, Blair T; Ugrinowitsch, Carlos; Tricoli, Valmor; Viveiros, Luís; de Rose, Dante; Aoki, Marcelo S

2011-08-01

This study examined the salivary hormone and immune responses of elite female athletes to 3 different resistance exercise schemes. Fourteen female basketball players each performed an endurance scheme (ES-4 sets of 12 reps, 60% of 1 repetition maximum (1RM) load, 1-minute rest periods), a strength-hypertrophy scheme (SHS-1 set of 5RM, 1 set of 4RM, 1 set of 3RM, 1 set of 2RM, and 1set of 1RM with 3-minute rest periods, followed by 3 sets of 10RM with 2-minute rest periods) and a power scheme (PS-3 sets of 10 reps, 50% 1RM load, 3-minute rest periods) using the same exercises (bench press, squat, and biceps curl). Saliva samples were collected at 07:30 hours, pre-exercise (Pre) at 09:30 hours, postexercise (Post), and at 17:30 hours. Matching samples were also taken on a nonexercising control day. The samples were analyzed for testosterone, cortisol (C), and immunoglobulin A concentrations. The total volume of load lifted differed among the 3 schemes (SHS > ES > PS, p < 0.05). Postexercise C concentrations increased after all schemes, compared to control values (p < 0.05). In the SHS, the postexercise C response was also greater than pre-exercise data (p < 0.05). The current findings confirm that high-volume resistance exercise schemes can stimulate greater C secretion because of higher metabolic demand. In terms of practical applications, acute changes in C may be used to evaluate the metabolic demands of different resistance exercise schemes, or as a tool for monitoring training strain.

Women Faculty Distressed: Descriptions and Consequences of Academic Contrapower Harassment.

PubMed

Lampman, C; Crew, E C; Lowery, S; Tompkins, K A; Mulder, M

2016-01-01

Academic contrapower harassment (ACPH) occurs when someone with seemingly less power in an educational setting (e.g., a student) harasses someone more powerful (e.g., a professor). A representative sample of 289 professors from U.S. institutions of higher education described their worst incident with ACPH. Open-ended responses were coded using a keyword text analysis. Compared to the experiences of men faculty, women faculty reported that students were more likely to challenge their authority, argue or refuse to follow course policies, and exhibit disrespectful or disruptive behaviors. Although sexual harassment was uncommon, men faculty were more likely than women faculty to recount such incidents. Women faculty reported significantly more negative outcomes as a result of ACPH (e.g., anxiety, stress-related illness, difficulty concentrating, wanting to quit) than men faculty, and negative outcomes were most likely to result from ACPH involving intimidation, threats, or bullying from students. Implications for the prevention and reporting of ACPH are discussed.

Development of procedures for calculating stiffness and damping of elastomers in engineering applications, part 6

NASA Technical Reports Server (NTRS)

Rieger, A.; Burgess, G.; Zorzi, E.

1980-01-01

An elastomer damper was designed, tested, and compared with the performance of a hydraulic damper for a power transmission shaft. The six button Viton-70 damper was designed so that the elastomer damper or the hydraulic damper could be activated without upsetting the imbalance condition of the assembly. This permitted a direct comparison of damper effectiveness. The elastomer damper consistently performed better than the hydraulic mount and permitted stable operation of the power transmission shaft to speeds higher than obtained with the squeeze film damper. Tests were performed on shear specimens of Viton-79, Buna-N, EPDM, and Neoprene to determine performance limitations imposed by strain, temperature, and frequency. Frequencies of between 110 Hz and 1100 Hz were surveyed with imposed strains between 0.0005 and 0.08 at temperatures of 32 C, 66 C, and 80 C. A set of design curves was generated in a unified format for each of the elastomer materials.

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

Aliprantis, Dionysios; El-Sharkawi, Mohamed; Muljadi, Eduard

The main objective of this special issue is to collect and disseminate publications that highlight recent advances and breakthroughs in the area of renewable energy resources. The use of these resources for production of electricity is increasing rapidly worldwide. As of 2015, a majority of countries have set renewable electricity targets in the 10%-40% range to be achieved by 2020-2030, with a few notable exceptions aiming for 100% generation by renewables. We are experiencing a truly unprecedented transition away from fossil fuels, driven by environmental, energy security, and socio-economic factors.Electric machines can be found in a wide range of renewablemore » energy applications, such as wind turbines, hydropower and hydrokinetic systems, flywheel energy storage devices, and low-power energy harvesting systems. Hence, the design of reliable, efficient, cost-effective, and controllable electric machines is crucial in enabling even higher penetrations of renewable energy systems in the smart grid of the future. In addition, power electronic converter design and control is critical, as they provide essential controllability, flexibility, grid interface, and integration functions.« less

Macro- and microlevel processes affect food choice and nutritional status in the republic of the marshall islands.

PubMed

Gittelsohn, Joel; Haberle, Heather; Vastine, Amy E; Dyckman, William; Palafox, Neal A

2003-01-01

Despite its relative isolation from the world stage and lack of resources, the Marshall Islands serve as an example of the interaction between global political power, macroeconomic forces and local cultural factors. At the national level, patterns of food importation and government programs encourage the consumption of high fat foods. These factors have fostered dependency on Western foods and a loss of traditional food practices. Beliefs come into play as microlevel factors that influence food choice and aspects of lifestyle. Nearly three quarters of women are overweight or obese in this setting. Obesity in women is associated with greater age, higher education and more imported food consumption. Over a third of children ages 1-5 y are stunted, with stunting associated with worse economic status, less active feeding, increased consumption of imported foods and urban residence. What can be done at the microlevel is constrained by macrolevel factors of disempowerment. In this way, issues of power and belief are played out in the bodies of individuals.

The arcsine is asinine: the analysis of proportions in ecology.

PubMed

Warton, David I; Hui, Francis K C

2011-01-01

The arcsine square root transformation has long been standard procedure when analyzing proportional data in ecology, with applications in data sets containing binomial and non-binomial response variables. Here, we argue that the arcsine transform should not be used in either circumstance. For binomial data, logistic regression has greater interpretability and higher power than analyses of transformed data. However, it is important to check the data for additional unexplained variation, i.e., overdispersion, and to account for it via the inclusion of random effects in the model if found. For non-binomial data, the arcsine transform is undesirable on the grounds of interpretability, and because it can produce nonsensical predictions. The logit transformation is proposed as an alternative approach to address these issues. Examples are presented in both cases to illustrate these advantages, comparing various methods of analyzing proportions including untransformed, arcsine- and logit-transformed linear models and logistic regression (with or without random effects). Simulations demonstrate that logistic regression usually provides a gain in power over other methods.

Snow load effect on earth's rotation and gravitational field, 1979-1985

NASA Technical Reports Server (NTRS)

Chao, B. Fong; O'Connor, William P.; Chang, Alfred T. C.; Hall, Dorothy K.; Foster, James L.

1987-01-01

A global, monthly snow depth data set has been generated from the Nimbus 7 satellite observations using passive microwave remote-sensing techniques. Seven years of data, 1979-1985, are analyzed to compute the snow load effects on the earth's rotation and low-degree zonal gravitational field. The resultant time series show dominant seasonal cycles. The annual peak-to-peak variation in J2 is found to be 2.3 x 10 to the -10th, that in J3 to be 1.1 x 10 to the -10th, and believed to decrease rapidly for higher degrees. The corresponding change in the length of day is 41 micro-s. The annual wobble excitation is (4.9 marc sec, -109 deg) for the prograde motion component and (4.8 marc sec, -28 deg) for the retrograde motion component. The excitation power of the Chandler wobble due to the snow load is estimated to be about 25 dB less than the power needed to maintain the observed Chandler wobble.

Program for refan JT8D engine design, fabrication and test, phase 2

NASA Technical Reports Server (NTRS)

Glass, J. A.; Zimmerman, E. S.; Scaramella, V. M.

1975-01-01

The objective of the JT8D refan program was to design, fabricate, and test certifiable modifications of the JT8D engine which would reduce noise generated by JT8D powered aircraft. This was to be accomplished without affecting reliability and maintainability, at minimum retrofit cost, and with no performance penalty. The mechanical design, engine performance and stability characteristics at sea-level and altitude, and the engine noise characteristics of the test engines are documented. Results confirmed the structural integrity of the JT8D-109. Engine operation was stable throughout the airplane flight envelope. Fuel consumption of the test engines was higher than that required to meet the goal of no airplane performance penalty, but the causes were identified and corrected during a normal pre-certification engine development program. Compared to the baseline JT8D-109 engine, the acoustically treated JT8D-109 engine showed noise reductions of 6 PNdB at takeoff and 11 PNdB at a typical approach power setting.

Women Faculty Distressed: Descriptions and Consequences of Academic Contrapower Harassment

PubMed Central

Lampman, C.; Crew, E. C.; Lowery, S.; Tompkins, K. A.; Mulder, M.

2015-01-01

Academic contrapower harassment (ACPH) occurs when someone with seemingly less power in an educational setting (e.g., a student) harasses someone more powerful (e.g., a professor). A representative sample of 289 professors from U.S. institutions of higher education described their worst incident with ACPH. Open-ended responses were coded using a keyword text analysis. Compared to the experiences of men faculty, women faculty reported that students were more likely to challenge their authority, argue or refuse to follow course policies, and exhibit disrespectful or disruptive behaviors. Although sexual harassment was uncommon, men faculty were more likely than women faculty to recount such incidents. Women faculty reported significantly more negative outcomes as a result of ACPH (e.g., anxiety, stress-related illness, difficulty concentrating, wanting to quit) than men faculty, and negative outcomes were most likely to result from ACPH involving intimidation, threats, or bullying from students. Implications for the prevention and reporting of ACPH are discussed. PMID:28239435

A wide bandgap silicon carbide (SiC) gate driver for high-temperature and high-voltage applications

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

Lamichhane, Ranjan; Ericson, Milton Nance; Frank, Steven Shane

2014-01-01

Limitations of silicon (Si) based power electronic devices can be overcome with Silicon Carbide (SiC) because of its remarkable material properties. SiC is a wide bandgap semiconductor material with larger bandgap, lower leakage currents, higher breakdown electric field, and higher thermal conductivity, which promotes higher switching frequencies for high power applications, higher temperature operation, and results in higher power density devices relative to Si [1]. The proposed work is focused on design of a SiC gate driver to drive a SiC power MOSFET, on a Cree SiC process, with rise/fall times (less than 100 ns) suitable for 500 kHz tomore » 1 MHz switching frequency applications. A process optimized gate driver topology design which is significantly different from generic Si circuit design is proposed. The ultimate goal of the project is to integrate this gate driver into a Toyota Prius plug-in hybrid electric vehicle (PHEV) charger module. The application of this high frequency charger will result in lighter, smaller, cheaper, and a more efficient power electronics system.« less

18 CFR 284.503 - Market-power determination.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Market-power determination. 284.503 Section 284.503 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY... that complies with the following: (a) The applicant must set forth its specific request and adequately...

18 CFR 284.503 - Market-power determination.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Market-power determination. 284.503 Section 284.503 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY... that complies with the following: (a) The applicant must set forth its specific request and adequately...

18 CFR 284.503 - Market-power determination.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 18 Conservation of Power and Water Resources 1 2014-04-01 2014-04-01 false Market-power determination. 284.503 Section 284.503 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY... that complies with the following: (a) The applicant must set forth its specific request and adequately...

18 CFR 284.503 - Market-power determination.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Market-power determination. 284.503 Section 284.503 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY... that complies with the following: (a) The applicant must set forth its specific request and adequately...

Plant Disease Severity Assessment-How Rater Bias, Assessment Method, and Experimental Design Affect Hypothesis Testing and Resource Use Efficiency.

PubMed

Chiang, Kuo-Szu; Bock, Clive H; Lee, I-Hsuan; El Jarroudi, Moussa; Delfosse, Philippe

2016-12-01

The effect of rater bias and assessment method on hypothesis testing was studied for representative experimental designs for plant disease assessment using balanced and unbalanced data sets. Data sets with the same number of replicate estimates for each of two treatments are termed "balanced" and those with unequal numbers of replicate estimates are termed "unbalanced". The three assessment methods considered were nearest percent estimates (NPEs), an amended 10% incremental scale, and the Horsfall-Barratt (H-B) scale. Estimates of severity of Septoria leaf blotch on leaves of winter wheat were used to develop distributions for a simulation model. The experimental designs are presented here in the context of simulation experiments which consider the optimal design for the number of specimens (individual units sampled) and the number of replicate estimates per specimen for a fixed total number of observations (total sample size for the treatments being compared). The criterion used to gauge each method was the power of the hypothesis test. As expected, at a given fixed number of observations, the balanced experimental designs invariably resulted in a higher power compared with the unbalanced designs at different disease severity means, mean differences, and variances. Based on these results, with unbiased estimates using NPE, the recommended number of replicate estimates taken per specimen is 2 (from a sample of specimens of at least 30), because this conserves resources. Furthermore, for biased estimates, an apparent difference in the power of the hypothesis test was observed between assessment methods and between experimental designs. Results indicated that, regardless of experimental design or rater bias, an amended 10% incremental scale has slightly less power compared with NPEs, and that the H-B scale is more likely than the others to cause a type II error. These results suggest that choice of assessment method, optimizing sample number and number of replicate estimates, and using a balanced experimental design are important criteria to consider to maximize the power of hypothesis tests for comparing treatments using disease severity estimates.

Adaptive Set-Based Methods for Association Testing.

PubMed

Su, Yu-Chen; Gauderman, William James; Berhane, Kiros; Lewinger, Juan Pablo

2016-02-01

With a typical sample size of a few thousand subjects, a single genome-wide association study (GWAS) using traditional one single nucleotide polymorphism (SNP)-at-a-time methods can only detect genetic variants conferring a sizable effect on disease risk. Set-based methods, which analyze sets of SNPs jointly, can detect variants with smaller effects acting within a gene, a pathway, or other biologically relevant sets. Although self-contained set-based methods (those that test sets of variants without regard to variants not in the set) are generally more powerful than competitive set-based approaches (those that rely on comparison of variants in the set of interest with variants not in the set), there is no consensus as to which self-contained methods are best. In particular, several self-contained set tests have been proposed to directly or indirectly "adapt" to the a priori unknown proportion and distribution of effects of the truly associated SNPs in the set, which is a major determinant of their power. A popular adaptive set-based test is the adaptive rank truncated product (ARTP), which seeks the set of SNPs that yields the best-combined evidence of association. We compared the standard ARTP, several ARTP variations we introduced, and other adaptive methods in a comprehensive simulation study to evaluate their performance. We used permutations to assess significance for all the methods and thus provide a level playing field for comparison. We found the standard ARTP test to have the highest power across our simulations followed closely by the global model of random effects (GMRE) and a least absolute shrinkage and selection operator (LASSO)-based test. © 2015 WILEY PERIODICALS, INC.

Planck intermediate results. LI. Features in the cosmic microwave background temperature power spectrum and shifts in cosmological parameters

NASA Astrophysics Data System (ADS)

Planck Collaboration; Aghanim, N.; Akrami, Y.; Ashdown, M.; Aumont, J.; Baccigalupi, C.; Ballardini, M.; Banday, A. J.; Barreiro, R. B.; Bartolo, N.; Basak, S.; Benabed, K.; Bersanelli, M.; Bielewicz, P.; Bonaldi, A.; Bonavera, L.; Bond, J. R.; Borrill, J.; Bouchet, F. R.; Burigana, C.; Calabrese, E.; Cardoso, J.-F.; Challinor, A.; Chiang, H. C.; Colombo, L. P. L.; Combet, C.; Crill, B. P.; Curto, A.; Cuttaia, F.; de Bernardis, P.; de Rosa, A.; de Zotti, G.; Delabrouille, J.; Di Valentino, E.; Dickinson, C.; Diego, J. M.; Doré, O.; Ducout, A.; Dupac, X.; Dusini, S.; Efstathiou, G.; Elsner, F.; Enßlin, T. A.; Eriksen, H. K.; Fantaye, Y.; Finelli, F.; Forastieri, F.; Frailis, M.; Franceschi, E.; Frolov, A.; Galeotta, S.; Galli, S.; Ganga, K.; Génova-Santos, R. T.; Gerbino, M.; González-Nuevo, J.; Górski, K. M.; Gratton, S.; Gruppuso, A.; Gudmundsson, J. E.; Herranz, D.; Hivon, E.; Huang, Z.; Jaffe, A. H.; Jones, W. C.; Keihänen, E.; Keskitalo, R.; Kiiveri, K.; Kim, J.; Kisner, T. S.; Knox, L.; Krachmalnicoff, N.; Kunz, M.; Kurki-Suonio, H.; Lagache, G.; Lamarre, J.-M.; Lasenby, A.; Lattanzi, M.; Lawrence, C. R.; Le Jeune, M.; Levrier, F.; Lewis, A.; Liguori, M.; Lilje, P. B.; Lilley, M.; Lindholm, V.; López-Caniego, M.; Lubin, P. M.; Ma, Y.-Z.; Macías-Pérez, J. F.; Maggio, G.; Maino, D.; Mandolesi, N.; Mangilli, A.; Maris, M.; Martin, P. G.; Martínez-González, E.; Matarrese, S.; Mauri, N.; McEwen, J. D.; Meinhold, P. R.; Mennella, A.; Migliaccio, M.; Millea, M.; Miville-Deschênes, M.-A.; Molinari, D.; Moneti, A.; Montier, L.; Morgante, G.; Moss, A.; Narimani, A.; Natoli, P.; Oxborrow, C. A.; Pagano, L.; Paoletti, D.; Partridge, B.; Patanchon, G.; Patrizii, L.; Pettorino, V.; Piacentini, F.; Polastri, L.; Polenta, G.; Puget, J.-L.; Rachen, J. P.; Racine, B.; Reinecke, M.; Remazeilles, M.; Renzi, A.; Rocha, G.; Rossetti, M.; Roudier, G.; Rubiño-Martín, J. A.; Ruiz-Granados, B.; Salvati, L.; Sandri, M.; Savelainen, M.; Scott, D.; Sirignano, C.; Sirri, G.; Stanco, L.; Suur-Uski, A.-S.; Tauber, J. A.; Tavagnacco, D.; Tenti, M.; Toffolatti, L.; Tomasi, M.; Tristram, M.; Trombetti, T.; Valiviita, J.; Van Tent, F.; Vielva, P.; Villa, F.; Vittorio, N.; Wandelt, B. D.; Wehus, I. K.; White, M.; Zacchei, A.; Zonca, A.

2017-11-01

The six parameters of the standard ΛCDM model have best-fit values derived from the Planck temperature power spectrum that are shifted somewhat from the best-fit values derived from WMAP data. These shifts are driven by features in the Planck temperature power spectrum at angular scales that had never before been measured to cosmic-variance level precision. We have investigated these shifts to determine whether they are within the range of expectation and to understand their origin in the data. Taking our parameter set to be the optical depth of the reionized intergalactic medium τ, the baryon density ωb, the matter density ωm, the angular size of the sound horizon θ∗, the spectral index of the primordial power spectrum, ns, and Ase- 2τ (where As is the amplitude of the primordial power spectrum), we have examined the change in best-fit values between a WMAP-like large angular-scale data set (with multipole moment ℓ < 800 in the Planck temperature power spectrum) and an all angular-scale data set (ℓ < 2500Planck temperature power spectrum), each with a prior on τ of 0.07 ± 0.02. We find that the shifts, in units of the 1σ expected dispersion for each parameter, are { Δτ,ΔAse- 2τ,Δns,Δωm,Δωb,Δθ∗ } = { -1.7,-2.2,1.2,-2.0,1.1,0.9 }, with a χ2 value of 8.0. We find that this χ2 value is exceeded in 15% of our simulated data sets, and that a parameter deviates by more than 2.2σ in 9% of simulated data sets, meaning that the shifts are not unusually large. Comparing ℓ < 800 instead to ℓ> 800, or splitting at a different multipole, yields similar results. We examined the ℓ < 800 model residuals in the ℓ> 800 power spectrum data and find that the features there that drive these shifts are a set of oscillations across a broad range of angular scales. Although they partly appear similar to the effects of enhanced gravitational lensing, the shifts in ΛCDM parameters that arise in response to these features correspond to model spectrum changes that are predominantly due to non-lensing effects; the only exception is τ, which, at fixed Ase- 2τ, affects the ℓ> 800 temperature power spectrum solely through the associated change in As and the impact of that on the lensing potential power spectrum. We also ask, "what is it about the power spectrum at ℓ < 800 that leads to somewhat different best-fit parameters than come from the full ℓ range?" We find that if we discard the data at ℓ < 30, where there is a roughly 2σ downward fluctuation in power relative to the model that best fits the full ℓ range, the ℓ < 800 best-fit parameters shift significantly towards the ℓ < 2500 best-fit parameters. In contrast, including ℓ < 30, this previously noted "low-ℓ deficit" drives ns up and impacts parameters correlated with ns, such as ωm and H0. As expected, the ℓ < 30 data have a much greater impact on the ℓ < 800 best fit than on the ℓ < 2500 best fit. So although the shifts are not very significant, we find that they can be understood through the combined effects of an oscillatory-like set of high-ℓ residuals and the deficit in low-ℓ power, excursions consistent with sample variance that happen to map onto changes in cosmological parameters. Finally, we examine agreement between PlanckTT data and two other CMB data sets, namely the Planck lensing reconstruction and the TT power spectrum measured by the South Pole Telescope, again finding a lack of convincing evidence of any significant deviations in parameters, suggesting that current CMB data sets give an internally consistent picture of the ΛCDM model.

Field-scale investigation of pulverized coal mill power consumption

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

Ganguli, R.; Bandopadhyay, S.

2008-08-15

Twenty field-scale tests were conducted in a 28 MW pulverized coal power plant in Healy, Alaska, to examine mill power consumption in relation to coal grind size. The intent in this field-scale study was to verify if grind size truly impacted power consumption by a detectable amount. The regression model developed from the data indicates that grind size does impact mill power consumption, with finer grinds consuming significantly more power than coarser grinds. However, other factors such as coal hardness (i.e. the lower the Hardgrove Grindability Index, or the harder the coal, the higher the power consumption) and mill throughputmore » (i.e., the higher the throughput, the higher the power consumption) had to be included before the impact of grind size could be isolated. It was also observed that combining amperage and flow rate into a single parameter, i.e., specific amperage, hurt modeling. Cost analysis based on the regression model indicate a power savings of $19,972 per year if the coal were ground to 50% passing 76 {mu}m rather than the industry standard of 70% passing 76 {mu}m. The study also demonstrated that size reduction constituted a significant portion of the power consumption.« less

Variability in large-scale wind power generation: Variability in large-scale wind power generation

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

Kiviluoma, Juha; Holttinen, Hannele; Weir, David

2015-10-25

The paper demonstrates the characteristics of wind power variability and net load variability in multiple power systems based on real data from multiple years. Demonstrated characteristics include probability distribution for different ramp durations, seasonal and diurnal variability and low net load events. The comparison shows regions with low variability (Sweden, Spain and Germany), medium variability (Portugal, Ireland, Finland and Denmark) and regions with higher variability (Quebec, Bonneville Power Administration and Electric Reliability Council of Texas in North America; Gansu, Jilin and Liaoning in China; and Norway and offshore wind power in Denmark). For regions with low variability, the maximum 1more » h wind ramps are below 10% of nominal capacity, and for regions with high variability, they may be close to 30%. Wind power variability is mainly explained by the extent of geographical spread, but also higher capacity factor causes higher variability. It was also shown how wind power ramps are autocorrelated and dependent on the operating output level. When wind power was concentrated in smaller area, there were outliers with high changes in wind output, which were not present in large areas with well-dispersed wind power.« less

Unconventional High Density Vertically Aligned Conducting Polymer

DTIC Science & Technology

2014-08-21

DISTRIBUTION/AVAILABILITY STATEMENT Unlimited 13. SUPPLEMENTARY NOTES 14. ABSTRACT Supercapacitors are promising energy storage devices due to their higher...order to meet the demands of a wide range of energy technologies, supercapacitors with higher energy and power densities are required. Although many past...applications. Supercapacitors are promising energy storage devices due to their higher energy density than dielectric capacitors and higher power density and

InP MMIC Chip Set for Power Sources Covering 80-170 GHz

NASA Technical Reports Server (NTRS)

Ngo, Catherine

2001-01-01

We will present a Monolithic Millimeter-wave Integrated Circuit (MMIC) chip set which provides high output-power sources for driving diode frequency multipliers into the terahertz range. The chip set was fabricated at HRL Laboratories using a 0.1-micrometer gate-length InAlAs/InGaAs/InP high electron mobility transistor (HEMT) process, and features transistors with an f(sub max) above 600 GHz. The HRL InP HEMT process has already demonstrated amplifiers in the 60-200 GHz range. In this paper, these high frequency HEMTs form the basis for power sources up to 170 GHz. A number of state-of-the-art InP HEMT MMICs will be presented. These include voltage-controlled and fixed-tuned oscillators, power amplifiers, and an active doubler. We will first discuss an 80 GHz voltage-controlled oscillator with 5 GHz of tunability and at least 17 mW of output power, as well as a 120 GHz oscillator providing 7 mW of output power. In addition, we will present results of a power amplifier which covers the full WRIO waveguide band (75-110 GHz), and provides 40-50 mW of output power. Furthermore, we will present an active doubler at 164 GHz providing 8% bandwidth, 3 mW of output power, and an unprecedented 2 dB of conversion loss for an InP HEMT MMIC at this frequency. Finally, we will demonstrate a power amplifier to cover 140-170 GHz with 15-25 mW of output power and 8 dB gain. These components can form a power source in the 155-165 GHz range by cascading the 80 GHz oscillator, W-band power amplifier, 164 GHz active doubler and final 140-170 GHz power amplifier for a stable, compact local oscillator subsystem, which could be used for atmospheric science or astrophysics radiometers.

The muon content of EAS as a function of primary energy

NASA Technical Reports Server (NTRS)

Blake, P. R.; Nash, W. F.; Saich, M. S.; Sephton, A. J.

1985-01-01

The muon content of extensive air showers (EAS) was measured over the wide primary energy range 10 to the 16th power to 10 to the 20th power eV. It is reported that the relative muon content of EAS decreases smoothly over the energy range 10 to the 17th power to 10 to the 19th power eV and concluded that the primary cosmic ray flux has a constant mass composition over this range. It is also reported that an apparent significant change in the power index occurs below 10 to the 17th power eV rho sub c (250 m) sup 0.78. Such a change indicates a significant change in primary mass composition in this range. The earlier conclusions concerning EAS of energy 10 to the 17th power eV are confirmed. Analysis of data in the 10 to the 16th power - 10 to the 17th power eV range revealed a previously overlooked selection bias in the data set. The full analysis of the complete data set in the energy range 10 to the 16th power - 10 to the 17th power ev with the selection bias eliminated is presented.

Fine and ultrafine particle emissions from microwave popcorn.

PubMed

Zhang, Q; Avalos, J; Zhu, Y

2014-04-01

This study characterized fine (PM2.5 ) and ultrafine particle (UFP, diameter < 100 nm) emissions from microwave popcorn and analyzed influential factors. Each pre-packed popcorn bag was cooked in a microwave oven enclosed in a stainless steel chamber for 3 min. The number concentration and size distribution of UFPs and PM2.5 mass concentration were measured inside the chamber repeatedly for five different flavors under four increasing power settings using either the foil-lined original package or a brown paper bag. UFPs and PM2.5 generated by microwaving popcorn were 150-560 and 350-800 times higher than the emissions from microwaving water, respectively. About 90% of the total particles emitted were in the ultrafine size range. The emitted PM concentrations varied significantly with flavor. Replacing the foil-lined original package with a brown paper bag significantly reduced the peak concentration by 24-87% for total particle number and 36-70% for PM2.5 . A positive relationship was observed between both UFP number and PM2.5 mass and power setting. The emission rates of microwave popcorn ranged from 1.9 × 10(10) to 8.0 × 10(10) No./min for total particle number and from 134 to 249 μg/min for PM2.5 . © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Mobile Uninterruptible Power Supply

NASA Technical Reports Server (NTRS)

Mears, Robert L.

1990-01-01

Proposed mobile unit provides 20 kVA of uninterruptible power. Used with mobile secondary power-distribution centers to provide power to test equipment with minimal cabling, hazards, and obstacles. Wheeled close to test equipment and system being tested so only short cable connections needed. Quickly moved and set up in new location. Uninterruptible power supply intended for tests which data lost or equipment damaged during even transient power failure.

Low cost high efficiency GaAs monolithic RF module for SARSAT distress beacons

NASA Technical Reports Server (NTRS)

Petersen, W. C.; Siu, D. P.; Cook, H. F.

1991-01-01

Low cost high performance (5 Watts output) 406 MHz beacons are urgently needed to realize the maximum utilization of the Search and Rescue Satellite-Aided Tracking (SARSAT) system spearheaded in the U.S. by NASA. Although current technology can produce beacons meeting the output power requirement, power consumption is high due to the low efficiency of available transmitters. Field performance is currently unsatisfactory due to the lack of safe and reliable high density batteries capable of operation at -40 C. Low cost production is also a crucial but elusive requirement for the ultimate wide scale utilization of this system. Microwave Monolithics Incorporated (MMInc.) has proposed to make both the technical and cost goals for the SARSAT beacon attainable by developing a monolithic GaAs chip set for the RF module. This chip set consists of a high efficiency power amplifier and a bi-phase modulator. In addition to implementing the RF module in Monolithic Microwave Integrated Circuit (MMIC) form to minimize ultimate production costs, the power amplifier has a power-added efficiency nearly twice that attained with current commercial technology. A distress beacon built using this RF module chip set will be significantly smaller in size and lighter in weight due to a smaller battery requirement, since the 406 MHz signal source and the digital controller have far lower power consumption compared to the 5 watt power amplifier. All the program tasks have been successfully completed. The GaAs MMIC RF module chip set has been designed to be compatible with the present 406 MHz signal source and digital controller. A complete high performance low cost SARSAT beacon can be realized with only additional minor iteration and systems integration.

Drug addiction, love, and the higher power.

PubMed

Sussman, Steve; Reynaud, Michel; Aubin, Henri-Jean; Leventhal, Adam M

2011-09-01

This discussion piece suggests that reliance on a Higher Power in drug abuse recovery programs is entertained among some addicts for its psychobiological effects. Prayer, meditation, early romantic love, and drug abuse may have in common activation of mesolimbic dopaminergic pathways of the brain and the generation of intense emotional states. In this sense, reliance on a Higher Power may operate as a substitute addiction, which replaces the psychobiological functions formerly served by drug use. Implications of this perspective are discussed.

Overview and Meteorological Validation of the Wind Integration National Dataset toolkit

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

Draxl, C.; Hodge, B. M.; Clifton, A.

2015-04-13

The Wind Integration National Dataset (WIND) Toolkit described in this report fulfills these requirements, and constitutes a state-of-the-art national wind resource data set covering the contiguous United States from 2007 to 2013 for use in a variety of next-generation wind integration analyses and wind power planning. The toolkit is a wind resource data set, wind forecast data set, and wind power production and forecast data set derived from the Weather Research and Forecasting (WRF) numerical weather prediction model. WIND Toolkit data are available online for over 116,000 land-based and 10,000 offshore sites representing existing and potential wind facilities.

Quality assessment of data discrimination using self-organizing maps.

PubMed

Mekler, Alexey; Schwarz, Dmitri

2014-10-01

One of the important aspects of the data classification problem lies in making the most appropriate selection of features. The set of variables should be small and, at the same time, should provide reliable discrimination of the classes. The method for the discriminating power evaluation that enables a comparison between different sets of variables will be useful in the search for the set of variables. A new approach to feature selection is presented. Two methods of evaluation of the data discriminating power of a feature set are suggested. Both of the methods implement self-organizing maps (SOMs) and the newly introduced exponents of the degree of data clusterization on the SOM. The first method is based on the comparison of intraclass and interclass distances on the map. Another method concerns the evaluation of the relative number of best matching unit's (BMUs) nearest neighbors of the same class. Both methods make it possible to evaluate the discriminating power of a feature set in cases when this set provides nonlinear discrimination of the classes. Current algorithms in program code can be downloaded for free at http://mekler.narod.ru/Science/Articles_support.html, as well as the supporting data files. Copyright © 2014 Elsevier Inc. All rights reserved.

Do wealth distributions follow power laws? Evidence from ‘rich lists’

NASA Astrophysics Data System (ADS)

Brzezinski, Michal

2014-07-01

We use data on the wealth of the richest persons taken from the 'rich lists' provided by business magazines like Forbes to verify if the upper tails of wealth distributions follow, as often claimed, a power-law behaviour. The data sets used cover the world's richest persons over 1996-2012, the richest Americans over 1988-2012, the richest Chinese over 2006-2012, and the richest Russians over 2004-2011. Using a recently introduced comprehensive empirical methodology for detecting power laws, which allows for testing the goodness of fit as well as for comparing the power-law model with rival distributions, we find that a power-law model is consistent with data only in 35% of the analysed data sets. Moreover, even if wealth data are consistent with the power-law model, they are usually also consistent with some rivals like the log-normal or stretched exponential distributions.

Lessons from the Power Company.

ERIC Educational Resources Information Center

Dagley, Dave

1992-01-01

Numerous studies have used the power metaphor in the physical science sense to describe power in the organizational sense. This paper views school as an electrical distribution system to illustrate how power operates in schools and offers eight lessons for administrators desiring to effect positive empowerment results in school settings. (26…

Comparative study of joint analysis of microarray gene expression data in survival prediction and risk assessment of breast cancer patients

PubMed Central

2016-01-01

Abstract Microarray gene expression data sets are jointly analyzed to increase statistical power. They could either be merged together or analyzed by meta-analysis. For a given ensemble of data sets, it cannot be foreseen which of these paradigms, merging or meta-analysis, works better. In this article, three joint analysis methods, Z -score normalization, ComBat and the inverse normal method (meta-analysis) were selected for survival prognosis and risk assessment of breast cancer patients. The methods were applied to eight microarray gene expression data sets, totaling 1324 patients with two clinical endpoints, overall survival and relapse-free survival. The performance derived from the joint analysis methods was evaluated using Cox regression for survival analysis and independent validation used as bias estimation. Overall, Z -score normalization had a better performance than ComBat and meta-analysis. Higher Area Under the Receiver Operating Characteristic curve and hazard ratio were also obtained when independent validation was used as bias estimation. With a lower time and memory complexity, Z -score normalization is a simple method for joint analysis of microarray gene expression data sets. The derived findings suggest further assessment of this method in future survival prediction and cancer classification applications. PMID:26504096

Relative codon adaptation: a generic codon bias index for prediction of gene expression.

PubMed

Fox, Jesse M; Erill, Ivan

2010-06-01

The development of codon bias indices (CBIs) remains an active field of research due to their myriad applications in computational biology. Recently, the relative codon usage bias (RCBS) was introduced as a novel CBI able to estimate codon bias without using a reference set. The results of this new index when applied to Escherichia coli and Saccharomyces cerevisiae led the authors of the original publications to conclude that natural selection favours higher expression and enhanced codon usage optimization in short genes. Here, we show that this conclusion was flawed and based on the systematic oversight of an intrinsic bias for short sequences in the RCBS index and of biases in the small data sets used for validation in E. coli. Furthermore, we reveal that how the RCBS can be corrected to produce useful results and how its underlying principle, which we here term relative codon adaptation (RCA), can be made into a powerful reference-set-based index that directly takes into account the genomic base composition. Finally, we show that RCA outperforms the codon adaptation index (CAI) as a predictor of gene expression when operating on the CAI reference set and that this improvement is significantly larger when analysing genomes with high mutational bias.

In vitro assessment of fiber sweeping speed during Q-switched 532-nm laser tissue ablation

NASA Astrophysics Data System (ADS)

Rajabhandharaks, Danop; Kang, Hyun Wook; Ko, Woo Jin; Stinson, Douglas; Choi, Benjamin

2011-03-01

Photoselective vaporization of the prostate (PVP) is considered a minimally invasive procedure to treat benign prostatic hyperplasia (BPH). During the PVP, the prostate gland is irradiated by the 532-nm laser and the fiber is swept and dragged along the urethra. In this study the speed of sweeping fiber during the PVP is being investigated. In vitro porcine kidney model was used (N=100) throughout the experiment. A Q-switched 532-nm laser, equipped with sidefiring 750-Um fiber, was employed and set to power levels of 120 and 180 W. The speed of fiber sweeping was the only variable in this study and varied at 0 (i.e. no sweeping), 0.5, 1.0, 1.5, and 2.0 sweep/s. Ablation rate, depth, and coagulation thickness were quantified. Based on the current settings, ablation rate decreased as sweeping speed increased and was maximized between 0 to 1.0 sweep/s for 120-W power level and between 0 to 0.5 sweep/s for 180-W power level. Ablation rate at 180 W was higher than that at 120 W, regardless of sweeping speed. Ablation depth at both 120 and 180 W was maximized at 0 sweep/s and decreased 35% at 0.5 sweep/s. The overall coagulation thickness was less than 1.5 mm and comparable from 0 to 1.5 sweep/s (0.8~0.9 mm) and increased at 2.0 sweep/s (~1.1 mm). This study demonstrated that tissue ablation performance was contingent upon sweeping speed and maximized at slow sweeping speed due to longer laser-tissue interaction time and larger area coverage by the 532-nm light.

Robust joint score tests in the application of DNA methylation data analysis.

PubMed

Li, Xuan; Fu, Yuejiao; Wang, Xiaogang; Qiu, Weiliang

2018-05-18

Recently differential variability has been showed to be valuable in evaluating the association of DNA methylation to the risks of complex human diseases. The statistical tests based on both differential methylation level and differential variability can be more powerful than those based only on differential methylation level. Anh and Wang (2013) proposed a joint score test (AW) to simultaneously detect for differential methylation and differential variability. However, AW's method seems to be quite conservative and has not been fully compared with existing joint tests. We proposed three improved joint score tests, namely iAW.Lev, iAW.BF, and iAW.TM, and have made extensive comparisons with the joint likelihood ratio test (jointLRT), the Kolmogorov-Smirnov (KS) test, and the AW test. Systematic simulation studies showed that: 1) the three improved tests performed better (i.e., having larger power, while keeping nominal Type I error rates) than the other three tests for data with outliers and having different variances between cases and controls; 2) for data from normal distributions, the three improved tests had slightly lower power than jointLRT and AW. The analyses of two Illumina HumanMethylation27 data sets GSE37020 and GSE20080 and one Illumina Infinium MethylationEPIC data set GSE107080 demonstrated that three improved tests had higher true validation rates than those from jointLRT, KS, and AW. The three proposed joint score tests are robust against the violation of normality assumption and presence of outlying observations in comparison with other three existing tests. Among the three proposed tests, iAW.BF seems to be the most robust and effective one for all simulated scenarios and also in real data analyses.

Assessment of policy impacts on carbon capture and sequestration and bioenergy for U.S.' coal and natural gas power plants

NASA Astrophysics Data System (ADS)

Spokas, K.; Patrizio, P.; Leduc, S.; Mesfun, S.; Kraxner, F.

2017-12-01

Reducing electricity-sector emissions relies heavily on countries' abilities to either transition away from carbon-intensive energy generation or to sequester its resultant emissions with carbon capture and storage (CCS) technologies. The use of biomass energy technologies in conjunction with carbon capture and sequestration (BECCS) presents the opportunity for net reductions in atmospheric carbon dioxide. In this study, we investigate the limitations of several common policy mechanisms to incentivize the deployment of BECCS using the techno-economic spatial optimization model BeWhere (www.iiasa.ac.at/bewhere). We consider a set of coal and natural gas power plants in the United States (U.S.) selected using a screening process that considers capacity, boiler age, and capacity factor for electricity-generation units from the EPA 2014 eGRID database. The set makes up 470 GW of generation, and produces 8,400 PJ and 2.07 GtCO2 annually. Co-firing up to 15% for coal power plants is considered, using woody-biomass residues sourced from certified and managed U.S. forests obtained from the G4M (www.iiasa.ac.at/g4m) and GeoWiki (www.geo-wiki.org) database. Geologic storage is considered with injectivity and geomechanical limitations to ensure safe storage. Costs are minimized under two policy mechanisms: a carbon tax and geologic carbon sequestration credits, such as the Q45 credits. Results show that the carbon tax scenario incentivizes co-firing at low to medium carbon taxes, but is replaced by CCS at higher tax values. Carbon taxes do not strongly incentivize BECCS, as negative emissions associated with sequestering carbon content are not accounted as revenue. On the other hand, carbon credit scenarios result in significant CCS deployment, but lack any incentive for co-firing.

Comparison of two U.S. power-plant carbon dioxide emissions data sets

USGS Publications Warehouse

Ackerman, K.V.; Sundquist, E.T.

2008-01-01

Estimates of fossil-fuel CO2 emissions are needed to address a variety of climate-change mitigation concerns over a broad range of spatial and temporal scales. We compared two data sets that report power-plant CO 2 emissions in the conterminous U.S. for 2004, the most recent year reported in both data sets. The data sets were obtained from the Department of Energy's Energy Information Administration (EIA) and the Environmental Protection Agency's eGRID database. Conterminous U.S. total emissions computed from the data sets differed by 3.5% for total plant emissions (electricity plus useful thermal output) and 2.3% for electricity generation only. These differences are well within previous estimates of uncertainty in annual U.S. fossil-fuel emissions. However, the corresponding average absolute differences between estimates of emissions from individual power plants were much larger, 16.9% and 25.3%, respectively. By statistical analysis, we identified several potential sources of differences between EIA and eGRID estimates for individual plants. Estimates that are based partly or entirely on monitoring of stack gases (reported by eGRID only) differed significantly from estimates based on fuel consumption (as reported by EIA). Differences in accounting methods appear to explain differences in estimates for emissions from electricity generation from combined heat and power plants, and for total and electricity generation emissions from plants that burn nonconventional fuels (e.g., biomass). Our analysis suggests the need for care in utilizing emissions data from individual power plants, and the need for transparency in documenting the accounting and monitoring methods used to estimate emissions.

DC Microgrids Scoping Study. Estimate of Technical and Economic Benefits

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

Backhaus, Scott N.; Swift, Gregory William; Chatzivasileiadis, Spyridon

Microgrid demonstrations and deployments are expanding in US power systems and around the world. Although goals are specific to each site, these microgrids have demonstrated the ability to provide higher reliability and higher power quality than utility power systems and improved energy utilization. The vast majority of these microgrids are based on AC power transfer because this has been the traditionally dominant power delivery scheme. Independently, manufacturers, power system designers and researchers are demonstrating and deploying DC power distribution systems for applications where the end-use loads are natively DC, e.g., computers, solid-state lighting, and building networks. These early DC applicationsmore » may provide higher efficiency, added flexibility, reduced capital costs over their AC counterparts. Further, when onsite renewable generation, electric vehicles and storage systems are present, DC-based microgrids may offer additional benefits. Early successes from these efforts raises a question - can a combination of microgrid concepts and DC distribution systems provide added benefits beyond what has been achieved individually?« less

Eastern Wind Data Set | Grid Modernization | NREL

Science.gov Websites

cell was computed by combining these data sets with a composite turbine power curve. Wind power plants wind speed at the site. Adjustments were made for model biases, wake losses, wind gusts, turbine and conversion was also updated to better reflect future wind turbine technology. The 12-hour discontinuity was

47 CFR 25.146 - Licensing and operating rules for the non-geostationary orbit Fixed-Satellite Service in the 10.7...

Code of Federal Regulations, 2014 CFR

2014-10-01

...) Single-entry validation equivalent power flux-density, in the space-to-Earth direction, (EPFD down) limits. (i) Provide a set of power flux-density (PFD) masks, on the surface of the Earth, for each space..., in the space-to-Earth direction, (additional operational EPFD down ) limits. (i) Provide a set of...

--No Title--

Science.gov Websites

$offtext $stitle set definition sets G Power Generators /gen1*gen2/ F Fuels /oil,gas/ K Constants in the fuel consumption equations 0 1 2 gen1.oil 1.4609 .15186 .00145 gen1.gas 1.5742 .16310 .001358 gen2.oil 0.8008 .20310 .000916 gen2.gas 0.7266 .22560 .000778; PARAMETER PMAX(G) Maximum power outputs

The effect of active recovery on power performance during the bench press exercise.

PubMed

Lopes, Felipe A S; Panissa, Valéria L G; Julio, Ursula F; Menegon, Elton M; Franchini, Emerson

2014-03-27

The objective of this study was to verify the effect of active and passive recovery on blood lactate concentration and power performance. Twelve male subjects were submitted to a maximal strength test in the the bench press, a maximal aerobic test in the bench step, and to four sets of bench press exercise performed as fast and as long as possible, using 80% of maximal strength when active or passive recovery was performed. The maximum number of repetitions, mean and peak power in eccentric and concentric phases were computed and blood lactate concentration was measured. Comparisons for the variables were made using a two-way variance analysis (recovery type and set numer) with repeated measures in the second factor. When significant differences were detected (p < 0.05), a Tukey post-hoc test was used. There was a main effect of set number on maximum number of repetitions (p < 0.05) (1 > 2, 3, and 4; 2 > 3 and 4; 3 > 4). Mean and peak power in both eccentric and concentric phases also differed across sets (1 > 2, 3, and 4; 2 > 4). There was also a main effect for the recovery type, with lower values (p < 0.05) observed for the active recovery compared to the passive one. It can be concluded that active recovery resulted in lower lactate concentration, but did not improve power performance in the bench press exercise.

Eradication of Cytomegalovirus from Human Milk by Microwave Irradiation: A Pilot Study.

PubMed

Ben-Shoshan, Moshe; Mandel, Dror; Lubetzky, Ronit; Dollberg, Shaul; Mimouni, Francis B

2016-05-01

Cytomegalovirus (CMV)-infected human milk (HM) can lead to significant CMV morbidity and mortality in preterm very-low-birth weight infants. The eradication of CMV in HM while preserving its properties poses a major clinical challenge. We aimed to compare two methods used to neutralize the virus in HM, one recognized as partially effective (freezing) and another not tested to date (microwave exposure). We sampled HM from 31 CMV-seropositive mothers whose infants were hospitalized at the Lis Maternity Hospital. Fifteen samples that were positive for CMV antigen were divided into five 5 mL aliquots: the first a control, the second was frozen at -20°C for 1 day, the third was frozen at -200°C for 3 days, and the fourth and fifth aliquots were exposed for 30 seconds to microwave radiation at a low-power setting (500 W) and high-power setting (750 W), respectively. Only microwave radiation at a high-power setting led to complete neutralization of CMV in all samples. Low-power microwave irradiation had a 13% failure rate while 3-day freezing and 1-day freezing had failure rates of 7% and 20%, respectively. It is possible to eradicate CMV successfully in HM by using microwave radiation at a high-power setting. Further studies are needed to evaluate the effect of microwave heating on breast milk properties.

The Effect of Active Recovery on Power Performance During the Bench Press Exercise

PubMed Central

Lopes, Felipe A. S.; Panissa, Valéria L. G.; Julio, Ursula F.; Menegon, Elton M.; Franchini, Emerson

2014-01-01

The objective of this study was to verify the effect of active and passive recovery on blood lactate concentration and power performance. Twelve male subjects were submitted to a maximal strength test in the the bench press, a maximal aerobic test in the bench step, and to four sets of bench press exercise performed as fast and as long as possible, using 80% of maximal strength when active or passive recovery was performed. The maximum number of repetitions, mean and peak power in eccentric and concentric phases were computed and blood lactate concentration was measured. Comparisons for the variables were made using a two-way variance analysis (recovery type and set numer) with repeated measures in the second factor. When significant differences were detected (p < 0.05), a Tukey post-hoc test was used. There was a main effect of set number on maximum number of repetitions (p < 0.05) (1 > 2, 3, and 4; 2 > 3 and 4; 3 > 4). Mean and peak power in both eccentric and concentric phases also differed across sets (1 > 2, 3, and 4; 2 > 4). There was also a main effect for the recovery type, with lower values (p < 0.05) observed for the active recovery compared to the passive one. It can be concluded that active recovery resulted in lower lactate concentration, but did not improve power performance in the bench press exercise. PMID:25031684

Experimental testing of prototype face gears for helicopter transmissions

NASA Technical Reports Server (NTRS)

Handschuh, R.; Lewicki, D.; Bossler, R.

1992-01-01

An experimental program to test the feasibility of using face gears in a high-speed and high-power environment was conducted. Four face gear sets were tested, two sets at a time, in a closed-loop test stand at pinion rotational speeds to 19,100 rpm and to 271 kW. The test gear sets were one-half scale of the helicopter design gear set. Testing the gears at one-eighth power, the test gear set had slightly increased bending and compressive stresses when compared to the full scale design. The tests were performed in the LeRC spiral bevel gear test facility. All four sets of gears successfully ran at 100 percent of design torque and speed for 30 million pinion cycles, and two sets successfully ran at 200 percent of torque for an additional 30 million pinion cycles. The results, although limited, demonstrated the feasibility of using face gears for high-speed, high-load applications.

Toward power scaling in an acetylene mid-infrared hollow-core optical fiber gas laser: effects of pressure, fiber length, and pump power

NASA Astrophysics Data System (ADS)

Weerasinghe, H. W. Kushan; Dadashzadeh, Neda; Thirugnanasambandam, Manasadevi P.; Debord, Benoît.; Chafer, Matthieu; Gérôme, Frédéric; Benabid, Fetah; Corwin, Kristan L.; Washburn, Brian R.

2018-02-01

The effect of gas pressure, fiber length, and optical pump power on an acetylene mid-infrared hollow-core optical fiber gas laser (HOFGLAS) is experimentally determined in order to scale the laser to higher powers. The absorbed optical power and threshold power are measured for different pressures providing an optimum pressure for a given fiber length. We observe a linear dependence of both absorbed pump energy and lasing threshold for the acetylene HOFGLAS, while maintaining a good mode quality with an M-squared of 1.15. The threshold and mode behavior are encouraging for scaling to higher pressures and pump powers.

A Feasibility Study of CO2-Based Rankine Cycle Powered by Solar Energy

NASA Astrophysics Data System (ADS)

Zhang, Xin-Rong; Yamaguchi, Hiroshi; Fujima, Katsumi; Enomoto, Masatoshi; Sawada, Noboru

An experiment study was carried out in order to investigate feasibility of CO2-based Rankine cycle powered by solar energy. The proposed cycle is to achieve a cogeneration of heat and power, which consists of evacuated solar tube collectors, power generating turbine, heat recovery system, and feed pump. The Rankine cycle of the system utilizes solar collectors to convert CO2 into high-temperature supercritical state, used to drive a turbine and produce electrical power. The cycle also recovers thermal energy, which can be used for absorption refrigerator, air conditioning, hot water supply so on for a building. A set of experimental set-up was constructed to investigate the performance of the CO2-based Rankine cycle. The results show the cycle can achieve production of heat and power with reasonable thermodynamics efficiency and has a great potential of the application of the CO2-based Rankine cycle powered by solar energy. In addition, some research interests related to the present study will also be discussed in this paper.

Higher Learning: Developing Students' Powers of Learning in Higher Education

ERIC Educational Resources Information Center

Bourner, Tom

2009-01-01

This article is about student learning, specifically the problem of what a university can do to develop its students' powers of learning. The broad approach is to discover what we can learn from the university's long experience with developing students' critical faculties and then apply the lessons to developing students' powers of learning. The…

38. SITE BUILDING 004 ELECTRIC POWER STATION AT INTERIOR ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

38. SITE BUILDING 004 - ELECTRIC POWER STATION AT INTERIOR - OBLIQUE VIEW AT FLOOR LEVEL SHOWING DIESEL ENGINE/GENERATOR SET NUMBER 5. - Cape Cod Air Station, Technical Facility-Scanner Building & Power Plant, Massachusetts Military Reservation, Sandwich, Barnstable County, MA

Copper chloride cathode for a secondary battery

NASA Technical Reports Server (NTRS)

Bugga, Ratnakumar V. (Inventor); Distefano, Salvador (Inventor); Nagasubramanian, Ganesan (Inventor); Bankston, Clyde P. (Inventor)

1990-01-01

Higher energy and power densities are achieved in a secondary battery based on molten sodium and a solid, ceramic separator such as a beta alumina and a molten catholyte such as sodium tetrachloroaluminate and a copper chloride cathode. The higher cell voltage of copper chloride provides higher energy densities and the higher power density results from increased conductivity resulting from formation of copper as discharge proceeds.

Advertising emergency department wait times.

PubMed

Weiner, Scott G

2013-03-01

Advertising emergency department (ED) wait times has become a common practice in the United States. Proponents of this practice state that it is a powerful marketing strategy that can help steer patients to the ED. Opponents worry about the risk to the public health that arises from a patient with an emergent condition self-triaging to a further hospital, problems with inaccuracy and lack of standard definition of the reported time, and directing lower acuity patients to the higher cost ED setting instead to primary care. Three sample cases demonstrating the pitfalls of advertising ED wait times are discussed. Given the lack of rigorous evidence supporting the practice and potential adverse effects to the public health, caution about its use is advised.

Personal spiritual values and quality of life: evidence from Chinese college students.

PubMed

Zhang, Kaili Chen; Hui, C Harry; Lam, Jasmine; Lau, Esther Yuet Ying; Cheung, Shu-Fai; Mok, Doris Shui Ying

2014-08-01

Values are guiding principles in our life. While some studies found spiritual values to be "healthier," Sagiv and Schwartz (Eur J Soc Psychol 30:177-198, 2000) showed that people holding non-spiritual values were higher on affective well-being. We examined the predictive power of these two types of values with a longitudinal data set collected from Chinese students mainly in Hong Kong. Structural equation modeling revealed that spiritual values (as well as family income) positively predicted quality of life a year later. Non-spiritual, self-enhancement values, did not show any association. Results suggest that developing spiritual values may promote well-being through enabling individuals to find meaning and purpose in life.

The Power of Poincaré: Elucidating the Hidden Symmetries in Focal Conic Domains

NASA Astrophysics Data System (ADS)

Matsumoto, Elisabetta A.; Alexander, Gareth P.; Chen, Bryan Gin-Ge; Kamien, Randall D.

2011-03-01

Focal conic domains are typically the ``smoking gun'' by which smectic liquid crystalline phases are identified. The geometry of the equally spaced smectic layers is highly generic but, at the same time, difficult to work with. We develop an approach to the study of focal sets in smectics which exploits a hidden Poincaré symmetry revealed only by viewing the smectic layers as projections from one-higher dimension. We use this perspective to shed light upon the concentric cyclides of Dupin and several classic focal conic textures which exhibit a more widespread level of geometric organization as in Friedel's law of corresponding cones, the networks and trellises expounded by Bouligand, or Apollonian packings.

Achievement, attributions, self-efficacy, and goal setting by accounting undergraduates.

PubMed

Cheng, Pi-Yueh; Chiou, Wen-Bin

2010-02-01

Correlations were examined between two measures of accounting self-efficacy achievement goal setting, attributions, and scores on the Accounting Practice Achievement Test, obtained 1 yr. apart for 124 freshmen in junior college. Analysis indicated favorable attribution contributed to a higher mean score on accounting self-efficacy. Students with higher perceived self-efficacy performed better on the proficiency tests. Those with higher self-efficacy also set higher goals for subsequent achievement tests. Moreover, students who set higher achievement goals performed better. Goal setting mediated the relation of initial self-efficacy with subsequent test performance. However, the amount of variance accounted for by self-efficacy was small. An effective method for enhancing performance on an accounting achievement test might be to increase beneficial attributions, self-efficacy in accounting, and to encourage setting reasonable achievement goals.

Determining optimal torsional ultrasound power for cataract surgery with automatic longitudinal pulses at maximum vacuum ex vivo.

PubMed

Ronquillo, Cecinio C; Zaugg, Brian; Stagg, Brian; Kirk, Kevin R; Gupta, Isha; Barlow, William R; Pettey, Jeff H; Olson, Randall J

2014-12-01

To determine the optimal longitudinal power settings for Infiniti OZil Intelligent Phaco (IP) at varying torsional amplitude settings; and to test the hypothesis that increasing longitudinal power is more important at lower torsional amplitudes to achieve efficient phacoemulsification. Laboratory investigation. setting: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah. procedure: Individual porcine nuclei were fixed in formalin, then cut into 2.0 mm cubes. Lens cube phacoemulsification was done using OZil IP at 60%, 80%, and 100% torsional amplitude with 0%, 10%, 20%, 30%, 50%, 75%, or 100% longitudinal power. All experiments were done using a 20 gauge 0.9 mm bent reverse bevel phaco tip at constant vacuum (550 mm Hg), aspiration rate (40 mL/min), and bottle height (50 cm). main outcome measure: Complete lens particle phacoemulsification (efficiency). Linear regression analysis showed a significant increase in efficiency with increasing longitudinal power at 60% torsional amplitude (R(2) = 0.7269, P = .01) and 80% torsional amplitude (R(2) = 0.6995, P = .02) but not at 100% amplitude (R(2) = 0.3053, P = .2). Baseline comparison of 60% or 80% vs 100% torsional amplitude without longitudinal power showed increased efficiency at 100% (P = .0004). Increasing longitudinal power to 20% abolished the efficiency difference between 80% vs 100% amplitudes. In contrast, 75% longitudinal power abolished the efficiency difference between 60% vs 100% torsional amplitudes. Results suggest that longitudinal power becomes more critical at increasing phacoemulsification efficiencies at torsional amplitudes less than 100%. Increasing longitudinal power does not further increase efficiency at maximal torsional amplitudes. Copyright © 2014 Elsevier Inc. All rights reserved.

Respiratory cycle-related electroencephalographic changes during sleep in healthy children and in children with sleep disordered breathing.

PubMed

Immanuel, Sarah A; Pamula, Yvonne; Kohler, Mark; Martin, James; Kennedy, Declan; Saint, David A; Baumert, Mathias

2014-08-01

To investigate respiratory cycle-related electroencephalographic changes (RCREC) in healthy children and in children with sleep disordered breathing (SDB) during scored event-free (SEF) breathing periods of sleep. Interventional case-control repeated measurements design. Paediatric sleep laboratory in a hospital setting. Forty children with SDB and 40 healthy, age- and sex-matched children. Adenotonsillectomy in children with SDB and no intervention in controls. Overnight polysomnography; electroencephalography (EEG) power variations within SEF respiratory cycles in the overall and frequency band-specific EEG within stage 2 nonrapid eye movement (NREM) sleep, slow wave sleep (SWS), and rapid eye movement (REM) sleep. Within both groups there was a decrease in EEG power during inspiration compared to expiration across all sleep stages. Compared to controls, RCREC in children with SDB in the overall EEG were significantly higher during REM and frequency band specific RCRECs were higher in the theta band of stage 2 and REM sleep, alpha band of SWS and REM sleep, and sigma band of REM sleep. This between-group difference was not significant postadenotonsillectomy. The presence of nonrandom respiratory cycle-related electroencephalographic changes (RCREC) in both healthy children and in children with sleep disordered breathing (SDB) during NREM and REM sleep has been demonstrated. The RCREC values were higher in children with SDB, predominantly in REM sleep and this difference reduced after adenotonsillectomy. Immanuel SA, Pamula Y, Kohler M, Martin J, Kennedy D, Saint DA, Baumert M. Respiratory cycle-related electroencephalographic changes during sleep in healthy children and in children with sleep disordered breathing.

Effect of Operating and Sampling Conditions on the Exhaust Gas Composition of Small-Scale Power Generators

PubMed Central

Smits, Marianne; Vanpachtenbeke, Floris; Horemans, Benjamin; De Wael, Karolien; Hauchecorne, Birger; Van Langenhove, Herman; Demeestere, Kristof; Lenaerts, Silvia

2012-01-01

Small stationary diesel engines, like in generator sets, have limited emission control measures and are therefore responsible for 44% of the particulate matter (PM) emissions in the United States. The diesel exhaust composition depends on operating conditions of the combustion engine. Furthermore, the measurements are influenced by the used sampling method. This study examines the effect of engine loading and exhaust gas dilution on the composition of small-scale power generators. These generators are used in different operating conditions than road-transport vehicles, resulting in different emission characteristics. Experimental data were obtained for gaseous volatile organic compounds (VOC) and PM mass concentration, elemental composition and nitrate content. The exhaust composition depends on load condition because of its effect on fuel consumption, engine wear and combustion temperature. Higher load conditions result in lower PM concentration and sharper edged particles with larger aerodynamic diameters. A positive correlation with load condition was found for K, Ca, Sr, Mn, Cu, Zn and Pb adsorbed on PM, elements that originate from lubricating oil or engine corrosion. The nitrate concentration decreases at higher load conditions, due to enhanced nitrate dissociation to gaseous NO at higher engine temperatures. Dilution on the other hand decreases PM and nitrate concentration and increases gaseous VOC and adsorbed metal content. In conclusion, these data show that operating and sampling conditions have a major effect on the exhaust gas composition of small-scale diesel generators. Therefore, care must be taken when designing new experiments or comparing literature results. PMID:22442670

Statistical Properties of Ribbon Evolution and Reconnection Electric Fields in Eruptive and Confined Flares.

PubMed

Hinterreiter, J; Veronig, A M; Thalmann, J K; Tschernitz, J; Pötzi, W

2018-01-01

A statistical study of the chromospheric ribbon evolution in H[Formula: see text] two-ribbon flares was performed. The data set consists of 50 confined (62%) and eruptive (38%) flares that occurred from June 2000 to June 2015. The flares were selected homogeneously over the H[Formula: see text] and Geostationary Operational Environmental Satellite (GOES) classes, with an emphasis on including powerful confined flares and weak eruptive flares. H[Formula: see text] filtergrams from the Kanzelhöhe Observatory in combination with Michelson Doppler Imager (MDI) and Helioseismic and Magnetic Imager (HMI) magnetograms were used to derive the ribbon separation, the ribbon-separation velocity, the magnetic-field strength, and the reconnection electric field. We find that eruptive flares reveal statistically larger ribbon separation and higher ribbon-separation velocities than confined flares. In addition, the ribbon separation of eruptive flares correlates with the GOES SXR flux, whereas no clear dependence was found for confined flares. The maximum ribbon-separation velocity is not correlated with the GOES flux, but eruptive flares reveal on average a higher ribbon-separation velocity (by ≈ 10 km s -1 ). The local reconnection electric field of confined ([Formula: see text]) and eruptive ([Formula: see text]) flares correlates with the GOES flux, indicating that more powerful flares involve stronger reconnection electric fields. In addition, eruptive flares with higher electric-field strengths tend to be accompanied by faster coronal mass ejections. The online version of this article (10.1007/s11207-018-1253-1) contains supplementary material, which is available to authorized users.

The virtual digital nuclear power plant: A modern tool for supporting the lifecycle of VVER-based nuclear power units

NASA Astrophysics Data System (ADS)

Arkadov, G. V.; Zhukavin, A. P.; Kroshilin, A. E.; Parshikov, I. A.; Solov'ev, S. L.; Shishov, A. V.

2014-10-01

The article describes the "Virtual Digital VVER-Based Nuclear Power Plant" computerized system comprising a totality of verified initial data (sets of input data for a model intended for describing the behavior of nuclear power plant (NPP) systems in design and emergency modes of their operation) and a unified system of new-generation computation codes intended for carrying out coordinated computation of the variety of physical processes in the reactor core and NPP equipment. Experiments with the demonstration version of the "Virtual Digital VVER-Based NPP" computerized system has shown that it is in principle possible to set up a unified system of computation codes in a common software environment for carrying out interconnected calculations of various physical phenomena at NPPs constructed according to the standard AES-2006 project. With the full-scale version of the "Virtual Digital VVER-Based NPP" computerized system put in operation, the concerned engineering, design, construction, and operating organizations will have access to all necessary information relating to the NPP power unit project throughout its entire lifecycle. The domestically developed commercial-grade software product set to operate as an independently operating application to the project will bring about additional competitive advantages in the modern market of nuclear power technologies.

Nuclear-powered ships

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

Not Available

1992-07-01

This paper reports that using Puget Sound Naval Shipyard as a model, GAO examined the Navy's accounting practices at nuclear shipyards. In fiscal year 1991, Puget Sound worked on 24 nuclear-powered and three conventionally powered ships. About 31 percent of the workdays and 35 percent of total costs were for nuclear work. The average cost per workday for nuclear labor was 25 percent higher than for non-nuclear work, and the average cost per day for overhead for nuclear work was about 60 percent higher. These higher costs are due to the complexity of nuclear work, which requires a higher levelmore » of services, and the higher cost of specially trained workers and specialized shipyard departments that support nuclear work.« less

Planning and Resource Management in an Intelligent Automated Power Management System

NASA Technical Reports Server (NTRS)

Morris, Robert A.

1991-01-01

Power system management is a process of guiding a power system towards the objective of continuous supply of electrical power to a set of loads. Spacecraft power system management requires planning and scheduling, since electrical power is a scarce resource in space. The automation of power system management for future spacecraft has been recognized as an important R&D goal. Several automation technologies have emerged including the use of expert systems for automating human problem solving capabilities such as rule based expert system for fault diagnosis and load scheduling. It is questionable whether current generation expert system technology is applicable for power system management in space. The objective of the ADEPTS (ADvanced Electrical Power management Techniques for Space systems) is to study new techniques for power management automation. These techniques involve integrating current expert system technology with that of parallel and distributed computing, as well as a distributed, object-oriented approach to software design. The focus of the current study is the integration of new procedures for automatically planning and scheduling loads with procedures for performing fault diagnosis and control. The objective is the concurrent execution of both sets of tasks on separate transputer processors, thus adding parallelism to the overall management process.

Leakage of power from dipole to higher multipoles due to non-symmetric beam shape of the CMB missions

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

Das, Santanu; Souradeep, Tarun, E-mail: santanud@iucaa.ernet.in, E-mail: tarun@iucaa.ernet.in

2015-05-01

A number of studies of WMAP and Planck claimed the low multipole (specially quadrupole) power deficiency in CMB power spectrum. Anomaly in the orientations of the low multipoles have also been claimed. There is a possibility that the power deficiency at low multipoles may not be of primordial origin and is only an observation artifact coming from the scan procedure adapted in the WMAP or Planck satellites. Therefore, it is always important to investigate all the observational artifacts that can mimic them. The CMB dipole which is much higher than the quadrupole can leak to the higher multipoles due tomore » the non-symmetric beam shape of the WMAP or Planck. We observe that a non-negligible amount of power from the dipole can get transferred to the quadrupole and the higher multipoles due to the non-symmetric beam shapes and contaminate the observed measurements. The orientation of the quadrupole generated by this power transfer is surprisingly very close to the quadrupole observed from the WMAP and Planck maps. However, our analysis shows that the orientation of the quadrupole can not be explained using only the dipole power leakage. In this paper we calculate the amount of quadrupole power leakage for different WMAP bands. For Planck we present the results in terms of upper limits on asymmetric beam parameters that can lead to significant amount of power leakage.« less

2013 R&D 100 Award: New tech could mean more power for fiber lasers

ScienceCinema

Dawson, Jay

2018-01-16

An LLNL team of six physicists has developed a new technology that is a stepping stone to enable some of the limitations on high-power fiber lasers to be overcome. Their technology, dubbed "Efficient Mode-Converters for High-Power Fiber Amplifiers," allows the power of fiber lasers to be increased while maintaining high beam quality. Currently, fiber lasers are used in machining, on factory floors and in a number of defense applications and can produce tens of kilowatts of power.The conventional fiber laser design features a circular core and has fundamental limitations that make it impractical to allow higher laser power unless the core area is increased. LLNL researchers have pioneered a design to increase the laser's core area along the axis of the ribbon fiber. Their design makes it difficult to use a conventional laser beam, so the LLNL team converted the beam into a profile that propagates into the ribbon fiber and is converted back once it is amplified. The use of this LLNL technology will permit the construction of higher power lasers for lower costs and increase the power of fiber lasers from tens of kilowatts of power to about 100 kilowatts and potentially even higher.

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

Zhang, Jie; Jain, Rishabh; Hodge, Bri-Mathias

A data-driven methodology is developed to analyze how ambient and wake turbulence affect the power generation of wind turbine(s). Using supervisory control and data acquisition (SCADA) data from a wind plant, we select two sets of wind velocity and power data for turbines on the edge of the plant that resemble (i) an out-of-wake scenario and (ii) an in-wake scenario. For each set of data, two surrogate models are developed to represent the turbine(s) power generation as a function of (i) the wind speed and (ii) the wind speed and turbulence intensity. Three types of uncertainties in turbine(s) power generationmore » are investigated: (i) the uncertainty in power generation with respect to the reported power curve; (ii) the uncertainty in power generation with respect to the estimated power response that accounts for only mean wind speed; and (iii) the uncertainty in power generation with respect to the estimated power response that accounts for both mean wind speed and turbulence intensity. Results show that (i) the turbine(s) generally produce more power under the in-wake scenario than under the out-of-wake scenario with the same wind speed; and (ii) there is relatively more uncertainty in the power generation under the in-wake scenario than under the out-of-wake scenario.« less

Airborne Observations of Aerosol Emissions from F-16 Aircraft

NASA Technical Reports Server (NTRS)

Anderson, B. E.; Cofer, W. R.; McDougal, D. S.

1999-01-01

We presented results from the SASS Near-Field Interactions Flight (SNIF-III) Experiment which was conducted during May and June 1997 in collaboration with the Vermont and New Jersey Air National Guard Units. The project objectives were to quantify the fraction of fuel sulfur converted to S(VI) species by jet engines and to gain a better understanding of particle formation and growth processes within aircraft wakes. Size and volatility segregated aerosol measurements along with sulfur species measurements were recorded in the exhaust of F-16 aircraft equipped with F-100 engines burning fuels with a range of fuel S concentrations at different altitudes and engine power settings. A total of 10 missions were flown in which F-16 exhaust plumes were sampled by an instrumented T-39 Sabreliner aircraft. On six of the flights, measurements were obtained behind the same two aircraft, one burning standard JP-8 fuel and the other either approximately 28 ppm or 1100 ppm S fuel or an equal mixture of the two (approximately 560 ppm S). A pair of flights was conducted for each fuel mixture, one at 30,000 ft altitude and the other starting at 35,000 ft and climbing to higher altitudes if contrail conditions were not encountered at the initial flight level. In each flight, the F-16s were operated at two power settings, approx. 80% and full military power. Exhaust emissions were sampled behind both aircraft at each flight level, power setting, and fuel S concentration at an initial aircraft separation of 30 m, gradually widening to about 3 km. Analyses of the aerosol data in the cases where fuel S was varied suggest results were consistent with observations from project SUCCESS, i.e., a significant fraction of the fuel S was oxidized to form S(VI) species and volatile particle emission indices (EIs) in comparably aged plumes exhibited a nonlinear dependence upon the fuel S concentration. For the high sulfur fuel, volatile particle EIs in 10-second-old-plumes were 2 to 3 x 10 (exp 17) / kg of fuel burned and exhibited no obvious trend with engine power setting or flight altitude. In contrast, about 8-fold fewer particles were observed in similarly aged plumes from the same aircraft burning fuel with 560 ppm S content and EIs of 1 x 10(exp 15)/ kg of fuel burned were observed in the 28 ppm S fuel case. Moreover, data recorded as a function of plume age indicates that formation and growth of the volatile particles proceeds more slowly as the fuel S level is reduced. For example, ultrafine particle concentrations appear to stabilize within 5 seconds after emission in the 1100 ppm S cases but are still increasing in 20-second old plumes produced from burning the 560 ppm S fuel.

Sex, Grades and Power in Higher Education in Ghana and Tanzania

ERIC Educational Resources Information Center

Morley, Louise

2011-01-01

Quantitative increases tell a partial story about the quality of women's participation in higher education. Women students' reporting of sexual harassment has been noteworthy in a recent study that I directed on widening participation in higher education in Ghana and Tanzania. The hierarchical and gendered power relations within universities have…

Power and Agenda-Setting in Tanzanian Health Policy: An Analysis of Stakeholder Perspectives

PubMed Central

Fischer, Sara Elisa; Strandberg-Larsen, Martin

2016-01-01

Background: Global health policy is created largely through a collaborative process between development agencies and aid-recipient governments, yet it remains unclear whether governments retain ownership over the creation of policy in their own countries. An assessment of the power structure in this relationship and its influence over agenda-setting is thus the first step towards understanding where progress is still needed in policy-making for development. Methods: This study employed qualitative policy analysis methodology to examine how health-related policy agendas are adopted in low-income countries, using Tanzania as a case study. Semi-structured, in-depth, key informant interviews with 11 policy-makers were conducted on perspectives of the agenda-setting process and its actors. Kingdon’s stream theory was chosen as the lens through which to interpret the data analysis. Results: This study demonstrates that while stakeholders each have ways of influencing the process, the power to do so can be assessed based on three major factors: financial incentives, technical expertise, and influential position. Since donors often have two or all of these elements simultaneously a natural power imbalance ensues, whereby donor interests tend to prevail over recipient government limitations in prioritization of agendas. One way to mediate these imbalances seems to be the initiation of meaningful policy dialogue. Conclusion: In Tanzania, the agenda-setting process operates within a complex network of factors that interact until a "policy window" opens and a decision is made. Power in this process often lies not with the Tanzanian government but with the donors, and the contrast between latent presence and deliberate use of this power seems to be based on the donor ideology behind giving aid (defined here by funding modality). Donors who used pooled funding (PF) modalities were less likely to exploit their inherent power, whereas those who preferred to maintain maximum control over the aid they provided (ie, non-pooled funders) more readily wielded their intrinsic power to push their own priorities. PMID:27285513

Power and Agenda-Setting in Tanzanian Health Policy: An Analysis of Stakeholder Perspectives.

PubMed

Fischer, Sara Elisa; Strandberg-Larsen, Martin

2016-02-09

Global health policy is created largely through a collaborative process between development agencies and aid-recipient governments, yet it remains unclear whether governments retain ownership over the creation of policy in their own countries. An assessment of the power structure in this relationship and its influence over agenda-setting is thus the first step towards understanding where progress is still needed in policy-making for development. This study employed qualitative policy analysis methodology to examine how health-related policy agendas are adopted in low-income countries, using Tanzania as a case study. Semi-structured, in-depth, key informant interviews with 11 policy-makers were conducted on perspectives of the agenda-setting process and its actors. Kingdon's stream theory was chosen as the lens through which to interpret the data analysis. This study demonstrates that while stakeholders each have ways of influencing the process, the power to do so can be assessed based on three major factors: financial incentives, technical expertise, and influential position. Since donors often have two or all of these elements simultaneously a natural power imbalance ensues, whereby donor interests tend to prevail over recipient government limitations in prioritization of agendas. One way to mediate these imbalances seems to be the initiation of meaningful policy dialogue. In Tanzania, the agenda-setting process operates within a complex network of factors that interact until a "policy window" opens and a decision is made. Power in this process often lies not with the Tanzanian government but with the donors, and the contrast between latent presence and deliberate use of this power seems to be based on the donor ideology behind giving aid (defined here by funding modality). Donors who used pooled funding (PF) modalities were less likely to exploit their inherent power, whereas those who preferred to maintain maximum control over the aid they provided (ie, non-pooled funders) more readily wielded their intrinsic power to push their own priorities. © 2016 by Kerman University of Medical Sciences.

Effects of β-alanine supplementation during a 5-week strength training program: a randomized, controlled study.

PubMed

Maté-Muñoz, José Luis; Lougedo, Juan H; Garnacho-Castaño, Manuel V; Veiga-Herreros, Pablo; Lozano-Estevan, María Del Carmen; García-Fernández, Pablo; de Jesús, Fernando; Guodemar-Pérez, Jesús; San Juan, Alejandro F; Domínguez, Raúl

2018-01-01

β-Alanine (BA) is a non-essential amino acid that has been shown to enhance exercise performance. The purpose of this investigation was to determine if BA supplementation improved the adaptive response to five weeks of a resistance training program. Thirty healthy, strength-trained individuals were randomly assigned to the experimental groups placebo (PLA) or BA. Over 5 weeks of strength training, subjects in BA took 6.4 g/day of BA as 8 × 800 mg doses each at least 1.5 h apart. The training program consisted of 3 sessions per week in which three different leg exercises were conducted as a circuit (back squat, barbell step ups and loaded jumping lunges). The program started with 3 sets of 40 s of work per exercise and rest periods between sets of 120 s in the first week. This training volume was then gradually built up to 5 sets of 20 s work/60 s rest in the fifth week. The work load during the program was set by one of the authors according to the individual's perceived effort the previous week. The variables measured were average velocity, peak velocity, average power, peak power, and load in kg in a back squat, incremental load, one-repetition maximum (1RM) test. In addition, during the rest period, jump ability (jump height and power) was assessed on a force platform. To compare data, a general linear model with repeated measures two-way analysis of variance was used. Significantly greater training improvements were observed in the BA group versus PLA group ( p  = 0.045) in the variables average power at 1RM (BA: 42.65%, 95% CI, 432.33, 522.52 VS. PLA: 21.07%, 95% CI, 384.77, 482.19) and average power at maximum power output ( p  = 0.037) (BA: 20.17%, 95% CI, 637.82, 751.90 VS. PLA; 10.74%, 95% CI, 628.31, 751.53). The pre- to post training average power gain produced at 1RM in BA could be explained by a greater maximal strength gain, or load lifted at 1RM ( p  = 0.014) (24 kg, 95% CI, 19.45, 28.41 VS. 16 kg, 95% CI, 10.58, 20.25) and in the number of sets executed ( p  = 0.025) in the incremental load test (BA: 2.79 sets, 95% CI, 2.08, 3.49 VS. PLA: 1.58 sets, 95% CI, 0.82, 2.34). β-Alanine supplementation was effective at increasing power output when lifting loads equivalent to the individual's maximal strength or when working at maximum power output. The improvement observed at 1RM was explained by a greater load lifted, or strength gain, in response to training in the participants who took this supplement.

Tactical Determinants of Setting Zone in Elite Men'S Volleyball

PubMed Central

Afonso, Jose; Esteves, Francisca; Araújo, Rui; Thomas, Luke; Mesquita, Isabel

2012-01-01

The interactions between two opposing teams lead to the emergence of unique game patterns. In volleyball, attack efficacy emerges as the strongest predictor of the final result and thus it becomes of foremost importance to understand which game patterns afford the attaining of higher attack efficacies. These rely on the quality of the setting action. In turn, the serve and the serve reception constrain the setter's actions and the attacker's efficacy. Therefore, the purpose of this study was to examine predictors of the setting zone in elite-level men's volleyball. Thirty-one matches of the 2007 World Cup were analyzed, in total 5117 rallies. The dependent variable was the setting zone, and the independent variables were the server player, serve type, serve direction, serve depth, reception zone, receiver player and reception type. Multinomial logistic regression was applied, in order to obtain the estimated likelihood of occurrence of the dependent variable, based on the values of the independent variables (p < 0.05). Only the serve direction showed not to be predictive of the setting zone. Concerning the remaining variables, the tennis jump serve, serves from the middle-player, deep serves, reception near the endline or sidelines, reception by the zone 4 attackers when in defensive zone, and low reception all proved to impair the quality of reception, demanding the setter to play more often in the not acceptable setting zone. Results suggest that, at this level, practice of serve-reception should preferably cover the deep tennis jump serve, and attempt to afford the libero more opportunities to receive. By focusing on the variables with the most predictive power, performers may better allocate their attention towards the most pertinent cues at each moment. Knowledge of these interactive models provides valuable insights into the dynamics of the action sequences, affording coaches important information and guidance. Key pointsA set of key variables interact and allow predicting the setting zone, an important variable in determining attack efficacy in high-level men's volleyball.The tennis jump serve, deep serves, receptions near the endline or sidelines, serves from the middle-players, receptions by the zone 4 attackers when in defensive zone, and low reception enhance the utilization of non-ideal setting zones.By focusing on the variables with the most predictive power, performers may better allocate their attention towards the most pertinent cues at each moment.Knowledge of these interactive models provides valuable insights into the dynamics of the action sequences, affording coaches important information and guidance. PMID:24149123

EFFECTS OF A DEEP MIXED SHELL ON SOLAR g-MODES, p-MODES, AND NEUTRINO FLUX

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

Wolff, Charles L.

2009-08-10

A mixed-shell model that reflects g-modes away from the Sun's center is developed further by calibrating its parameters and evaluating a mixing mechanism: buoyancy. The shell roughly doubles g-mode oscillation periods and would explain why there is no definitive detection of their periods. But the shell has only minor effects on most p-modes. The model provides a mechanism for causing short-term fluctuations in neutrino flux and makes plausible the correlations between this flux and solar activity levels. Relations are derived for a shell heated asymmetrically by transient increases in nuclear burning in small 'hot spots'. The size of these spotsmore » and the timing of a heating event are governed by sets(l) of standing asymptotic g-modes, coupled by a maximal principle that greatly enhances their excitation and concentrates power toward the equator, assisting the detection of higher-l sets. Signals from all sets, except one, in the range 2 {<=} l {<=} 8 are identified by difference periods between consecutive radial states using the method of Garcia et al. and reinterpreting their latest spectrum. This confirms two detections of sets in a similar range of l by their rotation rates. The mean radius of shell mixing is r{sub m} = 0.16 R{sub sun}, which improves an earlier independent estimate of 0.18 by the author. The shell may cause the unexplained dip in measured sound speed at its location. Another sound speed error, centered near 0.67 R{sub sun}, and reversing flows in the same place with a period originally near 1.3 yr suggest that the g-modes are depositing there about 3% of the solar luminosity. That implies the shell at r{sub m} is receiving a similar magnitude of power, which would be enough energy to mix the corresponding shell in a standard solar model in <<10{sup 7} yr.« less

Where Have All the Interactions Gone? Estimating the Coverage of Two-Hybrid Protein Interaction Maps

PubMed Central

Huang, Hailiang; Jedynak, Bruno M; Bader, Joel S

2007-01-01

Yeast two-hybrid screens are an important method for mapping pairwise physical interactions between proteins. The fraction of interactions detected in independent screens can be very small, and an outstanding challenge is to determine the reason for the low overlap. Low overlap can arise from either a high false-discovery rate (interaction sets have low overlap because each set is contaminated by a large number of stochastic false-positive interactions) or a high false-negative rate (interaction sets have low overlap because each misses many true interactions). We extend capture–recapture theory to provide the first unified model for false-positive and false-negative rates for two-hybrid screens. Analysis of yeast, worm, and fly data indicates that 25% to 45% of the reported interactions are likely false positives. Membrane proteins have higher false-discovery rates on average, and signal transduction proteins have lower rates. The overall false-negative rate ranges from 75% for worm to 90% for fly, which arises from a roughly 50% false-negative rate due to statistical undersampling and a 55% to 85% false-negative rate due to proteins that appear to be systematically lost from the assays. Finally, statistical model selection conclusively rejects the Erdös-Rényi network model in favor of the power law model for yeast and the truncated power law for worm and fly degree distributions. Much as genome sequencing coverage estimates were essential for planning the human genome sequencing project, the coverage estimates developed here will be valuable for guiding future proteomic screens. All software and datasets are available in Datasets S1 and S2, Figures S1–S5, and Tables S1−S6, and are also available from our Web site, http://www.baderzone.org. PMID:18039026

Hospitals, market share, and consolidation.

PubMed

Cutler, David M; Scott Morton, Fiona

2013-11-13

A large reduction in use of inpatient care combined with the incentives in the Affordable Care Act is leading to significant consolidation in the hospital industry. What was once a set of independent hospitals having arms-length relationships with physicians and clinicians who provide ambulatory care is becoming a small number of locally integrated health systems, generally built around large, prestigious academic medical centers. The typical region in the United States has 3 to 5 consolidated health systems, spanning a wide range of care settings, and a smaller fringe of health care centers outside those systems. Consolidated health systems have advantages and drawbacks. The advantages include the ability to coordinate care across different practitioners and sites of care. Offsetting this is the potential for higher prices resulting from greater market power. Market power increases because it is difficult for insurers to bargain successfully with one of only a few health systems. Antitrust authorities are examining these consolidated systems as they form, but broad conclusions are difficult to draw because typically the creation of a system will generate both benefit and harm and each set of facts will be different. Moreover, the remedies traditionally used (eg, blocking the transaction or requiring that the parties divest assets) by antitrust authorities in cases of net harm are limited. For this reason, local governments may want to introduce new policies that help ensure consumers gain protection in the event of consolidation, such as insurance products that charge consumers more for high-priced clinicians and health care centers, bundling payments to clinicians and health care organizations to eliminate the incentives of big institutions to simply provide more care, and establishing area-specific price or spending targets.