Active Power Control of Waked Wind Farms: Preprint

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

Fleming, Paul A; van Wingerden, Jan-Willem; Pao, Lucy

Active power control can be used to balance the total power generated by wind farms with the power consumed on the electricity grid. With the increasing penetration levels of wind energy, there is an increasing need for this ancillary service. In this paper, we show that the tracking of a certain power reference signal provided by the transmission system operator can be significantly improved by using feedback control at the wind farm level. We propose a simple feedback control law that significantly improves the tracking behavior of the total power output of the farm, resulting in higher performance scores. Themore » effectiveness of the proposed feedback controller is demonstrated using high-fidelity computational fluid dynamics simulations of a small wind farm.« less

Challenging empowerment: AIDS-affected South African children and the need for a multi-level relational approach.

PubMed

Ansell, Nicola

2014-01-01

Critics of empowerment have highlighted the concept's mutability, focus on individual transformation, one-dimensionality and challenges of operationalisation. Relating these critiques to children's empowerment raises new challenges. Drawing on scholarship on children's subjecthood and exercise of power, alongside empirical research with children affected by AIDS, I argue that empowerment envisaged as individual self-transformation and increased capacity to act independently offers little basis for progressive change. Rather it is essential to adopt a relational approach that recognises the need to transform power relationships at multiple levels. This analysis has implications for our wider understanding of empowerment in the 21st century.

How to Apply Feedback to Improve Subjective Wellbeing of Government Servants Engaged in Environmental Protection in China?

PubMed Central

Wang, Xinmeng; Zhang, Na; Li, Miaomiao

2018-01-01

Background In order to improve subjective wellbeing of government servants engaged in environmental protection who work in high power distance in China, it is important to understand the impact mechanism of feedback. This study aims to analyze how feedback environment influences subjective wellbeing through basic psychological needs satisfaction and analyzing the moderating role of power distance. Method The study was designed as a cross-sectional study of 492 government servants engaged in environment protection in Shandong, China. Government servants who agreed to participate answered self-report questionnaires concerning demographic conditions, supervisor feedback environment, basic psychological need satisfaction, and power distance as well as subjective wellbeing. Results Employees in higher levels of supervisor feedback environment were more likely to experience subjective wellbeing. Full mediating effects were found for basic psychological needs satisfaction. Specifically, supervisor feedback environment firstly led to increased basic psychological needs satisfaction, which in turn resulted in increased subjective wellbeing. Additional analysis showed that the mediating effect of basic psychological needs satisfaction was stronger for employees who work in high power distance than in low power distance. Conclusion The results from the study indicate that supervisor feedback environment plays a vital role in improving subjective wellbeing of government servants engaged in environmental protection through basic psychological needs satisfaction, especially in high power distance. PMID:29662901

Knowledge of and Attitude to Nuclear Power among Residents around Tianwan Nuclear Power Plant in Jiangsu of China

PubMed Central

Yu, Ningle; Zhang, Yimei; Wang, Jin; Cao, Xingjiang; Fan, Xiangyong; Xu, Xiaosan; Wang, Furu

2012-01-01

Aims: The aims of this paper were to determine the level of knowledge of and attitude to nuclear power among residents around Tianwan Nuclear power plant in Jiangsu of China. Design: A descriptive, cross-sectional design was adopted. Participants: 1,616 eligible participants who lived around the Tianwan nuclear power plant within a radius of 30km and at least 18 years old were recruited into our study and accepted epidemiological survey. Methods: Data were collected through self-administered questionnaires consisting of a socio-demographic sheet. Inferential statistics, t-test, ANOVA test and multivariate regression analysis were used to compare the differences between each subgroup and correlation analysis was conducted to understand the relationship between different factors and dependent variables. Results: Our investigation found that the level of awareness and acceptance of nuclear power was generally not high. Respondents' gender, age, marital status, residence, educational level, family income and the distance away from the nuclear power plant are important effect factors to the knowledge of and attitude to nuclear power. Conclusions: The public concerns about nuclear energy's impact are widespread. The level of awareness and acceptance of nuclear power needs to be improved urgently. PMID:22811610

US power plant sites at risk of future sea-level rise

NASA Astrophysics Data System (ADS)

Bierkandt, R.; Auffhammer, M.; Levermann, A.

2015-12-01

Unmitigated greenhouse gas emissions may increase global mean sea-level by about 1 meter during this century. Such elevation of the mean sea-level enhances the risk of flooding of coastal areas. We compute the power capacity that is currently out-of-reach of a 100-year coastal flooding but will be exposed to such a flood by the end of the century for different US states, if no adaptation measures are taken. The additional exposed capacity varies strongly among states. For Delaware it is 80% of the mean generated power load. For New York this number is 63% and for Florida 43%. The capacity that needs additional protection compared to today increases by more than 250% for Texas, 90% for Florida and 70% for New York. Current development in power plant building points towards a reduced future exposure to sea-level rise: proposed and planned power plants are less exposed than those which are currently operating. However, power plants that have been retired or canceled were less exposed than those operating at present. If sea-level rise is properly accounted for in future planning, an adaptation to sea-level rise may be costly but possible.

Parallel Optical Random Access Memory (PORAM)

NASA Technical Reports Server (NTRS)

Alphonse, G. A.

1989-01-01

It is shown that the need to minimize component count, power and size, and to maximize packing density require a parallel optical random access memory to be designed in a two-level hierarchy: a modular level and an interconnect level. Three module designs are proposed, in the order of research and development requirements. The first uses state-of-the-art components, including individually addressed laser diode arrays, acousto-optic (AO) deflectors and magneto-optic (MO) storage medium, aimed at moderate size, moderate power, and high packing density. The next design level uses an electron-trapping (ET) medium to reduce optical power requirements. The third design uses a beam-steering grating surface emitter (GSE) array to reduce size further and minimize the number of components.

Managing nurses through disciplinary power: a Foucauldian analysis of workplace violence.

PubMed

St-Pierre, Isabelle; Holmes, Dave

2008-04-01

This paper describes discipline as a specific technique of power which constitutes, in our view, a form of institutional violence. The need to create and maintain safe and healthy work environments for healthcare professionals is well documented. Foucault's concept of disciplinary power was used to explore institutional violence from a critical perspective. Violence is identified as an important factor in the recruitment and retention of healthcare professionals. Given the shortage of such professionals, there is an urgent need to take a fresh look at their working environments and working conditions. Power, surveillance and disciplinary techniques are used at all levels of hospital management to control and contain both human resources and costs. By associating common workplace practices with institutional violence, employers who have a policy of zero tolerance toward workplace violence will need to re-examine their current ways of operating.

Jointly determining significance levels of primary and replication studies by controlling the false discovery rate in two-stage genome-wide association studies.

PubMed

Jiang, Wei; Yu, Weichuan

2017-01-01

In genome-wide association studies, we normally discover associations between genetic variants and diseases/traits in primary studies, and validate the findings in replication studies. We consider the associations identified in both primary and replication studies as true findings. An important question under this two-stage setting is how to determine significance levels in both studies. In traditional methods, significance levels of the primary and replication studies are determined separately. We argue that the separate determination strategy reduces the power in the overall two-stage study. Therefore, we propose a novel method to determine significance levels jointly. Our method is a reanalysis method that needs summary statistics from both studies. We find the most powerful significance levels when controlling the false discovery rate in the two-stage study. To enjoy the power improvement from the joint determination method, we need to select single nucleotide polymorphisms for replication at a less stringent significance level. This is a common practice in studies designed for discovery purpose. We suggest this practice is also suitable in studies with validation purpose in order to identify more true findings. Simulation experiments show that our method can provide more power than traditional methods and that the false discovery rate is well-controlled. Empirical experiments on datasets of five diseases/traits demonstrate that our method can help identify more associations. The R-package is available at: http://bioinformatics.ust.hk/RFdr.html .

Fission Surface Power Technology Development Status

NASA Technical Reports Server (NTRS)

Palac, Donald T.; Mason, Lee S.; Harlow, Scott

2009-01-01

With the potential future deployment of a lunar outpost there is expected to be a clear need for a high-power, lunar surface power source to support lunar surface operations independent of the day-night cycle, and Fission Surface Power (FSP) is a very effective solution for power levels above a couple 10 s of kWe. FSP is similarly enabling for the poorly illuminated surface of Mars. The power levels/requirements for a lunar outpost option are currently being studied, but it is known that cost is clearly a predominant concern to decision makers. This paper describes the plans of NASA and the DOE to execute an affordable fission surface power system technology development project to demonstrate sufficient technology readiness of an affordable FSP system so viable and cost-effective FSP system options will be available when high power lunar surface system choices are expected to be made in the early 2010s.

U.S. electric power sector transitions required to achieve 80% reductions in economy-wide greenhouse gas emissions: Results based on a state-level model of the U.S. energy system

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

Iyer, Gokul C.; Clarke, Leon E.; Edmonds, James A.

The United States has articulated a deep decarbonization strategy for achieving a reduction in economy-wide greenhouse gas (GHG) emissions of 80% below 2005 levels by 2050. Achieving such deep emissions reductions will entail a major transformation of the energy system and of the electric power sector in particular. , This study uses a detailed state-level model of the U.S. energy system embedded within a global integrated assessment model (GCAM-USA) to demonstrate pathways for the evolution of the U.S. electric power sector that achieve 80% economy-wide reductions in GHG emissions by 2050. The pathways presented in this report are based onmore » feedback received during a workshop of experts organized by the U.S. Department of Energy’s Office of Energy Policy and Systems Analysis. Our analysis demonstrates that achieving deep decarbonization by 2050 will require substantial decarbonization of the electric power sector resulting in an increase in the deployment of zero-carbon and low-carbon technologies such as renewables and carbon capture utilization and storage. The present results also show that the degree to which the electric power sector will need to decarbonize and low-carbon technologies will need to deploy depends on the nature of technological advances in the energy sector, the ability of end-use sectors to electrify and level of electricity demand.« less

High Voltage Design Concepts for Launch Vehicles and Orbital Spacecraft Applications

NASA Technical Reports Server (NTRS)

Hall, David K.; Kirkici, Hulya; Hillard, G. Barry; Schweickart, Daniel; Dunbar, Bill

2000-01-01

With the advent of design concepts such as, electromechanical actuation and "more electric" initiatives, has come the need for electrical power buses and electronic equipment to operate at higher than normal dc voltages to meet power requirements while keeping current levels to manageable levels. This new bus voltage has been typically 270 Volts dc nominal for launch vehicles, and 120 Volt dc for the International Space Station. This paper will discuss the new design applications for high voltage dc power in existing and future launch vehicles and spacecraft and the potential problems associated therewith. These new applications must be operational from lift-off, ascent, on orbit and descent in all of the pressure and temperature conditions for each, i.e. through the "Paschen region" twice. This paper will also attempt to stimulate an interest in the academic and professional communities to support and conduct research needed for design data applicable to high voltage dc usage.

Defense Standardization Program Journal, July/December 2007

DTIC Science & Technology

2007-12-01

during the standard next review cycle, and identified areas where supplemental standards are needed. ENTERPRISE POWER SECURITY AND CONTINUITY Continual...availability of electric power at the enterprise level is essential for busi- ness functions, safety, and the public well-being.Yet many practical...challenges exist related to keeping critical operations, equipment, or facilities powered when the Peieeaeuiyivle ail ad acn teholg tatsnee electric grid is

Integrated Inverter And Battery Charger

NASA Technical Reports Server (NTRS)

Rippel, Wally E.

1988-01-01

Circuit combines functions of dc-to-ac inversion (for driving ac motor in battery-powered vehicle) and ac-to-dc conversion (for charging battery from ac line when vehicle not in use). Automatically adapts to either mode. Design of integrated inverter/charger eliminates need for duplicate components, saves space, reduces weight and cost of vehicle. Advantages in other applications : load-leveling systems, standby ac power systems, and uninterruptible power supplies.

Power electronics for low power arcjets

NASA Technical Reports Server (NTRS)

Hamley, John A.; Hill, Gerald M.

1991-01-01

In anticipation of the needs of future light-weight, low-power spacecraft, arcjet power electronics in the 100 to 400 W operating range were developed. Limited spacecraft power and thermal control capacity of these small spacecraft emphasized the need for high efficiency. Power topologies similar to those in the higher 2 kW and 5 to 30 kW power range were implemented, including a four transistor bridge switching circuit, current mode pulse-width modulated control, and an output current averaging inductor with an integral pulse generation winding. Reduction of switching transients was accomplished using a low inductance power distribution network, and no passive snubber circuits were necessary for power switch protection. Phase shift control of the power bridge was accomplished using an improved pulse width modulation to phase shift converter circuit. These features, along with conservative magnetics designs allowed power conversion efficiencies of greater than 92.5 percent to be achieved into resistive loads over the entire operating range of the converter. Electromagnetic compatibility requirements were not considered in this work, and control power for the converter was derived from AC mains. Addition of input filters and control power converters would result in an efficiency of on the order of 90 percent for a flight unit. Due to the developmental nature of arcjet systems at this power level, the exact nature of the thruster/power processor interface was not quantified. Output regulation and current ripple requirements of 1 and 20 percent respectively, as well as starting techniques, were derived from the characteristics of the 2 kW system but an open circuit voltage in excess of 175 V was specified. Arcjet integration tests were performed, resulting in successful starts and stable arcjet operation at power levels as low as 240 W with simulated hydrazine propellants.

Power and Identity in the Creative Writing Classroom

ERIC Educational Resources Information Center

Leahy, Anna, Ed.

2005-01-01

This book remaps theories and practices for teaching creative writing at university and college level. This collection critiques well-established approaches for teaching creative writing in all genres and builds a comprehensive and adaptable pedagogy based on issues of authority, power, and identity. A long-needed reflection, this book shapes…

Framework for Mapping of Receiver Interference Tolerance Masks to Tolerable Effective Isotropic Radiated Power Levels : GPS ABC Workshop V RTCA Washington, DC October 14, 2016.

DOT National Transportation Integrated Search

2016-10-14

Outline : : Interference Tolerance Mask (ITM) to Effective Isotropic Radiated Power (IRP) for the particular case of a single transmitter : : ITM() to IRP() for the general case of multiple transmitters : : Input parameters needed to solv...

Radioisotope Reduction Using Solar Power for Outer Planetary Missions

NASA Technical Reports Server (NTRS)

Fincannon, James

2008-01-01

Radioisotope power systems have historically been (and still are) the power system of choice from a mass and size perspective for outer planetary missions. High demand for and limited availability of radioisotope fuel has made it necessary to investigate alternatives to this option. Low mass, high efficiency solar power systems have the potential for use at low outer planetary temperatures and illumination levels. This paper documents the impacts of using solar power systems instead of radioisotope power for all or part of the power needs of outer planetary spacecraft and illustrates the potential fuel savings of such an approach.

Advanced components for spaceborne infrared astronomy

NASA Technical Reports Server (NTRS)

Davidson, A. W.

1984-01-01

The need for improved cryogenic components to be used in future spaceborne infrared astronomy missions was identified. Improved low noise cryogenic amplifiers operated with infrared detectors, and better cryogenic actuators and motors with extremely low power dissipation are needed. The feasibility of achieving technological breakthroughs in both of these areas was studied. An improved silicon junction field effect transistor (JFET) could be developed if: (1) high purity silicon; (2) optimum dopants; and (3) very high doping levels are used. The feasibility of a simple stepper motor equipped with superconducting coils is demonstrated by construction of such a device based on a standard commercial motor. It is found that useful levels of torque at immeasurably low power levels were achieved. It is concluded that with modest development and optimization efforts, significant performance gains is possible for both cryogenic preamplifiers and superconducting motors and actuators.

Self-Powered Implantable Skin-Like Glucometer for Real-Time Detection of Blood Glucose Level In Vivo

NASA Astrophysics Data System (ADS)

Zhang, Wanglinhan; Zhang, Linlin; Gao, Huiling; Yang, Wenyan; Wang, Shuai; Xing, Lili; Xue, Xinyu

2018-06-01

Implantable bioelectronics for analyzing physiological biomarkers has recently been recognized as a promising technique in medical treatment or diagnostics. In this study, we developed a self-powered implantable skin-like glucometer for real-time detection of blood glucose level in vivo. Based on the piezo-enzymatic-reaction coupling effect of GOx@ZnO nanowire, the device under an applied deformation can actively output piezoelectric signal containing the glucose-detecting information. No external electricity power source or battery is needed for this device, and the outputting piezoelectric voltage acts as both the biosensing signal and electricity power. A practical application of the skin-like glucometer implanted in mouse body for detecting blood glucose level has been simply demonstrated. These results provide a new technique path for diabetes prophylaxis and treatment.

Conflict resolution efforts through stakeholder mapping in Labanan Research Forest, Berau, East Kalimantan, Indonesia

NASA Astrophysics Data System (ADS)

Wiati, C. B.; Indriyanti, S. Y.; Maharani, R.; Subarudi

2018-04-01

Conflict resolution in Labanan Research Forest (LRF) by the Dipterocarps Forest Ecosystem Research and Development Center (Balai Besar Penelitian dan Pengembangan Ekosistem Hutan Dipterokarpa – B2P2EHD) needs support from other parties that are also interested in such forest management. This paper aimed to presented conflict resolution in LRF through stakeholder mapping for its engagement. This research was conducted for seven months (June to December 2015) with interviews and literature study as its data collection. Collected data were analysed by a stakeholder analysis and matrix based on their interest and power levels. Two important findings were: (1) There are 19 parties having interests in the existence of LRF should be engaged; (2) Conflict resolution of LRF can be achieved: (a) ensuring key stakeholders which have high interest and high power level has same perception in existence and management of LRF, (b) establishing a partnership with primary stakeholders which have high interest and high power levels; (c) building partnerships between primary stakeholders which have high interest but low power levels, (d) building partnerships between key and secondary stakeholders which have low interest but high power levels and (e) gaining support from primary and secondary stakeholders which have low interest and low power levels. Stakeholder mapping is an important tool for tenure conflict resolution through mapping the power and interest of the conflicted parties and finding the proper parties to be approached.

High energy efficiency and high power density proton exchange membrane fuel cells: Electrode kinetics and mass transport

NASA Technical Reports Server (NTRS)

Srinivasan, Supramaniam; Velev, Omourtag A.; Parthasathy, Arvind; Manko, David J.; Appleby, A. John

1991-01-01

The development of proton exchange membrane (PEM) fuel cell power plants with high energy efficiencies and high power densities is gaining momentum because of the vital need of such high levels of performance for extraterrestrial (space, underwater) and terrestrial (power source for electric vehicles) applications. Since 1987, considerable progress has been made in achieving energy efficiencies of about 60 percent at a current density of 200 mA/sq cm and high power densities (greater than 1 W/sq cm) in PEM fuel cells with high (4 mg/sq cm) or low (0.4 mg/sq cm) platinum loadings in electrodes. The following areas are discussed: (1) methods to obtain these high levels of performance with low Pt loading electrodes - by proton conductor impregnation into electrodes, localization of Pt near front surface; (2) a novel microelectrode technique which yields electrode kinetic parameters for oxygen reduction and mass transport parameters; (3) demonstration of lack of water transport from anode to cathode; (4) modeling analysis of PEM fuel cell for comparison with experimental results and predicting further improvements in performance; and (5) recommendations of needed research and development for achieving the above goals.

Future Concepts for Modular, Intelligent Aerospace Power Systems

NASA Technical Reports Server (NTRS)

Button, Robert M.; Soeder, James F.

2004-01-01

Nasa's resent commitment to Human and Robotic Space Exploration obviates the need for more affordable and sustainable systems and missions. Increased use of modularity and on-board intelligent technologies will enable these lofty goals. To support this new paradigm, an advanced technology program to develop modular, intelligent power management and distribution (PMAD) system technologies is presented. The many benefits to developing and including modular functionality in electrical power components and systems are shown to include lower costs and lower mass for highly reliable systems. The details of several modular technologies being developed by NASA are presented, broken down into hierarchical levels. Modularity at the device level, including the use of power electronic building blocks, is shown to provide benefits in lowering the development time and costs of new power electronic components.

Development of a robust space power system decision model

NASA Astrophysics Data System (ADS)

Chew, Gilbert; Pelaccio, Dennis G.; Jacobs, Mark; Stancati, Michael; Cataldo, Robert

2001-02-01

NASA continues to evaluate power systems to support human exploration of the Moon and Mars. The system(s) would address all power needs of surface bases and on-board power for space transfer vehicles. Prior studies have examined both solar and nuclear-based alternatives with respect to individual issues such as sizing or cost. What has not been addressed is a comprehensive look at the risks and benefits of the options that could serve as the analytical framework to support a system choice that best serves the needs of the exploration program. This paper describes the SAIC developed Space Power System Decision Model, which uses a formal Two-step Analytical Hierarchy Process (TAHP) methodology that is used in the decision-making process to clearly distinguish candidate power systems in terms of benefits, safety, and risk. TAHP is a decision making process based on the Analytical Hierarchy Process, which employs a hierarchic approach of structuring decision factors by weights, and relatively ranks system design options on a consistent basis. This decision process also includes a level of data gathering and organization that produces a consistent, well-documented assessment, from which the capability of each power system option to meet top-level goals can be prioritized. The model defined on this effort focuses on the comparative assessment candidate power system options for Mars surface application(s). This paper describes the principles of this approach, the assessment criteria and weighting procedures, and the tools to capture and assess the expert knowledge associated with space power system evaluation. .

Material challenges for transducer designers in the 21st century

NASA Astrophysics Data System (ADS)

Lindberg, Jan F.

2002-07-01

The modern U.S. Navy is rapidly evolving to meet the challenges of operating in the littorals. This focus changes the rules, especially to the designers of sonar systems that now need to aggressively engage quiet diesel electric submarine threats and neutralize sophisticated underwater mines. These new responsibilities dictate that new concepts be developed. To meet these new demands on the sonar system, transducer designers are being tasked to design transducers and to utilize new materials to address performance requirements that were never even imagined a decade ago. Sensor needs are no longer limited to pressure types but now have to sense velocity or acceleration. Sources are challenged to both frequency extent and power levels. The need to physically move sources off of submarines and surface combatants and onto vehicles with limited energy capabilities prompt the challenge of efficient bandwidth and high coupling. These are the needs of the 'next Navy'; the needs of the 'Navy after next' will present an even more demanding scenario. The future will demand revolutionary technology at the micro level with devices utilizing new power sources and new materials.

PCB-level Electro thermal Coupling Simulation Analysis

NASA Astrophysics Data System (ADS)

Zhou, Runjing; Shao, Xuchen

2017-10-01

Power transmission network needs to transmit more current with the increase of the power density. The problem of temperature rise and the reliability is becoming more and more serious. In order to accurately design the power supply system, we must consider the influence of the power supply system including Joule heat, air convection and other factors. Therefore, this paper analyzes the relationship between the electric circuit and the thermal circuit on the basis of the theory of electric circuit and thermal circuit.

POWOW: A Modular, High Power Spacecraft Concept

NASA Technical Reports Server (NTRS)

Brandhorst, Henry W., Jr.

2000-01-01

A robust space infrastructure encompasses a broad range of mission needs along with an imperative to reduce costs of satellites meeting those needs. A critical commodity for science, commercial and civil satellites is power at an affordable cost. The POWOW (POwer WithOut Wires) spacecraft concept was created to provide, at one end of the scale, multi-megawatts of power yet also be composed of modules that can meet spacecraft needs in the kilowatt range. With support from the NASA-sponsored Space Solar Power Exploratory Research and Technology Program, the POWOW spacecraft concept was designed to meet Mars mission needs - while at the same time having elements applicable to a range of other missions. At Mars, the vehicle would reside in an aerosynchronous orbit and beam power to a variety of locations on the surface. It is the purpose of this paper to present the latest concept design results. The Space Power Institute along with four companies: Able Engineering, Inc., Entech, Inc., Primex Aerospace Co., and TECSTAR have produced a modular, power-rich electrically propelled spacecraft design that meets these requirements. In addition, it also meets a range of civil and commercial needs. The spacecraft design is based on multijunction Ill-V solar cells, the new Stretched Lens Aurora (SLA) module, a lightweight array design based on a multiplicity of 8 kW end-of-life subarrays and electric thrusters. The solar cells have excellent radiation resistance and efficiencies above 30%. The SLA has a concentration ratio up to 15x while maintaining an operating temperature of 80 C. The design of the 8 kW array building block will be presented and its applicability to commercial and government missions will be discussed. Electric propulsion options include Hall, MPD and ion thrusters of various power levels and trade studies have been conducted to define the most advantageous options. The present baseline spacecraft design providing 900 kW using technologies expected to be available in 2003 will be described. Areal power densities of nearly 400 W/meters squared at 80 C operating temperatures and wing level specific powers of over 400 W/kg are projected. Details of trip times and payloads to Mars will be presented as well as trade studies of various electric propulsion options. Trip times compare favorably with chemical propulsion options. Because the design is modular, learning curve methodology can be applied to determine expected cost reductions. These results will also be included. This paper has not been presented at a previous meeting.

Pulsed Magnetic Field Driven Gas Core Reactors for Space Power & Propulsion Applications

NASA Technical Reports Server (NTRS)

Anghaie, Samim; Smith, Blair; Knight, Travis; Butler, Carey

2003-01-01

The present results indicated that: 1. A pulsed magnetic driven fission power concept, PMD-GCR is developed for closed (NER) and semi-open (NTR) operations. 2. In power mode, power is generated at alpha less than 1 for power levels of hundreds of KW or higher 3. IN semi open NTR mode, PMD-GCR generates thrust at I(sub sp) approx. 5,000 s and jet power approx. 5KW/Kg. 4. PMD-GCR is highly subcritical and is actively driven to critically. 5. Parallel path with fusion R&D needs in many areas including magnet and plasma.

The cost of large numbers of hypothesis tests on power, effect size and sample size.

PubMed

Lazzeroni, L C; Ray, A

2012-01-01

Advances in high-throughput biology and computer science are driving an exponential increase in the number of hypothesis tests in genomics and other scientific disciplines. Studies using current genotyping platforms frequently include a million or more tests. In addition to the monetary cost, this increase imposes a statistical cost owing to the multiple testing corrections needed to avoid large numbers of false-positive results. To safeguard against the resulting loss of power, some have suggested sample sizes on the order of tens of thousands that can be impractical for many diseases or may lower the quality of phenotypic measurements. This study examines the relationship between the number of tests on the one hand and power, detectable effect size or required sample size on the other. We show that once the number of tests is large, power can be maintained at a constant level, with comparatively small increases in the effect size or sample size. For example at the 0.05 significance level, a 13% increase in sample size is needed to maintain 80% power for ten million tests compared with one million tests, whereas a 70% increase in sample size is needed for 10 tests compared with a single test. Relative costs are less when measured by increases in the detectable effect size. We provide an interactive Excel calculator to compute power, effect size or sample size when comparing study designs or genome platforms involving different numbers of hypothesis tests. The results are reassuring in an era of extreme multiple testing.

Voltage Impacts of Utility-Scale Distributed Wind

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

Allen, A.

2014-09-01

Although most utility-scale wind turbines in the United States are added at the transmission level in large wind power plants, distributed wind power offers an alternative that could increase the overall wind power penetration without the need for additional transmission. This report examines the distribution feeder-level voltage issues that can arise when adding utility-scale wind turbines to the distribution system. Four of the Pacific Northwest National Laboratory taxonomy feeders were examined in detail to study the voltage issues associated with adding wind turbines at different distances from the sub-station. General rules relating feeder resistance up to the point of turbinemore » interconnection to the expected maximum voltage change levels were developed. Additional analysis examined line and transformer overvoltage conditions.« less

Performance Evaluation of Electrochem's PEM Fuel Cell Power Plant for NASA's 2nd Generation Reusable Launch Vehicle

NASA Technical Reports Server (NTRS)

Kimble, Michael C.; Hoberecht, Mark

2003-01-01

NASA's Next Generation Launch Technology (NGLT) program is being developed to meet national needs for civil and commercial space access with goals of reducing the launch costs, increasing the reliability, and reducing the maintenance and operating costs. To this end, NASA is considering an all- electric capability for NGLT vehicles requiring advanced electrical power generation technology at a nominal 20 kW level with peak power capabilities six times the nominal power. The proton exchange membrane (PEM) fuel cell has been identified as a viable candidate to supply this electrical power; however, several technology aspects need to be assessed. Electrochem, Inc., under contract to NASA, has developed a breadboard power generator to address these technical issues with the goal of maximizing the system reliability while minimizing the cost and system complexity. This breadboard generator operates with dry hydrogen and oxygen gas using eductors to recirculate the gases eliminating gas humidification and blowers from the system. Except for a coolant pump, the system design incorporates passive components allowing the fuel cell to readily follow a duty cycle profile and that may operate at high 6:1 peak power levels for 30 second durations. Performance data of the fuel cell stack along with system performance is presented to highlight the benefits of the fuel cell stack design and system design for NGLT vehicles.

Variable Frequency Operations of an Offshore Wind Power Plant with HVDC-VSC: Preprint

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

Gevorgian, V.; Singh, M.; Muljadi, E.

2011-12-01

In this paper, a constant Volt/Hz operation applied to the Type 1 wind turbine generator. Various control aspects of Type 1 generators at the plant level and at the turbine level will be investigated. Based on DOE study, wind power generation may reach 330 GW by 2030 at the level of penetration of 20% of the total energy production. From this amount of wind power, 54 GW of wind power will be generated at offshore wind power plants. The deployment of offshore wind power plants requires power transmission from the plant to the load center inland. Since this power transmissionmore » requires submarine cable, there is a need to use High-Voltage Direct Current (HVDC) transmission. Otherwise, if the power is transmitted via alternating current, the reactive power generated by the cable capacitance may cause an excessive over voltage in the middle of the transmission distance which requires unnecessary oversized cable voltage breakdown capability. The use of HVDC is usually required for transmission distance longer than 50 kilometers of submarine cables to be economical. The use of HVDC brings another advantage; it is capable of operating at variable frequency. The inland substation will be operated to 60 Hz synched with the grid, the offshore substation can be operated at variable frequency, thus allowing the wind power plant to be operated at constant Volt/Hz. In this paper, a constant Volt/Hz operation applied to the Type 1 wind turbine generator. Various control aspects of Type 1 generators at the plant level and at the turbine level will be investigated.« less

Ultra-low power, Zeno effect based optical modulation in a degenerate V-system with a tapered nano fiber in atomic vapor.

PubMed

Salit, K; Salit, M; Krishnamurthy, Subramanian; Wang, Y; Kumar, P; Shahriar, M S

2011-11-07

We demonstrate an ultra-low light level optical modulator using a tapered nano fiber embedded in a hot rubidium vapor. The control and signal beams are co-propagating but orthogonally polarized, leading to a degenerate V-system involving coherent superpositions of Zeeman sublevels. The modulation is due primarily to the quantum Zeno effect for the signal beam induced by the control beam. For a control power of 40 nW and a signal power of 100 pW, we observe near 100% modulation. The ultra-low power level needed for the modulation is due to a combination of the Zeno effect and the extreme field localization in the evanescent field around the taper.

Energy Use and Power Levels in New Monitors and Personal Computers

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

Roberson, Judy A.; Homan, Gregory K.; Mahajan, Akshay

2002-07-23

Our research was conducted in support of the EPA ENERGY STAR Office Equipment program, whose goal is to reduce the amount of electricity consumed by office equipment in the U.S. The most energy-efficient models in each office equipment category are eligible for the ENERGY STAR label, which consumers can use to identify and select efficient products. As the efficiency of each category improves over time, the ENERGY STAR criteria need to be revised accordingly. The purpose of this study was to provide reliable data on the energy consumption of the newest personal computers and monitors that the EPA can usemore » to evaluate revisions to current ENERGY STAR criteria as well as to improve the accuracy of ENERGY STAR program savings estimates. We report the results of measuring the power consumption and power management capabilities of a sample of new monitors and computers. These results will be used to improve estimates of program energy savings and carbon emission reductions, and to inform rev isions of the ENERGY STAR criteria for these products. Our sample consists of 35 monitors and 26 computers manufactured between July 2000 and October 2001; it includes cathode ray tube (CRT) and liquid crystal display (LCD) monitors, Macintosh and Intel-architecture computers, desktop and laptop computers, and integrated computer systems, in which power consumption of the computer and monitor cannot be measured separately. For each machine we measured power consumption when off, on, and in each low-power level. We identify trends in and opportunities to reduce power consumption in new personal computers and monitors. Our results include a trend among monitor manufacturers to provide a single very low low-power level, well below the current ENERGY STAR criteria for sleep power consumption. These very low sleep power results mean that energy consumed when monitors are off or in active use has become more important in terms of contribution to the overall unit energy consumption (UEC). Cur rent ENERGY STAR monitor and computer criteria do not specify off or on power, but our results suggest opportunities for saving energy in these modes. Also, significant differences between CRT and LCD technology, and between field-measured and manufacturer-reported power levels reveal the need for standard methods and metrics for measuring and comparing monitor power consumption.« less

Results of the harmonics measurement program at the John F. Long photovoltaic house

NASA Astrophysics Data System (ADS)

Campen, G. L.

1982-03-01

Photovoltaic (PV) systems used in single-family dwellings require an inverter to act as an interface between the direct-current (dc) power output of the PV unit and the alternating-current (ac) power needed by house loads. A type of inverter known as line commutated injects harmonic currents on the ac side and requires large amounts of reactive power. Large numbers of such PV installations could lead to unacceptable levels of harmonic voltages on the utility system, and the need to increase the utility's deliver of reactive power could result in significant cost increases. The harmonics and power-factor effects are examined for a single PV installation using a line-commutated inverter. The magnitude and phase of various currents and voltages from the fundamental to the 13th harmonic were recorded both with and without the operation of the PV system.

Development of a 500-Watt portable generator

NASA Astrophysics Data System (ADS)

Knochenhauer, Robert John

In many commercial and recreational environments where power is unavailable, there is a need for lightweight, efficient, reasonably priced and quiet power sources that can recharge batteries for various portable devices. The current benchmark device is the Honda EU1000i, a 1000-Watt (peak) generator that weighs only 29 pounds (dry) and has a respectable noise level of 59 dB (at 7 meters) under peak power loading. The intent of this thesis study is to focus on the thermal management of a novel generator design that develops peak power of 500-Watts, weighs in at less than 20 pounds (dry) and has a reasonably low noise level at peak power loading. Through the course of this assessment, two key lessons are learned: • Liquid cooling at this scale is possible, but not practical • Renewable power sources (wind turbines and/or solar panels) are viable alternatives when used in environments that offer suitable conditions.

Climate and water resource change impacts and adaptation potential for US power supply

DOE PAGES

Miara, Ariel; Macknick, Jordan E.; Vorosmarty, Charles J.; ...

2017-10-30

Power plants that require cooling currently (2015) provide 85% of electricity generation in the United States. These facilities need large volumes of water and sufficiently cool temperatures for optimal operations, and projected climate conditions may lower their potential power output and affect reliability. We evaluate the performance of 1,080 thermoelectric plants across the contiguous US under future climates (2035-2064) and their collective performance at 19 North American Electric Reliability Corporation (NERC) sub-regions. Joint consideration of engineering interactions with climate, hydrology and environmental regulations reveals the region-specific performance of energy systems and the need for regional energy security and climate-water adaptationmore » strategies. Despite climate-water constraints on individual plants, the current power supply infrastructure shows potential for adaptation to future climates by capitalizing on the size of regional power systems, grid configuration and improvements in thermal efficiencies. Without placing climate-water impacts on individual plants in a broader power systems context, vulnerability assessments that aim to support adaptation and resilience strategies misgauge the extent to which regional energy systems are vulnerable. As a result, climate-water impacts can lower thermoelectric reserve margins, a measure of systems-level reliability, highlighting the need to integrate climate-water constraints on thermoelectric power supply into energy planning, risk assessments, and system reliability management.« less

Climate and water resource change impacts and adaptation potential for US power supply

NASA Astrophysics Data System (ADS)

Miara, Ariel; Macknick, Jordan E.; Vörösmarty, Charles J.; Tidwell, Vincent C.; Newmark, Robin; Fekete, Balazs

2017-11-01

Power plants that require cooling currently (2015) provide 85% of electricity generation in the United States. These facilities need large volumes of water and sufficiently cool temperatures for optimal operations, and projected climate conditions may lower their potential power output and affect reliability. We evaluate the performance of 1,080 thermoelectric plants across the contiguous US under future climates (2035-2064) and their collective performance at 19 North American Electric Reliability Corporation (NERC) sub-regions. Joint consideration of engineering interactions with climate, hydrology and environmental regulations reveals the region-specific performance of energy systems and the need for regional energy security and climate-water adaptation strategies. Despite climate-water constraints on individual plants, the current power supply infrastructure shows potential for adaptation to future climates by capitalizing on the size of regional power systems, grid configuration and improvements in thermal efficiencies. Without placing climate-water impacts on individual plants in a broader power systems context, vulnerability assessments that aim to support adaptation and resilience strategies misgauge the extent to which regional energy systems are vulnerable. Climate-water impacts can lower thermoelectric reserve margins, a measure of systems-level reliability, highlighting the need to integrate climate-water constraints on thermoelectric power supply into energy planning, risk assessments, and system reliability management.

Climate and water resource change impacts and adaptation potential for US power supply

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

Miara, Ariel; Macknick, Jordan E.; Vorosmarty, Charles J.

Power plants that require cooling currently (2015) provide 85% of electricity generation in the United States. These facilities need large volumes of water and sufficiently cool temperatures for optimal operations, and projected climate conditions may lower their potential power output and affect reliability. We evaluate the performance of 1,080 thermoelectric plants across the contiguous US under future climates (2035-2064) and their collective performance at 19 North American Electric Reliability Corporation (NERC) sub-regions. Joint consideration of engineering interactions with climate, hydrology and environmental regulations reveals the region-specific performance of energy systems and the need for regional energy security and climate-water adaptationmore » strategies. Despite climate-water constraints on individual plants, the current power supply infrastructure shows potential for adaptation to future climates by capitalizing on the size of regional power systems, grid configuration and improvements in thermal efficiencies. Without placing climate-water impacts on individual plants in a broader power systems context, vulnerability assessments that aim to support adaptation and resilience strategies misgauge the extent to which regional energy systems are vulnerable. As a result, climate-water impacts can lower thermoelectric reserve margins, a measure of systems-level reliability, highlighting the need to integrate climate-water constraints on thermoelectric power supply into energy planning, risk assessments, and system reliability management.« less

High performance TWT development for the microwave power module

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

Whaley, D.R.; Armstrong, C.M.; Groshart, G.

1996-12-31

Northrop Grumman`s ongoing development of microwave power modules (MPM) provides microwave power at various power levels, frequencies, and bandwidths for a variety of applications. Present day requirements for the vacuum power booster traveling wave tubes of the microwave power module are becoming increasingly more demanding, necessitating the need for further enhancement of tube performance. The MPM development program at Northrop Grumman is designed specifically to meet this need by construction and test of a series of new tubes aimed at verifying computation and reaching high efficiency design goals. Tubes under test incorporate several different helix designs, as well as varyingmore » electron gun and magnetic confinement configurations. Current efforts also include further development of state-of-the-art TWT modeling and computational methods at Northrop Grumman incorporating new, more accurate models into existing design tools and developing new tools to be used in all aspects of traveling wave tube design. Current status of the Northrop Grumman MPM TWT development program will be presented.« less

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

Milligan, Michael; Bloom, Aaron P; Townsend, Aaron

Defining flexibility has been a challenge that a number of industry members and researchers have attempted to address in recent years. With increased variability and uncertainty of variable generation (VG), the resources on the system will have to be more flexible to adjust output, so that power output ranges, power ramp rates, and energy duration sustainability are sufficient to meet the needs of balancing supply with demand at various operational timescales. This chapter discusses whether existing market designs provide adequate incentives for resources to offer their flexibility into the market to meet the increased levels of variability and uncertainty introducedmore » by VG in the short-term operational time frame. It presents a definition of flexibility and discusses how increased levels of VG require increased needs for flexibility on power systems. Following this introductory material, the chapter examines how existing market designs ensure that resources have the right incentives to provide increased flexibility, and then discusses a number of emerging market design elements that impact flexibility incentives.« less

Prediction and characterization of application power use in a high-performance computing environment

DOE PAGES

Bugbee, Bruce; Phillips, Caleb; Egan, Hilary; ...

2017-02-27

Power use in data centers and high-performance computing (HPC) facilities has grown in tandem with increases in the size and number of these facilities. Substantial innovation is needed to enable meaningful reduction in energy footprints in leadership-class HPC systems. In this paper, we focus on characterizing and investigating application-level power usage. We demonstrate potential methods for predicting power usage based on a priori and in situ characteristics. Lastly, we highlight a potential use case of this method through a simulated power-aware scheduler using historical jobs from a real scientific HPC system.

Public participation in water resources management: Restructuring model of upstream Musi watershed

NASA Astrophysics Data System (ADS)

Andriani, Yuli; Zagloel, T. Yuri M.; Koestoer, R. H.; Suparmoko, M.

2017-11-01

Water is the source of life needed by living things. Human as one of living most in needs of water. Because the population growth follows the geometrical progression, while the natural resource increases calculates the arithmetic. Humans besides needing water also need land for shelter and for their livelihood needs, such as gardening or rice farmers. If the water absorption area is reduced, water availability will decrease. Therefore it is necessary to conduct an in-depth study of water resources management involving the community. The purpose of this study is to analyze community participation in water resources management, so that its availability can still meet the needs of living and sustainable. The method that used the level of community participation according to Arstein theory. The results obtained that community participation is at the level of partnership and power delegation. This level of participation is at the level of participation that determines the sustainability of water resources for present and future generations.

Standby battery requirements for telecommunications power

NASA Astrophysics Data System (ADS)

May, G. J.

The requirements for standby power for telecommunications are changing as the network moves from conventional systems to Internet Protocol (IP) telephony. These new systems require higher power levels closer to the user but the level of availability and reliability cannot be compromised if the network is to provide service in the event of a failure of the public utility. Many parts of these new networks are ac rather than dc powered with UPS systems for back-up power. These generally have lower levels of reliability than dc systems and the network needs to be designed such that overall reliability is not reduced through appropriate levels of redundancy. Mobile networks have different power requirements. Where there is a high density of nodes, continuity of service can be reasonably assured with short autonomy times. Furthermore, there is generally no requirement that these networks are the provider of last resort and therefore, specifications for continuity of power are directed towards revenue protection and overall reliability targets. As a result of these changes, battery requirements for reserve power are evolving. Shorter autonomy times are specified for parts of the network although a large part will continue to need support for hours rather minutes. Operational temperatures are increasing and battery solutions that provide longer life in extreme conditions are becoming important. Different battery technologies will be discussed in the context of these requirements. Conventional large flooded lead/acid cells both with pasted and tubular plates are used in larger central office applications but the majority of requirements are met with valve-regulated lead/acid (VRLA) batteries. The different types of VRLA battery will be described and their suitability for various applications outlined. New developments in battery construction and battery materials have improved both performance and reliability in recent years. Alternative technologies are also being proposed for telecommunications power, either different battery chemistries including lithium batteries, flywheel energy storage or the use of fuel cells. These will be evaluated and the position of lead/acid batteries in the medium term for this important market will be assessed.

Predicting the Inflow Distortion Tone Noise of the NASA Glenn Advanced Noise Control Fan with a Combined Quadrupole-Dipole Model

NASA Technical Reports Server (NTRS)

Koch, L. Danielle

2012-01-01

A combined quadrupole-dipole model of fan inflow distortion tone noise has been extended to calculate tone sound power levels generated by obstructions arranged in circumferentially asymmetric locations upstream of a rotor. Trends in calculated sound power level agreed well with measurements from tests conducted in 2007 in the NASA Glenn Advanced Noise Control Fan. Calculated values of sound power levels radiated upstream were demonstrated to be sensitive to the accuracy of the modeled wakes from the cylindrical rods that were placed upstream of the fan to distort the inflow. Results indicate a continued need to obtain accurate aerodynamic predictions and measurements at the fan inlet plane as engineers work towards developing fan inflow distortion tone noise prediction tools.

Air Force Information Management (IM): A 1990 Snapshot and 1995 Future Look at Air Force IM Needs and Preferred Education/Training Approaches

DTIC Science & Technology

1990-12-01

small powerful computers to businesses and homes on an international scale (29:74). Relatively low cost, high computing power , and ease of operation were...is performed. In large part, today’s AF IM professional has been inundated with powerful new technologies which were rapidly introduced and inserted...state that, "In a survey of five years of MIS research, we fouind the averane levels of statistical power to be relatively low (5:104). In their own

Up gradation of LHCD system for rf power level up to 2MW for SST1

NASA Astrophysics Data System (ADS)

Sharma, P. K.; Ambulkar, K. K.; Parmar, P. R.; Virani, C. G.; Thakur, A. L.; Kulkarni, S. V.; Lhcd Group

2010-02-01

To operate superconducting steadystate tokamak (SST1) for 1000 seconds, lower hybrid current drive (LHCD) system has been designed at a frequency of 3.7 GHz., which would couple 1.0 MW CW of microwave power to the shaped plasma. The system consists of various rf passive components and transmission line, employing which the rf power from the source is transported to the antenna. During calibration of transmission line, it was observed that the losses in the transmission line is substantial and eventually would lead to less coupled power to the plasma. Further it is anticipated that more LH power would be required for advanced operation of SST1 machine. Thus it is decided to upgrade the existing LHCD system to 2 MW CW power level. The proposed up gradation would demand several infra structural changes and needs to be addressed. Due to lack of space, we have proposed a scheme in which additional two klystrons, along with existing two klystrons would be accommodated in the existing space. The low rf power requirements have also been increased to cater the new needs. Accordingly additional cooling requirements have been proposed to accommodate the two new klystrons. The DAC and auxiliary power supplies have been also designed. The new up graded LHCD system would address several key technological issues. Firstly it would establish the operation of four klystrons at rated power in parallel employing single RHVPS (80kV, 70A). Secondly it would establish the operation of two high power klystrons operation at rated power when their collectors are cooled in series. In this paper we would present the various requirements for up-gradation of LHCD system to 2MW. The main requirements like high power rf source, along with modified support structure, low power rf systems to drive the high power rf source, auxiliary power supplies required for high power rf source, DAC system improvement, cooling improvements, etc. would be discussed.

Demonstration of passively cooled high-power Yb fiber amplifier

NASA Astrophysics Data System (ADS)

Bradford, Joshua; Cook, Justin; Antonio-Lopez, Jose Enrique; Shah, Larry; Amezcua Correa, Rodrigo; Richardson, Martin

2018-02-01

This work investigates the feasibility of passive cooling in high-power Yb amplifiers. Experimentally, an all-glass airclad step-index (ACSI) amplifier is diode-pumped with 400W and provides 200W power levels. With only natural convection to extract heat, core temperatures are estimated near 130°C with no degradation of performance relative to cooled architectures. Further, advanced analysis techniques allow for core temperature determination using thermal interferometry without the need for complicated stabilization or calibration.

Insulation Requirements of High-Voltage Power Systems in Future Spacecraft

NASA Technical Reports Server (NTRS)

Qureshi, A. Haq; Dayton, James A., Jr.

1995-01-01

The scope, size, and capability of the nation's space-based activities are limited by the level of electrical power available. Long-term projections show that there will be an increasing demand for electrical power in future spacecraft programs. The level of power that can be generated, conditioned, transmitted, and used will have to be considerably increased to satisfy these needs, and increased power levels will require that transmission voltages also be increased to minimize weight and resistive losses. At these projected voltages, power systems will not operate satisfactorily without the proper electrical insulation. Open or encapsulated power supplies are currently used to keep the volume and weight of space power systems low and to protect them from natural and induced environmental hazards. Circuits with open packaging are free to attain the pressure of the outer environment, whereas encapsulated circuits are imbedded in insulating materials, which are usually solids, but could be liquids or gases. Up to now, solid insulation has usually been chosen for space power systems. If the use of solid insulation is continued, when voltages increase, the amount of insulation for encapsulation also will have to increase. This increased insulation will increase weight and reduce system reliability. Therefore, non-solid insulation media must be examined to satisfy future spacecraft power and voltage demands. In this report, we assess the suitability of liquid, space vacuum, and gas insulation for space power systems.

SPECIAL CLASSES FOR STUDENTS WITH SPECIAL NEEDS.

ERIC Educational Resources Information Center

DOWELL, G.L.

A SPECIAL 3-YEAR TRAINING PROGRAM IN FARM POWER AND MACHINERY WAS DEVELOPED TO PROVIDE FOR DIFFERENT LEVELS OF STUDENT ACHIEVEMENT AND TO HELP MEET THE NEED FOR SKILLED WORKERS IN THE MISSISSIPPI DELTA AREA. CHANGES IN THE LEARNING ENVIRONMENT OF STUDENTS TRANSFERRED FROM REGULAR VOCATIONAL AGRICULTURE CLASSES TO THE SPECIAL CLASSES PROVIDE A MORE…

Need for power and the choice of technologies: State decisions on electric power facilities

NASA Astrophysics Data System (ADS)

1981-06-01

The decision-making processes at the state level regarding the licensing of electric generating facilities were assessed. The basic issues addressed are the need for power and choice of technology: state decisions which directly influence and affect the nation's energy supply, and the tradeoffs involved in meeting energy demand. The areas of special emphasis included the legal mechanisms and regulatory procedures used to determine and resolve these issues. The effectiveness of state decision-making was assessed, focusing on legal and administrative histories and accommodation of interests of concerned parties. Recent innovations to enhance the decision-making process were also assessed where applicable. No particular substantive results are advocated in the findings. The recommendations presented are broad in scope.

Power laws in covariability of anxiety and depression among newly diagnosed patients with major depressive episode, panic disorder and controls.

PubMed

Katerndahl, David A

2009-06-01

Although symptoms of anxiety and depression correlate, they may covary in irregular and unpredictable ways. This non-linear covariation may be important to psychiatric diagnosis, treatment and relapse. This non-linear anxiety-depression interaction suggests that power laws may be observed. Power laws are statistical distributions found when systems vary in complex ways at the interface between chaotic dynamics and periodic dynamics, such that data points vary randomly but are still partially correlated with each other. Such non-linear dynamics and relationships should result in characteristic patterns of interaction among patients, stressors and treatment. This is important because non-linear dynamics could affect our understanding of mental disorders, the need for varied treatment approaches and patterns of early response to treatment. To determine whether the relationships between anxiety and depression levels, changes and rates of change follow power law distributions among patients with newly diagnosed major depressive episode (MDE), panic disorder (PD) and neither disorder (controls). Time series of hourly mood variation. Setting Acute and continuity primary care clinics. Five adult patients presenting each with MDE, PD and controls based on DSM-IV criteria. Four patients in each group completed 30 days of assessments. MAIN AND SECONDARY OUTCOME MEASURES: Hourly self-assessments (while awake) of levels of anxiety and depression using visual analogue scales for a 30-day period. Covariation in level of symptoms, in the change of symptoms and in the rate of change were assessed. Anxiety-depression matrices were prepared for pooled subjects. Power laws were sought using log-log plots of frequency versus order of that frequency. Although visual inspection of plots for symptoms levels, change and rates of change all suggest power laws, statistical assessments provide stronger support for power laws in symptom change than for either symptom levels or rates of change. Adjusted R(2) terms are larger for MDE and PD subjects compared with controls while the inverse slope is about 2.5 for controls and 1.7-1.9 for those with MDE or PD. This study found that power laws may be present in both the symptom change data for all three diagnostic groups. Evidence for power laws in symptom levels and rates of change was less compelling. The inverse slopes suggest that the anxiety-depression relationships among subjects with PD and major depression are similar but differ from those among controls. First, power laws suggest a scale-free relationship; the differences seen in transition from symptom level to change level may reflect that complex events at the level of mood assessment affect change in mood. Second, this covariation may be due to external factors acting on the patient or multiple internal interrelated factors. Third, different factors and populations can yield different slopes. Future research is needed to confirm these preliminary findings and to understand the origin of these dynamics.

Mathematical modelling of Bit-Level Architecture using Reciprocal Quantum Logic

NASA Astrophysics Data System (ADS)

Narendran, S.; Selvakumar, J.

2018-04-01

Efficiency of high-performance computing is on high demand with both speed and energy efficiency. Reciprocal Quantum Logic (RQL) is one of the technology which will produce high speed and zero static power dissipation. RQL uses AC power supply as input rather than DC input. RQL has three set of basic gates. Series of reciprocal transmission lines are placed in between each gate to avoid loss of power and to achieve high speed. Analytical model of Bit-Level Architecture are done through RQL. Major drawback of reciprocal Quantum Logic is area, because of lack in proper power supply. To achieve proper power supply we need to use splitters which will occupy large area. Distributed arithmetic uses vector- vector multiplication one is constant and other is signed variable and each word performs as a binary number, they rearranged and mixed to form distributed system. Distributed arithmetic is widely used in convolution and high performance computational devices.

Quantifying CO2 Emissions from Individual Power Plants using OCO-2 Observations

NASA Astrophysics Data System (ADS)

Nassar, R.; Hill, T. G.; McLinden, C. A.; Wunch, D.; Jones, D. B. A.; Crisp, D.

2017-12-01

In order to better manage anthropogenic CO2 emissions, improved methods of quantifying emissions are needed at all spatial scales from the national level down to the facility level. Although the Orbiting Carbon Observatory 2 (OCO-2) satellite was not designed for monitoring power plant emissions, we show that in select cases, CO2 observations from OCO-2 can be used to quantify daily CO2 emissions from individual mid- to large-sized coal power plants by fitting the data to plume model simulations. Emission estimates for US power plants are within 1-13% of reported daily emission values enabling application of the approach to international sites that lack detailed emission information. These results affirm that a constellation of future CO2 imaging satellites, optimized for point sources, could be used for the Monitoring, Reporting and Verification (MRV) of CO2 emissions from individual power plants to support the implementation of climate policies.

Quantifying CO2 Emissions From Individual Power Plants From Space

NASA Astrophysics Data System (ADS)

Nassar, Ray; Hill, Timothy G.; McLinden, Chris A.; Wunch, Debra; Jones, Dylan B. A.; Crisp, David

2017-10-01

In order to better manage anthropogenic CO2 emissions, improved methods of quantifying emissions are needed at all spatial scales from the national level down to the facility level. Although the Orbiting Carbon Observatory 2 (OCO-2) satellite was not designed for monitoring power plant emissions, we show that in some cases, CO2 observations from OCO-2 can be used to quantify daily CO2 emissions from individual middle- to large-sized coal power plants by fitting the data to plume model simulations. Emission estimates for U.S. power plants are within 1-17% of reported daily emission values, enabling application of the approach to international sites that lack detailed emission information. This affirms that a constellation of future CO2 imaging satellites, optimized for point sources, could monitor emissions from individual power plants to support the implementation of climate policies.

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

Bishofberger, Kip A.

Within Building 19 of TA-53, a screen room has been evaluated for use as a reverb chamber (with deep gratitude to Dale Dalmas and Greg Dale for their assistance). With minimal additional sealing of the chamber, we expect the Q to increase even more, and thus field levels for the same RF source power. Future studies need to determine leakage field levels, which will define maximum achievable field levels.

State participation in the creation of fuel-cell-based power plants to meet civilian demand in Russia

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

Pekhota, F.N.

1996-04-01

At present, up to 70% of Russian territory is not covered by central electrical distribution systems. In the field of fuel cell power plants, Russia is at parity with the leading foreign countries with respect to both technical and economic performance and the level of research being conducted. Civilian use of these generating systems on a broad scale, however, demands that a number of problems be solved, particularly those relating to the need for longer plant service life, lower unit cost of electricity, etc. The Ministry of Science and technical Policy of the Russian Federation issued a decree creating amore » new are of concentration, `Fuel Cell Based Power Plants for Civilian Needs,` in the GNTPR `Environmentally Clean Power Industry,` which will form the basis for financial support in this area out of the federal budget.« less

Wireless Actuation of Micromechanical Resonators

NASA Astrophysics Data System (ADS)

Mateen, Farrukh; Maedler, Carsten; Erramilli, Shyamsunder; Mohanty, Pritiraj

Wireless transfer of power is of fundamental and technical interest with applications ranging from remote operation of electronics, biomedical implants, and device actuation where hard-wired power sources are neither desirable nor practical. In particular, biomedical implants in the body or the brain need small footprint power receiving elements for wireless charging, which can be accomplished by micromechanical resonators. In contrast for fundamental experiments, ultra low-power wireless operation of micromechanical resonators in the microwave range makes low-temperature studies of mechanical systems in the quantum regime possible, where heat carried by the electrical wires in standard actuation techniques is detrimental to maintaining the resonator in a quantum state. We demonstrate successful actuation of micron-sized silicon-based piezoelectric resonators with resonance frequencies from 36 MHz to 120 MHz, at power levels of nanowatts and distances of about 3 feet, including polarization, distance and power dependence measurements. Our demonstration of wireless actuation of micromechanical resonators via electric-field coupling down to nanowatt levels enables a multitude of applications based on micromechanical resonators, inaccessible until now.

Reactor power system deployment and startup

NASA Technical Reports Server (NTRS)

Wetch, J. R.; Nelin, C. J.; Britt, E. J.; Klein, G.

1985-01-01

This paper addresses issues that should receive further examination in the near-term as concept selection for development of a U.S. space reactor power system is approached. The issues include: the economics, practicality and system reliability associated with transfer of nuclear spacecraft from low earth shuttle orbits to operational orbits, via chemical propulsion versus nuclear electric propulsion; possible astronaut supervised reactor and nuclear electric propulsion startup in low altitude Shuttle orbit; potential deployment methods for nuclear powered spacecraft from Shuttle; the general public safety of low altitude startup and nuclear safe and disposal orbits; the question of preferred reactor power level; and the question of frozen versus molten alkali metal coolant during launch and deployment. These issues must be considered now because they impact the SP-100 concept selection, power level selection, weight and size limits, use of deployable radiators, reliability requirements, and economics, as well as the degree of need for and the urgency of developing space reactor power systems.

A Techno-Economic Assessment of Hybrid Cooling Systems for Coal- and Natural-Gas-Fired Power Plants with and without Carbon Capture and Storage.

PubMed

Zhai, Haibo; Rubin, Edward S

2016-04-05

Advanced cooling systems can be deployed to enhance the resilience of thermoelectric power generation systems. This study developed and applied a new power plant modeling option for a hybrid cooling system at coal- or natural-gas-fired power plants with and without amine-based carbon capture and storage (CCS) systems. The results of the plant-level analyses show that the performance and cost of hybrid cooling systems are affected by a range of environmental, technical, and economic parameters. In general, when hot periods last the entire summer, the wet unit of a hybrid cooling system needs to share about 30% of the total plant cooling load in order to minimize the overall system cost. CCS deployment can lead to a significant increase in the water use of hybrid cooling systems, depending on the level of CO2 capture. Compared to wet cooling systems, widespread applications of hybrid cooling systems can substantially reduce water use in the electric power sector with only a moderate increase in the plant-level cost of electricity generation.

Low-level laser therapy equipment needs calibration before clinical use

NASA Astrophysics Data System (ADS)

Machado de Senna, André; Machado-de-sena, Rosa Maria; Facundes, Arseni Lázaro; Barros Nepomuceno, Patrícia; Sávya Florentino, Wanilza; Olegário de Araújo, Ronyere

2018-04-01

Many factors can influence the radiant power delivered by the low-level laser therapy (LLLT) equipment, such as its cleaning and condition, as well as the use of plastic films for protecting the laser or even its time of use. Radiant power is an important factor to consider because it affects the amount of energy delivered to the target tissue. The difference between real radiant power (RRP) and nominal radiant power (NRP) may interfere in the expected results, because the delivered energy is different from the desired energy. Purpose: The objective of this study was to compare the NRP with the RRP offered by LLLT devices under clinical conditions of use. Material and Methods: For data collection to this study, 61 LLLT devices used in private and public dental practices in the state of Tocantins, Brazil, were evaluated. Three consecutive power measurements were performed at one-minute intervals and then the average of the measured power was calculated. The RRP was compared to the NRP. Results: The equipment presented NRP from 30 to 500mW while RRP ranged from 17.3 to 107.0mW. Discussion and Conclusion: The mean power measured in clinical conditions of use of the laser equipment was different from the nominal power reported by the manufacturers of the devices (p<0,01). The RRP ranged between 12.92% and 107% of NRP. This fact is worrisome, since one of the most important parameters for the success of the treatment of an injury using LLLT is the energy (power x time) delivered. These findings reinforce the need of calibrating the equipment before each laser application in order to avoid failures in the therapeutic conduct.

High Energy Lithium-Ion VES Cells And Batteries Performances

NASA Astrophysics Data System (ADS)

Castric, A.-F.; Lawson, S.; Borthomieu, Y.

2011-10-01

b Saft's Space VES range of lithium-ion cells have been designed specifically to meet the satellites on-board power need, while meeting the legitimate high levels of requirements for space products. The purpose of the paper is to develop how the VES batteries designs have progressively evolved in order to accommodate the needs, requirements and constraints evolutions. The following topics will be presented: - Description of the main design features of the VES Li- ion batteries. - How the optimised battery configuration is selected against the required EOL power need or other constraints. - Presentation of the batteries performances (electrical, mechanical, thermal, interface, weight, ...). - Measures implemented in order to maintain these performances, and to guarantee the best product quality as per space standards.

Distribution and progression of add power among people in need of near correction.

PubMed

Han, Xiaotong; Lee, Pei Ying; Liu, Chi; He, Mingguang

2018-04-16

This study helps to better understand the need and trend in presbyopic add power in the aging society. Distribution and progression of presbyopic add power in East Asian population is largely unknown. Prospective cohort study. About 303 participants from a population-based study of residents aged 35 years and older in Guangzhou, China. Visual acuity (VA) test and non-cycloplegic automated refraction were performed at baseline in 2008 and the 6-year follow-up per standardized protocol. Participants with presenting near VA ≤ 20/40 underwent distance subjective refraction and add power measurement by increasing plus lens at a standard distance of 40 cm at each visit. Add power at baseline and follow-ups. Mean (standard deviation) age of the study participants was 57.6 (11.1) years and 50.2% were female. The mean add power at baseline was 1.43, 1.73, 2.03 and 2.20 diopters (D) for individuals in the age groups of 35-44, 45-54, 55-64 and 65+ years, respectively. Participants with older age and lower educational level had significantly higher add power requirements (P < 0.001). The overall 6-year increase in add power was 0.15D (95% CI: 0.06 to 0.25), and was smaller in myopic subjects (P = 0.03). Baseline age and add power, but not changes in biometric factors, were associated with longitudinal change in add power (P < 0.001). Distribution and progression of add power in Chinese was different from that previously suggested by Caucasian studies. More studies are needed to establish up-to-date age-related add power prescription norms for population of different ethnicities. © 2018 Royal Australian and New Zealand College of Ophthalmologists.

Modeling the value of integrated U.S. and Canadian power sector expansion

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

Beiter, Philipp; Cole, Wesley J.; Steinberg, Daniel C.

The U.S.-Canadian power system has evolved into a highly integrated grid. Cross-border transmission and coordination of system operations create an interconnected power system with combined imports and exports of electricity of greater than 77 TWh per year. Currently, more than 5 GW of new international transmission lines are in various stages of permitting and development. These transmission lines may enable even greater integration and coordination of the U.S. and Canadian systems, which can in turn increase the reliability and flexibility of North America's electricity grid and help address challenges associated with integrating high levels of variable renewables. Using a versionmore » of the National Renewable Energy Laboratory's Regional Energy Deployment System (ReEDS) model that incorporates Canada, this analysis quantifies the differences in the evolution of the power system under scenarios in which cross-border transmission capacity is restricted to today's levels, and scenarios in which new transmission is less restricted. These impacts are analyzed under a 'business-as-usual' reference scenario and a scenario in which deep cuts in power sector carbon dioxide emissions levels are achieved. A set of key impact metrics is analyzed, including 1) the composition of generating capacity by technology, 2) system costs, 3) wholesale electricity prices, 4) international electricity exports and imports, 5) transmission capacity, and 6) carbon dioxide emission levels. When new cross-border transmission is not allowed, the United States needs additional capacity (primarily natural gas and renewable energy) to meet domestic needs, while total Canadian capacity is lower because less capacity is needed to export to the United States. This effect is amplified under the carbon cap scenario. Impacts vary on a regional basis, largely due to the different relative sizes of the generation portfolio between countries and regions and the relative impact from cross-border electricity trade. The total impact from restricting cross-border trade on carbon emissions and average wholesale electricity prices is limited, due to the relative size of the domestic power systems and the cross-border trade volume. Lastly, cross-border transmission capacity is projected to more than double under the unrestricted transmission capacity scenarios, which exceeds the rate of projected domestic transmission capacity additions in each country.« less

Modeling the value of integrated U.S. and Canadian power sector expansion

DOE PAGES

Beiter, Philipp; Cole, Wesley J.; Steinberg, Daniel C.

2017-03-15

The U.S.-Canadian power system has evolved into a highly integrated grid. Cross-border transmission and coordination of system operations create an interconnected power system with combined imports and exports of electricity of greater than 77 TWh per year. Currently, more than 5 GW of new international transmission lines are in various stages of permitting and development. These transmission lines may enable even greater integration and coordination of the U.S. and Canadian systems, which can in turn increase the reliability and flexibility of North America's electricity grid and help address challenges associated with integrating high levels of variable renewables. Using a versionmore » of the National Renewable Energy Laboratory's Regional Energy Deployment System (ReEDS) model that incorporates Canada, this analysis quantifies the differences in the evolution of the power system under scenarios in which cross-border transmission capacity is restricted to today's levels, and scenarios in which new transmission is less restricted. These impacts are analyzed under a 'business-as-usual' reference scenario and a scenario in which deep cuts in power sector carbon dioxide emissions levels are achieved. A set of key impact metrics is analyzed, including 1) the composition of generating capacity by technology, 2) system costs, 3) wholesale electricity prices, 4) international electricity exports and imports, 5) transmission capacity, and 6) carbon dioxide emission levels. When new cross-border transmission is not allowed, the United States needs additional capacity (primarily natural gas and renewable energy) to meet domestic needs, while total Canadian capacity is lower because less capacity is needed to export to the United States. This effect is amplified under the carbon cap scenario. Impacts vary on a regional basis, largely due to the different relative sizes of the generation portfolio between countries and regions and the relative impact from cross-border electricity trade. The total impact from restricting cross-border trade on carbon emissions and average wholesale electricity prices is limited, due to the relative size of the domestic power systems and the cross-border trade volume. Lastly, cross-border transmission capacity is projected to more than double under the unrestricted transmission capacity scenarios, which exceeds the rate of projected domestic transmission capacity additions in each country.« less

High-power piezoelectric acoustic-electric power feedthru for metal walls

NASA Astrophysics Data System (ADS)

Bao, Xiaoqi; Biederman, Will; Sherrit, Stewart; Badescu, Mircea; Bar-Cohen, Yoseph; Jones, Christopher; Aldrich, Jack; Chang, Zensheu

2008-03-01

Piezoelectric acoustic-electric power feed-through devices transfer electric power wirelessly through a solid wall using elastic waves. This approach allows for the elimination of the need for holes through structures for cabling or electrical feed-thrus . The technology supplies power to electric equipment inside sealed containers, vacuum or pressure vessels, etc where holes in the wall are prohibitive or may result in significant performance degradation or requires complex designs. In the our previous work, 100-W of electric power was transferred through a metal wall by a small, piezoelectric device with a simple-structure. To meet requirements of higher power applications, the feasibility to transfer kilowatts level power was investigated. Pre-stressed longitudinal piezoelectric feed-thru devices were analyzed by finite element modeling. An equivalent circuit model was developed to predict the characteristics of power transfer to different electric loads. Based on the analytical results, a prototype device was designed, fabricated and successfully demonstrated to transfer electric power at a level of 1-kW. Methods of minimizing plate wave excitation on the wall were also analyzed. Both model analysis and experimental results are presented in detail in this paper.

Design of megawatt power level heat pipe reactors

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

Mcclure, Patrick Ray; Poston, David Irvin; Dasari, Venkateswara Rao

An important niche for nuclear energy is the need for power at remote locations removed from a reliable electrical grid. Nuclear energy has potential applications at strategic defense locations, theaters of battle, remote communities, and emergency locations. With proper safeguards, a 1 to 10-MWe (megawatt electric) mobile reactor system could provide robust, self-contained, and long-term power in any environment. Heat pipe-cooled fast-spectrum nuclear reactors have been identified as a candidate for these applications. Heat pipe reactors, using alkali metal heat pipes, are perfectly suited for mobile applications because their nature is inherently simpler, smaller, and more reliable than “traditional” reactors.more » The goal of this project was to develop a scalable conceptual design for a compact reactor and to identify scaling issues for compact heat pipe cooled reactors in general. Toward this goal two detailed concepts were developed, the first concept with more conventional materials and a power of about 2 MWe and a the second concept with less conventional materials and a power level of about 5 MWe. A series of more qualitative advanced designs were developed (with less detail) that show power levels can be pushed to approximately 30 MWe.« less

ECH Technology Development

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

Temkin, Richard

2014-12-24

Electron Cyclotron Heating (ECH) is needed for plasma heating, current drive, plasma stability control, and other applications in fusion energy sciences research. The program of fusion energy sciences supported by U. S. DOE, Office of Science, Fusion Energy Sciences relies on the development of ECH technology to meet the needs of several plasma devices working at the frontier of fusion energy sciences research. The largest operating ECH system in the world is at DIII-D, consisting of six 1 MW, 110 GHz gyrotrons capable of ten second pulsed operation, plus two newer gyrotrons. The ECH Technology Development research program investigated themore » options for upgrading the DIII-D 110 GHz ECH system. Options included extending present-day 1 MW technology to 1.3 – 1.5 MW power levels or developing an entirely new approach to achieve up to 2 MW of power per gyrotron. The research consisted of theoretical research and designs conducted by Communication and Power Industries of Palo Alto, CA working with MIT. Results of the study would be validated in a later phase by research on short pulse length gyrotrons at MIT and long pulse / cw gyrotrons in industry. This research follows a highly successful program of development that has led to the highly reliable, six megawatt ECH system at the DIII-D tokamak. Eventually, gyrotrons at the 1.5 megawatt to multi-megawatt power level will be needed for heating and current drive in large scale plasmas including ITER and DEMO.« less

Sustainable energy at the 100 W level for scientific sites on the Antarctic Plateau: Lessons learned from the Polar Experiment Network for Geospace Upper atmosphere Investigations-Automatic Geophysical Observatory project

NASA Astrophysics Data System (ADS)

Melville, R.; Stillinger, A.; Gerrard, A.; Weatherwax, A.

2014-04-01

The need to provide power to unmanned instrumentation over the course of an entire year on the Antarctic plateau presents a large number of engineering and logistical challenges. Designs formulated in ideal laboratory environments often fail in the Antarctic due to the harsh operating conditions, and field experience is necessary to achieve year-round operation in the 100 W power range. In this paper we present our current power design for the Automatic Geophysical Observatories; a design based on over two decades of experience on the ice and allows for relatively continuous operation at the aforementioned power level. We also discuss our various implementation methods, both failures and successes, in an effort assist other unmanned deployments on the ice.

Sustainable energy at the 100 W level for scientific sites on the Antarctic Plateau: lessons learned from the Polar Experiment Network for Geospace Upper atmosphere Investigations-Automatic Geophysical Observatory project.

PubMed

Melville, R; Stillinger, A; Gerrard, A; Weatherwax, A

2014-04-01

The need to provide power to unmanned instrumentation over the course of an entire year on the Antarctic plateau presents a large number of engineering and logistical challenges. Designs formulated in ideal laboratory environments often fail in the Antarctic due to the harsh operating conditions, and field experience is necessary to achieve year-round operation in the 100 W power range. In this paper we present our current power design for the Automatic Geophysical Observatories; a design based on over two decades of experience on the ice and allows for relatively continuous operation at the aforementioned power level. We also discuss our various implementation methods, both failures and successes, in an effort assist other unmanned deployments on the ice.

Nonproliferation Challenges in Space Defense Technology - PANEL

NASA Technical Reports Server (NTRS)

Houts, Michael G.

2016-01-01

The use of highly enriched uranium (HEU) almost always "helps" space fission systems. Nuclear Thermal Propulsion (NTP) and high power fission electric systems appear able to use < 20% enriched uranium with minimal / acceptable performance impacts. However, lower power, "entry level" systems may be needed for space fission technology to be developed and utilized. Low power (i.e. approx.1 kWe) fission systems may have an unacceptable performance penalty if LEU is used instead of HEU. Are there Ways to Support Non-Proliferation Objectives While Simultaneously Helping Enable the Development and Utilization of Modern Space Fission Power and Propulsion Systems?

Low-Rank Coal Grinding Performance Versus Power Plant Performance

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

Rajive Ganguli; Sukumar Bandopadhyay

2008-12-31

The intent of this project was to demonstrate that Alaskan low-rank coal, which is high in volatile content, need not be ground as fine as bituminous coal (typically low in volatile content) for optimum combustion in power plants. The grind or particle size distribution (PSD), which is quantified by percentage of pulverized coal passing 74 microns (200 mesh), affects the pulverizer throughput in power plants. The finer the grind, the lower the throughput. For a power plant to maintain combustion levels, throughput needs to be high. The problem of particle size is compounded for Alaskan coal since it has amore » low Hardgrove grindability index (HGI); that is, it is difficult to grind. If the thesis of this project is demonstrated, then Alaskan coal need not be ground to the industry standard, thereby alleviating somewhat the low HGI issue (and, hopefully, furthering the salability of Alaskan coal). This project studied the relationship between PSD and power plant efficiency, emissions, and mill power consumption for low-rank high-volatile-content Alaskan coal. The emissions studied were CO, CO{sub 2}, NO{sub x}, SO{sub 2}, and Hg (only two tests). The tested PSD range was 42 to 81 percent passing 76 microns. Within the tested range, there was very little correlation between PSD and power plant efficiency, CO, NO{sub x}, and SO{sub 2}. Hg emissions were very low and, therefore, did not allow comparison between grind sizes. Mill power consumption was lower for coarser grinds.« less

Low Mass Muscle Actuators (LoMMAs) Using Electroactive Polymers

NASA Technical Reports Server (NTRS)

Bar-Cohen, Y.; Xue, T.; Joffe, B.; Lih, S. S.; Willis, P.; Simpson, J.; Smith, J.; Clair, T.; Shahinpoor, M.

1997-01-01

NASA is using actuation devices for many space applications and there is an increasing need to cut their cost as well as reduce their size, mass, and power consumption. Existing transducing actuators, such as piezoceramics, are inducing limited displacement levels. Potentially, electroactive polymers (so called EAP) can be formed as inexpensive, low-mass, low-power, miniature muscle actuators that are superior to the widely used actuators.

A Hybrid Multilevel Storage Architecture for Electric Power Dispatching Big Data

NASA Astrophysics Data System (ADS)

Yan, Hu; Huang, Bibin; Hong, Bowen; Hu, Jing

2017-10-01

Electric power dispatching is the center of the whole power system. In the long run time, the power dispatching center has accumulated a large amount of data. These data are now stored in different power professional systems and form lots of information isolated islands. Integrating these data and do comprehensive analysis can greatly improve the intelligent level of power dispatching. In this paper, a hybrid multilevel storage architecture for electrical power dispatching big data is proposed. It introduces relational database and NoSQL database to establish a power grid panoramic data center, effectively meet power dispatching big data storage needs, including the unified storage of structured and unstructured data fast access of massive real-time data, data version management and so on. It can be solid foundation for follow-up depth analysis of power dispatching big data.

Evaluation of semiconductor devices for Electric and Hybrid Vehicle (EHV) ac-drive applications, volume 1

NASA Technical Reports Server (NTRS)

Lee, F. C.; Chen, D. Y.; Jovanovic, M.; Hopkins, D. C.

1985-01-01

The results of evaluation of power semiconductor devices for electric hybrid vehicle ac drive applications are summarized. Three types of power devices are evaluated in the effort: high power bipolar or Darlington transistors, power MOSFETs, and asymmetric silicon control rectifiers (ASCR). The Bipolar transistors, including discrete device and Darlington devices, range from 100 A to 400 A and from 400 V to 900 V. These devices are currently used as key switching elements inverters for ac motor drive applications. Power MOSFETs, on the other hand, are much smaller in current rating. For the 400 V device, the current rating is limited to 25 A. For the main drive of an electric vehicle, device paralleling is normally needed to achieve practical power level. For other electric vehicle (EV) related applications such as battery charger circuit, however, MOSFET is advantageous to other devices because of drive circuit simplicity and high frequency capability. Asymmetrical SCR is basically a SCR device and needs commutation circuit for turn off. However, the device poses several advantages, i.e., low conduction drop and low cost.

Nuclear option

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

Olson, P.S.

The energy demand complexion of this country is always changing and promises to change in the future. The nuclear industry is responding to changing energy demands through standards writing activities. Since the oil embargo of 1973, there has been a change in the mix of fuels contributing to energy growth in this country; virtually all of the energy growth has come from coal and nuclear power. The predicted expansion of coal use by 1985, over 1977 level, is 37%, while the use of oil is expected to decline by 17%. Use of nuclear power is expected to increase 62% frommore » the 1977 level. The feasibility of using nuclear energy to meet the needs of the USA for electric power is discussed.« less

A DC Transformer

NASA Technical Reports Server (NTRS)

Youngquist, Robert C.; Ihlefeld, Curtis M.; Starr, Stanley O.

2013-01-01

A component level dc transformer is described in which no alternating currents or voltages are present. It operates by combining features of a homopolar motor and a homopolar generator, both de devices, such that the output voltage of a de power supply can be stepped up (or down) with a corresponding step down (or up) in current. The basic theory for this device is developed, performance predictions are made, and the results from a small prototype are presented. Based on demonstrated technology in the literature, this de transformer should be scalable to low megawatt levels, but it is more suited to high current than high voltage applications. Significant development would be required before it could achieve the kilovolt levels needed for de power transmission.

Wind-Friendly Flexible Ramping Product Design in Multi-Timescale Power System Operations

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

Cui, Mingjian; Zhang, Jie; Wu, Hongyu

With increasing wind power penetration in the electricity grid, system operators are recognizing the need for additional flexibility, and some are implementing new ramping products as a type of ancillary service. However, wind is generally thought of as causing the need for ramping services, not as being a potential source for the service. In this paper, a multi-timescale unit commitment and economic dispatch model is developed to consider the wind power ramping product (WPRP). An optimized swinging door algorithm with dynamic programming is applied to identify and forecast wind power ramps (WPRs). Designed as positive characteristics of WPRs, the WPRPmore » is then integrated into the multi-timescale dispatch model that considers new objective functions, ramping capacity limits, active power limits, and flexible ramping requirements. Numerical simulations on the modified IEEE 118-bus system show the potential effectiveness of WPRP in increasing the economic efficiency of power system operations with high levels of wind power penetration. It is found that WPRP not only reduces the production cost by using less ramping reserves scheduled by conventional generators, but also possibly enhances the reliability of power system operations. Moreover, wind power forecasts play an important role in providing high-quality WPRP service.« less

Understanding the impact of power in organizations.

PubMed

King, C; Koliner, A

1999-03-01

Although implementation of Shared Governance appears to have failed, it failed primarily on the surface. Many staff nurses actively involved in the Shared Governance movement not only were empowered but were dramatically affected on a professional level. Several council chairpersons were empowered to assume management roles in the transition back to the hierarchial model--a manifestation of their professional growth and development. At the unit level, several units lobbied the new leadership to allow them to continue to do peer review and unit-based council management of unit governance issues. Three councils lobbied to continue to do their work, although in a modified role, in the reestablished hierarchial structure. The three remaining councils were those of Practice, Quality, and Research. If nurse leaders at any level within the organization are to guide their departments forward while in the throes of the current chaos in health care, they must develop and use their power bases, both formal and informal, as individuals and then as leaders. Russell Coile identifies the need for more clinical expertise (expert power) on the executive team of health care organizations. He predicts that 50% of the executive team will be nurses and physicians and that only health care executives with an MBA or financial backgrounds, who also have well-developed informal power bases with skills in relationship development, facilitation, and networking, will be part of the new system. Those with a diversified informal power base will be most successful in guiding their organization to its destination. The future for nursing leaders is in the sharing of information; it is about embracing diversity and recognizing the contributions others can make that are refreshingly different; it is also about clearly defining a balance in life, because balanced leaders who have found a way to nurture and meet their own needs are better positioned to do the same for others. Ultimately, understanding the impact of power in an organization, regardless of organizational structure, begins with understanding and defining your own power base.

Customized dynamic splinting: orthoses that promote optimal function and recovery after radial nerve injury: a case report.

PubMed

McKee, Pat; Nguyen, Cecilia

2007-01-01

Radial nerve injury is a relatively common occurrence and recovery depends on the level of injury and extent of connective tissue damage. Orthoses (splints) are often provided to compensate for lost motor power. This article chronicles the recovery, over 27 months, of a 76-year-old woman who sustained a high radial nerve injury of her dominant arm during surgery for total shoulder replacement (Delta Reverse). Customized, low-profile dynamic splints, unlike any previously published design, were developed to address her goals for functional independence and the biological needs of the tissues. Dynamic power was provided to the wrist, fingers, and thumb by elastic cords and thin, flexible thermoplastic, without the need of an outrigger, thus avoiding the need for wire bending and cutting. At the outset, the splint was forearm-based and when wrist extension power was recovered, a hand-based splint was designed. Eventually, a circumferential hand-based thumb-stabilizing splint fulfilled most of the remaining orthotic requirements.

Attitude maneuvers of a solar-powered electric orbital transfer vehicle

NASA Astrophysics Data System (ADS)

Jenkin, Alan B.

1992-08-01

Attitude maneuver requirements of a solar-powered electric orbital transfer vehicle have been studied in detail. This involved evaluation of the yaw, pitch, and roll profiles and associated angular accelerations needed to simultaneously steer the vehicle thrust vector and maintain the solar array pointed toward the sun. Maintaining the solar array pointed exactly at the sun leads to snap roll maneuvers which have very high (theoretically unbounded) accelerations, thereby imposing large torque requirements. The problem is exacerbated by the large solar arrays which are needed to generate the high levels of power needed by electric propulsion devices. A method of eliminating the snap roll maneuvers is presented. The method involves the determination of relaxed roll profiles which approximate a forced transition between alternate exact roll profiles and incur only small errors in solar array pointing. The method makes it feasible to perform the required maneuvers using currently available attitude control technology such as reaction wheels, hot gas jets, or gimballed main engines.

Wide spectral band beam analysis

NASA Astrophysics Data System (ADS)

Aharon, Oren

2015-03-01

The reality in laser beam profiling is that measurements are performed over a wide spectrum of wavelengths and power ranges. Many applications use multiple laser wavelengths with very different power levels, a fact which dictates a need for a better measuring tool. Rapid progress in the fiber laser area has increased the demand for lasers in the wavelength range of 900 - 1030 nm, while the telecommunication market has increased the demand for wavelength range of 1300nm - 1600 nm, on the other hand the silicone chip manufacturing and mass production requirements tend to lower the laser wavelength towards the 190nm region. In many cases there is a need to combine several lasers together in order to perform a specific task. A typical application is to combine one visible laser for pointing, with a different laser for material processing with a very different wavelength and power level. The visible laser enables accurate pointing before the second laser is operated. The beam profile of the intensity distribution is an important parameter that indicates how a laser beam will behave in an application. Currently a lab, where many different lasers are used, will find itself using various laser beam profilers from several vendors with different specifications and accuracies. It is the propose of this article to present a technological breakthrough in the area of detectors, electronics and optics allowing intricate measurements of lasers with different wavelength and with power levels that vary many orders of magnitude by a single beam profiler.

Literature Survey on Operational Voltage Control and Reactive Power Management on Transmission and Sub-Transmission Networks

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

Elizondo, Marcelo A.; Samaan, Nader A.; Makarov, Yuri V.

Voltage and reactive power system control is generally performed following usual patterns of loads, based on off-line studies for daily and seasonal operations. This practice is currently challenged by the inclusion of distributed renewable generation, such as solar. There has been focus on resolving this problem at the distribution level; however, the transmission and sub-transmission levels have received less attention. This paper provides a literature review of proposed methods and solution approaches to coordinate and optimize voltage control and reactive power management, with an emphasis on applications at transmission and sub-transmission level. The conclusion drawn from the survey is thatmore » additional research is needed in the areas of optimizing switch shunt actions and coordinating all available resources to deal with uncertain patterns from increasing distributed renewable generation in the operational time frame. These topics are not deeply explored in the literature.« less

Experimental clean combustor program: Diesel no. 2 fuel addendum, phase 3

NASA Technical Reports Server (NTRS)

Gleason, C. C.; Bahr, D. W.

1979-01-01

A CF6-50 engine equipped with an advanced, low emission, double annular combustor was operated 4.8 hours with No. 2 diesel fuel. Fourteen steady-state operating conditions ranging from idle to full power were investigated. Engine/combustor performance and exhaust emissions were obtained and compared to JF-5 fueled test results. With one exception, fuel effects were very small and in agreement with previously obtained combustor test rig results. At high power operating condition, the two fuels produced virtually the same peak metal temperatures and exhaust emission levels. At low power operating conditions, where only the pilot stage was fueled, smoke levels tended to be significantly higher with No. 2 diesel fuel. Additional development of this combustor concept is needed in the areas of exit temperature distribution, engine fuel control, and exhaust emission levels before it can be considered for production engine use.

Priority setting for health in the context of devolution in Kenya: implications for health equity and community-based primary care

PubMed Central

McCollum, Rosalind; Theobald, Sally; Otiso, Lilian; Martineau, Tim; Karuga, Robinson; Barasa, Edwine; Molyneux, Sassy; Taegtmeyer, Miriam

2018-01-01

Abstract Devolution changes the locus of power within a country from central to sub-national levels. In 2013, Kenya devolved health and other services from central government to 47 new sub-national governments (known as counties). This transition seeks to strengthen democracy and accountability, increase community participation, improve efficiency and reduce inequities. With changing responsibilities and power following devolution reforms, comes the need for priority-setting at the new county level. Priority-setting arises as a consequence of the needs and demand for healthcare resources exceeding the resources available, resulting in the need for some means of choosing between competing demands. We sought to explore the impact of devolution on priority-setting for health equity and community health services. We conducted key informant and in-depth interviews with health policymakers, health providers and politicians from 10 counties (n = 269 individuals) and 14 focus group discussions with community members based in 2 counties (n = 146 individuals). Qualitative data were analysed using the framework approach. We found Kenya’s devolution reforms were driven by the need to demonstrate responsiveness to county contexts, with positive ramifications for health equity in previously neglected counties. The rapidity of the process, however, combined with limited technical capacity and guidance has meant that decision-making and prioritization have been captured and distorted for political and power interests. Less visible community health services that focus on health promotion, disease prevention and referral have been neglected within the prioritization process in favour of more tangible curative health services. The rapid transition in power carries a degree of risk of not meeting stated objectives. As Kenya moves forward, decision-makers need to address the community health gap and lay down institutional structures, processes and norms which promote health equity for all Kenyans. PMID:29846599

Multimode Directional Coupler for Utilization of Harmonic Frequencies from TWTAs

NASA Technical Reports Server (NTRS)

Simmons, Rainee N.; Wintucky, Edwin G.

2013-01-01

A novel waveguide multimode directional coupler (MDC) intended for the measurement and potential utilization of the second and higher order harmonic frequencies from high-power traveling wave tube amplifiers (TWTAs) has been successfully designed, fabricated, and tested. The design is based on the characteristic multiple propagation modes of the electrical and magnetic field components of electromagnetic waves in a rectangular waveguide. The purpose was to create a rugged, easily constructed, more efficient waveguide- based MDC for extraction and exploitation of the second harmonic signal from the RF output of high-power TWTs used for space communications. The application would be a satellitebased beacon source needed for Qband and V/W-band atmospheric propagation studies. The MDC could function as a CW narrow-band source or as a wideband source for study of atmospheric group delay effects on highdata- rate links. The MDC is fabricated from two sections of waveguide - a primary one for the fundamental frequency and a secondary waveguide for the second harmonic - that are joined together such that the second harmonic higher order modes are selectively coupled via precision- machined slots for propagation in the secondary waveguide. In the TWTA output waveguide port, both the fundamental and the second harmonic signals are present. These signals propagate in the output waveguide as the dominant and higher order modes, respectively. By including an appropriate mode selective waveguide directional coupler, such as the MDC presented here at the output of the TWTA, the power at the second harmonic can be sampled and amplified to the power level needed for atmospheric propagation studies. The important conclusions from the preliminary test results for the multimode directional coupler are: (1) the second harmonic (Ka-band) can be measured and effectively separated from the fundamental (Ku-band) with no coupling of the latter, (2) power losses in the fundamental frequency are negligible, and (3) the power level of the extracted second harmonic is sufficient for further amplification to power levels needed for practical applications. It was also demonstrated that third order and potentially higher order harmonics are measurable with this device. The design is frequency agnostic, and with the appropriate choice of waveguides, is easily scaled to higher frequency TWTs. The MDC has the same function but with a number of important advantages over the conventional diplexer.

The wave-tide-river delta classification revisited: Introducing the effects of Humans on delta equilibriu

NASA Astrophysics Data System (ADS)

Besset, M.; Anthony, E.; Sabatier, F.

2016-12-01

The influence of physical processes on river deltas has long been identified, mainly on the basis of delta morphology. A cuspate delta is considered as wave-dominated, a delta with finger-like extensions is characterized as river-dominated, and a delta with estuarine re-entrants is considered tide-dominated (Galloway, 1975). The need for a more quantitative classification is increasingly recognized, and is achievable through quantified combinations, a good example being Syvitski and Saito (2007) wherein the joint influence of marine power - wave and tides - is compared to that of river influence. This need is further justified as deltas become more and more vulnerable. Going forward from the Syvitski and Saito (2007) approach, we confront, from a large database on 60 river deltas, the maximum potential power of waves and the tidal range (both representing marine power), and the specific stream power and river sediment supply reflecting an increasingly human-impacted river influence. The results show that 45 deltas (75%) have levels of marine power that are significantly higher than those of specific stream power. Five deltas have sufficient stream power to counterbalance marine power but a present sediment supply inadequate for them to be statistically considered as river-dominated. Six others have a sufficient sediment supply but a specific stream power that is not high enough for them to be statistically river-dominated. A major manifestation of the interplay of these parameters is accelerated delta erosion worldwide, shifting the balance towards marine power domination. Deltas currently eroding are mainly influenced by marine power (93%), and small deltas (< 300 km2 of deltaic protuberance) are the most vulnerable (82%). These high levels of erosion domination, compounded by accelerated subsidence, are related to human-induced sediment supply depletion and changes in water discharge in the face of the sediment-dispersive capacity of waves and currents.

Non-Strategic Nuclear Targeting in a Non-Nuclear Army

DTIC Science & Technology

1994-06-03

their needs. After all, the nucler planners and target analysts at corps level must surely consider their preparedness an important issue. Also...controlled escalation (the nuclear signal) and its ability to apply nuclear power in a decisive manner. A hedge against the emergence of an overwhelming...manuals envision NSNF as powerful yet flexible alternatives to the more destabilizing strategic nuclear weapons. NSNF could be used as a show of

Daily Peak Load Forecasting of Next Day using Weather Distribution and Comparison Value of Each Nearby Date Data

NASA Astrophysics Data System (ADS)

Ito, Shigenobu; Yukita, Kazuto; Goto, Yasuyuki; Ichiyanagi, Katsuhiro; Nakano, Hiroyuki

By the development of industry, in recent years; dependence to electric energy is growing year by year. Therefore, reliable electric power supply is in need. However, to stock a huge amount of electric energy is very difficult. Also, there is a necessity to keep balance between the demand and supply, which changes hour after hour. Consequently, to supply the high quality and highly dependable electric power supply, economically, and with high efficiency, there is a need to forecast the movement of the electric power demand carefully in advance. And using that forecast as the source, supply and demand management plan should be made. Thus load forecasting is said to be an important job among demand investment of electric power companies. So far, forecasting method using Fuzzy logic, Neural Net Work, Regression model has been suggested for the development of forecasting accuracy. Those forecasting accuracy is in a high level. But to invest electric power in higher accuracy more economically, a new forecasting method with higher accuracy is needed. In this paper, to develop the forecasting accuracy of the former methods, the daily peak load forecasting method using the weather distribution of highest and lowest temperatures, and comparison value of each nearby date data is suggested.

AMTEC: High efficiency static conversion for space power

NASA Technical Reports Server (NTRS)

Bankston, C. P.; Shirbacheh, M.

1986-01-01

Future manned and unmanned space missions will require reliable, high efficiency energy conversion systems. For a manned Mars mission, power levels in the range of 10 to 100 kWe will be needed. The Alkali Metal Thermoelectric Converter (AMTEC) is a direct energy conversion technology with the potential to meet these needs. The AMTEC is a thermally regenerative electrochemical device that derives its operation from the sodium ion conducting properties of beta-alumina solid electrolyte (BASE). To date, an efficiency of 19%, area power density of 1 W/sq cm, and a lifetime of 10,000 hours at high temperature were demonstrated in laboratory devices. Systems studies show that projected AMTEC systems equal or surpass the performance of other static or dynamic systems in applications of 1 kWe-1 MWe. Thus, the laboratory experiments and applications studies conducted to date have shown that the AMTEC posseses great potential. In order to bring this technology to the stage where prototype units can be built and operated, several technical issues must be addressed. These include the need for long life, high power electrodes, minimization of radiative parasitic losses, and high temperature seals. In summary, the evidence shows that if AMTEC is developed, it can play a significant role in future space power applications.

Evaluating gaze-driven power wheelchair with navigation support for persons with disabilities.

PubMed

Wästlund, Erik; Sponseller, Kay; Pettersson, Ola; Bared, Anders

2015-01-01

This article describes a novel add-on for powered wheelchairs that is composed of a gaze-driven control system and a navigation support system. The add-on was tested by three users. All of the users were individuals with severe disabilities and no possibility of moving independently. The system is an add-on to a standard power wheelchair and can be customized for different levels of support according to the cognitive level, motor control, perceptual skills, and specific needs of the user. The primary aim of this study was to test the functionality and safety of the system in the user's home environment. The secondary aim was to evaluate whether access to a gaze-driven powered wheelchair with navigation support is perceived as meaningful in terms of independence and participation. The results show that the system has the potential to provide safe, independent indoor mobility and that the users perceive doing so as fun, meaningful, and a way to reduce dependency on others. Independent mobility has numerous benefits in addition to psychological and emotional well-being. By observing users' actions, caregivers and healthcare professionals can assess the individual's capabilities, which was not previously possible. Rehabilitation can be better adapted to the individual's specific needs, and driving a wheelchair independently can be a valuable, motivating training tool.

Power Grid Maintenance Scheduling Intelligence Arrangement Supporting System Based on Power Flow Forecasting

NASA Astrophysics Data System (ADS)

Xie, Chang; Wen, Jing; Liu, Wenying; Wang, Jiaming

With the development of intelligent dispatching, the intelligence level of network control center full-service urgent need to raise. As an important daily work of network control center, the application of maintenance scheduling intelligent arrangement to achieve high-quality and safety operation of power grid is very important. By analyzing the shortages of the traditional maintenance scheduling software, this paper designs a power grid maintenance scheduling intelligence arrangement supporting system based on power flow forecasting, which uses the advanced technologies in maintenance scheduling, such as artificial intelligence, online security checking, intelligent visualization techniques. It implements the online security checking of maintenance scheduling based on power flow forecasting and power flow adjusting based on visualization, in order to make the maintenance scheduling arrangement moreintelligent and visual.

Grey Comprehensive Evaluation of Biomass Power Generation Project Based on Group Judgement

NASA Astrophysics Data System (ADS)

Xia, Huicong; Niu, Dongxiao

2017-06-01

The comprehensive evaluation of benefit is an important task needed to be carried out at all stages of biomass power generation projects. This paper proposed an improved grey comprehensive evaluation method based on triangle whiten function. To improve the objectivity of weight calculation result of only reference comparison judgment method, this paper introduced group judgment to the weighting process. In the process of grey comprehensive evaluation, this paper invited a number of experts to estimate the benefit level of projects, and optimized the basic estimations based on the minimum variance principle to improve the accuracy of evaluation result. Taking a biomass power generation project as an example, the grey comprehensive evaluation result showed that the benefit level of this project was good. This example demonstrates the feasibility of grey comprehensive evaluation method based on group judgment for benefit evaluation of biomass power generation project.

Small solar thermal electric power plants with early commercial potential

NASA Technical Reports Server (NTRS)

Jones, H. E.; Bisantz, D. J.; Clayton, R. N.; Heiges, H. H.; Ku, A. C.

1979-01-01

Cost-effective small solar thermal electric power plants (1- to 10-MW nominal size) offer an attractive way of helping the world meet its future energy needs. The paper describes the characteristics of a conceptual near-term plant (about 1 MW) and a potential 1990 commercial version. The basic system concept is one in which steam is generated using two-axis tracking, parabolic dish, and point-focusing collectors. The steam is transported through low-loss piping to a central steam turbine generator unit where it is converted to electricity. The plants have no energy storage and their output power level varies with the solar insolation level. This system concept, which is firmly based on state-of-the-art technology, is projected to offer one of the fastest paths for U.S. commercialization of solar thermal electric power plants through moderate technology advances and mass production.

Can hybrid solar-fossil power plants mitigate CO2 at lower cost than PV or CSP?

PubMed

Moore, Jared; Apt, Jay

2013-03-19

Fifteen of the United States and several nations require a portion of their electricity come from solar energy. We perform an engineering-economic analysis of hybridizing concentrating solar thermal power with fossil fuel in an Integrated Solar Combined Cycle (ISCC) generator. We construct a thermodynamic model of an ISCC plant in order to examine how much solar and fossil electricity is produced and how such a power plant would operate, given hourly solar resource data and hourly electricity prices. We find that the solar portion of an ISCC power plant has a lower levelized cost of electricity than stand-alone solar power plants given strong solar resource in the US southwest and market conditions that allow the capacity factor of the solar portion of the power plant to be above 21%. From a local government perspective, current federal subsidies distort the levelized cost of electricity such that photovoltaic electricity is slightly less expensive than the solar electricity produced by the ISCC. However, if the cost of variability and additional transmission lines needed for stand-alone solar power plants are taken into account, the solar portion of an ISCC power plant may be more cost-effective.

Remotely Powered Reconfigurable Receiver for Extreme Environment Sensing Platforms

NASA Technical Reports Server (NTRS)

Sheldon, Douglas J.

2012-01-01

Wireless sensors connected in a local network offer revolutionary exploration capabilities, but the current solutions do not work in extreme environments of low temperatures (200K) and low to moderate radiation levels (<50 krad). These sensors (temperature, radiation, infrared, etc.) would need to operate outside the spacecraft/ lander and be totally independent of power from the spacecraft/lander. Flash memory field-programmable gate arrays (FPGAs) are being used as the main signal processing and protocol generation platform in a new receiver. Flash-based FPGAs have been shown to have at least 100 reduced standby power and 10 reduction operating power when compared to normal SRAM-based FPGA technology.

Deep Space Systems Technology Program Future Deliveries

NASA Technical Reports Server (NTRS)

Salvo, Christopher G.; Keuneke, Matthew S.

2000-01-01

NASA is in a period of frequent launches of low cost deep space missions with challenging performance needs. The modest budgets of these missions make it impossible for each to develop its own technology, therefore, efficient and effective development and insertion of technology for these missions must be approached at a higher level than has been done in the past. The Deep Space Systems Technology Program (DSST), often referred to as X2000, has been formed to address this need. The program is divided into a series of "Deliveries" that develop and demonstrate a set of spacecraft system capabilities with broad applicability for use by multiple missions. The First Delivery Project, to be completed in 2001, will provide a one MRAD-tolerant flight computer, power switching electronics, efficient radioisotope power source, and a transponder with services at 8.4 GHz and 32 GHz bands. Plans call for a Second Delivery in late 2003 to enable complete deep space systems in the 10 to 50 kg class, and a Third Delivery built around Systems on a Chip (extreme levels of electronic and microsystems integration) around 2006. Formulation of Future Deliveries (past the First Delivery) is ongoing and includes plans for such developments as highly miniaturized digital/analog/power electronics, optical communications, multifunctional structures, miniature lightweight propulsion, advanced thermal control techniques, highly efficient radioisotope power sources, and a unified flight ground software architecture to support the needs of future highly intelligent space systems. All developments are targeted at broad applicability and reuse, and will be commercialized within the US.

Differential effects of power rehabilitation on physical performance and higher-level functional capacity among community-dwelling older adults with a slight degree of frailty.

PubMed

Ota, Atsuhiko; Yasuda, Nobufumi; Horikawa, Shunichi; Fujimura, Takashi; Ohara, Hiroshi

2007-03-01

Evidence is still insufficient regarding the effects of Power Rehabilitation (PR) on physical performance and higher-level functional capacity of community-dwelling frail elderly people. This nonrandomized controlled interventional trial consisted of 46 community-dwelling elderly individuals with light levels of long-term care needs. They were allocated to the intervention (I-group, n = 24) and control (C-group, n = 22) groups. Of them, 32 persons (17 in the I-group; 15 in the C-group) (median age, 77 years; sex, 28% male) completed the study. The I-group subjects underwent PR twice a week for 12 weeks. The outcomes were physical performance (muscle strength, balance, flexibility, and mobility) and higher-level functional capacity as evaluated by the Tokyo Metropolitan Institute of Gerontology Index of Competence (TMIG-IC) and the level of long-term care need as certified by the public long-term care insurance. The I-group demonstrated a significant improvement in the measured value of the timed up-and-go test (median change, a decrease of 4.4 seconds versus a decrease of 0.2 seconds, p = 0.033) and the timed 10-meter walk (a decrease of 3.0 seconds versus an increase of 0.2 seconds, p = 0.007) in comparison with the C-group. No significant change was observed in the TMIG-IC scores or in the level of long-term care need in the I-group. PR improved mobility of community-dwelling frail elderly people; however, such improvement did not translate into higher-level functional capacity. Our findings demonstrate the difficulty in transferring the positive effects associated with PR into an improvement in higher-level functional capacity.

Pulsed Energy Systems for Generating Plasmas

NASA Technical Reports Server (NTRS)

Rose, M. Franklin; Shotts, Z.

2005-01-01

This paper will describe the techniques needed to electrically generate highly ionized dense plasmas for a variety of applications. The components needed in pulsed circuits are described in terms of general performance parameters currently available from commercial vendors. Examples of pulsed systems using these components are described and technical data from laboratory experiments presented. Experimental data are given for point designs, capable of multi-megawatt power levels.

The Impact of Project GLAD on Students' Literacy and Science Learning: Year 1 Results from a Cluster-Randomized Trial of Sheltered Instruction

ERIC Educational Resources Information Center

Deussen, Theresa; Autio, Elizabeth; Roccograndi, Angela; Hanita, Makoto

2014-01-01

With the increased population of English learners (ELs), educators need programs that help students access academic content while learning to understand, speak, read, and write English (Tharp, Estrada, Dalteen, & Yamaguchi 2000; Echevarria, Short & Powers, 2006). ELs come into U.S. schools needing to learn the same grade-level content as…

Assessment of Space Power Related Measurement Requirements of the Strategic Defense Initiative

DTIC Science & Technology

1989-04-01

calibration techniques are available and estimated uncertainties vary between 5 and 10%. At low rf power levels (~ 10mW ), NIST maintains standard calibration... bands single or dual six-port automatic network analyzers [24] are used as transfer systems with detectors calibrated using the NIST micro calorimeter...Probable designs for the multimegawatt space reactor program indicate the need to measure neutron fluxes up to 1016 neutrons/cm2- s (1019 neutrons

Injected Water Augments Cooling In Turboshaft Engine

NASA Technical Reports Server (NTRS)

Biesiadny, Thomas J.; Berger, Brett; Klann, Gary A.; Clark, David A.

1989-01-01

Report describes experiments in which water injected into compressor-bleed cooling air of aircraft turboshaft engine. Injection of water previously suggested as way to provide additional cooling needed to sustain operation at power levels higher than usual. Involves turbine-inlet temperatures high enough to shorten lives of first-stage high-pressure turbine blades. Latent heat of vaporization of injected water serves as additional heat sink to maintain blades at design operating temperatures during high-power operation.

Multiple high-intensity focused ultrasound probes for kidney-tissue ablation.

PubMed

Häcker, Axel; Chauhan, Sunita; Peters, Kristina; Hildenbrand, Ralf; Marlinghaus, Ernst; Alken, Peter; Michel, Maurice Stephan

2005-10-01

To investigate kidney-tissue ablation by high-intensity focused ultrasound (HIFU) using multiple and single probes. Ultrasound beams (1.75 MHz) produced by a piezoceramic element (focal distance 80 mm) were focused at the center of renal parenchyma. One of the three probes (mounted on a jig) could also be used for comparison with a single probe at comparable power ratings. Lesion dimensions were examined in perfused and unperfused ex vivo porcine kidneys at different power levels (40, 60, and 80 W) and treatment times (4, 6, and 8 seconds). At identical power levels, the lesions induced by multiple probes were larger than those induced by a single probe. Lesion size increased with increasing pulse duration and generator power. The sizes and shapes of the lesions were predictably repeatable in all samples. Lesions in perfused kidneys were smaller than those in unperfused kidneys. Ex vivo, kidney-tissue ablation by means of multiple HIFU probes offers significant advantages over single HIFU probes in respect of lesion size and formation. These advantages need to be confirmed by tests in vivo at higher energy levels.

Closed Brayton Cycle Power Conversion Unit for Fission Surface Power Phase I Final Report

NASA Technical Reports Server (NTRS)

Fuller, Robert L.

2010-01-01

A Closed Brayton cycle power conversion system has been developed to support the NASA fission surface power program. The goal is to provide electricity from a small nuclear reactor heat source for surface power production for lunar and Mars environments. The selected media for a heat source is NaK 78 with water as a cooling source. The closed Brayton cycle power was selected to be 12 kWe output from the generator terminals. A heat source NaK temperature of 850 K plus or minus 25 K was selected. The cold source water was selected at 375 K plus or minus 25 K. A vacuum radiation environment of 200 K is specified for environmental operation. The major components of the system are the power converter, the power controller, and the top level data acquisition and control unit. The power converter with associated sensors resides in the vacuum radiation environment. The power controller and data acquisition system reside in an ambient laboratory environment. Signals and power are supplied across the pressure boundary electrically with hermetic connectors installed on the vacuum vessel. System level analyses were performed on working fluids, cycle design parameters, heater and cooling temperatures, and heat exchanger options that best meet the needs of the power converter specification. The goal is to provide a cost effective system that has high thermal-to-electric efficiency in a compact, lightweight package.

Scientific Challenges in Sustainable Energy Technology

NASA Astrophysics Data System (ADS)

Lewis, Nathan

2006-03-01

This presentation will describe and evaluate the challenges, both technical, political, and economic, involved with widespread adoption of renewable energy technologies. First, we estimate the available fossil fuel resources and reserves based on data from the World Energy Assessment and World Energy Council. In conjunction with the current and projected global primary power production rates, we then estimate the remaining years of supply of oil, gas, and coal for use in primary power production. We then compare the price per unit of energy of these sources to those of renewable energy technologies (wind, solar thermal, solar electric, biomass, hydroelectric, and geothermal) to evaluate the degree to which supply/demand forces stimulate a transition to renewable energy technologies in the next 20-50 years. Secondly, we evaluate the greenhouse gas buildup limitations on carbon-based power consumption as an unpriced externality to fossil-fuel consumption, considering global population growth, increased global gross domestic product, and increased energy efficiency per unit of globally averaged GDP, as produced by the Intergovernmental Panel on Climate Change (IPCC). A greenhouse gas constraint on total carbon emissions, in conjunction with global population growth, is projected to drive the demand for carbon-free power well beyond that produced by conventional supply/demand pricing tradeoffs, at potentially daunting levels relative to current renewable energy demand levels. Thirdly, we evaluate the level and timescale of R&D investment that is needed to produce the required quantity of carbon-free power by the 2050 timeframe, to support the expected global energy demand for carbon-free power. Fourth, we evaluate the energy potential of various renewable energy resources to ascertain which resources are adequately available globally to support the projected global carbon-free energy demand requirements. Fifth, we evaluate the challenges to the chemical sciences to enable the cost-effective production of carbon-free power on the needed scale by the 2050 timeframe. Finally, we discuss the effects of a change in primary power technology on the energy supply infrastructure and discuss the impact of such a change on the modes of energy consumption by the energy consumer and additional demands on the chemical sciences to support such a transition in energy supply.

Parallel dispatch: a new paradigm of electrical power system dispatch

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

Zhang, Jun Jason; Wang, Fei-Yue; Wang, Qiang

Modern power systems are evolving into sociotechnical systems with massive complexity, whose real-time operation and dispatch go beyond human capability. Thus, the need for developing and applying new intelligent power system dispatch tools are of great practical significance. In this paper, we introduce the overall business model of power system dispatch, the top level design approach of an intelligent dispatch system, and the parallel intelligent technology with its dispatch applications. We expect that a new dispatch paradigm, namely the parallel dispatch, can be established by incorporating various intelligent technologies, especially the parallel intelligent technology, to enable secure operation of complexmore » power grids, extend system operators U+02BC capabilities, suggest optimal dispatch strategies, and to provide decision-making recommendations according to power system operational goals.« less

Foundational Report Series. Advanced Distribution management Systems for Grid Modernization (Importance of DMS for Distribution Grid Modernization)

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

Wang, Jianhui

2015-09-01

Grid modernization is transforming the operation and management of electric distribution systems from manual, paper-driven business processes to electronic, computer-assisted decisionmaking. At the center of this business transformation is the distribution management system (DMS), which provides a foundation from which optimal levels of performance can be achieved in an increasingly complex business and operating environment. Electric distribution utilities are facing many new challenges that are dramatically increasing the complexity of operating and managing the electric distribution system: growing customer expectations for service reliability and power quality, pressure to achieve better efficiency and utilization of existing distribution system assets, and reductionmore » of greenhouse gas emissions by accommodating high penetration levels of distributed generating resources powered by renewable energy sources (wind, solar, etc.). Recent “storm of the century” events in the northeastern United States and the lengthy power outages and customer hardships that followed have greatly elevated the need to make power delivery systems more resilient to major storm events and to provide a more effective electric utility response during such regional power grid emergencies. Despite these newly emerging challenges for electric distribution system operators, only a small percentage of electric utilities have actually implemented a DMS. This paper discusses reasons why a DMS is needed and why the DMS may emerge as a mission-critical system that will soon be considered essential as electric utilities roll out their grid modernization strategies.« less

Suitability of representative electrochemical energy storage technologies for ramp-rate control of photovoltaic power

NASA Astrophysics Data System (ADS)

Jiang, Yu; Fletcher, John; Burr, Patrick; Hall, Charles; Zheng, Bowen; Wang, Da-Wei; Ouyang, Zi; Lennon, Alison

2018-04-01

Photovoltaic (PV) systems can exhibit rapid variances in their power output due to irradiance changes which can destabilise an electricity grid. This paper presents a quantitative comparison of the suitability of different electrochemical energy storage system (ESS) technologies to provide ramp-rate control of power in PV systems. Our investigations show that, for PV systems ranging from residential rooftop systems to megawatt power systems, lithium-ion batteries with high energy densities (up to 600 Wh L-1) require the smallest power-normalised volumes to achieve the ramp rate limit of 10% min-1 with 100% compliance. As the system size increases, the ESS power-normalised volume requirements are significantly reduced due to aggregated power smoothing, with high power lithium-ion batteries becoming increasingly more favourable with increased PV system size. The possibility of module-level ramp-rate control is also introduced, and results show that achievement of a ramp rate of 10% min-1 with 100% compliance with typical junction box sizes will require ESS energy and power densities of 400 Wh L-1 and 2300 W L-1, respectively. While module-level ramp-rate control can reduce the impact of solar intermittence, the requirement is challenging, especially given the need for low cost and long cycle life.

Blood-Brain Barrier Disruption Caused by Ultrasound Bursts Combined with Microbubbles Depends on Anesthesia

NASA Astrophysics Data System (ADS)

McDannold, Nathan; Zhang, Yongzhi; Vykhodtseva, Natalia

2011-09-01

Prior works on BBB disruption via inter-arterial infusions of osmotic agents have shown a strong dependence on anesthesia. Here, we investigated whether different anesthesia agents can affect ultrasound-induced BBB disruption. A piston transducer fired through a rubber aperture (frequency: 532 kHz, diameter: 4 cm, aperture diameter: 16 mm) was used to generate the ultrasound fields, and sonications combined with an ultrasound contrast agent were performed at 5 power levels. BBB disruption was quantified by measuring the MRI contrast enhancement in T1-weighted MRI, and erythrocyte extravasation characterized in light microscopy. For each exposure level tested, experiments performed with ketamine/xylazine resulted in significantly greater (P<0.05) enhancement than with isoflurane/oxygen. The onset of severe red blood cell extravasation occurred at lower power levels with ketamine/xylazine. These results suggest ultrasound-induced BBB disruption can depend on anesthesia agent, possibly due effects on the vasculature. These results suggest that care is needed in comparing experiments with different anesthesia agents and physiological factors need to be considered with ultrasound-induced BBB disruption.

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

Chung, Ching-Yen; Youn, Edward; Chynoweth, Joshua

As Electric Vehicles (EVs) increase, charging infrastructure becomes more important. When during the day there is a power shortage, the charging infrastructure should have the options to either shut off the power to the charging stations or to lower the power to the EVs in order to satisfy the needs of the grid. This paper proposes a design for a smart charging infrastructure capable of providing power to several EVs from one circuit by multiplexing power and providing charge control and safety systems to prevent electric shock. The safety design is implemented in different levels that include both the servermore » and the smart charging stations. With this smart charging infrastructure, the shortage of energy in a local grid could be solved by our EV charging management system.« less

Solar Electric Propulsion for Future NASA Missions

NASA Technical Reports Server (NTRS)

Landis, Geoffrey A.; Oleson, Steven R.; Mercer, Carolyn R.

2015-01-01

Use of high-power solar arrays, at power levels ranging from approximately 500 KW to several megawatts, has been proposed for a solar-electric propulsion (SEP) demonstration mission, using a photovoltaic array to provide energy to a high-power xenon-fueled engine. One of the proposed applications of the high-power SEP technology is a mission to rendezvous with an asteroid and move it into lunar orbit for human exploration, the Asteroid Retrieval mission. The Solar Electric Propulsion project is dedicated to developing critical technologies to enable trips to further away destinations such as Mars or asteroids. NASA needs to reduce the cost of these ambitious exploration missions. High power and high efficiency SEP systems will require much less propellant to meet those requirements.

Electromagnetic interference of power conditioners for solar electric propulsion

NASA Technical Reports Server (NTRS)

Whittlesey, A. C.; Macie, T. W.

1973-01-01

Electrical, multikilowatt power conditioning (PC) equipment needed on board a spacecraft utilizing solar electric propulsion creates an electromagnetic environment that is potentially deterimental to the science, navigation, and radio communication hardware. Within the scope of the solar electric propulsion system technology program, three lightweight, 2.5-kW PCs were evaluated in terms of their electromagnetic characteristics. It was found that the levels of radiated and conducted interference exceeded the levels anticipated for a solar electric propulsion mission. These noise emissions, however, were the result of deficient interference design in these models, rather than a basic inability to control interference in this type of PC.

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

Adult mental health needs and expenditure in Australia.

PubMed

Burgess, Philip; Pirkis, Jane; Buckingham, Bill; Burns, Jane; Eagar, Kathy; Eckstein, Gary

2004-06-01

Relatively little international work has examined whether mental health resource allocation matches need. This study aimed to determine whether adult mental health resources in Australia are being distributed equitably. Individual measures of need were extrapolated to Australian Areas, and Area-based proxies of need were considered. Particular attention was paid to the prevalence of mental health problems, since this is arguably the most objective measure of need. The extent to which these measures predicted public sector, private sector and total adult mental health expenditure at an Area level was examined. In the public sector, 41.6% of expenditure variation was explained by the prevalence of affective disorders, personality disorders, cognitive impairment and psychosis, as well as the Area's level of economic resources and State/Territory effects. In the private sector, 72.4% of expenditure variation was explained by service use and State/Territory effects (with an alternative model incorporating service use and State/Territory supply of private psychiatrists explaining 69.4% of expenditure variation). A relatively high proportion (58.7%) of total expenditure variation could be explained by service utilisation and State/Territory effects. For services to be delivered equitably, the majority of variation in expenditure would have to be accounted for by appropriate measures of need. The best model for public sector expenditure included an appropriate measure of need but had relatively poor explanatory power. The models for private sector and total expenditure had greater explanatory power, but relied on less appropriate measures of need. It is concluded that mental health services in Australia are not yet being delivered equitably.

Balancing autonomy and utilization of solar power and battery storage for demand based microgrids

NASA Astrophysics Data System (ADS)

Lawder, Matthew T.; Viswanathan, Vilayanur; Subramanian, Venkat R.

2015-04-01

The growth of intermittent solar power has developed a need for energy storage systems in order to decouple generation and supply of energy. Microgrid (MG) systems comprising of solar arrays with battery energy storage studied in this paper desire high levels of autonomy, seeking to meet desired demand at all times. Large energy storage capacity is required for high levels of autonomy, but much of this expensive capacity goes unused for a majority of the year due to seasonal fluctuations of solar generation. In this paper, a model-based study of MGs comprised of solar generation and battery storage shows the relationship between system autonomy and battery utilization applied to multiple demand cases using a single particle battery model (SPM). The SPM allows for more accurate state-of-charge and utilization estimation of the battery than previous studies of renewably powered systems that have used empirical models. The increased accuracy of battery state estimation produces a better assessment of system performance. Battery utilization will depend on the amount of variation in solar insolation as well as the type of demand required by the MG. Consumers must balance autonomy and desired battery utilization of a system within the needs of their grid.

OAST Space Theme Workshop. Volume 2: Theme summary. 1: Space power (no. 7). A. Theme statement. B. 26 April 1976 presentation. C. Summary. D. Initiative action

NASA Technical Reports Server (NTRS)

1976-01-01

A long-lived space-based system that converts on-orbit solar and/or nuclear energy to a suitable form for distribution to using space systems is described. Mission applications, requirements, issues, problems, benefits, and technology thrusts are identified for the multipurpose power platform. Power levels of at least 10-100Kw are required for space manufacturing, satellites, and space station operations. Two Mw are needed for a proposed passive radar system. Propulsion system requirements are in the 100Kw-100Mw range.

Thin-Film Magnetic-Field-Response Fluid-Level Sensor for Non-Viscous Fluids

NASA Technical Reports Server (NTRS)

Woodard, Stanley E.; Shams, Qamar A.; Fox, Robert L.; Taylor, Bryant D.

2008-01-01

An innovative method has been developed for acquiring fluid-level measurements. This method eliminates the need for the fluid-level sensor to have a physical connection to a power source or to data acquisition equipment. The complete system consists of a lightweight, thin-film magnetic-field-response fluid-level sensor (see Figure 1) and a magnetic field response recorder that was described in Magnetic-Field-Response Measurement-Acquisition System (LAR-16908-1), NASA Tech Briefs, Vol. 30, No. 6 (June 2006), page 28. The sensor circuit is a capacitor connected to an inductor. The response recorder powers the sensor using a series of oscillating magnetic fields. Once electrically active, the sensor responds with its own harmonic magnetic field. The sensor will oscillate at its resonant electrical frequency, which is dependent upon the capacitance and inductance values of the circuit.

Marsh birds and the North American Breeding Bird Survey: judging the value of a landscape level survey for habitat specialist species with low detection rates

USGS Publications Warehouse

Sauer, J.R.

1999-01-01

The North American Breeding Bird Survey was started in 1966, and provides information on population change for >400 species of birds. it covers the continental United States, Canada, and Alaska, and is conducted once each year, in June, by volunteer observers. A 39.4 kIn roadside survey route is driven starting 30 min before sunrise, and a 3 min point count is conducted at each of 50 stops spaced every 0.8 kIn. Existing analyses of the data are internet-based (http://www.mbr-pwrc.usgs.govlbbslbbs.html), and include maps of relative abundance, estimates of population change including trends (%/yr), composite annual indices (pattern in time), and maps of population trend (pattern in space). At least 36 species of marsh birds are encountered on the BBS, and the survey provides estimates with greatly varying levels of efficiency for the species. It is often difficult to understand how well the BBS surveys a species. Often, efficiency is judged by estimating trend and its variance for a species, then by calculating power and needed samples to detect a prespecified trend over some time period (e.g., a 2%/yr trend over 31 yr). Unfortunately, this approach is not always valid, as estimated trends and variances can be of little use if the population is poorly sampled. Lurking concerns with BBS data include (1) incomplete coverage of species range; (2) undersampling of habitats; and (3) low and variable visibility of birds during point counts. It is difficult to evaluate these concerns, because known populations do not exist for comparison with counts, and detection rates are time-consuming and costly to estimate. I evaluated the efficiency of the BBS for selected rails (Rallidae) and snipes (Scolopacidae), presenting estimates of population trend over 1966-1996 (T), power to detect 2%/yr trend over 31 yr, needed samples to achieve power of 0.75 with alpha= 0.1, number of survey routes with data for the species (N), average abundance on survey routes (RA), and maps of relative abundance. Examples include Yellow Rail (Coturnicops noveboracensis) (T=12 %/yr; P= 0.0085; N =28; routes; RA=0.05; Power=0.37; Needed samples=85), Black Rail (Laterallus jamaicensis) (No trend data or power information available, N =8), Clapper Rail (Rallus longirostris) (T=1.9%/yr; P=0.55; N =64; RA=0.31; Power=0.35; Needed samples=590), King Rail (Rallus elegans) (T=-4.2 %/yr; P= 0.03; N =76; Power=0.41; Needed samples=159), Sora (Porzana carolina) (T=0.98 %/yr; P= 0.24; N =720; RA= 0.92; Power=0.69; Needed samples= 377), and Common Snipe (Gallinago gallinago) (T=-0.24 %/yr; P= 0.54; N =1412; RA= 2.19; Power=0.98; Needed samples=205). With regard to quality of BBS data, marsh birds fall into 3 categories: (1) almost never encountered on BBS routes; (2) encountered at extremely low abundances on BBS routes; and (3) probably fairly well sampled by BBS roadside counts. BBS data can provide useful information for many marsh bird species, but users should be aware of the limitations of the BBS sample for monitoring species that have low visibility from point counts and prefer habitats not often encountered on roadsides.

Wind power error estimation in resource assessments.

PubMed

Rodríguez, Osvaldo; Del Río, Jesús A; Jaramillo, Oscar A; Martínez, Manuel

2015-01-01

Estimating the power output is one of the elements that determine the techno-economic feasibility of a renewable project. At present, there is a need to develop reliable methods that achieve this goal, thereby contributing to wind power penetration. In this study, we propose a method for wind power error estimation based on the wind speed measurement error, probability density function, and wind turbine power curves. This method uses the actual wind speed data without prior statistical treatment based on 28 wind turbine power curves, which were fitted by Lagrange's method, to calculate the estimate wind power output and the corresponding error propagation. We found that wind speed percentage errors of 10% were propagated into the power output estimates, thereby yielding an error of 5%. The proposed error propagation complements the traditional power resource assessments. The wind power estimation error also allows us to estimate intervals for the power production leveled cost or the investment time return. The implementation of this method increases the reliability of techno-economic resource assessment studies.

Wind Power Error Estimation in Resource Assessments

PubMed Central

Rodríguez, Osvaldo; del Río, Jesús A.; Jaramillo, Oscar A.; Martínez, Manuel

2015-01-01

Estimating the power output is one of the elements that determine the techno-economic feasibility of a renewable project. At present, there is a need to develop reliable methods that achieve this goal, thereby contributing to wind power penetration. In this study, we propose a method for wind power error estimation based on the wind speed measurement error, probability density function, and wind turbine power curves. This method uses the actual wind speed data without prior statistical treatment based on 28 wind turbine power curves, which were fitted by Lagrange's method, to calculate the estimate wind power output and the corresponding error propagation. We found that wind speed percentage errors of 10% were propagated into the power output estimates, thereby yielding an error of 5%. The proposed error propagation complements the traditional power resource assessments. The wind power estimation error also allows us to estimate intervals for the power production leveled cost or the investment time return. The implementation of this method increases the reliability of techno-economic resource assessment studies. PMID:26000444

A comprehensive approach to reactive power scheduling in restructured power systems

NASA Astrophysics Data System (ADS)

Shukla, Meera

Financial constraints, regulatory pressure, and need for more economical power transfers have increased the loading of interconnected transmission systems. As a consequence, power systems have been operated close to their maximum power transfer capability limits, making the system more vulnerable to voltage instability events. The problem of voltage collapse characterized by a severe local voltage depression is generally believed to be associated with inadequate VAr support at key buses. The goal of reactive power planning is to maintain a high level of voltage security, through installation of properly sized and located reactive sources and their optimal scheduling. In case of vertically-operated power systems, the reactive requirement of the system is normally satisfied by using all of its reactive sources. But in case of different scenarios of restructured power systems, one may consider a fixed amount of exchange of reactive power through tie lines. Reviewed literature suggests a need for optimal scheduling of reactive power generation for fixed inter area reactive power exchange. The present work proposed a novel approach for reactive power source placement and a novel approach for its scheduling. The VAr source placement technique was based on the property of system connectivity. This is followed by development of optimal reactive power dispatch formulation which facilitated fixed inter area tie line reactive power exchange. This formulation used a Line Flow-Based (LFB) model of power flow analysis. The formulation determined the generation schedule for fixed inter area tie line reactive power exchange. Different operating scenarios were studied to analyze the impact of VAr management approach for vertically operated and restructured power systems. The system loadability, losses, generation and the cost of generation were the performance measures to study the impact of VAr management strategy. The novel approach was demonstrated on IEEE 30 bus system.

Strengthening stakeholder involvement in health workforce governance: why we need to talk about power.

PubMed

Kuhlmann, Ellen; Burau, Viola

2018-01-01

There is now widespread agreement on the benefits of an integrated, people-centred health workforce, but the implementation of new models is difficult. We argue that we need to think about stakeholders and power, if we want to ensure change in the health workforce. We discuss these issues from a governance perspective and suggest a critical approach to stakeholder involvement as an indicator of good governance. Three models of involving stakeholders in health workforce governance can be identified: corporatist professional involvement either in a continental European model of conservative corporatism or in a Nordic model of public corporatism; managerialist and market-centred involvement of professions as organizational agents; and a more inclusive, network-based involvement of plural professional experts at different levels of governance. The power relations embedded in these models of stakeholder involvement have different effects on capacity building for an integrated health workforce.

State-level emergency preparedness and response capabilities.

PubMed

Watkins, Sharon M; Perrotta, Dennis M; Stanbury, Martha; Heumann, Michael; Anderson, Henry; Simms, Erin; Huang, Monica

2011-03-01

Prior assessments of public health readiness had identified gaps in radiation preparedness. In recent years, preparedness planning has involved an "all-hazards" approach. Current assessment of the national status related to radiation public health emergency preparedness capabilities at the state and local health department levels was needed. A survey of state health departments related to radiation readiness was undertaken in 2010 by the Council of State and Territorial Epidemiologists (CSTE). States with nuclear power plants were instructed to consider their responses exclusive of capabilities and resources related to the plants given that the emergency response plans for nuclear power plants are specific and unique. Thirty-eight (76%) state health departments responded to the survey, including 26 of the 31 states with nuclear power plants. Specific strengths noted at the state level included that the majority of states had a written radiation response plan and most plans include a detailed section for communications issues during a radiation emergency. In addition, more than half of the states indicated that their relationship with federal partners is sufficient to provide resources for radiation emergencies, indicating the importance states placed on federal resources and expertise. Specific weaknesses are discussed and include that most states had completed little to no planning for public health surveillance to assess potential human health impacts of a radiation event; less than half had written plans to address exposure assessment, environmental sampling, human specimen collection and analysis, and human health assessment. Few reported having sufficient resources to do public health surveillance, radiation exposure assessment, laboratory functions and other capabilities. Levels of planning, resources and partnerships varied among states, those with nuclear power plants were better prepared. Gaps were evident in all states; however and additional training and resources are needed to ensure adequate levels of preparedness. Overall results of this assessment indicate that in most measures of public health capacity and capability, states are poorly prepared to adequately respond to a major radiation emergency event. Specific recommendations are noted in the discussion.

Diode Pumped Alkaline Laser System: A High Powered, Low SWaP Directed Energy Option for Ballistic Missile Defense High-Level Summary - April 2017

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

Wisoff, P. J.

The Diode-Pumped Alkali Laser (DPAL) system is an R&D effort funded by the Missile Defense Agency (MDA) underway at Lawrence Livermore National Laboratory (LLNL). MDA has described the characteristics needed for a Boost Phase directed energy (DE) weapon to work against ICBM-class threat missiles. In terms of the platform, the mission will require a high altitude Unmanned Aerial Vehicle (UAV) that can fly in the “quiet” stratosphere and display long endurance – i.e., days on station. In terms of the laser, MDA needs a high power, low size and weight laser that could be carried by such a platform andmore » deliver lethal energy to an ICBM-class threat missile from hundreds of kilometers away. While both the military and industry are pursuing Directed Energy for tactical applications, MDA’s objectives pose a significantly greater challenge than other current efforts in terms of the power needed from the laser, the low size and weight required, and the range, speed, and size of the threat missiles. To that end, MDA is funding two R&D efforts to assess the feasibility of a high power (MWclass) and low SWaP (size, weight and power) laser: a fiber combining laser (FCL) project at MIT’s Lincoln Laboratory, and LLNL’s Diode-Pumped Alkali Laser (DPAL) system.« less

Development of self-powered wireless high temperature electrochemical sensor for in situ corrosion monitoring of coal-fired power plant.

PubMed

Aung, Naing Naing; Crowe, Edward; Liu, Xingbo

2015-03-01

Reliable wireless high temperature electrochemical sensor technology is needed to provide in situ corrosion information for optimal predictive maintenance to ensure a high level of operational effectiveness under the harsh conditions present in coal-fired power generation systems. This research highlights the effectiveness of our novel high temperature electrochemical sensor for in situ coal ash hot corrosion monitoring in combination with the application of wireless communication and an energy harvesting thermoelectric generator (TEG). This self-powered sensor demonstrates the successful wireless transmission of both corrosion potential and corrosion current signals to a simulated control room environment. Copyright © 2014 ISA. All rights reserved.

EMTP based stability analysis of space station electric power system in a test bed environment

NASA Technical Reports Server (NTRS)

Dravid, Narayan V.; Kacpura, Thomas J.; Oconnor, Andrew M.

1992-01-01

The Space Station Freedom Electric Power System (EPS) will convert solar energy into electric energy and distribute the same using an 'all dc', Power Management and Distribution (PMAD) System. Power conditioning devices (dc to dc converters) are needed to interconnect parts of this system operating at different nominal voltage levels. Operation of such devices could generate under damped oscillations (instability) under certain conditions. Criteria for instability are examined and verified for a single device. Suggested extension of the criteria to a system operation is examined by using the EMTP model of the PMAD DC test bed. Wherever possible, data from the test bed is compared with the modeling results.

EMTP based stability analysis of Space Station Electric Power System in a test bed environment

NASA Technical Reports Server (NTRS)

Dravid, Narayan V.; Kacpura, Thomas J.; O'Connor, Andrew M.

1992-01-01

The Space Station Freedom Electric Power System (EPS) will convert solar energy into electric energy and distribute the same using an 'all dc', Power Management and Distribution (PMAD) System. Power conditioning devices (dc to dc converters) are needed to interconnect parts of this system operating at different nominal voltage levels. Operation of such devices could generate under damped oscillations (instability) under certain conditions. Criteria for instability are examined and verified for a single device. Suggested extension of the criteria to a system operation is examined by using the EMTP model of the PMAD dc test bed. Wherever possible, data from the test bed is compared with the modeling results.

Estimating Energy Consumption of Mobile Fluid Power in the United States

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

Lynch, Lauren; Zigler, Bradley T.

This report estimates the market size and energy consumption of mobile off-road applications utilizing hydraulic fluid power, and summarizes technology gaps and implementation barriers. Mobile fluid power is the use of hydraulic fluids under pressure to transmit power in mobile equipment applications. The mobile off-road fluid power sector includes various uses of hydraulic fluid power equipment with fundamentally diverse end-use application and operational requirements, such as a skid steer loader, a wheel loader or an agriculture tractor. The agriculture and construction segments dominate the mobile off-road fluid power market in component unit sales volume. An estimated range of energy consumedmore » by the mobile off-road fluid power sector is 0.36 - 1.8 quads per year, which was 1.3 percent - 6.5 percent of the total energy consumed in 2016 by the transportation sector. Opportunities for efficiency improvements within the fluid power system result from needs to level and reduce the peak system load requirements and develop new technologies to reduce fluid power system level losses, both of which may be facilitated by characterizing duty cycles to define standardized performance test methods. There are currently no commonly accepted standardized test methods for evaluating equipment level efficiency over a duty cycle. The off-road transportation sector currently meets criteria emissions requirements, and there are no efficiency regulations requiring original equipment manufacturers (OEM) to invest in new architecture development to improve the fuel economy of mobile off-road fluid power systems. In addition, the end-user efficiency interests are outweighed by low equipment purchase or lease price concerns, required payback periods, and reliability and durability requirements of new architecture. Current economics, low market volumes with high product diversity, and regulation compliance challenge OEM investment in commercialization of new architecture development.« less

Advanced space power PEM fuel cell systems

NASA Technical Reports Server (NTRS)

Vanderborgh, N. E.; Hedstrom, J.; Huff, J. R.

1989-01-01

A model showing mass and heat transfer in proton exchange membrane (PEM) single cells is presented. For space applications, stack operation requiring combined water and thermal management is needed. Advanced hardware designs able to combine these two techniques are available. Test results are shown for membrane materials which can operate with sufficiently fast diffusive water transport to sustain current densities of 300 ma per square centimeter. Higher power density levels are predicted to require active water removal.

Design Trade-off Between Performance and Fault-Tolerance of Space Onboard Computers

NASA Astrophysics Data System (ADS)

Gorbunov, M. S.; Antonov, A. A.

2017-01-01

It is well known that there is a trade-off between performance and power consumption in onboard computers. The fault-tolerance is another important factor affecting performance, chip area and power consumption. Involving special SRAM cells and error-correcting codes is often too expensive with relation to the performance needed. We discuss the possibility of finding the optimal solutions for modern onboard computer for scientific apparatus focusing on multi-level cache memory design.

Smart Grid Development Issues for Terrestrial and Space Applications

NASA Technical Reports Server (NTRS)

Soeder, James F.

2011-01-01

The development of the so called Smart Grid has as many definitions as individuals working in the area. Based on the technology or technologies that are of interest, be it high speed communication, renewable generation, smart meters, energy storage, advanced sensors, etc. they can become the individual defining characteristic of the Smart Grid. In reality the smart grid encompasses all of these items and quite at bit more. This discussion attempts to look at what the needs are for the grid of the future, such as the issues of increased power flow capability, use of renewable energy, increased security and efficiency and common power and data standards. It also shows how many of these issues are common with the needs of NASA for future exploration programs. A common theme to address both terrestrial and space exploration issues is to develop micro-grids that advertise the ability to enable the load leveling of large power generation facilities. However, for microgrids to realize their promise there needs to a holistic systems approach to their development and integration. The overall system integration issues are presented along with potential solution methodologies.

Smart Grid Development Issues for Terrestrial and Space Applications

NASA Technical Reports Server (NTRS)

Soeder, James F.

2014-01-01

The development of the so called Smart Grid has as many definitions as individuals working in the area. Based on the technology or technologies that are of interest, be it high speed communication, renewable generation, smart meters, energy storage, advanced sensors, etc. they can become the individual defining characteristic of the Smart Grid. In reality the smart grid encompasses all of these items and quite at bit more. This discussion attempts to look at what the needs are for the grid of the future, such as the issues of increased power flow capability, use of renewable energy, increased security and efficiency and common power and data standards. It also shows how many of these issues are common with the needs of NASA for future exploration programs. A common theme to address both terrestrial and space exploration issues is to develop micro-grids that advertise the ability to enable the load leveling of large power generation facilities. However, for microgrids to realize their promise there needs to a holistic systems approach to their development and integration. The overall system integration issues are presented along with potential solution methodologies.

Power Watch - A global, open database of power plants that supports research on climate, water and air pollution impact of the global power sector.

NASA Astrophysics Data System (ADS)

Friedrich, J.; Kressig, A.; Van Groenou, S.; McCormick, C.

2017-12-01

Challenge The lack of transparent, accessible, and centralized power sector data inhibits the ability to research the impact of the global power sector. information gaps for citizens, analysts, and decision makers worldwide create barriers to sustainable development efforts. The need for transparent, accessible, and centralized information is especially important to enhance the commitments outlined in the recently adopted Paris Agreement and Sustainable Development Goals. Offer Power Watch will address this challenge by creating a comprehensive, open-source platform on the world's power systems. The platform hosts data on 85% of global installed electrical capacity and for each power plant will include data points on installed capacity, fuel type, annual generation, commissioning year, with more characteristics like emissions, particulate matter, annual water demand and more added over time. Most of the data is reported from national level sources, but annual generation and other operational characteristiscs are estimated via Machine Learning modeling and remotely sensed data when not officially reported. In addition, Power Watch plans to provide a suite of tools that address specific decision maker needs, such as water risk assessments and air pollution modeling. Impact Through open data, the platform and its tools will allow reserachers to do more analysis of power sector impacts and perform energy modeling. It will help catalyze accountability for policy makers, businesses, and investors and will inform and drive the transition to a clean energy future while reaching development targets.

Petawatt pulsed-power accelerator

DOEpatents

Stygar, William A.; Cuneo, Michael E.; Headley, Daniel I.; Ives, Harry C.; Ives, legal representative; Berry Cottrell; Leeper, Ramon J.; Mazarakis, Michael G.; Olson, Craig L.; Porter, John L.; Wagoner; Tim C.

2010-03-16

A petawatt pulsed-power accelerator can be driven by various types of electrical-pulse generators, including conventional Marx generators and linear-transformer drivers. The pulsed-power accelerator can be configured to drive an electrical load from one- or two-sides. Various types of loads can be driven; for example, the accelerator can be used to drive a high-current z-pinch load. When driven by slow-pulse generators (e.g., conventional Marx generators), the accelerator comprises an oil section comprising at least one pulse-generator level having a plurality of pulse generators; a water section comprising a pulse-forming circuit for each pulse generator and a level of monolithic triplate radial-transmission-line impedance transformers, that have variable impedance profiles, for each pulse-generator level; and a vacuum section comprising triplate magnetically insulated transmission lines that feed an electrical load. When driven by LTD generators or other fast-pulse generators, the need for the pulse-forming circuits in the water section can be eliminated.

Using Maslow's hierarchy to highlight power imbalances between visiting health professional student volunteers and the host community: An applied qualitative study.

PubMed

Evans, Tracey; Akporuno, Orezioghene; Owens, Katrina M; Lickers, Brittany; Marlinga, Jazmin; Lin, Henry C; Loh, Lawrence C

2017-01-01

Health professional students from high-income countries increasingly participate in short-term experiences in global health (STEGH) conducted abroad. One common criticism of STEGH is the inherent power differential that exists between visiting learners and the local community. To highlight this power differential, this paper explores perceived benefits as described by volunteer and community respondents and applies Maslow's hierarchy of needs to commonly identified themes in each respondent group. A semistructured survey was used to collect qualitative responses from both volunteers and community members located in a Dominican Republic community, that is, a hotspot for traditionally conducted STEGH. Thematic analysis identified themes of perceived benefits from both respondent groups; each group's common themes were then classified and compared within Maslow's hierarchy of needs. Each respondent group identified resource provision as a perceived benefit of STEGH, but volunteer respondents primarily focused on the provision of highly-skilled, complex resources while community respondents focused on basic necessities (food, water, etc.) Volunteer respondents were also the only group to also mention spiritual/religious/life experiences, personal skills development, and relationships as perceived benefits. Applying Maslow's hierarchy thus demonstrates a difference in needs: community respondents focused on benefits that address deficiency needs at the bottom of the hierarchy while volunteers focused on benefits addressing self-transcendence/actualization needs at the top of the hierarchy. The perceived difference in needs met by STEGH between volunteers and the host community within Maslow's hierarchy may drive an inherent power differential. Refocusing STEGH on the relationship level of the hierarchy (i.e., focusing on partnerships) might help mitigate this imbalance and empower host communities.

Clinical Assessment of Adolescents Involved in Satanism.

ERIC Educational Resources Information Center

Clark, Cynthia M.

1994-01-01

Describes Satanism as destructive religion that promises power, dominance, and gratification and that may seduce adolescents who feel alienated, alone, angry, and desperate. Explores psychosocial needs of adolescents that are met by participation in Satanic worship. Includes method for determining adolescents' level of involvement and assessment…

The Powers That Be: AAVE as the Composition Curriculum.

ERIC Educational Resources Information Center

Richardson, Elaine

This Powerpoint presentation argues that the problems encountered in implementing African-centered curriculum into the university composition classroom attest to the need for African centered education in kindergarten through university level educational institutions. The solution of the problem of African American students' disproportionate…

A study on economic power dispatch grid connected PV power plant in educational institutes

NASA Astrophysics Data System (ADS)

Singh, Kuldip; Kumar, M. Narendra; Mishra, Satyasis

2018-04-01

India has main concerns on environment and escalation of fuel prices with respect to diminution of fossil fuel reserves and the major focus on renewable Energy sources for power generation to fulfill the present and future energy demand. Installation of PV power plants in the Educational Institutions has grown up drastically throughout India. More PV power plant are integrated with load and grid through net metering. Therefore, this paper is an analysis of the 75kWp PV plant at chosen buses, considering the need of minimum demand from the grid. The case study is carried out for different generation level throughout the day and year w.r.t load and climate changes, load sharing on grid. The economic dispatch model developed for PV plant integrated with Grid.

Power inversion design for ocean wave energy harvesting

NASA Astrophysics Data System (ADS)

Talebani, Anwar N.

The needs for energy sources are increasing day by day because of several factors, such as oil depletion, and global climate change due to the higher level of CO2, so the exploration of various renewable energy sources is very promising area of study. The available ocean waves can be utilized as free source of energy as the water covers 70% of the earth surface. This thesis presents the ocean wave energy as a source of renewable energy. By addressing the problem of designing efficient power electronics system to deliver 5 KW from the induction generator to the grid with less possible losses and harmonics as possible and to control current fed to the grid to successfully harvest ocean wave energy. We design an AC-DC full bridge rectifier converter, and a DC-DC boost converter to harvest wave energy from AC to regulated DC. In order to increase the design efficiency, we need to increase the power factor from (0.5-0.6) to 1. This is accomplished by designing the boost converter with power factor correction in continues mode with RC circuit as an input to the boost converter power factor correction. This design results in a phase shift between the input current and voltage of the full bridge rectifier to generate a small reactive power. The reactive power is injected to the induction generator to maintain its functionality by generating a magnetic field in its stator. Next, we design a single-phase pulse width modulator full bridge voltage source DC-AC grid-tied mode inverter to harvest regulated DC wave energy to AC. The designed inverter is modulated by inner current loop, to control current injected to the grid with minimal filter component to maintain power quality at the grid. The simulation results show that our design successfully control the current level fed to the grid. It is noteworthy that the simulated efficiency is higher than the calculated one since we used an ideal switch in the simulated circuit.

The Ames Power Monitoring System

NASA Technical Reports Server (NTRS)

Osetinsky, Leonid; Wang, David

2003-01-01

The Ames Power Monitoring System (APMS) is a centralized system of power meters, computer hardware, and specialpurpose software that collects and stores electrical power data by various facilities at Ames Research Center (ARC). This system is needed because of the large and varying nature of the overall ARC power demand, which has been observed to range from 20 to 200 MW. Large portions of peak demand can be attributed to only three wind tunnels (60, 180, and 100 MW, respectively). The APMS helps ARC avoid or minimize costly demand charges by enabling wind-tunnel operators, test engineers, and the power manager to monitor total demand for center in real time. These persons receive the information they need to manage and schedule energy-intensive research in advance and to adjust loads in real time to ensure that the overall maximum allowable demand is not exceeded. The APMS (see figure) includes a server computer running the Windows NT operating system and can, in principle, include an unlimited number of power meters and client computers. As configured at the time of reporting the information for this article, the APMS includes more than 40 power meters monitoring all the major research facilities, plus 15 Windows-based client personal computers that display real-time and historical data to users via graphical user interfaces (GUIs). The power meters and client computers communicate with the server using Transmission Control Protocol/Internet Protocol (TCP/IP) on Ethernet networks, variously, through dedicated fiber-optic cables or through the pre-existing ARC local-area network (ARCLAN). The APMS has enabled ARC to achieve significant savings ($1.2 million in 2001) in the cost of power and electric energy by helping personnel to maintain total demand below monthly allowable levels, to manage the overall power factor to avoid low power factor penalties, and to use historical system data to identify opportunities for additional energy savings. The APMS also provides power engineers and electricians with the information they need to plan modifications in advance and perform day-to-day maintenance of the ARC electric-power distribution system.

Power management and distribution system for a More-Electric Aircraft (MADMEL) -- Program status

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

Maldonado, M.A.; Shah, N.M.; Cleek, K.J.

1995-12-31

A number of technology breakthroughs in recent years have rekindled the concept of a more-electric aircraft. High-power solid-state switching devices, electrohydrostatic actuators (EHAs), electromechanical actuators (EMAs), and high-power generators are just a few examples of component developments that have made dramatic improvements in properties such as weight, size, power, and cost. However, these components cannot be applied piecemeal. A complete, and somewhat revolutionary, system design approach is needed to exploit the benefits that a more-electric aircraft can provide. A five-phase Power Management and Distribution System for a More-Electric Aircraft (MADMEL) program was awarded by the Air Force to the Northrop/Grumman,more » Military Aircraft Division team in September 1991. The objective of the program is to design, develop, and demonstrate an advanced electrical power generation and distribution system for a more-electric aircraft (MEA). The MEA emphasizes the use of electrical power in place of hydraulics, pneumatic, and mechanical power to optimize the performance and life cycle cost of the aircraft. This paper presents an overview of the MADMEL program and a top-level summary of the program results, development and testing of major components to date. In Phase 1 and Phase 2 studies, the electrical load requirements were established and the electrical power system architecture was defined for both near-term (NT-year 1996) and far-term (FT-year 2003) MEA application. The detailed design and specification for the electrical power system (EPS), its interface with the Vehicle Management System, and the test set-up were developed under the recently completed Phase 3. The subsystem level hardware fabrication and testing will be performed under the on-going Phase 4 activities. The overall system level integration and testing will be performed in Phase 5.« less

Integrated topology for an aircraft electric power distribution system using MATLAB and ILP optimization technique and its implementation

NASA Astrophysics Data System (ADS)

Madhikar, Pratik Ravindra

The most important and crucial design feature while designing an Aircraft Electric Power Distribution System (EPDS) is reliability. In EPDS, the distribution of power is from top level generators to bottom level loads through various sensors, actuators and rectifiers with the help of AC & DC buses and control switches. As the demands of the consumer is never ending and the safety is utmost important, there is an increase in loads and as a result increase in power management. Therefore, the design of an EPDS should be optimized to have maximum efficiency. This thesis discusses an integrated tool that is based on a Need Based Design method and Fault Tree Analysis (FTA) to achieve the optimum design of an EPDS to provide maximum reliability in terms of continuous connectivity, power management and minimum cost. If an EPDS is formulated as an optimization problem then it can be solved with the help of connectivity, cost and power constraints by using a linear solver to get the desired output of maximum reliability at minimum cost. Furthermore, the thesis also discusses the viability and implementation of the resulted topology on typical large aircraft specifications.

Automating a spacecraft electrical power system using expert systems

NASA Technical Reports Server (NTRS)

Lollar, L. F.

1991-01-01

Since Skylab, Marshall Space Flight Center (MSFC) has recognized the need for large electrical power systems (EPS's) in upcoming Spacecraft. The operation of the spacecraft depends on the EPS. Therefore, it must be efficient, safe, and reliable. In 1978, as a consequence of having to supply a large number of EPS personnel to monitor and control Skylab, the Electrical power Branch of MSFC began the autonomously managed power system (AMPS) project. This project resulted in the assembly of a 25-kW high-voltage dc test facility and provided the means of getting man out of the loop as much as possible. AMPS includes several embedded controllers which allow a significant level of autonomous operation. More recently, the Electrical Division at MSFC has developed the space station module power management and distribution (SSM/PMAD) breadboard to investigate managing and distributing power in the Space Station Freedom habitation and laboratory modules. Again, the requirement for a high level of autonomy for the efficient operation over the lifetime of the station and for the benefits of enhanced safety has been demonstrated. This paper describes the two breadboards and the hierarchical approach to automation which was developed through these projects.

Stability Assessment of a System Comprising a Single Machine and Inverter with Scalable Ratings

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

Johnson, Brian B; Lin, Yashen; Gevorgian, Vahan

Synchronous machines have traditionally acted as the foundation of large-scale electrical infrastructures and their physical properties have formed the cornerstone of system operations. However, with the increased integration of distributed renewable resources and energy-storage technologies, there is a need to systematically acknowledge the dynamics of power-electronics inverters - the primary energy-conversion interface in such systems - in all aspects of modeling, analysis, and control of the bulk power network. In this paper, we assess the properties of coupled machine-inverter systems by studying an elementary system comprised of a synchronous generator, three-phase inverter, and a load. The inverter model is formulatedmore » such that its power rating can be scaled continuously across power levels while preserving its closed-loop response. Accordingly, the properties of the machine-inverter system can be assessed for varying ratios of machine-to-inverter power ratings. After linearizing the model and assessing its eigenvalues, we show that system stability is highly dependent on the inverter current controller and machine exciter, thus uncovering a key concern with mixed machine-inverter systems and motivating the need for next-generation grid-stabilizing inverter controls.« less

Investigation of the Low Power Stage of an 1178 nm Raman System

DTIC Science & Technology

2013-12-23

LEANNE HENRY, DR-III, DAF KENTON T. WOOD, DR-IV, DAF Work Unit Manager Chief, Laser Division This report is published in the...and 1069 nm pumped Raman laser system where the second Stokes is amplified in a 1121 nm resonator defined by high reflector fiber Bragg gratings (FBGs...the gratings was found to impact the performance of the laser and needs to be dealt with in order to obtain high 1178 nm output power levels. In order

Corruption in the Kenya Police Force and Impacts on Kenyan Security: Investigating the Need for Police Reforms

DTIC Science & Technology

2017-03-21

against the citizens. Kenya Police have always been linked with abuse of power with impunity when tackling crime or executing their duties. For example...Therefore, ethical police code of conducts in American 14 policing were established in the efforts to control excessive use of power while...occurs when the police encounter with the citizens during their routine enforcement of the law. The high -level of negative attitudes among Kenyans to the

Combinatorial FSK modulation for power-efficient high-rate communications

NASA Technical Reports Server (NTRS)

Wagner, Paul K.; Budinger, James M.; Vanderaar, Mark J.

1991-01-01

Deep-space and satellite communications systems must be capable of conveying high-rate data accurately with low transmitter power, often through dispersive channels. A class of noncoherent Combinatorial Frequency Shift Keying (CFSK) modulation schemes is investigated which address these needs. The bit error rate performance of this class of modulation formats is analyzed and compared to the more traditional modulation types. Candidate modulator, demodulator, and digital signal processing (DSP) hardware structures are examined in detail. System-level issues are also discussed.

A helicopter handling-qualities study of the effects of engine response characteristics, height-control dynamics, and excess power on nap-of-the-Earth operations

NASA Technical Reports Server (NTRS)

Corliss, L. D.

1982-01-01

The helicopter configuration with an rpm-governed gas-turbine engine was examined. A wide range of engine response time, vehicle damping and sensitivity, and excess power levels was studied. The data are compared with the existing handling-qualities specifications, MIL-F-83300 and AGARD 577, and in general show a need for higher minimums when performing such NOE maneuvers as a dolphin and bob-up task.

Good practice in social care: the views of people with severe and complex needs and those who support them.

PubMed

Gridley, Kate; Brooks, Jenni; Glendinning, Caroline

2014-11-01

This paper reports findings drawn from a study of good practice in English social care for adults with disability and older people with severe and complex needs. People with severe and complex needs are a relatively small proportion of adult social care service users, but they are growing in numbers and have resource-intensive needs. The study involved qualitative research with adults with disability and older people with severe and complex needs, family carers and members of specialist organisations (n = 67), focusing on the features of social care services they considered to be good practice. Data were collected between August 2010 and June 2011. The approach to data collection was flexible, to accommodate participants' communication needs and preferences, including face-to-face and telephone interviews, Talking Mats(©) sessions and a focus group. Data were managed using Framework and analysed thematically. Features of good practice were considered at three levels: (i) everyday support; (ii) service organisation; and (iii) commissioning. Findings relating to the first two of these are presented here. Participants emphasised the importance of person-centred ways of working at all levels. Personalisation, as currently implemented in English social care, aims to shift power from professionals to service users through the allocation of personal budgets. This approach focuses very much on the role of the individual in directing his/her own support arrangements. However, participants in this study also stressed the importance of ongoing professional support, for example, from a specialist key worker or case manager to co-ordinate diverse services and ensure good practice at an organisational level. The paper argues that, despite the recent move to shift power from professionals to service users, people with the most complex needs still value support from professionals and appropriate organisational support. Without these, they risk being excluded from the benefits that personalisation, properly supported, could yield. © 2014 John Wiley & Sons Ltd.

Managing autonomy levels in the SSM/PMAD testbed. [Space Station Power Management and Distribution

NASA Technical Reports Server (NTRS)

Ashworth, Barry R.

1990-01-01

It is pointed out that when autonomous operations are mixed with those of a manual nature, concepts concerning the boundary of operations and responsibility become clouded. The space station module power management and distribution (SSM/PMAD) automation testbed has the need for such mixed-mode capabilities. The concept of managing the SSM/PMAD testbed in the presence of changing levels of autonomy is examined. A knowledge-based approach to implementing autonomy management in the distributed SSM/PMAD utilizing a centralized planning system is presented. Its knowledge relations and system-wide interactions are discussed, along with the operational nature of the currently functioning SSM/PMAD knowledge-based systems.

An Overview of the Regulation of Low Dose Radiation in the Nuclear and Non-nuclear Industries

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

Menon, Shankar; Valencia, Luis; Teunckens, Lucien

Now that increasing numbers of nuclear power stations are reaching the end of their commercially useful lives, the management of the large quantities of very low level radioactive material that arises during their decommissioning has become a major subject of discussion, with very significant economic implications. Much of this material can, in an environmentally advantageous manner, be recycled for reuse without radiological restrictions. Much larger quantities--2-3 orders of magnitude larger--of material, radiologically similar to the candidate material for recycling from the nuclear industry, arise in non-nuclear industries like coal, fertilizer, oil and gas, mining, etc. In such industries, naturally occurringmore » radioactivity is artificially concentrated in products, by-products or waste to form TENORM (Technologically Enhanced Naturally Occurring Radioactive Material). It is only in the last decade that the international community has become aware of the prevalence of TENORM, specially the activity levels and quantities arising in so many non-nuclear industries. The first reaction of international organizations seems to have been to propose different standards for the nuclear and non-nuclear industries, with very stringent release criteria for radioactive material from the regulated nuclear industry and up to thirty to a hundred times more liberal criteria for the release/exemption of TENORM from the as yet unregulated non-nuclear industries. There are significant strategic issues that need to be discussed and resolved. Some examples of these are: - Disposal aspects of long-lived nuclides, - The use of radioactive residues in building materials, - Commercial aspects of differing and discriminating criteria in competing power industries in a world of deregulated electric power production. Of even greater importance is the need for the discussion of certain basic issues, such as - The quantitative risk levels of exposure to ionizing radiation, - The need for in-depth studies on populations of the naturally high background dose level areas of the world, - The validity of the various calculation codes currently used to arrive at mass specific clearance levels for redundant material. The paper discusses these and other strategic issues regarding the management of redundant low radiation material from both the nuclear and non-nuclear industries, underlining the need for consistency in regulatory treatment.« less

How Low Can You Go? The Importance of Quantifying Minimum Generation Levels for Renewable Integration

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

Denholm, Paul L; Brinkman, Gregory L; Mai, Trieu T

One of the significant limitations of solar and wind deployment is declining value caused by the limited correlation of renewable energy supply and electricity demand as well as limited flexibility of the power system. Limited flexibility can result from thermal and hydro plants that cannot turn off or reduce output due to technical or economic limits. These limits include the operating range of conventional thermal power plants, the need for process heat from combined heat and power plants, and restrictions on hydro unit operation. To appropriately analyze regional and national energy policies related to renewable deployment, these limits must bemore » accurately captured in grid planning models. In this work, we summarize data sources and methods for U.S. power plants that can be used to capture minimum generation levels in grid planning tools, such as production cost models. We also provide case studies for two locations in the U.S. (California and Texas) that demonstrate the sensitivity of variable generation (VG) curtailment to grid flexibility assumptions which shows the importance of analyzing (and documenting) minimum generation levels in studies of increased VG penetration.« less

Wind deployment in the United States: states, resources, policy, and discourse.

PubMed

Wilson, Elizabeth J; Stephens, Jennie C

2009-12-15

A transformation in the way the United States produces and uses energy is needed to achieve greenhouse gas reduction targets for climate change mitigation. Wind power is an important low-carbon technology and the most rapidly growing renewable energy technology in the U.S. Despite recent advances in wind deployment, significant state-by-state variation in wind power distribution cannot be explained solely by wind resource patterns nor by state policy. Other factors embedded within the state-level socio-political context also contribute to wind deployment patterns. We explore this socio-political context in four U.S. states by integrating multiple research methods. Through comparative state-level analysis of the energy system, energy policy, and public discourse as represented in the media, we examine variation in the context for wind deployment in Massachusetts, Minnesota, Montana, and Texas. Our results demonstrate that these states have different patterns of wind deployment, are engaged in different debates about wind power, and appear to frame the risks and benefits of wind power in different ways. This comparative assessment highlights the complex variation of the state-level socio-political context and contributes depth to our understanding of energy technology deployment processes, decision-making, and outcomes.

The relationship between visitor characteristics and learning-associated behaviors in a science museum discovery space

NASA Astrophysics Data System (ADS)

Lozowski Boisvert, Dorothy; Jochums Slez, Brenda

As informal educational institutions, science museums must do more than entertain and amaze visitors. Museum educators must design exhibits that attract and hold the attention of visitors long enough so that the visitors become engaged with the exhibits and learn from them. In order for museum educators to develop such exhibits, more information is needed about the variables associated with learning in museums. This study contributes to the growing body of knowledge on informal education by examining the relationship between visitor characteristics and attraction, holding power, and visitor engagement.One hundred fifty-four visitors to a science museum discovery space were observed as they interacted freely with the exhibits. Trained volunteers recorded the subjects' movements including the exhibits at which they stopped (attraction), the amount of time spent at each exhibit (holding power), and behaviors indicative of subjects' engagement levels with the exhibits. Data indicated significant differences between age group and the holding power of exhibits. Though not significant statistically, a similar trend was noted between age group and attraction and visitor engagement level. No significant differences were found between gender or social grouping and attraction, holding power, or engagement levels.

Torsional ultrasonic technique for reactor vessel liquid level measurement

NASA Astrophysics Data System (ADS)

Dress, W. B.

A detailed study of an ultrasonic waveguide employed as a level, density, and temperature sensor was undertaken. The purpose was to show how such a device might be used in the nuclear power industry to provide reliable level information with a multifunction sensor, thus overcoming several of the errors that led to the accident at Three Mile Island. Some additional work is needed to answer the question raised by the current study, most noticably the damping effects of flowing water.

Stability Assessment of a System Comprising a Single Machine and Inverter with Scalable Ratings

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

Johnson, Brian B; Lin, Yashen; Gevorgian, Vahan

From the inception of power systems, synchronous machines have acted as the foundation of large-scale electrical infrastructures and their physical properties have formed the cornerstone of system operations. However, power electronics interfaces are playing a growing role as they are the primary interface for several types of renewable energy sources and storage technologies. As the role of power electronics in systems continues to grow, it is crucial to investigate the properties of bulk power systems in low inertia settings. In this paper, we assess the properties of coupled machine-inverter systems by studying an elementary system comprised of a synchronous generator,more » three-phase inverter, and a load. Furthermore, the inverter model is formulated such that its power rating can be scaled continuously across power levels while preserving its closed-loop response. Accordingly, the properties of the machine-inverter system can be assessed for varying ratios of machine-to-inverter power ratings and, hence, differing levels of inertia. After linearizing the model and assessing its eigenvalues, we show that system stability is highly dependent on the interaction between the inverter current controller and machine exciter, thus uncovering a key concern with mixed machine-inverter systems and motivating the need for next-generation grid-stabilizing inverter controls.« less

Advanced secondary batteries: Their applications, technological status, market and opportunity

NASA Astrophysics Data System (ADS)

Yao, M.

1989-03-01

Program planning for advanced battery energy storage technology is supported within the NEMO Program. Specifically this study had focused on the review of advanced battery applications; the development and demonstration status of leading battery technologies; and potential marketing opportunity. Advanced secondary (or rechargeable) batteries have been under development for the past two decades in the U.S., Japan, and parts of Europe for potential applications in electric utilities and for electric vehicles. In the electric utility applications, the primary aim of a battery energy storage plant is to facilitate peak power load leveling and/or dynamic operations to minimize the overall power generation cost. In the application for peak power load leveling, the battery stores the off-peak base load energy and is discharged during the period of peak power demand. This allows a more efficient use of the base load generation capacity and reduces the need for conventional oil-fired or gas-fire peak power generation equipment. Batteries can facilitate dynamic operations because of their basic characteristics as an electrochemical device capable of instantaneous response to the changing load. Dynamic operating benefits results in cost savings of the overall power plant operation. Battery-powered electric vehicles facilitate conservation of petroleum fuel in the transportation sector, but more importantly, they reduce air pollution in the congested inner cities.

New directions for space solar power

NASA Astrophysics Data System (ADS)

Mankins, John C.

2009-07-01

Several of the central issues associated with the eventual realization of the vision of solar power from space for terrestrial markets resolve around the expect costs associated with the assembly, inspection, maintenance and repair of future solar power satellite (SPS) stations. In past studies (for example, NASA's "Fresh Look Study", c. 1995-1997) efforts were made to reduce both the scale and mass of large, systems-level interfaces (e.g., the power management and distribution (PMAD) system) and on-orbit fixed infrastructures through the use of modular systems strategies. These efforts have had mixed success (as reflected in the projected on-orbit mass of various systems concepts. However, the author remains convinced of the importance of modular strategies for exceptionally large space systems in eventually realizing the vision of power from space. This paper will introduce some of the key issues associated with cost-competitive space solar power in terrestrial markets. It will examine some of the relevant SPS concepts and will assess the 'pros and cons' of each in terms of space assembly, maintenance and servicing (SAMS) requirements. The paper discusses at a high level some relevant concepts and technologies that may play r role in the eventual, successful resolution of these challenges. The paper concludes with an example of the kind of novel architectural approach for space solar power that is needed.

The Struggle for Technology: Towards a Realistic Political Theory of Technology.

PubMed

Verbeek, Peter-Paul

2017-01-01

Pieter Lemmens' neo-Marxist approach to technology urges us to rethink how to do political philosophy of technology. First, Lemmens' high level of abstraction raises the question of how empirically informed a political theory of technology needs to be. Second, his dialectical focus on a "struggle" between humans and technologies reveals the limits of neo-Marxism. Political philosophy of technology needs to return "to the things themselves". The political significance of technologies cannot be reduced to its origins in systems of production or social organization, but requires study at the micro-level, where technologies help to shape engagement, interaction, power, and social awareness.

The individual time trial as an optimal control problem

PubMed Central

de Jong, Jenny; Fokkink, Robbert; Olsder, Geert Jan; Schwab, AL

2017-01-01

In a cycling time trial, the rider needs to distribute his power output optimally to minimize the time between start and finish. Mathematically, this is an optimal control problem. Even for a straight and flat course, its solution is non-trivial and involves a singular control, which corresponds to a power that is slightly above the aerobic level. The rider must start at full anaerobic power to reach an optimal speed and maintain that speed for the rest of the course. If the course is flat but not straight, then the speed at which the rider can round the bends becomes crucial. PMID:29388631

The Influence of Wheelchair Propulsion Hand Pattern on Upper Extremity Muscle Power and Stress

PubMed Central

Slowik, Jonathan S.; Requejo, Philip S.; Mulroy, Sara J.; Neptune, Richard R.

2016-01-01

The hand pattern (i.e., full-cycle hand path) used during manual wheelchair propulsion is frequently classified as one of four distinct hand pattern types: arc, single loop, double loop and semicircular. Current clinical guidelines recommend the use of the semicircular pattern, which is based on advantageous levels of broad biomechanical metrics implicitly related to the demand placed on the upper extremity (e.g., lower cadence). However, an understanding of the influence of hand pattern on specific measures of upper extremity muscle demand (e.g., muscle power and stress) is needed to help make such recommendations, but these quantities are difficult and impractical to measure experimentally. The purpose of this study was to use musculoskeletal modeling and forward dynamics simulations to investigate the influence of the hand pattern used on specific measures of upper extremity muscle demand. The simulation results suggest that the double loop and semicircular patterns produce the most favorable levels of overall muscle stress and total muscle power. The double loop pattern had the lowest full-cycle and recovery-phase upper extremity demand but required high levels of muscle power during the relatively short contact phase. The semicircular pattern had the second-lowest full-cycle levels of overall muscle stress and total muscle power, and demand was more evenly distributed between the contact and recovery phases. These results suggest that in order to decrease upper extremity demand, manual wheelchair users should use either the double loop or semicircular pattern when propelling their wheelchairs at a self-selected speed on level ground. PMID:27062591

Historical Mass, Power, Schedule, and Cost Growth for NASA Spacecraft

NASA Technical Reports Server (NTRS)

Hayhurst, Marc R.; Bitten, Robert E.; Shinn, Stephen A.; Judnick, Daniel C.; Hallgrimson, Ingrid E.; Youngs, Megan A.

2016-01-01

Although spacecraft developers have been moving towards standardized product lines as the aerospace industry has matured, NASA's continual need to push the cutting edge of science to accomplish unique, challenging missions can still lead to spacecraft resource growth over time. This paper assesses historical mass, power, cost, and schedule growth for multiple NASA spacecraft from the last twenty years and compares to industry reserve guidelines to understand where the guidelines may fall short. Growth is assessed from project start to launch, from the time of the preliminary design review (PDR) to launch and from the time of the critical design review (CDR) to launch. Data is also assessed not just at the spacecraft bus level, but also at the subsystem level wherever possible, to help obtain further insight into possible drivers of growth. Potential recommendations to minimize spacecraft mass, power, cost, and schedule growth for future missions are also discussed.

Information flow and work productivity through integrated information technology

NASA Technical Reports Server (NTRS)

Wigand, R. T.

1985-01-01

The work environment surrounding integrated office systems is reviewed. The known effects of automated office technologies is synthesized and their known impact on work efficiency is reviewed. These effects are explored with regard to their impact on networks, work flow/processes, as well as organizational structure and power. Particular emphasis is given to structural changes due to the introduction of newer information technologies in organizations. The new information technologies have restructed the average organization's middle banks and, as a consequence, they have shrunk drastically. Organizational pyramids have flattened with fewer levels since executives have realized that they can get ahold of the needed information via the new technologies quicker and directly and do not have to rely on middle-level managers. Power shifts are typically accompanied with the introduction of these technologies resulting in the generation of a new form of organizational power.

A Sensemaking Perspective on Situation Awareness in Power Grid Operations

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

Greitzer, Frank L.; Schur, Anne; Paget, Mia L.

2008-07-21

With increasing complexity and interconnectivity of the electric power grid, the scope and complexity of grid operations continues to grow. New paradigms are needed to guide research to improve operations by enhancing situation awareness of operators. Research on human factors/situation awareness is described within a taxonomy of tools and approaches that address different levels of cognitive processing. While user interface features and visualization approaches represent the predominant focus of human factors studies of situation awareness, this paper argues that a complementary level, sensemaking, deserves further consideration by designers of decision support systems for power grid operations. A sensemaking perspective onmore » situation aware-ness may reveal new insights that complement ongoing human factors research, where the focus of the investigation of errors is to understand why the decision makers experienced the situation the way they did, or why what they saw made sense to them at the time.« less

Neural mechanisms to predict subjective level of fatigue in the future: a magnetoencephalography study

PubMed Central

Ishii, Akira; Tanaka, Masaaki; Watanabe, Yasuyoshi

2016-01-01

Fatigue is a major contributor to workplace accidents, morbidity, and mortality. To prevent the disruption of homeostasis and to concurrently accomplish an assigned workload, it is essential to control the level of workload based on the subjective estimation of the level of fatigue that will be experienced in the near future. In this study, we aimed to clarify the neural mechanisms related to predicting subjective levels of fatigue that would be experienced 60 min later, using magnetoencephalography. Sixteen healthy male volunteers participated in this study. In relation to the prediction, a decrease of alpha band power in the right Brodmann’s area (BA) 40 and BA 9 at 1200 to 1350 ms and that in the right BA 9 at 1350 to 1500 ms, and a decrease of gamma band power in the right BA 10 at 1500 to 1650 ms were observed. In addition, the decreased level of alpha band power in BA 9 at 1200 to 1350 ms was positively associated with the daily level of fatigue. These findings may help increase our understanding of the neural mechanisms activated to indicate the need to take a rest based on the prediction of the subjective fatigue in the future. PMID:27112115

Nuclear power propulsion system for spacecraft

NASA Astrophysics Data System (ADS)

Koroteev, A. S.; Oshev, Yu. A.; Popov, S. A.; Karevsky, A. V.; Solodukhin, A. Ye.; Zakharenkov, L. E.; Semenkin, A. V.

2015-12-01

The proposed designs of high-power space tugs that utilize solar or nuclear energy to power an electric jet engine are reviewed. The conceptual design of a nuclear power propulsion system (NPPS) is described; its structural diagram, gas circuit, and electric diagram are discussed. The NPPS incorporates a nuclear reactor, a thermal-to-electric energy conversion system, a system for the conversion and distribution of electric energy, and an electric propulsion system. Two criterion parameters were chosen in the considered NPPS design: the temperature of gaseous working medium at the nuclear reactor outlet and the rotor speed of turboalternators. The maintenance of these parameters at a given level guarantees that the needed electric voltage is generated and allows for power mode control. The processes of startup/shutdown and increasing/reducing the power, the principles of distribution of electric energy over loads, and the probable emergencies for the proposed NPPS design are discussed.

Radiation Hardened, Modulator ASIC for High Data Rate Communications

NASA Technical Reports Server (NTRS)

McCallister, Ron; Putnam, Robert; Andro, Monty; Fujikawa, Gene

2000-01-01

Satellite-based telecommunication services are challenged by the need to generate down-link power levels adequate to support high quality (BER approx. equals 10(exp 12)) links required for modem broadband data services. Bandwidth-efficient Nyquist signaling, using low values of excess bandwidth (alpha), can exhibit large peak-to-average-power ratio (PAPR) values. High PAPR values necessitate high-power amplifier (HPA) backoff greater than the PAPR, resulting in unacceptably low HPA efficiency. Given the high cost of on-board prime power, this inefficiency represents both an economical burden, and a constraint on the rates and quality of data services supportable from satellite platforms. Constant-envelope signals offer improved power-efficiency, but only by imposing a severe bandwidth-efficiency penalty. This paper describes a radiation- hardened modulator which can improve satellite-based broadband data services by combining the bandwidth-efficiency of low-alpha Nyquist signals with high power-efficiency (negligible HPA backoff).

Network, system, and status software enhancements for the autonomously managed electrical power system breadboard. Volume 2: Protocol specification

NASA Technical Reports Server (NTRS)

Mckee, James W.

1990-01-01

This volume (2 of 4) contains the specification, structured flow charts, and code listing for the protocol. The purpose of an autonomous power system on a spacecraft is to relieve humans from having to continuously monitor and control the generation, storage, and distribution of power in the craft. This implies that algorithms will have been developed to monitor and control the power system. The power system will contain computers on which the algorithms run. There should be one control computer system that makes the high level decisions and sends commands to and receive data from the other distributed computers. This will require a communications network and an efficient protocol by which the computers will communicate. One of the major requirements on the protocol is that it be real time because of the need to control the power elements.

Performance of Power Converters at Cryogenic Temperatures

NASA Technical Reports Server (NTRS)

Elbuluk, Malik E.; Gerber, Scott; Hammoud, Ahmad; Patterson, Richard L.

2001-01-01

Power converters capable of operation at cryogenic temperatures are anticipated to play an important role in the power system architecture of future NASA deep space missions. Design of such converters to survive cryogenic temperatures will improve the power system performance and reduce development and launch costs. Aerospace power systems are mainly a DC distribution network. Therefore, DC/DC and DC/AC converters provide the outputs needed to different loads at various power levels. Recently, research efforts have been performed at the NASA Glenn Research Center (GRC) to design and evaluate DC/DC converters that are capable of operating at cryogenic temperatures. This paper presents a summary of the research performed to evaluate the low temperature performance of five DC/DC converters. Various parameters were investigated as a function of temperature in the range of 20 to -196 C. Data pertaining to the output voltage regulation and efficiency of the converters is presented and discussed.

Early Market TRL/MRL Analysis

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

Ronnebro, Ewa; Stetson, Ned

he focus of this report is TRL/MRL analysis of hydrogen storage; it documents the methodology and results of an effort to identify hydrogen storage technologies’ technical and manufacturing readiness for early market motive and non-motive applications and to provide a path forward toward commercialization. Motive applications include materials handling equipment (MHE) and ground support equipment (GSE), such as forklifts, tow tractors, and specialty vehicles such as golf carts, lawn mowers and wheel chairs. Non-motive applications are portable, stationary or auxiliary power units (APUs) and include portable laptops, backup power, remote sensor power, and auxiliary power for recreational vehicles, hotels, hospitals,more » etc. Hydrogen storage technologies assessed include metal hydrides, chemical hydrides, sorbents, gaseous storage, and liquid storage. The assessments are based on a combination of Technology Readiness Level (TRL) and Manufacturing Readiness Level (MRL) designations that enable evaluation of hydrogen storage technologies at varying levels of development. The manufacturing status could be established from eight risk elements: Technical Maturity, Design, Materials, Cost & Funding, Process Capability, Personnel, Facilities and Manufacturing Planning. This approach provides a logical methodology and roadmap to enable the identification of hydrogen storage technologies, their advantages/disadvantages, gaps and R&D needs on an unbiased and transparent scale that is easily communicated to interagency partners. This technology readiness assessment (TRA) report documents the process used to conduct the TRA/MRA (technology and manufacturing readiness assessment), reports the TRL and MRL for each assessed technology and provides recommendations based on the findings. To investigate the state of the art and needs to mature the technologies, PNNL prepared a questionnaire to assign TRL and MRL for each hydrogen storage technology. The questionnaire was sent to identified hydrogen storage technology developers and manufacturers who were asked to perform a self-assessment. We included both domestic and international organizations including U.S. national laboratories, U.S. companies, European companies and Japanese companies. PNNL collected the data and performed an analysis to deduce the level of maturity and to provide program recommendations.« less

Biomass "Green" Power Vs. Coal "Traditional" Power: Who is the Largest Emitter in Humboldt County and How Should Regulations be Addressed?

NASA Astrophysics Data System (ADS)

Zurawski, A. M.

2016-12-01

The objective of this research is to study how emissions from a fossil fuel power plant compare to emissions from a biomass power plant, and how these results can be used to improve current air-quality regulations. Outdoor air quality transcends national and political boundaries. Air pollution monitoring is essential to maintaining quality of life for humans and ecosystems. Due to anthropogenic disturbances (primarily related to burning of fossil fuels), air- quality management has become a priority on a long list of environmental issues. Quantifying and monitoring the largest emitters of greenhouse gases and toxic pollutants is crucial to the creation and enforcement of appropriate environmental protection regulations. Emissions data were collected from January 2010 to January 2016 from sensors installed close to a biomass power plant, and sensors installed close to a fossil fuel and natural gas power plant, in Humboldt County, California. In Humboldt County, where air quality serves as a baseline of air pollution in the United States, data showed that the "green" biomass power plant emitted higher levels of particulate matter compared to the fossil fuel power plant. Additionally, the biomass power plant showed levels of CO2, NOx, and SO2 emissions that suggest its place as a "green" power source should be reconsidered. Our research suggests that regulations need to be reconsidered given the potential for high pollutant emissions from biomass plants.

Lessons in power: Lyndon Johnson revealed. A conversation with historian Robert A. Caro.

PubMed

Caro, Robert A

2006-04-01

No one can lead who does not first acquire power, and no leader can be great who does not know how to use that power. The trouble is that the combination of the two skills is rare. Amassing power requires ambition, a focused pragmatism, and a certain ruthlessness that is often at odds with the daring, idealistic vision needed to achieve great things with that power. The tension is as real in business as it is in politics. This magazine is replete with examples of successful senior managers who could not make the switch from ambitious executive to corporate leader because they did not know what to do with the power they had so expertly accumulated. Robert Caro is a student of power. For the past 27 years, the two-time Pulitzer prize-winning biographer of Robert Moses and Lyndon Johnson has focused on the question of how Johnson amassed and wielded power. Caro's deep understanding of the inner workings of power offers senior executives a nuanced picture of leadership at the highest level. In this wide-ranging conversation, Caro shares his insights about the nature of power, the complexity of ambition, and the role that the greater good can play in the making of a leader. Power doesn't always corrupt, he insists. But what it invariably does is reveal a leader's true nature. "Today, when CEOs have acquired more and more power to change our lives," Caro says,"they have become like presidents in their own right, and they, too, need to align themselves with something greater than themselves if they hope to become truly great leaders."

Hands-on Electrospray Ionization-Mass Spectrometry for Upper-Level Undergraduate and Graduate Students

ERIC Educational Resources Information Center

Stock, Naomi L.; March, Raymond E.

2014-01-01

Electrospray ionization-mass spectrometry (ESI-MS) is a powerful technique for the detection, identification, and quantification of organic compounds. As mass spectrometers have become more user-friendly and affordable, many students--often with little experience in mass spectrometry--find themselves needing to incorporate mass spectrometry into…

Poster: "Energy Search."

ERIC Educational Resources Information Center

Social Education, 1982

1982-01-01

Contains a poster dealing with energy uses for use in secondary-level classes. On the reverse side of the poster, there is a discussion of alternative energy resources. Activities in which students calculate the operating costs of solar-powered cars and the size of solar collectors needed to heat water are included. (AM)

Modeling the Discrimination Power of Physics Items

ERIC Educational Resources Information Center

Mesic, Vanes

2011-01-01

For the purposes of tailoring physics instruction in accordance with the needs and abilities of the students it is useful to explore the knowledge structure of students of different ability levels. In order to precisely differentiate the successive, characteristic states of student achievement it is necessary to use test items that possess…

ON THE SUBJECT OF HYPOTHESIS TESTING

PubMed Central

Ugoni, Antony

1993-01-01

In this paper, the definition of a statistical hypothesis is discussed, and the considerations which need to be addressed when testing a hypothesis. In particular, the p-value, significance level, and power of a test are reviewed. Finally, the often quoted confidence interval is given a brief introduction. PMID:17989768

Temperature control system for a J-module heat exchanger

DOEpatents

Basdekas, Demetrios L.; Macrae, George; Walsh, Joseph M.

1978-01-01

The level of primary fluid is controlled to change the effective heat transfer area of a heat exchanger utilized in a liquid metal nuclear power plant to eliminate the need for liquid metal control valves to regulate the flow of primary fluid and the temperature of the effluent secondary fluid.

Competency Based Curriculum for Clothing Services and Production Sewing.

ERIC Educational Resources Information Center

Blake, Charlotte

Designed to meet individual needs and learning levels of high school and postsecondary students enrolled in vocational training for occupations in clothing services and production sewing, this competency-based curriculum teaches skills in alterations, dressmaking, and power sewing machine operations. Skills are organized into 13 units: Awareness…

An Educative, Values-Engaged Approach to Evaluating STEM Educational Programs

ERIC Educational Resources Information Center

Greene, Jennifer C.; DeStefano, Lizanne; Burgon, Holli; Hall, Jori

2006-01-01

There is concern that the nation's schools are not preparing students to excel in science, technology, engineering, and mathematics (STEM) fields. At both precollege and postsecondary levels, much effort is needed to create and implement powerful STEM curricula, prepare and support highly qualified teachers, deliver effective instruction, and give…

High-power lasers for directed-energy applications.

PubMed

Sprangle, Phillip; Hafizi, Bahman; Ting, Antonio; Fischer, Richard

2015-11-01

In this article, we review and discuss the research programs at the Naval Research Laboratory (NRL) on high-power lasers for directed-energy (DE) applications in the atmosphere. Physical processes affecting propagation include absorption/scattering, turbulence, and thermal blooming. The power levels needed for DE applications require combining a number of lasers. In atmospheric turbulence, there is a maximum intensity that can be placed on a target that is independent of the initial beam spot size and laser beam quality. By combining a number of kW-class fiber lasers, scientists at the NRL have successfully demonstrated high-power laser propagation in a turbulent atmosphere and wireless recharging. In the NRL experiments, four incoherently combined fiber lasers having a total power of 5 kW were propagated to a target 3.2 km away. These successful high-power experiments in a realistic atmosphere formed the basis of the Navy's Laser Weapon System. We compare the propagation characteristics of coherently and incoherently combined beams without adaptive optics. There is little difference in the energy on target between coherently and incoherently combined laser beams for multi-km propagation ranges and moderate to high levels of turbulence. Unlike incoherent combining, coherent combining places severe constraints on the individual lasers. These include the requirement of narrow power spectral linewidths in order to have long coherence times as well as polarization alignment of all the lasers. These requirements are extremely difficult for high-power lasers.

Need for power, collective identity, and political skill: an investigation in Taiwan.

PubMed

Randel, Amy E; Wu, Anne

2011-01-01

Research on power motivation and political skill suggests that high need for power individuals who are oriented toward others will be perceived by supervisors as being politically skilled. McClelland (1973) theorized that high need for power individuals who reflect an orientation towards others will be perceived more favorably than those who are geared toward their own self-interest. In an employee-supervisor matched sample of 149 employees in a Taiwanese financial services organization, need for power was found to interact with an orientation toward others (collective identity) to affect supervisor ratings of political skill such that high need for power individuals exhibited greater political skill when they had a strong collective identity. This finding provides empirical evidence for the importance of the socialized view of power (McClelland, 1973) and shows when need for power relates to political skill using supervisor ratings rather than a self-report measure.

A High-power Electric Propulsion Test Platform in Space

NASA Technical Reports Server (NTRS)

Petro, Andrew J.; Reed, Brian; Chavers, D. Greg; Sarmiento, Charles; Cenci, Susanna; Lemmons, Neil

2005-01-01

This paper will describe the results of the preliminary phase of a NASA design study for a facility to test high-power electric propulsion systems in space. The results of this design study are intended to provide a firm foundation for subsequent detailed design and development activities leading to the deployment of a valuable space facility. The NASA Exploration Systems Mission Directorate is sponsoring this design project. A team from the NASA Johnson Space Center, Glenn Research Center, the Marshall Space Flight Center and the International Space Station Program Office is conducting the project. The test facility is intended for a broad range of users including government, industry and universities. International participation is encouraged. The objectives for human and robotic exploration of space can be accomplished affordably, safely and effectively with high-power electric propulsion systems. But, as thruster power levels rise to the hundreds of kilowatts and up to megawatts, their testing will pose stringent and expensive demands on existing Earth-based vacuum facilities. These considerations and the human access to near-Earth space provided by the International Space Station (ISS) have led to a renewed interest in space testing. The ISS could provide an excellent platform for a space-based test facility with the continuous vacuum conditions of the natural space environment and no chamber walls to modify the open boundary conditions of the propulsion system exhaust. The test platform could take advantage of the continuous vacuum conditions of the natural space environment. Space testing would provide open boundary conditions without walls, micro-gravity and a realistic thermal environment. Testing on the ISS would allow for direct observation of the test unit, exhaust plume and space-plasma interactions. When necessary, intervention by on-board personnel and post-test inspection would be possible. The ISS can provide electrical power, a location for diagnostic instruments, data handling and thermal control. The platform will be designed to accommodate the side-by-side testing of multiple types of electric thrusters. It is intended to be a permanent facility in which different thrusters can be tested over time. ISS crews can provide maintenance for the platform and change out thruster test units as needed. The primary objective of this platform is to provide a test facility for electric propulsion devices of interest for future exploration missions. These thrusters are expected to operate in the range of hundreds of kilowatts and above. However, a platform with this capability could also accommodate testing of thrusters that require much lower power levels. Testing at the higher power levels would be accomplished by using power fiom storage devices on the platform, which would be gradually recharged by the ISS power generation system. This paper will summarize the results of the preliminary phase of the study with an explanation of the user requirements and the initial conceptual design. The concept for test operations will also be described. The NASA project team is defining the requirements but they will also reflect the inputs of the broader electric propulsion community including those at universities, commercial enterprises and other government laboratories. As a facility on the International Space Station, the design requirements are also intended to encompass the needs of international users. Testing of electric propulsion systems on the space station will help advance the development of systems needed for exploration and could also serve the needs of other customers. Propulsion systems being developed for commercial and military applications could be tested and certification testing of mature thrusters could be accomplished in the space environment.

Behavioral and biochemical dissociation of arousal and homeostatic sleep need influenced by prior wakeful experience in mice.

PubMed

Suzuki, Ayako; Sinton, Christopher M; Greene, Robert W; Yanagisawa, Masashi

2013-06-18

Sleep is regulated by homeostatic mechanisms, and the low-frequency power in the electroencephalogram (delta power) during non-rapid eye movement sleep reflects homeostatic sleep need. Additionally, sleep is limited by circadian and environmentally influenced arousal. Little is known, however, about the underlying neural substrates for sleep homeostasis and arousal and about the potential link between them. Here, we subjected C57BL/6 mice to 6 h of sleep deprivation using two different methods: gentle handling and continual cage change. Both groups were deprived of sleep to a similar extent (>99%), and, as expected, the delta power increase during recovery sleep was quantitatively similar in both groups. However, in a multiple sleep latency test, the cage change group showed significantly longer sleep latencies than the gentle handling group, indicating that the cage change group had a higher level of arousal despite the similar sleep loss. To investigate the possible biochemical correlates of these behavioral changes, we screened for arousal-related and sleep need-related phosphoprotein markers from the diencephalon. We found that the abundance of highly phosphorylated forms of dynamin 1, a presynaptic neuronal protein, was associated with sleep latency in the multiple sleep latency test. In contrast, the abundance of highly phosphorylated forms of N-myc downstream regulated gene 2, a glial protein, was increased in parallel with delta power. The changes of these protein species disappeared after 2 h of recovery sleep. These results suggest that homeostatic sleep need and arousal can be dissociated behaviorally and biochemically and that phosphorylated N-myc downstream regulated gene 2 and dynamin 1 may serve as markers of homeostatic sleep need and arousal, respectively.

The impact of stakeholder values and power relations on community-based health insurance coverage: qualitative evidence from three Senegalese case studies.

PubMed

Mladovsky, Philipa; Ndiaye, Pascal; Ndiaye, Alfred; Criel, Bart

2015-07-01

Continued low rates of enrolment in community-based health insurance (CBHI) suggest that strategies proposed for scaling up are unsuccessfully implemented or inadequately address underlying limitations of CBHI. One reason may be a lack of incorporation of social and political context into CBHI policy. In this study, the hypothesis is proposed that values and power relations inherent in social networks of CBHI stakeholders can explain levels of CBHI coverage. To test this, three case studies constituting Senegalese CBHI schemes were studied. Transcripts of interviews with 64 CBHI stakeholders were analysed using inductive coding. The five most important themes pertaining to social values and power relations were: voluntarism, trust, solidarity, political engagement and social movements. Analysis of these themes raises a number of policy and implementation challenges for expanding CBHI coverage. First is the need to subsidize salaries for CBHI scheme staff. Second is the need to develop more sustainable internal and external governance structures through CBHI federations. Third is ensuring that CBHI resonates with local values concerning four dimensions of solidarity (health risk, vertical equity, scale and source). Government subsidies is one of the several potential strategies to achieve this. Fourth is the need for increased transparency in national policy. Fifth is the need for CBHI scheme leaders to increase their negotiating power vis-à-vis health service providers who control the resources needed for expanding CBHI coverage, through federations and a social movement dynamic. Systematically addressing all these challenges would represent a fundamental reform of the current CBHI model promoted in Senegal and in Africa more widely; this raises issues of feasibility in practice. From a theoretical perspective, the results suggest that studying values and power relations among stakeholders in multiple case studies is a useful complement to traditional health systems analysis. Published by Oxford University Press in association with The London School of Hygiene and Tropical Medicine © The Author 2014; all rights reserved.

Orbital Space Solar Power Option for a Lunar Village

NASA Technical Reports Server (NTRS)

Johnson, Les

2017-01-01

One of the most significant challenges to the implementation of a continuously manned lunar base is power. During the lunar day (14 Earth days), it is conceptually simple to deploy solar arrays to generate the estimated 35 kilowatts of continuous power required. However, generating this level of power during the lunar night (also 14 Earth days) has been an extremely difficult problem to solve. Conventional solutions range from the requirement that the base be located at the lunar south pole so as to take advantage of the continuous sunshine available there to developing a space-qualified nuclear reactor and power plant to generate the needed energy. There is a third option: Use the soon-to-be-available Space Launch System to place a space based solar power station in lunar orbit that would beam the needed energy to the lunar base. Several detailed studies have been performed by NASA, universities and others looking at the lunar south pole for locating the base. The results are encouraging: by taking advantage of the moon's orbital tilt, large solar arrays can be deployed there to track the sun continuously and generate the power needed to sustain the base. The problem with this approach is inherent to its design: it will only work at the lunar south pole. There is no other site on the Moon with geometry favorable to generating continuous solar power. NASA has also considered the development of a compact fission reactor and power plant to generate the needed power, allowing the base to be sited anywhere on the Moon. The problem with this approach is that there are no space fission reactors available, none are being planned and the cost of developing one is prohibitively expensive. Using an orbiting space based solar power station to generate electrical power and beam it to a base sited anywhere on the moon should therefore be considered. The technology to collect sunlight, generate greater than the estimated 35 kilowatts of power, and beam it to the surface using microwaves is available today. The problem with this concept in the past would have been the mass and packaging volume (for launch) required to put such a system in place in lunar orbit. This problem is potentially solved with the advent of the Space Launch System (SLS). The SLS, with its 70 mT launch capacity, it more than capable of placing such a system into lunar orbit in a single launch. This paper will examine the potential use of an SLS-launched, space solar power system in lunar orbit as the primary power source for a first-generation, continuously-occupied lunar base and compare it with the other power generation and storage options previously considered.

Cancer genetic counseling: communication and counselees' post-visit satisfaction, cognitions, anxiety, and needs fulfillment.

PubMed

Pieterse, Arwen H; van Dulmen, Alexandra M; Beemer, Frits A; Bensing, Jozien M; Ausems, Margreet G E M

2007-02-01

Little is known about the relation between communication during cancer genetic counseling and outcome. We assessed associations between counselor-counselee communication and counselee satisfaction, cognitions, anxiety, and fulfillment of major needs, corrected for pre-visit levels as appropriate. In total 171 consecutive new counselees, mainly referred for breast or colon cancer, received pre- and post-visit questionnaires assessing needs/fulfillment, knowledge, perceived control (PPC), anxiety (STAI), and satisfaction. Initial visits were videotaped and counselor eye gaze was recorded. Verbal communication was rated by Roter Interaction Analysis System (RIAS). Asking more medical questions was associated with lower satisfaction levels. Receiving more medical information was related to higher correct knowledge scores, higher reported fulfillment of some needs, and unrelated to perceptions of control. Receiving more psychosocial information and longer counselor eye gaze were related to higher anxiety scores. Longer visits were related to higher correct knowledge scores. Providing medical information appears the most powerful communication aspect to increase counselee satisfaction and address needs. More research is needed on how to address adequately (emotional) needs and increase feelings of control.

Power conditioning equipment for a thermoelectric outer planet spacecraft, volume 1, book 1

NASA Technical Reports Server (NTRS)

Andrews, R. E. (Editor)

1972-01-01

Equipment was designed to receive power from a radioisotope thermoelectric generator source, condition, distribute, and control this power for the spacecraft loads. The TOPS mission, aimed at a representative tour of the outer planets, would operate for an estimated 12 year period. Unique design characteristics required for the power conditioning equipment results from the long mission time and the need for autonomous on-board operations due to large communications distances and the associated time delays of ground initiated actions. The salient features of the selected power subsystem configuration are: (1) The PCE regulates the power from the radioisotope thermoelectric generator power source at 30 vdc by means of a quad-redundant shunt regulator; (2) 30 vdc power is used by certain loads, but is more generally inverted and distributed as square-wave ac power; (3) a protected bus is used to assure that power is always available to the control computer subsystem to permit corrective action to be initiated in response to fault conditions; and (4) various levels of redundancy are employed to provide high subsystem reliability.

Power Controller

NASA Technical Reports Server (NTRS)

1982-01-01

The device called the Power Factor Controller (PFC) offers exceptional energy conservation potential by virtue of its ability to sense shifts in the relationship between voltage and current flow, and to match them with the motor's need. Originating from the solar heating/cooling program, the PFC senses a light load, it cuts the voltage level to the minimum needed which in turn reduces current flow and heat loss. Laboratory tests showed that the PFC could reduce power used by six to eight percent under normal motor loads, and as much as 65 percent when the motor was idling. Over 150 companies have been granted NASA licenses for commercial use of this technology. One system that utilizes this technology is the Vectrol Energy System, (VES) produced by Vectrol, Inc. a subsidiary of Westinghouse. The VES is being used at Woodward & Lothrop, on their escalators. Energy use is regulated according to how many people are on the escalator at any time. It is estimated that the energy savings are between 30 to 40 percent.

Solar Pumped High Power Solid State Laser for Space Applications

NASA Technical Reports Server (NTRS)

Fork, Richard L.; Laycock, Rustin L.; Green, Jason J. A.; Walker, Wesley W.; Cole, Spencer T.; Frederick, Kevin B.; Phillips, Dane J.

2004-01-01

Highly coherent laser light provides a nearly optimal means of transmitting power in space. The simplest most direct means of converting sunlight to coherent laser light is a solar pumped laser oscillator. A key need for broadly useful space solar power is a robust solid state laser oscillator capable of operating efficiently in near Earth space at output powers in the multi hundred kilowatt range. The principal challenges in realizing such solar pumped laser oscillators are: (1) the need to remove heat from the solid state laser material without introducing unacceptable thermal shock, thermal lensing, or thermal stress induced birefringence to a degree that improves on current removal rates by several orders of magnitude and (2) to introduce sunlight at an effective concentration (kW/sq cm of laser cross sectional area) that is several orders of magnitude higher than currently available while tolerating a pointing error of the spacecraft of several degrees. We discuss strategies for addressing these challenges. The need to remove the high densities of heat, e.g., 30 kW/cu cm, while keeping the thermal shock, thermal lensing and thermal stress induced birefringence loss sufficiently low is addressed in terms of a novel use of diamond integrated with the laser material, such as Ti:sapphire in a manner such that the waste heat is removed from the laser medium in an axial direction and in the diamond in a radial direction. We discuss means for concentrating sunlight to an effective areal density of the order of 30 kW/sq cm. The method integrates conventional imaging optics, non-imaging optics and nonlinear optics. In effect we use a method that combines some of the methods of optical pumping solid state materials and optical fiber, but also address laser media having areas sufficiently large, e.g., 1 cm diameter to handle the multi-hundred kilowatt level powers needed for space solar power.

Cloud-Based Orchestration of a Model-Based Power and Data Analysis Toolchain

NASA Technical Reports Server (NTRS)

Post, Ethan; Cole, Bjorn; Dinkel, Kevin; Kim, Hongman; Lee, Erich; Nairouz, Bassem

2016-01-01

The proposed Europa Mission concept contains many engineering and scientific instruments that consume varying amounts of power and produce varying amounts of data throughout the mission. System-level power and data usage must be well understood and analyzed to verify design requirements. Numerous cross-disciplinary tools and analysis models are used to simulate the system-level spacecraft power and data behavior. This paper addresses the problem of orchestrating a consistent set of models, tools, and data in a unified analysis toolchain when ownership is distributed among numerous domain experts. An analysis and simulation environment was developed as a way to manage the complexity of the power and data analysis toolchain and to reduce the simulation turnaround time. A system model data repository is used as the trusted store of high-level inputs and results while other remote servers are used for archival of larger data sets and for analysis tool execution. Simulation data passes through numerous domain-specific analysis tools and end-to-end simulation execution is enabled through a web-based tool. The use of a cloud-based service facilitates coordination among distributed developers and enables scalable computation and storage needs, and ensures a consistent execution environment. Configuration management is emphasized to maintain traceability between current and historical simulation runs and their corresponding versions of models, tools and data.

Relation of the lunar power system to the SEI program and to landers

NASA Technical Reports Server (NTRS)

Criswell, David R.; Waldron, Robert D.

1992-01-01

The people of Earth will need more than 20,000 billion watts (GWe) of electric power by 2050 for a high level of prosperity. Power needs in the 22nd Century could exceed 100,000 GWe. By 2100 the total quantity of thermal energy used could fully deplete the known inventory (10(exp 7) GWt-Y) of all non-renewable sources on Earth except for deuterium and hydrogen for use in proposed fusion reactors. The labor, capital, and mass of power plants required to produce 1 GWe-Y of energy from present-day power plants is summarized. Fossil and nuclear plants respectively consume 80 to 190 M$ and 12 to 48 M$ of fuel per GWe-Y. The Lunar Power System (LPS) uses solar power bases on the moon to beam electric power to Earth. The LPS in the figure supplies load-following power to rectennas on Earth. Additional solar power conversion units are located across the lunar limb from their respective Earthward transmitting stations. LPS can be augmented by mirrors in polar orbit about the moon. The construction of rectennas on Earth determines the base cost (0.001s$/kWe-H) of LPS power. A manned International Lunar Base (ILB) can accelerate the development of LPS by providing the initial transportation and habitation facilities and base operations. ILB can greatly reduce up front costs and risks by emplacing a moderate scale LPS (1-100 GWe). LPS can accelerate the development of the ILB by providing greater funding than is reasonable to expect for purely scientific research. An international ILB/LPS program can foster world trust and prosperity.

Relation of the lunar power system to the SEI program and to landers

NASA Astrophysics Data System (ADS)

Criswell, David R.; Waldron, Robert D.

The people of Earth will need more than 20,000 billion watts (GWe) of electric power by 2050 for a high level of prosperity. Power needs in the 22nd Century could exceed 100,000 GWe. By 2100 the total quantity of thermal energy used could fully deplete the known inventory (10(exp 7) GWt-Y) of all non-renewable sources on Earth except for deuterium and hydrogen for use in proposed fusion reactors. The labor, capital, and mass of power plants required to produce 1 GWe-Y of energy from present-day power plants is summarized. Fossil and nuclear plants respectively consume 80 to 190 M$ and 12 to 48 M$ of fuel per GWe-Y. The Lunar Power System (LPS) uses solar power bases on the moon to beam electric power to Earth. The LPS in the figure supplies load-following power to rectennas on Earth. Additional solar power conversion units are located across the lunar limb from their respective Earthward transmitting stations. LPS can be augmented by mirrors in polar orbit about the moon. The construction of rectennas on Earth determines the base cost (0.001s$/kWe-H) of LPS power. A manned International Lunar Base (ILB) can accelerate the development of LPS by providing the initial transportation and habitation facilities and base operations. ILB can greatly reduce up front costs and risks by emplacing a moderate scale LPS (1-100 GWe). LPS can accelerate the development of the ILB by providing greater funding than is reasonable to expect for purely scientific research. An international ILB/LPS program can foster world trust and prosperity.

Community-level climate change vulnerability research: trends, progress, and future directions

NASA Astrophysics Data System (ADS)

McDowell, Graham; Ford, James; Jones, Julie

2016-03-01

This study systematically identifies, characterizes, and critically evaluates community-level climate change vulnerability assessments published over the last 25 years (n = 274). We find that while the field has advanced considerably in terms of conceptual framing and methodological approaches, key shortcomings remain in how vulnerability is being studied at the community-level. We argue that vulnerability research needs to more critically engage with the following: methods for evaluating future vulnerability, the relevance of vulnerability research for decision-making, interdependencies between social and ecological systems, attention to researcher / subject power dynamics, critical interpretation of key terms, and consideration of the potentially positive opportunities presented by a changing climate. Addressing these research needs is necessary for generating knowledge that supports climate-affected communities in navigating the challenges and opportunities ahead.

Temporal variations in Global Seismic Stations ambient noise power levels

USGS Publications Warehouse

Ringler, A.T.; Gee, L.S.; Hutt, C.R.; McNamara, D.E.

2010-01-01

Recent concerns about time-dependent response changes in broadband seismometers have motivated the need for methods to monitor sensor health at Global Seismographic Network (GSN) stations. We present two new methods for monitoring temporal changes in data quality and instrument response transfer functions that are independent of Earth seismic velocity and attenuation models by comparing power levels against different baseline values. Our methods can resolve changes in both horizontal and vertical components in a broad range of periods (∼0.05 to 1,000 seconds) in near real time. In this report, we compare our methods with existing techniques and demonstrate how to resolve instrument response changes in long-period data (>100 seconds) as well as in the microseism bands (5 to 20 seconds).

Space power for space

NASA Technical Reports Server (NTRS)

Mullin, J. P.

1978-01-01

The total energy demanded by space missions of the future is expected to exceed past needs by orders of magnitude. The unit costs of this energy must be reduced from present levels if these missions are to be carried out at projected budget levels. The broad employment of electric propulsion and the capability to utilize novel high power sensors hinge on the availability of systems lighter by factors of ten or more than have flown to date. The NASA program aimed at providing the technological basis to meet these demands is described in this paper. Research and technology efforts in areas of energy conversion, storage and management are covered. In addition, work aimed at evolving the understanding necessary to cope with space environment interactions and at advanced concepts is described.

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

Hu, Enyuan; Wang, Xuelong; Yu, Xiqian

The rechargeable lithium-ion battery (LIB) is the most promising energy storage system to power electric vehicles with high energy density and long cycling life. However, in order to meet customers’ demands for fast charging, the power performances of current LIBs need to be improved. From the cathode aspect, layer-structured cathode materials are widely used in today’s market and will continue to play important roles in the near future. The high rate capability of layered cathode materials during charging and discharging is critical to the power performance of the whole cell and the thermal stability is closely related to the safetymore » issues. Therefore, the in-depth understanding of structural changes of layered cathode materials during high rate charging/discharging and the thermal stability during heating are essential in developing new materials and improving current materials. Since structural changes take place from the atomic level to the whole electrode level, combination of characterization techniques covering multilength scales is quite important. Finally, in many cases, this means using comprehensive tools involving diffraction, spectroscopy, and imaging to differentiate the surface from the bulk and to obtain structural/chemical information with different levels of spatial resolution.« less

The Power Within: The Experimental Manipulation of Power Interacts with Trait BDD Symptoms to Predict Interoceptive Accuracy

PubMed Central

Kunstman, Jonathan W.; Clerkin, Elise M.; Palmer, Kateyln; Peters, M. Taylar; Dodd, Dorian R.; Smith, April R.

2015-01-01

Background and Objectives This study tested whether relatively low levels of interoceptive accuracy (IAcc) are associated with body dysmorphic disorder (BDD) symptoms. Additionally, given research indicating that power attunes individuals to their internal states, we sought to determine if state interoceptive accuracy could be improved through an experimental manipulation of power. Method Undergraduate women (N = 101) completed a baseline measure of interoceptive accuracy and then were randomized to a power or control condition. Participants were primed with power or a neutral control topic and then completed a post-manipulation measure of state IAcc. Trait BDD symptoms were assessed with a self-report measure. Results Controlling for baseline IAcc, within the control condition, there was a significant inverse relationship between trait BDD symptoms and interoceptive accuracy. Continuing to control for baseline IAcc, within the power condition, there was not a significant relationship between trait BDD symptoms and IAcc, suggesting that power may have attenuated this relationship. At high levels of BDD symptomology, there was also a significant simple effect of experimental condition, such that participants in the power (vs. control) condition had better interoceptive accuracy. These results provide initial evidence that power may positively impact interoceptive accuracy among those with high levels of BDD symptoms. Limitations This cross-sectional study utilized a demographically homogenous sample of women that reflected a broad range of symptoms; thus, although there were a number of participants reporting elevated BDD symptoms, these findings might not generalize to other populations or clinical samples. Conclusions . This study provides the first direct test of the relationship between trait BDD symptoms and IAcc, and provides preliminary evidence that among those with severe BDD symptoms, power may help connect individuals with their internal states. Future research testing the mechanisms linking BDD symptoms with IAcc, as well as how individuals can better connect with their internal experiences is needed. PMID:26295932

The power within: The experimental manipulation of power interacts with trait BDD symptoms to predict interoceptive accuracy.

PubMed

Kunstman, Jonathan W; Clerkin, Elise M; Palmer, Kateyln; Peters, M Taylar; Dodd, Dorian R; Smith, April R

2016-03-01

This study tested whether relatively low levels of interoceptive accuracy (IAcc) are associated with body dysmorphic disorder (BDD) symptoms. Additionally, given research indicating that power attunes individuals to their internal states, we sought to determine if state interoceptive accuracy could be improved through an experimental manipulation of power.. Undergraduate women (N = 101) completed a baseline measure of interoceptive accuracy and then were randomized to a power or control condition. Participants were primed with power or a neutral control topic and then completed a post-manipulation measure of state IAcc. Trait BDD symptoms were assessed with a self-report measure. Controlling for baseline IAcc, within the control condition, there was a significant inverse relationship between trait BDD symptoms and interoceptive accuracy. Continuing to control for baseline IAcc, within the power condition, there was not a significant relationship between trait BDD symptoms and IAcc, suggesting that power may have attenuated this relationship. At high levels of BDD symptomology, there was also a significant simple effect of experimental condition, such that participants in the power (vs. control) condition had better interoceptive accuracy. These results provide initial evidence that power may positively impact interoceptive accuracy among those with high levels of BDD symptoms.. This cross-sectional study utilized a demographically homogenous sample of women that reflected a broad range of symptoms; thus, although there were a number of participants reporting elevated BDD symptoms, these findings might not generalize to other populations or clinical samples. This study provides the first direct test of the relationship between trait BDD symptoms and IAcc, and provides preliminary evidence that among those with severe BDD symptoms, power may help connect individuals with their internal states. Future research testing the mechanisms linking BDD symptoms with IAcc, as well as how individuals can better connect with their internal experiences is needed.. Copyright © 2015 Elsevier Ltd. All rights reserved.

Sample Size in Clinical Cardioprotection Trials Using Myocardial Salvage Index, Infarct Size, or Biochemical Markers as Endpoint.

PubMed

Engblom, Henrik; Heiberg, Einar; Erlinge, David; Jensen, Svend Eggert; Nordrehaug, Jan Erik; Dubois-Randé, Jean-Luc; Halvorsen, Sigrun; Hoffmann, Pavel; Koul, Sasha; Carlsson, Marcus; Atar, Dan; Arheden, Håkan

2016-03-09

Cardiac magnetic resonance (CMR) can quantify myocardial infarct (MI) size and myocardium at risk (MaR), enabling assessment of myocardial salvage index (MSI). We assessed how MSI impacts the number of patients needed to reach statistical power in relation to MI size alone and levels of biochemical markers in clinical cardioprotection trials and how scan day affect sample size. Controls (n=90) from the recent CHILL-MI and MITOCARE trials were included. MI size, MaR, and MSI were assessed from CMR. High-sensitivity troponin T (hsTnT) and creatine kinase isoenzyme MB (CKMB) levels were assessed in CHILL-MI patients (n=50). Utilizing distribution of these variables, 100 000 clinical trials were simulated for calculation of sample size required to reach sufficient power. For a treatment effect of 25% decrease in outcome variables, 50 patients were required in each arm using MSI compared to 93, 98, 120, 141, and 143 for MI size alone, hsTnT (area under the curve [AUC] and peak), and CKMB (AUC and peak) in order to reach a power of 90%. If average CMR scan day between treatment and control arms differed by 1 day, sample size needs to be increased by 54% (77 vs 50) to avoid scan day bias masking a treatment effect of 25%. Sample size in cardioprotection trials can be reduced 46% to 65% without compromising statistical power when using MSI by CMR as an outcome variable instead of MI size alone or biochemical markers. It is essential to ensure lack of bias in scan day between treatment and control arms to avoid compromising statistical power. © 2016 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Scaling considerations for a multi-megawatt class supercritical CO2 brayton cycle and commercialization.

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

Fleming, Darryn D.; Holschuh, Thomas Vernon,; Conboy, Thomas M.

2013-11-01

Small-scale supercritical CO2 demonstration loops are successful at identifying the important technical issues that one must face in order to scale up to larger power levels. The Sandia National Laboratories supercritical CO2 Brayton cycle test loops are identifying technical needs to scale the technology to commercial power levels such as 10 MWe. The small size of the Sandia 1 MWth loop has demonstration of the split flow loop efficiency and effectiveness of the Printed Circuit Heat Exchangers (PCHXs) leading to the design of a fully recuperated, split flow, supercritical CO2 Brayton cycle demonstration system. However, there were many problems thatmore » were encountered, such as high rotational speeds in the units. Additionally, the turbomachinery in the test loops need to identify issues concerning the bearings, seals, thermal boundaries, and motor controller problems in order to be proved a reliable power source in the 300 kWe range. Although these issues were anticipated in smaller demonstration units, commercially scaled hardware would eliminate these problems caused by high rotational speeds at small scale. The economic viability and development of the future scalable 10 MWe solely depends on the interest of DOE and private industry. The Intellectual Property collected by Sandia proves that the ~10 MWe supercritical CO2 power conversion loop to be very beneficial when coupled to a 20 MWth heat source (either solar, geothermal, fossil, or nuclear). This paper will identify a commercialization plan, as well as, a roadmap from the simple 1 MWth supercritical CO2 development loop to a power producing 10 MWe supercritical CO2 Brayton loop.« less

Intermediate Levels of Autonomy within the SSM/PMAD Breadboard

NASA Technical Reports Server (NTRS)

Dugal-Whitehead, Norma R.; Walls, Bryan

1995-01-01

The Space Station Module Power Management and Distribution (SSM/PMAD) bread-board is a test bed for the development of advanced power system control and automation. Software control in the SSM/PMAD breadboard is through co-operating systems, called Autonomous Agents. Agents can be a mixture of algorithmic software and expert systems. The early SSM/PMAD system was envisioned as being completely autonomous. It soon became apparent, though, that there would always be a need for human intervention, at least as long as a human interacts with the system in any way. In a system designed only for autonomous operation, manual intervention meant taking full control of the whole system, and loosing whatever expertise was in the system. Several methods for allowing humans to interact at an appropriate level of control were developed. This paper examines some of these intermediate modes of autonomy. The least humanly intrusive mode is simple monitoring. The ability to modify future behavior by altering a schedule involves high-level interaction. Modification of operating activities comes next. The coarsest mode of control is individual, unplanned operation of individual Power System components. Each of these levels is integrated into the SSM/PMAD breadboard, with support for the user (such as warnings of the consequences of control decisions) at every level.

Nuclear Systems Kilopower Overview

NASA Technical Reports Server (NTRS)

Palac, Don; Gibson, Marc; Mason, Lee; Houts, Michael; McClure, Patrick; Robinson, Ross

2016-01-01

The Nuclear Systems Kilopower Project was initiated by NASAs Space Technology Mission Directorate Game Changing Development Program in fiscal year 2015 to demonstrate subsystem-level technology readiness of small space fission power in a relevant environment (Technology Readiness Level 5) for space science and human exploration power needs. The Nuclear Systems Kilopower Project consists of two elements. The primary element is the Kilopower Prototype Test, also called the Kilopower Reactor Using Stirling Technology(KRUSTY) Test. This element consists of the development and testing of a fission ground technology demonstrator of a 1 kWe fission power system. A 1 kWe system matches requirements for some robotic precursor exploration systems and future potential deep space science missions, and also allows a nuclear ground technology demonstration in existing nuclear test facilities at low cost. The second element, the Mars Kilopower Scalability Study, consists of the analysis and design of a scaled-up version of the 1 kWe reference concept to 10 kWe for Mars surface power projected requirements, and validation of the applicability of the KRUSTY experiment to key technology challenges for a 10 kWe system. If successful, these two elements will lead to initiation of planning for a technology demonstration of a 10 kWe fission power capability for Mars surface outpost power.

Parylene-C passivation and effects on rectennas' wireless power transfer performance

NASA Astrophysics Data System (ADS)

Cooper, Camille; Eldridge, Keisharra; Kim, Min H.; Yoon, Hargsoon; Choi, Sang H.; Song, Kyo D.

2014-04-01

In this study, the effect of Parylene-C coated as a passivation layer on various rectennas is investigated in terms of their wireless power transfer performance. A passivation has been used for protection of rectenna circuits and their packaging in order for protection of the circuit elements and electrical insulation. Especially, wireless power receiving rectennas attached on sensors or on moving vehicles such as airship needs proper protection while they are exposed to harsh environment. In this research, a layer of Parylene-C thin film is used for passivation on rectennas and electromagnetic coupling by the coating is assessed by the measurement of receiving power levels. In this research, an electrochemical analysis method will also be introduced to measure the degree of water protection by a Parylene-C layer.

The efficiency of ultrasonic oscillations transfer into the load

NASA Astrophysics Data System (ADS)

Abramov, O. V.; Abramov, V. O.; Mullakaev, M. S.; Artem'ev, V. V.

2009-11-01

The results of ultrasonic action to the substances have been presented. It is examined, the correlation between the electrical parameters of ultrasonic equipment and acoustic performances of the ultrasonic field in treating the medium, the efficiency of ultrasonic technological facility, and the peculiarities of oscillations introduced into the load under cavitation development. The correlation between the acoustic powers of oscillations securing the needed level of cavitation and desired technological effect, and the electrical parameters of the ultrasonic facility, first of all, the power, is established. The peculiarities of cavitation development in liquids with different physical-chemical properties (including the molten low-melting metals) have been studied, and the acoustic power of oscillations introduced into the load under input variation of electric power to the generator has been also estimated.

Stimulating investment in energy materials and technologies to combat climate change: an overview of learning curve analysis and niche market support.

PubMed

Foxon, Timothy J

2010-07-28

This paper addresses the probable levels of investment needed in new technologies for energy conversion and storage that are essential to address climate change, drawing on past evidence on the rate of cost improvements in energy technologies. A range of energy materials and technologies with lower carbon emissions over their life cycle are being developed, including fuel cells (FCs), hydrogen storage, batteries, supercapacitors, solar energy and nuclear power, and it is probable that most, if not all, of these technologies will be needed to mitigate climate change. High rates of innovation and deployment will be needed to meet targets such as the UK's goal of reducing its greenhouse gas emissions by 80 per cent by 2050, which will require significant levels of investment. Learning curves observed for reductions in unit costs of energy technologies, such as photovoltaics and FCs, can provide evidence on the probable future levels of investment needed. The paper concludes by making recommendations for policy measures to promote such investment from both the public and private sectors.

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

Baker, Kyri; Toomey, Bridget

Evolving power systems with increasing levels of stochasticity call for a need to solve optimal power flow problems with large quantities of random variables. Weather forecasts, electricity prices, and shifting load patterns introduce higher levels of uncertainty and can yield optimization problems that are difficult to solve in an efficient manner. Solution methods for single chance constraints in optimal power flow problems have been considered in the literature, ensuring single constraints are satisfied with a prescribed probability; however, joint chance constraints, ensuring multiple constraints are simultaneously satisfied, have predominantly been solved via scenario-based approaches or by utilizing Boole's inequality asmore » an upper bound. In this paper, joint chance constraints are used to solve an AC optimal power flow problem while preventing overvoltages in distribution grids under high penetrations of photovoltaic systems. A tighter version of Boole's inequality is derived and used to provide a new upper bound on the joint chance constraint, and simulation results are shown demonstrating the benefit of the proposed upper bound. The new framework allows for a less conservative and more computationally efficient solution to considering joint chance constraints, specifically regarding preventing overvoltages.« less

Comparative study between single core model and detail core model of CFD modelling on reactor core cooling behaviour

NASA Astrophysics Data System (ADS)

Darmawan, R.

2018-01-01

Nuclear power industry is facing uncertainties since the occurrence of the unfortunate accident at Fukushima Daiichi Nuclear Power Plant. The issue of nuclear power plant safety becomes the major hindrance in the planning of nuclear power program for new build countries. Thus, the understanding of the behaviour of reactor system is very important to ensure the continuous development and improvement on reactor safety. Throughout the development of nuclear reactor technology, investigation and analysis on reactor safety have gone through several phases. In the early days, analytical and experimental methods were employed. For the last four decades 1D system level codes were widely used. The continuous development of nuclear reactor technology has brought about more complex system and processes of nuclear reactor operation. More detailed dimensional simulation codes are needed to assess these new reactors. Recently, 2D and 3D system level codes such as CFD are being explored. This paper discusses a comparative study on two different approaches of CFD modelling on reactor core cooling behaviour.

A Figure-of-Merit for Designing High-Performance Inductive Power Transmission Links

PubMed Central

Kiani, Mehdi; Ghovanloo, Maysam

2014-01-01

Power transfer efficiency (PTE) and power delivered to the load (PDL) are two key inductive link design parameters that relate to the power source and driver specs, power loss, transmission range, robustness against misalignment, variations in loading, and interference with other devices. Designers need to strike a delicate balance between these two because designing the link to achieve high PTE will degrade the PDL and vice versa. We are proposing a new figure-of-merit (FoM), which can help designers to find out whether a two-, three-, or four-coil link is appropriate for their particular application and guide them through an iterative design procedure to reach optimal coil geometries based on how they weigh the PTE versus PDL for that application. Three design examples at three different power levels have been presented based on the proposed FoM for implantable microelectronic devices, handheld mobile devices, and electric vehicles. The new FoM suggests that the two-coil links are suitable when the coils are strongly coupled, and a large PDL is needed. Three-coil links are the best when the coils are loosely coupled, the coupling distance varies considerably, and large PDL is necessary. Finally, four-coil links are optimal when the PTE is paramount, the coils are loosely coupled, and their relative distance and alignment are stable. Measurement results support the accuracy of the theoretical design procedure and conclusions. PMID:25382898

A Figure-of-Merit for Designing High-Performance Inductive Power Transmission Links.

PubMed

Kiani, Mehdi; Ghovanloo, Maysam

2012-11-16

Power transfer efficiency (PTE) and power delivered to the load (PDL) are two key inductive link design parameters that relate to the power source and driver specs, power loss, transmission range, robustness against misalignment, variations in loading, and interference with other devices. Designers need to strike a delicate balance between these two because designing the link to achieve high PTE will degrade the PDL and vice versa. We are proposing a new figure-of-merit (FoM), which can help designers to find out whether a two-, three-, or four-coil link is appropriate for their particular application and guide them through an iterative design procedure to reach optimal coil geometries based on how they weigh the PTE versus PDL for that application. Three design examples at three different power levels have been presented based on the proposed FoM for implantable microelectronic devices, handheld mobile devices, and electric vehicles. The new FoM suggests that the two-coil links are suitable when the coils are strongly coupled, and a large PDL is needed. Three-coil links are the best when the coils are loosely coupled, the coupling distance varies considerably, and large PDL is necessary. Finally, four-coil links are optimal when the PTE is paramount, the coils are loosely coupled, and their relative distance and alignment are stable. Measurement results support the accuracy of the theoretical design procedure and conclusions.

A scheme for a high-power, low-cost transmitter for deep space applications

NASA Astrophysics Data System (ADS)

Scheffer, L. K.

2005-10-01

Applications such as planetary radars and spacecraft communications require transmitters with extremely high effective isotropic radiated power. Until now, this has been done by combining a high-power microwave source with a large reflective antenna. However, this arrangement has a number of disadvantages. It is costly, since the steerable reflector alone is quite expensive, and for spacecraft communications, the need to transmit hurts the receive performance. For planetary radars, the utilization is very low since the antenna must be shared with other applications such as radio astronomy or spacecraft communications. This paper describes a potential new way of building such transmitters with lower cost, greater versatility, higher reliability, and potentially higher power. The basic idea is a phased array with a very large number of low-power elements, built with mass production techniques that have been optimized for consumer markets. The antennas are built en mass on printed circuit boards and are driven by chips, built with consumer complementary metal-oxide-semiconductor technology, that adjust the phase of each element. Assembly and maintenance should be comparatively inexpensive since the boards need only be attached to large, flat, unmoving, ground-level infrastructure. Applications to planetary radar and spacecraft communications are examined. Although we would be unlikely to use such a facility in this way, an implication for Search for Extraterrestrial Intelligence (SETI) is that high-power beacons are easier to build than had been thought.

Pulse power 350 V nickel-metal hydride battery power-D-005-00181

NASA Astrophysics Data System (ADS)

Eskra, Michael D.; Ralston, Paula; Salkind, Alvin; Plivelich, Robert F.

Energy-storage devices are needed for applications requiring very high-power over short periods of time. Such devices have various military (rail guns, electromagnetic launchers, and DEW) and commercial applications, such as hybrid electric vehicles, vehicle starting (SLI), and utility peak shaving. The storage and delivery of high levels of burst power can be achieved with a capacitor, flywheel, or rechargeable battery. In order to reduce the weight and volume of many systems they must contain advanced state-of-the-art electrochemical or electromechanical power sources. There is an opportunity and a need to develop energy-storage devices that have improved high-power characteristics compared to existing ultra capacitors, flywheels or rechargeable batteries. Electro Energy, Inc. has been engaged in the development of bipolar nickel-metal hydride batteries, which may fulfil the requirements of some of these applications. This paper describes a module rated at 300 V (255 cells) (6 Ah). The volume of the module is 23 L and the mass is 56 kg. The module is designed to deliver 50 kW pulses of 10 s duration at 50% state-of-charge. Details of the mechanical design of the module, safety considerations, along with the results of initial electrical characterization testing by the customer will be discussed. Some discussion of the possibilities for design optimization is also included.

Overview and future direction for blackbody solar-pumped lasers

NASA Technical Reports Server (NTRS)

Deyoung, R. J.

1988-01-01

A review of solar-pumped blackbody lasers is given which addresses their present status and suggests future research directions. The blackbody laser concept is one system proposed to scale to multimegawatt power levels for space-to-space power transmissions for such applications as onboard spacecraft electrical or propulsion needs. Among the critical technical issues are the scalability to high powers and the laser wavelength which impacts the transmission optics size as well as the laser-to-electric converter at the receiver. Because present blackbody solar-pumped lasers will have laser wavelengths longer than 4 microns, simple photovoltaic converters cannot be used, and transmission optics will be large. Thus, future blackbody laser systems should emphasize near visible laser wavelengths.

A Study of the Relationship between Weather Variables and Electric Power Demand inside a Smart Grid/Smart World Framework

PubMed Central

Hernández, Luis; Baladrón, Carlos; Aguiar, Javier M.; Calavia, Lorena; Carro, Belén; Sánchez-Esguevillas, Antonio; Cook, Diane J.; Chinarro, David; Gómez, Jorge

2012-01-01

One of the main challenges of today's society is the need to fulfill at the same time the two sides of the dichotomy between the growing energy demand and the need to look after the environment. Smart Grids are one of the answers: intelligent energy grids which retrieve data about the environment through extensive sensor networks and react accordingly to optimize resource consumption. In order to do this, the Smart Grids need to understand the existing relationship between energy demand and a set of relevant climatic variables. All smart “systems” (buildings, cities, homes, consumers, etc.) have the potential to employ their intelligence for self-adaptation to climate conditions. After introducing the Smart World, a global framework for the collaboration of these smart systems, this paper presents the relationship found at experimental level between a range of relevant weather variables and electric power demand patterns, presenting a case study using an agent-based system, and emphasizing the need to consider this relationship in certain Smart World (and specifically Smart Grid and microgrid) applications.

A Case Study on Neural Inspired Dynamic Memory Management Strategies for High Performance Computing.

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

Vineyard, Craig Michael; Verzi, Stephen Joseph

As high performance computing architectures pursue more computational power there is a need for increased memory capacity and bandwidth as well. A multi-level memory (MLM) architecture addresses this need by combining multiple memory types with different characteristics as varying levels of the same architecture. How to efficiently utilize this memory infrastructure is an unknown challenge, and in this research we sought to investigate whether neural inspired approaches can meaningfully help with memory management. In particular we explored neurogenesis inspired re- source allocation, and were able to show a neural inspired mixed controller policy can beneficially impact how MLM architectures utilizemore » memory.« less

What Counts When it Comes to School Enjoyment and Aspiration in the Middle Grades.

PubMed

Smith, Megan L; Mann, Michael J; Georgieva, Zornitsa; Curtis, Reagan; Schimmel, Christine J

2016-01-01

Young adolescents, and the middle level educators who work with them, face many exciting but demanding challenges during this key period of development. According to stage-environment fit theory, the degree to which middle grades students perceive a good fit between their school environment and their needs impacts their academic and life outcomes. The authors endeavored to build on middle level research by studying the extent to which students' needs are supported by school environment factors and how this "fit" relates to two academic outcome variables: school enjoyment and aspiration. The sample consisted of middle grades students ( N = 1,027) between the ages of 10 and 14. Hierarchical logistic regression analyses were conducted. After controlling for age, ethnicity, and gender, four subscales (Social Skills Needs, Mental Health Needs, Academic and Career Needs, and School Support) were entered as potential predictors. Both models were significant and accounted for ~20% of the variance. This study suggests that middle level educators, counselors, and administrators may benefit from considering ways to enhance the match between students' and the middle grades' learning environment, especially by considering non-academic factors as a way to provide indirect, but powerful, support for academic and life success.

Are self-thinning constraints needed in a tree-specific mortality model?

Treesearch

Robert A. Monserud; Thomas Ledermann; Hubert Sterba

2005-01-01

Can a tree-specific mortality model elicit expected forest stand density dynamics without imposing stand-level constraints such as Reineke's maximum stand density index (SDImax) or the -3/2 power law of self-thinning? We examine this emergent properties question using the Austrian stand simulator PROGNAUS. This simulator was chosen...

Staying Power: The Impact of the TAP System on Retaining Teachers Nationwide

ERIC Educational Resources Information Center

Barnett, Joshua H.; Hudgens, Tanee M.

2014-01-01

Each year teacher turnover presents instructional, organizational, and financial burdens that impact students, teachers, schools, and communities. High levels of teacher turnover drain valuable resources and make it difficult to build a high performing, stable teaching faculty. This is particularly true in high need schools where teacher attrition…

Beyond Access: Effective Digital Learning for a Globalized World

ERIC Educational Resources Information Center

Best, Jane; Dunlap, Allison

2012-01-01

Digital learning, supporters say, has the power to help prepare students for the workforce, improve student learning and educator effectiveness, and bring high-quality education to those who can't otherwise access it. However, great variability exists among schools and districts in terms of level of development and needs. This policy brief serves…

SBOs Share Their Thoughts: Essential Technical and Leadership Skills

ERIC Educational Resources Information Center

McClain, E. Glenn, Jr.; King, Richard A.

2009-01-01

As an important cabinet-level position that reports directly to the superintendent and board of education, the school business official (SBO) often holds the second most powerful position in the district. Along with calls for fiscal and educational accountability, this elevated stature underscores the need for business officials to have leadership…

The size of a pilot study for a clinical trial should be calculated in relation to considerations of precision and efficiency.

PubMed

Sim, Julius; Lewis, Martyn

2012-03-01

To investigate methods to determine the size of a pilot study to inform a power calculation for a randomized controlled trial (RCT) using an interval/ratio outcome measure. Calculations based on confidence intervals (CIs) for the sample standard deviation (SD). Based on CIs for the sample SD, methods are demonstrated whereby (1) the observed SD can be adjusted to secure the desired level of statistical power in the main study with a specified level of confidence; (2) the sample for the main study, if calculated using the observed SD, can be adjusted, again to obtain the desired level of statistical power in the main study; (3) the power of the main study can be calculated for the situation in which the SD in the pilot study proves to be an underestimate of the true SD; and (4) an "efficient" pilot size can be determined to minimize the combined size of the pilot and main RCT. Trialists should calculate the appropriate size of a pilot study, just as they should the size of the main RCT, taking into account the twin needs to demonstrate efficiency in terms of recruitment and to produce precise estimates of treatment effect. Copyright © 2012 Elsevier Inc. All rights reserved.

Evaluation of Kapton pyrolysis, arc tracking, and flashover on SiO(x)-coated polyimide insulated samples of flat flexible current carriers for Space Station Freedom

NASA Technical Reports Server (NTRS)

Stueber, Thomas J.; Mundson, Chris

1993-01-01

Kapton polyimide wiring insulation was found to be vulnerable to pyrolization, arc tracking, and flashover when momentary short-circuit arcs have occurred on aircraft power systems. Short-circuit arcs between wire pairs can pyrolize the polyimide resulting in a conductive char between conductors that may sustain the arc (arc tracking). Furthermore, the arc tracking may spread (flashover) to other wire pairs within a wire bundle. Polyimide Kapton will also be used as the insulating material for the flexible current carrier (FCC) of Space Station Freedom (SSF). The FCC, with conductors in a planar type geometric layout as opposed to bundles, is known to sustain arc tracking at proposed SSF power levels. Tests were conducted in a vacuum bell jar that was designed to conduct polyimide pyrolysis, arc tracking, and flashover studies on samples of SSF's FCC. Test results will be reported concerning the minimal power level needed to sustain arc tracking and the FCC susceptibility to flashover. Results of the FCC arc tracking tests indicate that only 22 volt amps were necessary to sustain arc tracking (proposed SSF power level is 400 watts). FCC flashover studies indicate that the flashover event is highly unlikely.

Medical aspects of power generation, present and future.

PubMed

Linnemann, R E

1979-01-01

It can be seen that the radiation emissions of nuclear power plants are small indeed, compared to natural background radiation and other man-made sources of radiation. For example, the poulation is exposed to 100 times more radiation from television sets than from nuclear power reactors. The assumed risks to the people in this country from nuclear power reactors are also small compared to the normal risks which are tolerated in this society. The complete elimination of all hazards is a most difficult if not impossible task. If we need and desire a certain level of electrical energy, if we must choose between alternative sourves of the energy, then it is apparent that the total impact on our health from nuclear power generation of electricity, under normal operations and in consideration of catastrophic accident probabilities, is significantly less than that of continuing or increasing use of fossil fuels to generate electricity.

Power conditioning techniques

NASA Technical Reports Server (NTRS)

Baumann, E. D.

1989-01-01

The technological developments required to reduce the electrical power system component weights from the state-of-the-art 2.0 kg/kW to the range of 0.1 to 0.2 kg/kW are discussed. Power level requirements and their trends in aerospace applications are identified and presented. The projected weight and launch costs for a 1MW power converter built using state-of-the-art technology are established to illustrate the need for reliable, ultralightweight advanced power components. The key factors affecting converter weight are given and some of the tradeoffs between component ratings and circuit topology are identified. The weight and launch costs for a 1MW converter using 0.1 kg/kW technology are presented. Finally, the objectives and goals of the Multi-Megawatt Program at the NASA Lewis Research Center, which is funded by the SDIO through the Air Force, are given.

Wearable and Implantable Mechanical Energy Harvesters for Self-Powered Biomedical Systems.

PubMed

Hinchet, Ronan; Kim, Sang-Woo

2015-08-25

In this issue of ACS Nano, Tang et al. investigate the ability of a triboelectric nanogenerator (TENG) to self-power a low-level laser cure system for osteogenesis by studying the efficiency of a bone remodeling laser treatment that is powered by a skin-patch-like TENG instead of a battery. We outline this field by highlighting the motivations for self-powered biomedical systems and by discussing recent progress in nanogenerators. We note the overlap between biomedical devices and TENGs and their dawning synergy, and we highlight key prospects for future developments. Biomedical systems should be more autonomous. This advance could improve their body integration and fields of action, leading to new medical diagnostics and treatments. However, future self-powered biomedical systems will need to be more flexible, biocompatible, and biodegradable. These advances hold the promise of enabling new smart autonomous biomedical systems and contributing significantly to the Internet of Things.

Workshop on High Power ICH Antenna Designs for High Density Tokamaks

NASA Astrophysics Data System (ADS)

Aamodt, R. E.

1990-02-01

A workshop in high power ICH antenna designs for high density tokamaks was held to: (1) review the data base relevant to the high power heating of high density tokamaks; (2) identify the important issues which need to be addressed in order to ensure the success of the ICRF programs on CIT and Alcator C-MOD; and (3) recommend approaches for resolving the issues in a timely realistic manner. Some specific performance goals for the antenna system define a successful design effort. Simply stated these goals are: couple the specified power per antenna into the desired ion species; produce no more than an acceptable level of RF auxiliary power induced impurities; and have a mechanical structure which safely survives the thermal, mechanical and radiation stresses in the relevant environment. These goals are intimately coupled and difficult tradeoffs between scientific and engineering constraints have to be made.

Integrated soldier power and data system (ISPDS)

NASA Astrophysics Data System (ADS)

Ostroumov, Roman; Forrester, Thomas; Lee, Kang; Stephens, Robert; Lai, Anthony; Zahzah, Mohamad

2014-06-01

Physical Optics Corporation (POC) developed the body-worn Integrated Soldier Power and Data System (ISPDS), a configurable node for plug-in wired or wireless server/client or peer-to-peer computing with accommodations for power, sensor I/O interfaces, and energy harvesting. The enabling technology increases the efficacy of uniformed personnel and first responders and provides an option for reducing force structure associated with the need for hardware network infrastructure to enable a mobile digital communications architecture for dismounted troops. The ISPDS system addresses the DoD's need for an "intelligent" power control system in an effort to increase mission duration and maximize the first responders and warfighter's effectiveness without concern for the available energy resources (i.e., batteries). ISPDS maximizes durability and survivability, assesses influences that affect performance, and provides the network backbone and mobile node hardware. POC is producing two vest-integrated variants, one each for the U.S. Army PEO Ground Soldier and the Air Soldier, with each including state-of-the-art low-profile and robust wearable connectors, cabling, and harnesses, and an integrated low-profile power manager and conformal battery for data and power distribution. The innovative intelligent power controller (IPC), in the form of the ISPDS firmware and power sensing and control electronics, will enable ISPDS to optimize power levels both automatically and in accordance with manually set preferences. The IPC module is power dense and efficient, and adaptively provides lossless transfer of available harvested photovoltaic energy to the battery. The integrated systems were tested for suitable electrical, electromagnetic interference (EMI), and environmental performance as outlined in military standards such as MIL-STD- 810G and MIL STD-461F.

Uncertainties in Future Regional Sea Level Trends: How to Deal with the Internal Climate Variability?

NASA Astrophysics Data System (ADS)

Becker, M.; Karpytchev, M.; Hu, A.; Deser, C.; Lennartz-Sassinek, S.

2017-12-01

Today, the Climate models (CM) are the main tools for forecasting sea level rise (SLR) at global and regional scales. The CM forecasts are accompanied by inherent uncertainties. Understanding and reducing these uncertainties is becoming a matter of increasing urgency in order to provide robust estimates of SLR impact on coastal societies, which need sustainable choices of climate adaptation strategy. These CM uncertainties are linked to structural model formulation, initial conditions, emission scenario and internal variability. The internal variability is due to complex non-linear interactions within the Earth Climate System and can induce diverse quasi-periodic oscillatory modes and long-term persistences. To quantify the effects of internal variability, most studies used multi-model ensembles or sea level projections from a single model ran with perturbed initial conditions. However, large ensembles are not generally available, or too small, and computationally expensive. In this study, we use a power-law scaling of sea level fluctuations, as observed in many other geophysical signals and natural systems, which can be used to characterize the internal climate variability. From this specific statistical framework, we (1) use the pre-industrial control run of the National Center for Atmospheric Research Community Climate System Model (NCAR-CCSM) to test the robustness of the power-law scaling hypothesis; (2) employ the power-law statistics as a tool for assessing the spread of regional sea level projections due to the internal climate variability for the 21st century NCAR-CCSM; (3) compare the uncertainties in predicted sea level changes obtained from a NCAR-CCSM multi-member ensemble simulations with estimates derived for power-law processes, and (4) explore the sensitivity of spatial patterns of the internal variability and its effects on regional sea level projections.

Nilsson's Power Model connecting speed and road trauma: applicability by road type and alternative models for urban roads.

PubMed

Cameron, M H; Elvik, R

2010-11-01

Nilsson (1981) proposed power relationships connecting changes in traffic speeds with changes in road crashes at various levels of injury severity. Increases in fatal crashes are related to the 4(th) power of the increase in mean speed, increases in serious casualty crashes (those involving death or serious injury) according to the 3(rd) power, and increases in casualty crashes (those involving death or any injury) according to the 2(nd) power. Increases in numbers of crash victims at cumulative levels of injury severity are related to the crash increases plus higher powers predicting the number of victims per crash. These relationships are frequently applied in OECD countries to estimate road trauma reductions resulting from expected speed reductions. The relationships were empirically derived based on speed changes resulting from a large number of rural speed limit changes in Sweden during 1967-1972. Nilsson (2004) noted that there had been very few urban speed limit changes studied to test his power model. This paper aims to test the assumption that the model is equally applicable in all road environments. It was found that the road environment is an important moderator of Nilsson's power model. While Nilsson's model appears satisfactory for rural highways and freeways, the model does not appear to be directly applicable to traffic speed changes on urban arterial roads. The evidence of monotonically increasing powers applicable to changes in road trauma at increasing injury severity levels with changes in mean speed is weak. The estimated power applicable to serious casualties on urban arterial roads was significantly less than that on rural highways, which was also significantly less than that on freeways. Alternative models linking the parameters of speed distributions with road trauma are reviewed and some conclusions reached for their use on urban roads instead of Nilsson's model. Further research is needed on the relationships between serious road trauma and urban speeds. 2010 Elsevier Ltd. All rights reserved.

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.

Statistical properties of relative weight distributions of four salmonid species and their sampling implications

USGS Publications Warehouse

Hyatt, M.W.; Hubert, W.A.

2001-01-01

We assessed relative weight (Wr) distributions among 291 samples of stock-to-quality-length brook trout Salvelinus fontinalis, brown trout Salmo trutta, rainbow trout Oncorhynchus mykiss, and cutthroat trout O. clarki from lentic and lotic habitats. Statistics describing Wr sample distributions varied slightly among species and habitat types. The average sample was leptokurtotic and slightly skewed to the right with a standard deviation of about 10, but the shapes of Wr distributions varied widely among samples. Twenty-two percent of the samples had nonnormal distributions, suggesting the need to evaluate sample distributions before applying statistical tests to determine whether assumptions are met. In general, our findings indicate that samples of about 100 stock-to-quality-length fish are needed to obtain confidence interval widths of four Wr units around the mean. Power analysis revealed that samples of about 50 stock-to-quality-length fish are needed to detect a 2% change in mean Wr at a relatively high level of power (beta = 0.01, alpha = 0.05).

Status of Technological Advancements for Reducing Aircraft Gas Turbine Engine Pollutant Emissions

NASA Technical Reports Server (NTRS)

Rudey, R. A.

1975-01-01

Combustor test rig results indicate that substantial reductions from current emission levels of carbon monoxide (CO), total unburned hydrocarbons (THC), oxides of nitrogen (NOx), and smoke are achievable by employing varying degrees of technological advancements in combustion systems. Minor to moderate modifications to existing conventional combustors produced significant reductions in CO and THC emissions at engine low power (idle/taxi) operating conditions but did not effectively reduce NOx at engine full power (takeoff) operating conditions. Staged combusiton techniques were needed to simultaneously reduce the levels of all the emissions over the entire engine operating range (from idle to takeoff). Emission levels that approached or were below the requirements of the 1979 EPA standards were achieved with the staged combustion systems and in some cases with the minor to moderate modifications to existing conventional combustion systems. Results from research programs indicate that an entire new generation of combustor technology with extremely low emission levels may be possible in the future.

Impact of Radiation Hardness and Operating Temperatures of Silicon Carbide Electronics on Space Power System Mass

NASA Technical Reports Server (NTRS)

Juhasz, Albert J.; Tew, Roy C.; Schwarze, Gene E.

1998-01-01

The effect of silicon carbide (SiC) electronics operating temperatures on Power Management and Distribution (PMAD), or Power Conditioning (PC), subsystem radiator size and mass requirements was evaluated for three power output levels (100 kW(e) , 1 MW(e), and 10 MW(e)) for near term technology ( i.e. 1500 K turbine inlet temperature) Closed Cycle Gas Turbine (CCGT) power systems with a High Temperature Gas Reactor (HTGR) heat source. The study was conducted for assumed PC radiator temperatures ranging from 370 to 845 K and for three scenarios of electrical energy to heat conversion levels which needed to be rejected to space by means of the PC radiator. In addition, during part of the study the radiation hardness of the PC electronics was varied at a fixed separation distance to estimate its effect on the mass of the instrument rated reactor shadow shield. With both the PC radiator and the conical shadow shield representing major components of the overall power system the influence of the above on total power system mass was also determined. As expected, results show that the greatest actual mass savings achieved by the use of SiC electronics occur with high capacity power systems. Moreover, raising the PC radiator temperature above 600 K yields only small additional system mass savings. The effect of increased radiation hardness on total system mass is to reduce system mass by virtue of lowering the shield mass.

Comparison of seating, powered characteristics and functions and costs of electrically powered wheelchairs in a general population of users.

PubMed

Dolan, Michael John; Bolton, Megan Jennifer; Henderson, Graham Iain

2017-10-26

To profile and compare the seating and powered characteristics and functions of electrically powered wheelchairs (EPWs) in a general user population including equipment costs. Case notes of adult EPW users of a regional NHS service were reviewed retrospectively. Seating equipment complexity and type were categorized using the Edinburgh classification. Powered characteristics and functions, including control device type, were recorded. 482 cases were included; 53.9% female; mean duration EPW use 8.1 years (SD 7.4); rear wheel drive 88.0%; hand joystick 94.8%. Seating complexity: low 73.2%, medium 18.0%, high 8.7%. Most prevalent diagnoses: multiple sclerosis (MS) 25.3%, cerebral palsy (CP) 18.7%, muscular dystrophy (8.5%). Compared to CP users, MS users were significantly older at first use, less experienced, more likely to have mid-wheel drive and less complex seating. Additional costs for muscular dystrophy and spinal cord injury users were 3-4 times stroke users. This is the first large study of a general EPW user population using a seating classification. Significant differences were found between diagnostic groups; nevertheless, there was also high diversity within each group. The differences in provision and the equipment costs across diagnostic groups can be used to improve service planning. Implications for Rehabilitation At a service planning level, knowledge of a population's diagnostic group and age distribution can be used to inform decisions about the number of required EPWs and equipment costs. At a user level, purchasing decisions about powered characteristics and functions of EPWs and specialised seating equipment need to be taken on a case by case basis because of the diversity of users' needs within diagnostic groups. The additional equipment costs for SCI and MD users are several times those of stroke users and add between 60 and 70% of the cost of basic provision.

Microwatt power consumption maximum power point tracking circuit using an analogue differentiator for piezoelectric energy harvesting

NASA Astrophysics Data System (ADS)

Chew, Z. J.; Zhu, M.

2015-12-01

A maximum power point tracking (MPPT) scheme by tracking the open-circuit voltage from a piezoelectric energy harvester using a differentiator is presented in this paper. The MPPT controller is implemented by using a low-power analogue differentiator and comparators without the need of a sensing circuitry and a power hungry controller. This proposed MPPT circuit is used to control a buck converter which serves as a power management module in conjunction with a full-wave bridge diode rectifier. Performance of this MPPT control scheme is verified by using the prototyped circuit to track the maximum power point of a macro-fiber composite (MFC) as the piezoelectric energy harvester. The MFC was bonded on a composite material and the whole specimen was subjected to various strain levels at frequency from 10 to 100 Hz. Experimental results showed that the implemented full analogue MPPT controller has a tracking efficiency between 81% and 98.66% independent of the load, and consumes an average power of 3.187 μW at 3 V during operation.

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

Hoke, Anderson; Shirazi, Mariko; Chakraborty, Sudipta

As deployment of power electronic coupled generation such as photovoltaic (PV) systems increases, grid operators have shown increasing interest in calling on inverter-coupled generation to help mitigate frequency contingency events by rapidly surging active power into the grid. When responding to contingency events, the faster the active power is provided, the more effective it may be for arresting the frequency event. This paper proposes a predictive PV inverter control method for very fast and accurate control of active power. This rapid active power control method will increase the effectiveness of various higher-level controls designed to mitigate grid frequency contingency events,more » including fast power-frequency droop, inertia emulation, and fast frequency response, without the need for energy storage. The rapid active power control method, coupled with a maximum power point estimation method, is implemented in a prototype PV inverter connected to a PV array. The prototype inverter's response to various frequency events is experimentally confirmed to be fast (beginning within 2 line cycles and completing within 4.5 line cycles of a severe test event) and accurate (below 2% steady-state error).« less

Public acceptance of nuclear power among Malaysian students

NASA Astrophysics Data System (ADS)

Muhamad Pauzi, Anas; Saad, Juniza Md; Arif Abu Bakar, Asyraf; Hannan Damahuri, Abdul; Syukri, Nur Syamim Mohd

2018-01-01

Malaysian government’s aim to include nuclear energy for electricity generation has triggered various reactions from all especially the public. The objective of this study is to have a better understanding on the knowledge, sources of information of nuclear power and sources of energy chosen by Malaysian in 20 years’ time. Besides that, we want to examine the level of acceptance and perception of Malaysian towards nuclear energy and we want to identify the correlation between public perceptions with the acceptance towards nuclear power in Malaysia, and also to study the differences between perception and acceptance of nuclear power with gender and educational level. For this research methodology, the research questions are given orally or through paper-pencil and also social networking site such as Facebook or through electronic media application such as WhatsApp and Google docs. The data were analysed using a SPSS version 22.0 (Statistical Package for the Social Sciences). Results showed that more than 50% of the respondents have the knowledge of nuclear energy. A part of from that, only 39 % are confident government can afford to build NPP in Malaysia and 41 % disagree nuclear energy is the best option for future energy. From analysis using SPSS 22 we estimate negative perception will give a negative acceptance in term of support towards the use of nuclear energy in power generation in Malaysia. There are also slight correlation that the higher the level of education of Malaysian, the more negative the perception of Malaysian in accepting nuclear energy as source of power in Malaysia. Therefore in shaping a positive acceptance of NPP in Malaysia, the authorities need to educate the people with the knowledge of nuclear in order to overcome the negative perception towards nuclear power.

Messier: A Detailed NVM-Based DIMM Model for the SST Simulation Framework.

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

Awad, Amro; Voskuilen, Gwendolyn Renae; Rodrigues, Arun F.

2017-02-01

DRAM technology is the main building block of main memory, however, DRAM scaling is becoming very challenging. The main issues for DRAM scaling are the increasing error rates with each new generation, the geometric and physical constraints of scaling the capacitor part of the DRAM cells, and the high power consumption caused by the continuous need for refreshing cell values. At the same time, emerging Non- Volatile Memory (NVM) technologies, such as Phase-Change Memory (PCM), are emerging as promising replacements for DRAM. NVMs, when compared to current technologies e.g., NAND-based ash, have latencies comparable to DRAM. Additionally, NVMs are non-volatile,more » which eliminates the need for refresh power and enables persistent memory applications. Finally, NVMs have promising densities and the potential for multi-level cell (MLC) storage.« less

Assessment Of The Stirling Power Option for Space Science Applications

NASA Technical Reports Server (NTRS)

Schreiber, Jeffrey G.

2000-01-01

Free-piston Stirling technology efforts in the past typically were intended to address power needs in the multi-kilowatt range. The Stirling power option was attractive primarily because of the high conversion efficiency and potential for long life. In recent years, several technology efforts have focused on the free-piston Stirling power d convertor for space power applications, however the more recent efforts are intended to provide power at levels far below one kilowatt. Through a variety of projects funded by both NASA and DOE, the free-piston Stirling convertor technology has successfully demonstrated high efficiency and long life. Other areas of concern, such as control of multi-convertor systems, and vibration reduction have also been addressed. Efforts are being initiated to address issues such as electro-magnetic interference (EMI), radiation tolerance of organic materials, and the ability to operate through launch loads and survive with integrity. The status of the technology in these areas will be briefly discussed in this paper.

Social and structural violence and power relations in mitigating HIV risk of drug-using women in survival sex work.

PubMed

Shannon, Kate; Kerr, Thomas; Allinott, Shari; Chettiar, Jill; Shoveller, Jean; Tyndall, Mark W

2008-02-01

High rates of violence among street-level sex workers have been described across the globe, while in cities across Canada the disappearance and victimization of drug-using women in survival sex work is ongoing. Given the pervasive levels of violence faced by sex workers over the last decades, and extensive harm reduction and HIV prevention efforts operating in Vancouver, Canada, this research aimed to explore the role of social and structural violence and power relations in shaping the HIV risk environment and prevention practices of women in survival sex work. Through a participatory-action research project, a series of focus group discussions were conceptualized and co-facilitated by sex workers, community and research partners with a total of 46 women in early 2006. Based on thematic, content and theoretical analysis, the following key factors were seen to both directly and indirectly mediate women's agency and access to resources, and ability to practice HIV prevention and harm reduction: at the micro-level, boyfriends as pimps and the 'everyday violence' of bad dates; at the meso-level, a lack of safe places to take dates, and adverse impacts of local policing; and at the macro-level, dopesickness and the need to sell sex for drugs. Analysis of the narratives and daily lived experiences of women sex workers highlight the urgent need for a renewed HIV prevention strategy that moves beyond a solely individual-level focus to structural and environmental interventions, including legal reforms, that facilitate 'enabling environments' for HIV prevention.

Information content of IRIS spectra. [from Nimbus 4 satellite

NASA Technical Reports Server (NTRS)

Price, J. C.

1974-01-01

Spectra from the satellite instrument IRIS (infra red interferometer spectrometer) were examined to find the number of independent variables needed to describe these broadband high spectral resolution data. The radiated power in the atmospheric window from 771 to 981/cm was the first parameter chosen for fitting observed spectra. At succeeding levels of analysis the residual variability (observed spectrum - best fit spectrum) in an ensemble of observations was partioned into spectral eigenvectors. The eigenvector describing the largest fraction of this variability was examined for a strong spectral signature; the power in the corresponding spectral band was then used as the next fitting parameter. The measured power in nine spectral intervals, when inserted in the spectral fitting functions, was adequate to describe most spectra to within the noise level of IRIS. Considerations of relative signal strength and scales of atmospheric variability suggest a combination sounder (multichannel-broad field of view) scanner (window channel-small field of view) as an efficient observing instrument.

Preliminary design of an auxiliary power unit for the space shuttle: Component and system configuration screening analysis

NASA Technical Reports Server (NTRS)

Binsley, R. L.; Maddox, J. P.; Marcy, R. D.; Siegler, R. S.; Spies, R.

1971-01-01

The auxiliary power unit (APU) for the space shuttle is required to provide hydraulic and electrical power on board the booster and orbiter vehicles. Five systems and their associated components, which utilize hot gas turbines to supply horsepower at gearbox output pads, were studied. Hydrogen-oxygen and storable propellants were considered for the hot gas supply. All APU's were required to be self-contained with respect to dissipating internally generated heat. These five systems were evaluated relative to a consistent criteria. The system supplied with high pressure gaseous hydrogen and oxygen was recommended as the best approach. It included a two-stage pressure-compounded partial-admission turbine, a propellant conditioning system with recuperation, a control system, and a gearbox. The gearbox output used was 240 hp. At the close of the study a 400 hp level was considered more appropriate for meeting the prime shuttle vehicle needs, and an in-depth analysis of the system at the 400 hp output level was recommended.

AlGaAs phased array laser for optical communications

NASA Technical Reports Server (NTRS)

Carlson, N. W.

1989-01-01

Phased locked arrays of multiple AlGaAs diode laser emitters were investigated both in edge emitting and surface emitting configurations. CSP edge emitter structures, coupled by either evanescent waves or Y-guides, could not achieve the required powers (greater than or similar to 500 mW) while maintaining a diffraction limited, single lobed output beam. Indeed, although the diffraction limit was achieved in this type of device, it was at low powers and in the double lobed radiation pattern characteristic of out-of-phase coupling. Grating surface emitting (GSE) arrays were, therefore, investigated with more promising results. The incorporation of second order gratings in distribute Bragg reflector (DBR) structures allows surface emission, and can be configured to allow injection locking and lateral coupling to populate 2-D arrays that should be able to reach power levels commensurate with the needs of high performance, free space optical communications levels. Also, a new amplitude modulation scheme was developed for GSE array operation.

Information content in Iris spectra. [Infrared Interferometer Spectrometer of Nimbus 4 satellite

NASA Technical Reports Server (NTRS)

Price, J. C.

1975-01-01

Spectra from the satellite instrument Iris (infrared interferometer spectrometer) were examined to find the number of independent variables needed to describe the broad-band high-resolution spectral data. The radiated power in the atmospheric window from 771 to 981 per cm was the first parameter chosen for fitting observed spectra. At succeeding levels of analysis, the residual variability (observed spectrum minus best-fit spectrum) in an ensemble of observations was partitioned into spectral eigenvectors. The eigenvector describing the largest fraction of this variability was examined for a strong spectral signature; the power in the corresponding spectral band was then used as the next fitting parameter. The measured power in nine spectral intervals, when it was inserted in the spectral-fitting functions, was adequate to describe most spectra to within the noise level of Iris. Considerations of relative signal strength and scales of atmospheric variability suggest a combination sounder (multichannel, broad field of view) scanner (window channel, small field of view) as an efficient observing instrument.

The influence of control group reproduction on the statistical power of the Environmental Protection Agency's Medaka Extended One Generation Reproduction Test (MEOGRT).

PubMed

Flynn, Kevin; Swintek, Joe; Johnson, Rodney

2017-02-01

Because of various Congressional mandates to protect the environment from endocrine disrupting chemicals (EDCs), the United States Environmental Protection Agency (USEPA) initiated the Endocrine Disruptor Screening Program. In the context of this framework, the Office of Research and Development within the USEPA developed the Medaka Extended One Generation Reproduction Test (MEOGRT) to characterize the endocrine action of a suspected EDC. One important endpoint of the MEOGRT is fecundity of medaka breeding pairs. Power analyses were conducted to determine the number of replicates needed in proposed test designs and to determine the effects that varying reproductive parameters (e.g. mean fecundity, variance, and days with no egg production) would have on the statistical power of the test. The MEOGRT Reproduction Power Analysis Tool (MRPAT) is a software tool developed to expedite these power analyses by both calculating estimates of the needed reproductive parameters (e.g. population mean and variance) and performing the power analysis under user specified scenarios. Example scenarios are detailed that highlight the importance of the reproductive parameters on statistical power. When control fecundity is increased from 21 to 38 eggs per pair per day and the variance decreased from 49 to 20, the gain in power is equivalent to increasing replication by 2.5 times. On the other hand, if 10% of the breeding pairs, including controls, do not spawn, the power to detect a 40% decrease in fecundity drops to 0.54 from nearly 0.98 when all pairs have some level of egg production. Perhaps most importantly, MRPAT was used to inform the decision making process that lead to the final recommendation of the MEOGRT to have 24 control breeding pairs and 12 breeding pairs in each exposure group. Published by Elsevier Inc.

[An ultra-low power, wearable, long-term ECG monitoring system with mass storage].

PubMed

Liu, Na; Chen, Yingmin; Zhang, Wenzan; Luo, Zhangyuan; Jin, Xun; Ying, Weihai

2012-01-01

In this paper, we described an ultra-low power, wearable ECG system capable of long term monitoring and mass storage. This system is based on micro-chip PIC18F27J13 with consideration of its high level of integration and low power consumption. The communication with the micro-SD card is achieved through SPI bus. Through the USB, it can be connected to the computer for replay and disease diagnosis. Given its low power cost, lithium cells are used to support continuous ECG acquiring and storage for up to 15 days. Meanwhile, the wearable electrodes avoid the pains and possible risks in implanting. Besides, the mini size of the system makes long wearing possible for patients and meets the needs of long-term dynamic monitoring and mass storage requirements.

The US space station and its electric power system

NASA Technical Reports Server (NTRS)

Thomas, Ronald L.

1988-01-01

The United States has embarked on a major development program to have a space station operating in low earth orbit by the mid-1990s. This endeavor draws on the talents of NASA and most of the aerospace firms in the U.S. Plans are being pursued to include the participation of Canada, Japan, and the European Space Agency in the space station. From the start of the program these was a focus on the utilization of the space station for science, technology, and commercial endeavors. These requirements were utilized in the design of the station and manifest themselves in: pressurized volume; crew time; power availability and level of power; external payload accommodations; microgravity levels; servicing facilities; and the ability to grow and evolve the space station to meet future needs. President Reagan directed NASA to develop a permanently manned space station in his 1984 State of the Union message. Since then the definition phase was completed and the development phase initiated. A major subsystem of the space station is its 75 kW electric power system. The electric power system has characteristics similar to those of terrestrial power systems. Routine maintenance and replacement of failed equipment must be accomplished safely and easily and in a minimum time while providing reliable power to users. Because of the very high value placed on crew time it is essential that the power system operate in an autonomous mode to minimize crew time required. The power system design must also easily accommodate growth as the power demands by users are expected to grow. An overview of the U.S. space station is provided with special emphasis on its electrical power system.

Power-constrained supercomputing

NASA Astrophysics Data System (ADS)

Bailey, Peter E.

As we approach exascale systems, power is turning from an optimization goal to a critical operating constraint. With power bounds imposed by both stakeholders and the limitations of existing infrastructure, achieving practical exascale computing will therefore rely on optimizing performance subject to a power constraint. However, this requirement should not add to the burden of application developers; optimizing the runtime environment given restricted power will primarily be the job of high-performance system software. In this dissertation, we explore this area and develop new techniques that extract maximum performance subject to a particular power constraint. These techniques include a method to find theoretical optimal performance, a runtime system that shifts power in real time to improve performance, and a node-level prediction model for selecting power-efficient operating points. We use a linear programming (LP) formulation to optimize application schedules under various power constraints, where a schedule consists of a DVFS state and number of OpenMP threads for each section of computation between consecutive message passing events. We also provide a more flexible mixed integer-linear (ILP) formulation and show that the resulting schedules closely match schedules from the LP formulation. Across four applications, we use our LP-derived upper bounds to show that current approaches trail optimal, power-constrained performance by up to 41%. This demonstrates limitations of current systems, and our LP formulation provides future optimization approaches with a quantitative optimization target. We also introduce Conductor, a run-time system that intelligently distributes available power to nodes and cores to improve performance. The key techniques used are configuration space exploration and adaptive power balancing. Configuration exploration dynamically selects the optimal thread concurrency level and DVFS state subject to a hardware-enforced power bound. Adaptive power balancing efficiently predicts where critical paths are likely to occur and distributes power to those paths. Greater power, in turn, allows increased thread concurrency levels, CPU frequency/voltage, or both. We describe these techniques in detail and show that, compared to the state-of-the-art technique of using statically predetermined, per-node power caps, Conductor leads to a best-case performance improvement of up to 30%, and an average improvement of 19.1%. At the node level, an accurate power/performance model will aid in selecting the right configuration from a large set of available configurations. We present a novel approach to generate such a model offline using kernel clustering and multivariate linear regression. Our model requires only two iterations to select a configuration, which provides a significant advantage over exhaustive search-based strategies. We apply our model to predict power and performance for different applications using arbitrary configurations, and show that our model, when used with hardware frequency-limiting in a runtime system, selects configurations with significantly higher performance at a given power limit than those chosen by frequency-limiting alone. When applied to a set of 36 computational kernels from a range of applications, our model accurately predicts power and performance; our runtime system based on the model maintains 91% of optimal performance while meeting power constraints 88% of the time. When the runtime system violates a power constraint, it exceeds the constraint by only 6% in the average case, while simultaneously achieving 54% more performance than an oracle. Through the combination of the above contributions, we hope to provide guidance and inspiration to research practitioners working on runtime systems for power-constrained environments. We also hope this dissertation will draw attention to the need for software and runtime-controlled power management under power constraints at various levels, from the processor level to the cluster level.

Exploration of CIGAS Alloy System for Thin-Film Photovoltaics on Novel Lightweight and Flexible Substrates

NASA Technical Reports Server (NTRS)

Woods, Lawrence M.; Kalla, Ajay; Ribelin, Rosine

2007-01-01

Thin-film photovoltaics (TFPV) on lightweight and flexible substrates offer the potential for very high solar array specific power (W/kg). ITN Energy Systems, Inc. (ITN) is developing flexible TFPV blanket technology that has potential for specific power greater than 2000 W/kg (including space coatings) that could result in solar array specific power between 150 and 500 W/kg, depending on array size, when mated with mechanical support structures specifically designed to take advantage of the lightweight and flexible substrates.(1) This level of specific power would far exceed the current state of the art for spacecraft PV power generation, and meet the needs for future spacecraft missions.(2) Furthermore the high specific power would also enable unmanned aircraft applications and balloon or high-altitude airship (HAA) applications, in addition to modular and quick deploying tents for surface assets or lunar base power, as a result of the high power density (W/sq m) and ability to be integrated into the balloon, HAA or tent fabric. ITN plans to achieve the high specific power by developing single-junction and two-terminal monolithic tandem-junction PV cells using thin-films of high-efficiency and radiation resistant CuInSe2 (CIS) partnered with bandgap-tunable CIS-alloys with Ga (CIGS) or Al (CIAS) on novel lightweight and flexible substrates. Of the various thin-film technologies, single-junction and radiation resistant CIS and associated alloys with gallium, aluminum and sulfur have achieved the highest levels of TFPV device performance, with the best efficiency reaching 19.5% under AM1.5 illumination conditions and on thick glass substrates.(3) Thus, it is anticipated that single- and tandem-junction devices with flexible substrates and based on CIS and related alloys will achieve the highest levels of thin-film space and HAA solar array performance.

Hydro, wind and solar power as a base for a 100% renewable energy supply for South and Central America.

PubMed

Barbosa, Larissa de Souza Noel Simas; Bogdanov, Dmitrii; Vainikka, Pasi; Breyer, Christian

2017-01-01

Power systems for South and Central America based on 100% renewable energy (RE) in the year 2030 were calculated for the first time using an hourly resolved energy model. The region was subdivided into 15 sub-regions. Four different scenarios were considered: three according to different high voltage direct current (HVDC) transmission grid development levels (region, country, area-wide) and one integrated scenario that considers water desalination and industrial gas demand supplied by synthetic natural gas via power-to-gas (PtG). RE is not only able to cover 1813 TWh of estimated electricity demand of the area in 2030 but also able to generate the electricity needed to fulfil 3.9 billion m3 of water desalination and 640 TWhLHV of synthetic natural gas demand. Existing hydro dams can be used as virtual batteries for solar and wind electricity storage, diminishing the role of storage technologies. The results for total levelized cost of electricity (LCOE) are decreased from 62 €/MWh for a highly decentralized to 56 €/MWh for a highly centralized grid scenario (currency value of the year 2015). For the integrated scenario, the levelized cost of gas (LCOG) and the levelized cost of water (LCOW) are 95 €/MWhLHV and 0.91 €/m3, respectively. A reduction of 8% in total cost and 5% in electricity generation was achieved when integrating desalination and power-to-gas into the system.

Hydro, wind and solar power as a base for a 100% renewable energy supply for South and Central America

PubMed Central

Barbosa, Larissa de Souza Noel Simas; Bogdanov, Dmitrii; Vainikka, Pasi; Breyer, Christian

2017-01-01

Power systems for South and Central America based on 100% renewable energy (RE) in the year 2030 were calculated for the first time using an hourly resolved energy model. The region was subdivided into 15 sub-regions. Four different scenarios were considered: three according to different high voltage direct current (HVDC) transmission grid development levels (region, country, area-wide) and one integrated scenario that considers water desalination and industrial gas demand supplied by synthetic natural gas via power-to-gas (PtG). RE is not only able to cover 1813 TWh of estimated electricity demand of the area in 2030 but also able to generate the electricity needed to fulfil 3.9 billion m3 of water desalination and 640 TWhLHV of synthetic natural gas demand. Existing hydro dams can be used as virtual batteries for solar and wind electricity storage, diminishing the role of storage technologies. The results for total levelized cost of electricity (LCOE) are decreased from 62 €/MWh for a highly decentralized to 56 €/MWh for a highly centralized grid scenario (currency value of the year 2015). For the integrated scenario, the levelized cost of gas (LCOG) and the levelized cost of water (LCOW) are 95 €/MWhLHV and 0.91 €/m3, respectively. A reduction of 8% in total cost and 5% in electricity generation was achieved when integrating desalination and power-to-gas into the system. PMID:28329023

Informational need of emotional stress

NASA Astrophysics Data System (ADS)

Simonov, P. V.; Frolov, M. V.

According to the informational theory of emotions[1], emotions in humans depend on the power of some need (motivation) and the estimation by the subject of the probability (possibility) of the need staisfaction (the goal achievement). Low probability of need satisfaction leads to negative emotions, actively minimized by the subject. Increased probability of satisfaction, as compared to earlier forecast, generates positive emotions, which the subject tries to maximize, i.e. to enhance, to prolong, to repeat. The informational theory of emotions encompasses their reflective function, the laws of their appearance, the regulatory significance of emotions, and their role in organization of behavior. The level of emotional stress influences the operator's performance. A decrease in the emotional tonus leads to drowsiness, lack of vigilance, missing of significant signals and to slower reactions. An extremely high stress level disorganizes the activity, complicates it with a trend toward incorrect actions and reactions to insignificant signals (false alarms). The neurophysiological mechanisms of the influence of emotions on perceptual activity and operator performance as well as the significance of individuality are discussed.

Development of Intelligent Computer-Assisted Instruction Systems to Facilitate Reading Skills of Learning-Disabled Children

DTIC Science & Technology

1993-12-01

Unclassified/Unlimited 13. ABSTRACT ~Maximum 2W0 worr*J The purpose of this thesis is to develop a high-level model to create seli"adapting software which...Department of Computer Science ABSTRACT The purpose of this thesis is to develop a high-level model to create self-adapting software which teaches learning...stimulating and demanding. The power of the system model described herein is that it can vary as needed by the individual student. The system will

Reactor Testing and Qualification: Prioritized High-level Criticality Testing Needs

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

S. Bragg-Sitton; J. Bess; J. Werner

2011-09-01

Researchers at the Idaho National Laboratory (INL) were tasked with reviewing possible criticality testing needs to support development of the fission surface power system reactor design. Reactor physics testing can provide significant information to aid in development of technologies associated with small, fast spectrum reactors that could be applied for non-terrestrial power systems, leading to eventual system qualification. Several studies have been conducted in recent years to assess the data and analyses required to design and build a space fission power system with high confidence that the system will perform as designed [Marcille, 2004a, 2004b; Weaver, 2007; Parry et al.,more » 2008]. This report will provide a summary of previous critical tests and physics measurements that are potentially applicable to the current reactor design (both those that have been benchmarked and those not yet benchmarked), summarize recent studies of potential nuclear testing needs for space reactor development and their applicability to the current baseline fission surface power (FSP) system design, and provide an overview of a suite of tests (separate effects, sub-critical or critical) that could fill in the information database to improve the accuracy of physics modeling efforts as the FSP design is refined. Some recommendations for tasks that could be completed in the near term are also included. Specific recommendations on critical test configurations will be reserved until after the sensitivity analyses being conducted by Los Alamos National Laboratory (LANL) are completed (due August 2011).« less

Project Volunteer Power: Volunteers Serving the Job Needs of the Handicapped. Final Report.

ERIC Educational Resources Information Center

President's Committee on Employment of the Handicapped, Washington, DC.

The report covers the activities, results, and lessons learned in a project to test a new approach in developing greater opportunities in employment of the physically handicapped, mentally retarded, and mentally restored by harnessing the resources of leading volunteer women's organizations at the local level on a practical, planned basis. Project…

Are self-thinning contraints needed in a tree-specific mortality model.

Treesearch

Robert A. Monserud; Thomas Ledermann; Hubert Sterba

2005-01-01

Can a tree-specific mortality model elicit expected forest stand density dynamics without imposing stand-level constraints such as Reineke's maximum stand density index (SDI,) or the -312 power law of self-thinning? We examine this emergent properties question using the Austrian stand simulator PROGNAUS. This simulator was chosen specifically because it does not...

Calibration Study of POWER Performance Levels to the CASAS Scale. Research Brief No. 5

ERIC Educational Resources Information Center

Posey, Virginia

2005-01-01

The Adult Education and Family Literacy Act, as part of the Workforce Investment Act of 1998, requires programs to use standardized assessments to report learning gains for students in adult education programs. In addition, local and state agencies need an accountability tool for students who are difficult to assess adequately with a…

Do deep convolutional neural networks really need to be deep when applied for remote scene classification?

NASA Astrophysics Data System (ADS)

Luo, Chang; Wang, Jie; Feng, Gang; Xu, Suhui; Wang, Shiqiang

2017-10-01

Deep convolutional neural networks (CNNs) have been widely used to obtain high-level representation in various computer vision tasks. However, for remote scene classification, there are not sufficient images to train a very deep CNN from scratch. From two viewpoints of generalization power, we propose two promising kinds of deep CNNs for remote scenes and try to find whether deep CNNs need to be deep for remote scene classification. First, we transfer successful pretrained deep CNNs to remote scenes based on the theory that depth of CNNs brings the generalization power by learning available hypothesis for finite data samples. Second, according to the opposite viewpoint that generalization power of deep CNNs comes from massive memorization and shallow CNNs with enough neural nodes have perfect finite sample expressivity, we design a lightweight deep CNN (LDCNN) for remote scene classification. With five well-known pretrained deep CNNs, experimental results on two independent remote-sensing datasets demonstrate that transferred deep CNNs can achieve state-of-the-art results in an unsupervised setting. However, because of its shallow architecture, LDCNN cannot obtain satisfactory performance, regardless of whether in an unsupervised, semisupervised, or supervised setting. CNNs really need depth to obtain general features for remote scenes. This paper also provides baseline for applying deep CNNs to other remote sensing tasks.

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

Basher, A.M.H.

Poor control of steam generator water level of a nuclear power plant may lead to frequent nuclear reactor shutdowns. These shutdowns are more common at low power where the plant exhibits strong non-minimum phase characteristics and flow measurements at low power are unreliable in many instances. There is need to investigate this problem and systematically design a controller for water level regulation. This work is concerned with the study and the design of a suitable controller for a U-Tube Steam Generator (UTSG) of a Pressurized Water Reactor (PWR) which has time varying dynamics. The controller should be suitable for themore » water level control of UTSG without manual operation from start-up to full load transient condition. Some preliminary simulation results are presented that demonstrate the effectiveness of the proposed controller. The development of the complete control algorithm includes components such as robust output tracking, and adaptively estimating both the system parameters and state variables simultaneously. At the present time all these components are not completed due to time constraints. A robust tracking component of the controller for water level control is developed and its effectiveness on the parameter variations is demonstrated in this study. The results appear encouraging and they are only preliminary. Additional work is warranted to resolve other issues such as robust adaptive estimation.« less

Batteryless magneto-driven portable radiac

DOEpatents

Waechter, David A.; Bjarke, George O.; Trujillo, Faustin; Wolf, Michael A.; Umbarger, C. John

1986-01-01

A hand-powered alternator for generating an alternating voltage provides same through a rectifier to a high capacity capacitor which stores the resultant dc voltage and drives a voltage regulator to provide a constant low voltage output for a portable radiation detection instrument. The instrument includes a Geiger-Muller detector tube whose output is fed to a pulse detector and then through an event counter and LCD driver circuit to an LCD bar graph for visual display. An audio driver and an audio output is also provided. All circuitry used is low power so that the capacitor can be readily charged to a sufficient level to provide power for at least 30 minutes. A low voltage indicator is provided on the LCD display to indicate the need for manual recharging.

Examination of the Entry to Burn and Burn Control for the ITER 15 MA Baseline and Other Scenarios

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

Kesse, Charles E.; Kim, S-H.; Koechl, F.

2014-09-01

The entry to burn and flattop burn control in ITER will be a critical need from the first DT experiments. Simulations are used to address time-dependent behavior under a range of possible conditions that include injected power level, impurity content (W, Ar, Be), density evolution, H-mode regimes, controlled parameter (Wth, Pnet, Pfusion), and actuator (Paux, fueling, fAr), with a range of transport models. A number of physics issues at the L-H transition require better understanding to project to ITER, however, simulations indicate viable control with sufficient auxiliary power (up to 73 MW), while lower powers become marginal (as low asmore » 43 MW).« less

Solar Electric Propulsion (SEP) Tug Power System Considerations

NASA Technical Reports Server (NTRS)

Kerslake, Thomas W.; Bury, Kristen M.; Hojinicki, Jeffrey S.; Sajdak, Adam M.; Scheiddegger, Robert J.

2011-01-01

Solar electric propulsion (SEP) technology is truly at the "intersection of commercial and military space" as well as the intersection of NASA robotic and human space missions. Building on the use of SEP for geosynchronous spacecraft station keeping, there are numerous potential commercial and military mission applications for SEP stages operating in Earth orbit. At NASA, there is a resurgence of interest in robotic SEP missions for Earth orbit raising applications, 1-AU class heliocentric missions to near Earth objects (NEOs) and SEP spacecraft technology demonstrations. Beyond these nearer term robotic missions, potential future human space flight missions to NEOs with high-power SEP stages are being considered. To enhance or enable this broad class of commercial, military and NASA missions, advancements in the power level and performance of SEP technologies are needed. This presentation will focus on design considerations for the solar photovoltaic array (PVA) and electric power system (EPS) vital to the design and operation of an SEP stage. The engineering and programmatic pros and cons of various PVA and EPS technologies and architectures will be discussed in the context of operating voltage and power levels. The impacts of PVA and EPS design options on the remaining SEP stage subsystem designs, as well as spacecraft operations, will also be discussed.

Current status and future prospects of power generators using dielectric elastomers

NASA Astrophysics Data System (ADS)

Chiba, Seiki; Waki, Mikio; Kornbluh, Roy; Pelrine, Ron

2011-12-01

Electroactive polymer artificial muscle (EPAM), known collectively as dielectric elastomers in the literature, has been shown to offer unique capabilities as an actuator and is now being developed for a wide variety of generator applications. EPAM has several characteristics that make it potentially well suited for wave, water current, wind, human motion, and other environmental energy harvesting systems including a high energy density allowing for minimal EPAM material quantities, high energy conversion efficiency independent of frequency of operation and non-toxic and low-cost materials not susceptible to corrosion. Experiments have been performed on push-button and heel-mounted generator devices powered by human motion, ocean wave power harvesters mounted on buoys and water turbines. While the power output levels of such demonstration devices is small, the performance of these devices has supported the potential benefits of EPAM. For example, an electrical energy conversion efficiency of over 70% was achieved with small wave heights. The ability of EPAM to produce hydrogen fuel for energy storage was also demonstrated. Because the energy conversion principle of EPAM is capacitive in nature, the performance is largely independent of size and it should eventually be possible to scale up EPAM generators to the megawatt level to address a variety of electrical power needs.

Reclaiming Gender and Power in Sexual Violence Prevention in Adolescence.

PubMed

Miller, Elizabeth

2018-03-01

The Mentors in Violence Prevention (MVP) model seeks to address the root causes of gender violence using a bystander approach and leadership training to challenge structures of patriarchy. Emerging research on adolescent relationship abuse and sexual violence points to key modifiable targets-transforming gender norms, addressing homophobia, integrating with comprehensive sexuality education, and acknowledging the needs of youth already exposed to violence. A social justice-based bystander approach such as the MVP model should be part of a multi-level approach to sexual violence prevention that addresses gender and power, encourages healthy sexuality conversations, and provides safety and support for survivors.

Picking the Best from the All-Resources Menu: Advanced Tools for Resource Planning

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

Palmintier, Bryan S

Introduces the wide range of electric power systems modeling types and associated questions they can help answer. The presentation focusses on modeling needs for high levels of Distributed Energy Resources (DERs), renewables, and inverter-based technologies as alternatives to traditional centralized power systems. Covers Dynamics, Production Cost/QSTS, Metric Assessment, Resource Planning, and Integrated Simulations with examples drawn from NREL's past and on-going projects. Presented at the McKnight Foundation workshop on 'An All-Resources Approach to Planning for a More Dynamic, Low-Carbon Grid' exploring grid modernization options to replace retiring coal plants in Minnesota.

Exploring Venus by Solar Airplane

NASA Technical Reports Server (NTRS)

Landis, Geoffrey A.

2001-01-01

A solar-powered airplane is proposed to explore the atmospheric environment of Venus. Venus has several advantages for a solar airplane. At the top of the cloud level, the solar intensity is comparable to or greater than terrestrial solar intensities. The Earthlike atmospheric pressure means that the power required for flight is lower for Venus than that of Mars, and the slow rotation of Venus allows an airplane to be designed for continuous sunlight, with no energy storage needed for night-time flight. These factors mean that Venus is perhaps the easiest planet in the solar system for flight of a long-duration solar airplane.

Clinical assessment of adolescents involved in Satanism.

PubMed

Clark, C M

1994-01-01

Satanism is a destructive religion that promises power, dominance, and gratification to its practitioners. Unfortunately, some adolescents are seduced by these promises, often because they feel alienated, alone, angry, and desperate. This article explores the psychosocial needs of adolescents that are often met by participation in Satanic worship. Gratification of these needs, when met, may make leaving the cult a difficult and lengthy process. Included is a method for determining the adolescents' level of involvement and an assessment strategy for the therapeutic evaluation process. A brief overview of clinical intervention is also discussed.

Potential errors in using one anemometer to characterize the wind power over an entire rotor disk

NASA Technical Reports Server (NTRS)

Simon, R. L.

1982-01-01

Wind data collected at four levels on a 90-m tower in a prospective wind farm area are used to evaluate how well the 10-m wind speed data with and without intermittent vertical profile measurements compare with the 90-m tower data. If a standard, or even predictable, wind speed profile existed, there would be no need for a large, expensive tower. This cost differential becomes even more significant if several towers are needed to study a prospective wind farm.

Federal Geothermal Research Program Update Fiscal Year 2002

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

Not Available

2003-09-01

The Department of Energy (DOE) and its predecessors have conducted research and development (R&D) in geothermal energy since 1971. To develop the technology needed to harness the Nation's vast geothermal resources, DOE's Office of Geothermal Technologies oversees a network of national laboratories, industrial contractors, universities, and their subcontractors. The goals are: (1) Double the number of States with geothermal electric power facilities to eight by 2006; (2) Reduce the levelized cost of generating geothermal power to 3-5 cents per kWh by 2007; and (3) Supply the electrical power or heat energy needs of 7 million homes and businesses in themore » United States by 2010. This Federal Geothermal Program Research Update reviews the specific objectives, status, and accomplishments of DOE's Geothermal Program for Federal Fiscal Year (FY) 2002. The information contained in this Research Update illustrates how the mission and goals of the Office of Geothermal Technologies are reflected in each R&D activity. The Geothermal Program, from its guiding principles to the most detailed research activities, is focused on expanding the use of geothermal energy. balanced strategy for the Geothermal Program.« less

Merits of flywheels for spacecraft energy storage

NASA Technical Reports Server (NTRS)

Gross, S.

1984-01-01

Flywheel energy storage systems which have a very good potential for use in spacecraft are discussed. This system can be superior to alkaline secondary batteries and regenerable fuel cells in most of the areas that are important in spacecraft applications. Of special importance, relative to batteries, are lighter weight, longer cycle and operating life, and high efficiency which minimizes solar array size and the amount of orbital makeup fuel required. Flywheel systems have a long shelf life, give a precise state of charge indication, have modest thermal control needs, are capable of multiple discharges per orbit, have simple ground handling needs, and have characteristics which would be useful for military applications. The major disadvantages of flywheel energy storage systems are that: power is not available during the launch phase without special provisions; and in flight failure of units may force shutdown of good counter rotating units, amplifying the effects of failure and limiting power distribution system options; no inherent emergency power capability unless specifically designed for, and a high level of complexity compared with batteries. The potential advantages of the flywheel energy storage system far outweigh the disadvantages.

Default operational intervention levels (OILs) for severe nuclear power plant or spent fuel pool emergencies.

PubMed

McKenna, T; Kutkov, V; Vilar Welter, P; Dodd, B; Buglova, E

2013-05-01

Experience and studies show that for an emergency at a nuclear power plant involving severe core damage or damage to the fuel in spent fuel pools, the following actions may need to be taken in order to prevent severe deterministic health effects and reduce stochastic health effects: (1) precautionary protective actions and other response actions for those near the facility (i.e., within the zones identified by the International Atomic Energy Agency) taken immediately upon detection of facility conditions indicating possible severe damage to the fuel in the core or in the spent fuel pool; and (2) protective actions and other response actions taken based on environmental monitoring and sampling results following a release. This paper addresses the second item by providing default operational intervention levels [OILs, which are similar to the U.S. derived response levels (DRLs)] for promptly assessing radioactive material deposition, as well as skin, food, milk and drinking water contamination, following a major release of fission products from the core or spent fuel pool of a light water reactor (LWR) or a high power channel reactor (RBMK), based on the International Atomic Energy Agency's guidance.

The glass ceiling in Irish healthcare: a nursing perspective.

PubMed

Tracey, Catherine

2006-01-01

The purpose of this study is to describe and explore from the perspectives of top-level nurses holding the formal position of director of nursing their perceptions and interpretations of their experiences in the Irish healthcare system. This paper presents some findings from a nation-wide study, which is qualitative in approach using grounded theory methodology. Semi-structured interviews were conducted with 50 directors of nursing representing general and psychiatric nursing. The study in this paper was conducted in the context of a changing healthcare system, which emphasises the flattening of organisational pyramids. However, this study's findings indicate that, while structures might be changing, behaviours remain unaltered. In particular, the medicine nursing power base remains unchanged, while the power shift between nursing and general management continues to widen in favour of general management. Research in this paper shows that directors of nursing who chose to participate in this study may have different perceptions of experiences from those who chose not to participate. In the paper the reality is neither medicine nor general management, individually or collectively, are going to share or devolve power and influence to nursing. This study's findings indicate that nursing needs to confront this power imbalance. Nursing needs to take the first steps towards shattering the glass ceiling by really examining its own behaviours, in maintaining the status quo, in the traditional balance of power.

Enhancing the versatility of wireless biopotential acquisition for myoelectric prosthetic control.

PubMed

Bercich, Rebecca A; Wang, Zhi; Mei, Henry; Hammer, Lauren H; Seburn, Kevin L; Hargrove, Levi J; Irazoqui, Pedro P

2016-08-01

A significant challenge in rehabilitating upper-limb amputees with sophisticated, electric-powered prostheses is sourcing reliable and independent channels of motor control information sufficient to precisely direct multiple degrees of freedom simultaneously. In response to the expressed needs of clinicians, we have developed a miniature, batteryless recording device that utilizes emerging integrated circuit technology and optimal impedance matching for magnetic resonantly coupled (MRC) wireless power transfer to improve the performance and versatility of wireless electrode interfaces with muscle. In this work we describe the fabrication and performance of a fully wireless and batteryless EMG recording system and use of this system to direct virtual and electric-powered limbs in real-time. The advantage of using MRC to optimize power transfer to a network of wireless devices is exhibited by EMG collected from an array of eight devices placed circumferentially around a human subject's forearm. This is a comprehensive, low-cost, and non-proprietary solution that provides unprecedented versatility of configuration to direct myoelectric prostheses without wired connections to the body. The amenability of MRC to varied coil geometries and arrangements has the potential to improve the efficiency and robustness of wireless power transfer links at all levels of upper-limb amputation. Additionally, the wireless recording device's programmable flash memory and selectable features will grant clinicians the unique ability to adapt and personalize the recording system's functional protocol for patient- or algorithm-specific needs.

Preventing Raman Lasing in High-Q WGM Resonators

NASA Technical Reports Server (NTRS)

Savchenkov, Anatoliy; Matsko, Andrey; Strekalov, Dmitry; Maleki, Lute

2007-01-01

A generic design has been conceived to suppress the Raman effect in whispering- gallery-mode (WGM) optical resonators that have high values of the resonance quality factor (Q). Although it is possible to exploit the Raman effect (even striving to maximize the Raman gain to obtain Raman lasing), the present innovation is intended to satisfy a need that arises in applications in which the Raman effect inhibits the realization of the full potential of WGM resonators as frequency-selection components. Heretofore, in such applications, it has been necessary to operate high-Q WGM resonators at unattractively low power levels to prevent Raman lasing. (The Raman-lasing thresholds of WGM optical resonators are very low and are approximately proportional to Q(sup -2)). Heretofore, two ways of preventing Raman lasting at high power levels have been known, but both entail significant disadvantages: A resonator can be designed so that the optical field is spread over a relatively large mode volume to bring the power density below the threshold. For any given combination of Q and power level, there is certain mode volume wherein Raman lasing does not start. Unfortunately, a resonator that has a large mode volume also has a high spectral density, which is undesirable in a typical photonic application. A resonator can be cooled to the temperature of liquid helium, where the Raman spectrum is narrower and, therefore, the Raman gain is lower. However, liquid-helium cooling is inconvenient. The present design overcomes these disadvantages, making it possible to operate a low-spectral-density (even a single-mode) WGM resonator at a relatively high power level at room temperature, without risk of Raman lasing.

Study on key technologies of optimization of big data for thermal power plant performance

NASA Astrophysics Data System (ADS)

Mao, Mingyang; Xiao, Hong

2018-06-01

Thermal power generation accounts for 70% of China's power generation, the pollutants accounted for 40% of the same kind of emissions, thermal power efficiency optimization needs to monitor and understand the whole process of coal combustion and pollutant migration, power system performance data show explosive growth trend, The purpose is to study the integration of numerical simulation of big data technology, the development of thermal power plant efficiency data optimization platform and nitrogen oxide emission reduction system for the thermal power plant to improve efficiency, energy saving and emission reduction to provide reliable technical support. The method is big data technology represented by "multi-source heterogeneous data integration", "large data distributed storage" and "high-performance real-time and off-line computing", can greatly enhance the energy consumption capacity of thermal power plants and the level of intelligent decision-making, and then use the data mining algorithm to establish the boiler combustion mathematical model, mining power plant boiler efficiency data, combined with numerical simulation technology to find the boiler combustion and pollutant generation rules and combustion parameters of boiler combustion and pollutant generation Influence. The result is to optimize the boiler combustion parameters, which can achieve energy saving.

High-power VCSEL systems and applications

NASA Astrophysics Data System (ADS)

Moench, Holger; Conrads, Ralf; Deppe, Carsten; Derra, Guenther; Gronenborn, Stephan; Gu, Xi; Heusler, Gero; Kolb, Johanna; Miller, Michael; Pekarski, Pavel; Pollmann-Retsch, Jens; Pruijmboom, Armand; Weichmann, Ulrich

2015-03-01

Easy system design, compactness and a uniform power distribution define the basic advantages of high power VCSEL systems. Full addressability in space and time add new dimensions for optimization and enable "digital photonic production". Many thermal processes benefit from the improved control i.e. heat is applied exactly where and when it is needed. The compact VCSEL systems can be integrated into most manufacturing equipment, replacing batch processes using large furnaces and reducing energy consumption. This paper will present how recent technological development of high power VCSEL systems will extend efficiency and flexibility of thermal processes and replace not only laser systems, lamps and furnaces but enable new ways of production. High power VCSEL systems are made from many VCSEL chips, each comprising thousands of low power VCSELs. Systems scalable in power from watts to multiple ten kilowatts and with various form factors utilize a common modular building block concept. Designs for reliable high power VCSEL arrays and systems can be developed and tested on each building block level and benefit from the low power density and excellent reliability of the VCSELs. Furthermore advanced assembly concepts aim to reduce the number of individual processes and components and make the whole system even more simple and reliable.

A review on applications of magnetoelectric composites: from heterostructural uncooled magnetic sensors, energy harvesters to highly efficient power converters

NASA Astrophysics Data System (ADS)

Leung, Chung Ming; Li, Jiefang; Viehland, D.; Zhuang, X.

2018-07-01

Over the past two decades, magnetoelectric (ME) composites and their devices have been an important topic of research. Potential applications ranging from low-power sensing to high-power converters have been investigated. This review, first begins with a summary of multiferroic materials that work at room temperature. Such ME materials are usually in composites, and their ME effect generated as a product property of magnetostrictive and piezoelectric composite layers. After that, mechanisms, working principles, and applications of ME composites from heterostructural uncooled magnetic sensors, energy harvesters to highly efficient power converters will be discussed. First, the development of ME sensors in terms of materials and structures to enhance their sensitivities and to reduce noise level is reviewed and discussed. Second, the structure of ME-based energy harvesters is discussed and summarized. Third, the development of ME gyrators is summarized for power applications, including current/voltage conversion, power efficiency, power density and figures of merit. Results demonstrate that our ME gyrator has the ability to satisfy the needs of power conversion with superior efficiency (>90%), offering potential uses in power electronic applications.

The Sustainable Nuclear Future: Fission and Fusion E.M. Campbell Logos Technologies

NASA Astrophysics Data System (ADS)

Campbell, E. Michael

2010-02-01

Global industrialization, the concern over rising CO2 levels in the atmosphere and other negative environmental effects due to the burning of hydrocarbon fuels and the need to insulate the cost of energy from fuel price volatility have led to a renewed interest in nuclear power. Many of the plants under construction are similar to the existing light water reactors but incorporate modern engineering and enhanced safety features. These reactors, while mature, safe and reliable sources of electrical power have limited efficiency in converting fission power to useful work, require significant amounts of water, and must deal with the issues of nuclear waste (spent fuel), safety, and weapons proliferation. If nuclear power is to sustain its present share of the world's growing energy needs let alone displace carbon based fuels, more than 1000 reactors will be needed by mid century. For this to occur new reactors that are more efficient, versatile in their energy markets, require minimal or no water, produce less waste and more robust waste forms, are inherently safe and minimize proliferation concerns will be necessary. Graphite moderated, ceramic coated fuel, and He cooled designs are reactors that can satisfy these requirements. Along with other generation IV fast reactors that can further reduce the amounts of spent fuel and extend fuel resources, such a nuclear expansion is possible. Furthermore, facilities either in early operations or under construction should demonstrate the next step in fusion energy development in which energy gain is produced. This demonstration will catalyze fusion energy development and lead to the ultimate development of the next generation of nuclear reactors. In this presentation the role of advanced fission reactors and future fusion reactors in the expansion of nuclear power will be discussed including synergies with the existing worldwide nuclear fleet. )

Exposure to ultrafine particles and black carbon in diesel-powered commuter trains

NASA Astrophysics Data System (ADS)

Jeong, Cheol-Heon; Traub, Alison; Evans, Greg J.

2017-04-01

Ultrafine particle (UFP), black carbon (BC) and lung deposited surface area (LDSA) concentrations measured during 43 trips on diesel-powered commuter trains revealed elevated exposures under some conditions. When the passenger coaches were pulled by a locomotive, the geometric mean concentrations of UFP, LDSA, and BC were 18, 10, and 6 times higher than the exposure levels when the locomotive pushed the coaches, respectively. In addition, UFP, LDSA, and BC concentrations in pull-trains were 5, 3, and 4 times higher than concentrations measured while walking on city sidewalks, respectively. Exposure to these pollutants was most elevated in the coach located closest to the locomotive: geometric means were 126,000 # cm-3 for UFP, 249 μm2 cm-3 for LDSA, and 17,800 ng m-3 of BC; these concentrations are much higher than those previously reported for other modes of public transportation. Markedly high levels of diesel exhaust are present in passenger trains powered by diesel locomotives operated in pull-mode. Thus, it is recommended that immediate steps be taken to evaluate, and where needed, mitigate exposure in diesel-powered passenger trains, both commuter and inter-city.

Extending Wireless Rechargeable Sensor Network Life without Full Knowledge.

PubMed

Najeeb, Najeeb W; Detweiler, Carrick

2017-07-17

When extending the life of Wireless Rechargeable Sensor Networks (WRSN), one challenge is charging networks as they grow larger. Overcoming this limitation will render a WRSN more practical and highly adaptable to growth in the real world. Most charging algorithms require a priori full knowledge of sensor nodes' power levels in order to determine the nodes that require charging. In this work, we present a probabilistic algorithm that extends the life of scalable WRSN without a priori power knowledge and without full network exploration. We develop a probability bound on the power level of the sensor nodes and utilize this bound to make decisions while exploring a WRSN. We verify the algorithm by simulating a wireless power transfer unmanned aerial vehicle, and charging a WRSN to extend its life. Our results show that, without knowledge, our proposed algorithm extends the life of a WRSN on average 90% of what an optimal full knowledge algorithm can achieve. This means that the charging robot does not need to explore the whole network, which enables the scaling of WRSN. We analyze the impact of network parameters on our algorithm and show that it is insensitive to a large range of parameter values.

Extending Wireless Rechargeable Sensor Network Life without Full Knowledge

PubMed Central

Najeeb, Najeeb W.; Detweiler, Carrick

2017-01-01

When extending the life of Wireless Rechargeable Sensor Networks (WRSN), one challenge is charging networks as they grow larger. Overcoming this limitation will render a WRSN more practical and highly adaptable to growth in the real world. Most charging algorithms require a priori full knowledge of sensor nodes’ power levels in order to determine the nodes that require charging. In this work, we present a probabilistic algorithm that extends the life of scalable WRSN without a priori power knowledge and without full network exploration. We develop a probability bound on the power level of the sensor nodes and utilize this bound to make decisions while exploring a WRSN. We verify the algorithm by simulating a wireless power transfer unmanned aerial vehicle, and charging a WRSN to extend its life. Our results show that, without knowledge, our proposed algorithm extends the life of a WRSN on average 90% of what an optimal full knowledge algorithm can achieve. This means that the charging robot does not need to explore the whole network, which enables the scaling of WRSN. We analyze the impact of network parameters on our algorithm and show that it is insensitive to a large range of parameter values. PMID:28714936

Low-Power Analog Processing for Sensing Applications: Low-Frequency Harmonic Signal Classification

PubMed Central

White, Daniel J.; William, Peter E.; Hoffman, Michael W.; Balkir, Sina

2013-01-01

A low-power analog sensor front-end is described that reduces the energy required to extract environmental sensing spectral features without using Fast Fouriér Transform (FFT) or wavelet transforms. An Analog Harmonic Transform (AHT) allows selection of only the features needed by the back-end, in contrast to the FFT, where all coefficients must be calculated simultaneously. We also show that the FFT coefficients can be easily calculated from the AHT results by a simple back-substitution. The scheme is tailored for low-power, parallel analog implementation in an integrated circuit (IC). Two different applications are tested with an ideal front-end model and compared to existing studies with the same data sets. Results from the military vehicle classification and identification of machine-bearing fault applications shows that the front-end suits a wide range of harmonic signal sources. Analog-related errors are modeled to evaluate the feasibility of and to set design parameters for an IC implementation to maintain good system-level performance. Design of a preliminary transistor-level integrator circuit in a 0.13 μm complementary metal-oxide-silicon (CMOS) integrated circuit process showed the ability to use online self-calibration to reduce fabrication errors to a sufficiently low level. Estimated power dissipation is about three orders of magnitude less than similar vehicle classification systems that use commercially available FFT spectral extraction. PMID:23892765

H2 arcjet performance mapping program

NASA Astrophysics Data System (ADS)

1992-01-01

Work performed during the period of Mar. 1991 to Jan. 1992 is reviewed. High power H2 arcjets are being considered for electric powered orbit transfer vehicles (EOTV). Mission analyses indicate that the overall arcjet thrust efficiency is very important since increasing the efficiency increases the thrust, and thereby reduces the total trip time for the same power. For example, increasing the thrust efficiency at the same specific impulse from 30 to 40 percent will reduce the trip time by 25 percent. For a 200 day mission, this equates to 50 days, which results in lower ground costs and less time during which the payload is dormant. Arcjet performance levels of 1200 seconds specific impulse (lsp) at 35 to 40 percent efficiency with lifetimes over 1000 hours are needed to support EOTV missions. Because of the potential very high efficiency levels, the objective of this program was to evaluate the ability of a scaled Giannini-style thruster to achieve the performance levels while operating at a reduced nominal power of 10 kW. To meet this objective, a review of past literature was conducted; scaling relationships were developed and applied to establish critical dimensions; a development thruster was designed with the aid of the plasma analysis model KARNAC and finite element thermal modeling; test hardware was fabricated; and a series of performance tests were conducted in RRC's Cell 11 vacuum chamber with its null-balance thrust stand.

Fission Surface Power Technology Development Update

NASA Technical Reports Server (NTRS)

Palac, Donald T.; Mason, Lee S.; Houts, Michael G.; Harlow, Scott

2011-01-01

Power is a critical consideration in planning exploration of the surfaces of the Moon, Mars, and places beyond. Nuclear power is an important option, especially for locations in the solar system where sunlight is limited or environmental conditions are challenging (e.g., extreme cold, dust storms). NASA and the Department of Energy are maintaining the option for fission surface power for the Moon and Mars by developing and demonstrating technology for a fission surface power system. The Fission Surface Power Systems project has focused on subscale component and subsystem demonstrations to address the feasibility of a low-risk, low-cost approach to space nuclear power for surface missions. Laboratory demonstrations of the liquid metal pump, reactor control drum drive, power conversion, heat rejection, and power management and distribution technologies have validated that the fundamental characteristics and performance of these components and subsystems are consistent with a Fission Surface Power preliminary reference concept. In addition, subscale versions of a non-nuclear reactor simulator, using electric resistance heating in place of the reactor fuel, have been built and operated with liquid metal sodium-potassium and helium/xenon gas heat transfer loops, demonstrating the viability of establishing system-level performance and characteristics of fission surface power technologies without requiring a nuclear reactor. While some component and subsystem testing will continue through 2011 and beyond, the results to date provide sufficient confidence to proceed with system level technology readiness demonstration. To demonstrate the system level readiness of fission surface power in an operationally relevant environment (the primary goal of the Fission Surface Power Systems project), a full scale, 1/4 power Technology Demonstration Unit (TDU) is under development. The TDU will consist of a non-nuclear reactor simulator, a sodium-potassium heat transfer loop, a power conversion unit with electrical controls, and a heat rejection system with a multi-panel radiator assembly. Testing is planned at the Glenn Research Center Vacuum Facility 6 starting in 2012, with vacuum and liquid-nitrogen cold walls to provide simulation of operationally relevant environments. A nominal two-year test campaign is planned including a Phase 1 reactor simulator and power conversion test followed by a Phase 2 integrated system test with radiator panel heat rejection. The testing is expected to demonstrate the readiness and availability of fission surface power as a viable power system option for NASA's exploration needs. In addition to surface power, technology development work within this project is also directly applicable to in-space fission power and propulsion systems.

On Nibbles and Bytes: The Conundrum of Memory for Space Systems - NASA Electronic Parts and Packaging (NEPP) and Efforts in Memories

NASA Technical Reports Server (NTRS)

LaBel, Kenneth A.; Ladbury, Ray; Pellish, Jonathan; Sheldon, Douglas; Oldham, Timothy; Berg, Melanie D.; Cohn, Lewis M.

2009-01-01

Radiation requirements and trends. TID: 1) >90% of NASA applications are < 100 krads-Si in piecepart requirements. a) Many commercial devices (NVM and SDRAMs) meet or come close to this. b) Charge pump TID tolerance has improved an order magnitude over the last 10 years. 2) There are always a few programs with higher level needs and, of course, defense needs SEL: 1) Prefer none or rates that are considered low risk. a) Latent damage is a bear to deal with. 2) As we re packing cells tighter and even with lower Vdd, we re seeing SEL on commercial devices regularly (<90nm). a) Often in power conversion, I/O, or control areas. SEU: 1) It s not the bit errors, it s the SEFIs errors that are the biggest issues. a) Scrubbing concerns for risk, power, speed.

Chemicapacitors as a versatile platform for miniature gas and vapor sensors

NASA Astrophysics Data System (ADS)

Blue, Robert; Uttamchandani, Deepak

2017-02-01

Recent years have seen the rapid growth in the need for sensors throughout all areas of society including environmental sensing, health-care, public safety and manufacturing quality control. To meet this diverse need, sensors have to evolve from specialized and bespoke systems to miniaturized, low-power, low-cost (almost disposable) ubiquitous platforms. A technology that has been developed which gives a route to meet these challenges is the chemicapacitor sensor. To date the commercialization of these sensors has largely been restricted to humidity sensing, but in this review we examine the progress over recent years to expand this sensing technology to a wide range of gases and vapors. From sensors interrogated with laboratory instrumentation, chemicapacitor sensors have evolved into miniaturized units integrated with low power readout electronics that can selectively detect target molecules to ppm and sub-ppm levels within vapor mixtures.

Power Electronic Semiconductor Materials for Automotive and Energy Saving Applications - SiC, GaN, Ga2O3, and Diamond.

PubMed

Wellmann, Peter J

2017-11-17

Power electronics belongs to the future key technologies in order to increase system efficiency as well as performance in automotive and energy saving applications. Silicon is the major material for electronic switches since decades. Advanced fabrication processes and sophisticated electronic device designs have optimized the silicon electronic device performance almost to their theoretical limit. Therefore, to increase the system performance, new materials that exhibit physical and chemical properties beyond silicon need to be explored. A number of wide bandgap semiconductors like silicon carbide, gallium nitride, gallium oxide, and diamond exhibit outstanding characteristics that may pave the way to new performance levels. The review will introduce these materials by (i) highlighting their properties, (ii) introducing the challenges in materials growth, and (iii) outlining limits that need innovation steps in materials processing to outperform current technologies.

Power Electronic Semiconductor Materials for Automotive and Energy Saving Applications – SiC, GaN, Ga2O3, and Diamond

PubMed Central

2017-01-01

Power electronics belongs to the future key technologies in order to increase system efficiency as well as performance in automotive and energy saving applications. Silicon is the major material for electronic switches since decades. Advanced fabrication processes and sophisticated electronic device designs have optimized the silicon electronic device performance almost to their theoretical limit. Therefore, to increase the system performance, new materials that exhibit physical and chemical properties beyond silicon need to be explored. A number of wide bandgap semiconductors like silicon carbide, gallium nitride, gallium oxide, and diamond exhibit outstanding characteristics that may pave the way to new performance levels. The review will introduce these materials by (i) highlighting their properties, (ii) introducing the challenges in materials growth, and (iii) outlining limits that need innovation steps in materials processing to outperform current technologies. PMID:29200530

Investigation of High-alpha Lateral-directional Control Power Requirements for High-performance Aircraft

NASA Technical Reports Server (NTRS)

Foster, John V.; Ross, Holly M.; Ashley, Patrick A.

1993-01-01

Designers of the next-generation fighter and attack airplanes are faced with the requirements of good high-angle-of-attack maneuverability as well as efficient high speed cruise capability with low radar cross section (RCS) characteristics. As a result, they are challenged with the task of making critical design trades to achieve the desired levels of maneuverability and performance. This task has highlighted the need for comprehensive, flight-validated lateral-directional control power design guidelines for high angles of attack. A joint NASA/U.S. Navy study has been initiated to address this need and to investigate the complex flight dynamics characteristics and controls requirements for high-angle-of-attack lateral-directional maneuvering. A multi-year research program is underway which includes ground-based piloted simulation and flight validation. This paper will give a status update of this program that will include a program overview, description of test methodology and preliminary results.

Investigation of high-alpha lateral-directional control power requirements for high-performance aircraft

NASA Technical Reports Server (NTRS)

Foster, John V.; Ross, Holly M.; Ashley, Patrick A.

1993-01-01

Designers of the next-generation fighter and attack airplanes are faced with the requirements of good high angle-of-attack maneuverability as well as efficient high speed cruise capability with low radar cross section (RCS) characteristics. As a result, they are challenged with the task of making critical design trades to achieve the desired levels of maneuverability and performance. This task has highlighted the need for comprehensive, flight-validated lateral-directional control power design guidelines for high angles of attack. A joint NASA/U.S. Navy study has been initiated to address this need and to investigate the complex flight dynamics characteristics and controls requirements for high angle-of-attack lateral-directional maneuvering. A multi-year research program is underway which includes groundbased piloted simulation and flight validation. This paper will give a status update of this program that will include a program overview, description of test methodology and preliminary results.

An Innovative Very Low Thermal Power Waste Heat Recovery System for Thermal Control of Deep Space Missions: A Thermal Flask in Space

NASA Technical Reports Server (NTRS)

Bhandari, Pradeep

2015-01-01

Future missions to deep space, such as those to the outer planets (Jupiter, Saturn, etc.), which would rely on solar photovoltaic power, would need extremely large solar arrays to produce sufficient power for their operations because solar intensity is so low at those locations. Hence any additional power that would be needed for thermal control is extremely limited. Previous deep space missions like Juno (to Jupiter) required almost 200 W of electrical power for thermal control. This is prohibitively large for many future mission concepts, and leads to them needing very large solar arrays. For Saturn, where the solar flux is 1/4th the flux at Jupiter, this would entail an extremely large increase in the solar array size to accommodate the need for thermal survival power, which would be prohibitively large in size and mass, and very expensive. Hence there is a need to come up with a thermal architecture and design options that would not need such prohibitively large thermal power levels. One solution relies on harvesting the pre-existing waste heat from all the heat dissipation that would be present from operation of electronics, instruments, etc. for their own functionality. For example, for a generic Saturn mission, the various electronics would already dissipate about 200 Watts of heat that is simply "thrown away" to space from the spacecraft surfaces. The amount of thermal power that would be required for the safe thermal control of components within the spacecraft in deep space would be roughly of this magnitude for this class of spacecraft. So it makes good sense to try to harvest the waste heat and employ it to maintain the temperatures of all the components within their allowable limits. In particular, propulsion systems typically need to be kept above their freezing limits, around room temperature (15 C). Electronics needs to be kept typically above -40 C and batteries above -20 C. The next question becomes how to harvest this waste heat and direct it to the components that would need it for their survival. The proposed system utilizes a mechanically pumped, single phase fluid loop to pick up the waste heat from components attached to this loop's tubing and then directed to a thermal flask that has tubing attached to it. The thermal flask is cylindrically shaped and contains essentially all systems and components in the spacecraft within it, with the exception of the solar array, antennae, thrusters and various apertures of instruments, etc. to allow them an unobstructed view of space. Waste heat from the heat-dissipating components warms up the fluid and is carried to the flask surface and deposited on it via the fluid loop's flow. The entire flask is covered with Multi-Layered Insulation (MLI) to minimize the heat loss from the flask and allow it to remain warm. Hence the flask essentially creates a thermal environment within which the spacecraft components reside. The temperature of the components within the flask is then essentially the same as the temperature of the flask. This approach could be a very enabling feature for deep space missions. This paper describes the approach utilized for this thermal architecture, along with its mechanical and implementation aspects. Additionally it will compare and contrast this approach with the more conventional solutions utilized earlier.

Development of an undergraduate bioinformatics degree program at a liberal arts college.

PubMed

Bagga, Paramjeet S

2012-09-01

The highly interdisciplinary field of bioinformatics has emerged as a powerful modern science. There has been a great demand for undergraduate- and graduate-level trained bioinformaticists in the industry as well in the academia. In order to address the needs for trained bioinformaticists, its curriculum must be offered at the undergraduate level, especially at four-year colleges, where a majority of the United States gets its education. There are many challenges in developing an undergraduate-level bioinformatics program that needs to be carefully designed as a well-integrated and cohesive interdisciplinary curriculum that prepares the students for a wide variety of career options. This article describes the challenges of establishing a highly interdisciplinary undergraduate major, the development of an undergraduate bioinformatics degree program at Ramapo College of New Jersey, and lessons learned in the last 10 years during its management.

GaAs VLSI technology and circuit elements for DSP

NASA Astrophysics Data System (ADS)

Mikkelson, James M.

1990-10-01

Recent progress in digital GaAs circuit performance and complexity is presented to demonstrate the current capabilities of GaAs components. High density GaAs process technology and circuit design techniques are described and critical issues for achieving favorable complexity speed power and cost tradeoffs are reviewed. Some DSP building blocks are described to provide examples of what types of DSP systems could be implemented with present GaAs technology. DIGITAL GaAs CIRCUIT CAPABILITIES In the past few years the capabilities of digital GaAs circuits have dramatically increased to the VLSI level. Major gains in circuit complexity and power-delay products have been achieved by the use of silicon-like process technologies and simple circuit topologies. The very high speed and low power consumption of digital GaAs VLSI circuits have made GaAs a desirable alternative to high performance silicon in hardware intensive high speed system applications. An example of the performance and integration complexity available with GaAs VLSI circuits is the 64x64 crosspoint switch shown in figure 1. This switch which is the most complex GaAs circuit currently available is designed on a 30 gate GaAs gate array. It operates at 200 MHz and dissipates only 8 watts of power. The reasons for increasing the level of integration of GaAs circuits are similar to the reasons for the continued increase of silicon circuit complexity. The market factors driving GaAs VLSI are system design methodology system cost power and reliability. System designers are hesitant or unwilling to go backwards to previous design techniques and lower levels of integration. A more highly integrated system in a lower performance technology can often approach the performance of a system in a higher performance technology at a lower level of integration. Higher levels of integration also lower the system component count which reduces the system cost size and power consumption while improving the system reliability. For large gate count circuits the power per gate must be minimized to prevent reliability and cooling problems. The technical factors which favor increasing GaAs circuit complexity are primarily related to reducing the speed and power penalties incurred when crossing chip boundaries. Because the internal GaAs chip logic levels are not compatible with standard silicon I/O levels input receivers and output drivers are needed to convert levels. These I/O circuits add significant delay to logic paths consume large amounts of power and use an appreciable portion of the die area. The effects of these I/O penalties can be reduced by increasing the ratio of core logic to I/O on a chip. DSP operations which have a large number of logic stages between the input and the output are ideal candidates to take advantage of the performance of GaAs digital circuits. Figure 2 is a schematic representation of the I/O penalties encountered when converting from ECL levels to GaAs

Time for a new budget allocation model for hospital care in Stockholm?

PubMed

Andersson, Per-Åke; Bruce, Daniel; Walander, Anders; Viberg, Inga

2011-03-01

In Stockholm County Council (SLL), budgets for hospital care have been allocated to geographically responsible authorities for a long time. This hospital care includes all publicly financed specialist care, also privately owned hospitals, except private practitioner care. The old needs-index model, a 6D capitation matrix based on demography and socio-economy, was generated on linked individual data for 1994-96. In this paper the power of the old allocation model is evaluated by the use of new data for 2006. The analysis shows that most of the socioeconomic variables have lost their descriptive power in 10 years. Using a methodical search we also find an improved need-based allocation model for hospital care using the new data for 2006. By focusing on costly diagnoses, where the descriptive power has increased between 1996 and 2006, and by using some new socioeconomic variables, and by relying on birth and death prognoses, we are able to generate a matrix model with much higher coefficients-of-determinations in 1 year predictions. In addition, a more careful modelling of multi-morbidity, part-of-the-year inhabitants, episode definition and cost transformation is developed. The area-level cost residuals of registered versus predicted costs show stable signs over the years, indicating unexplained systematics. For the reduction of the residuals, accepting proven inpatient diagnoses but not the full costs, a mixed capitation/fee-for-service strategy is discussed. Once equivalent (e.g. full-year) observations are determined, the link between background and consumption is not on individual-level but on cell-level, as in current resource allocation studies in the United Kingdom.

Assessing power of large river fish monitoring programs to detect population changes: the Missouri River sturgeon example

USGS Publications Warehouse

Wildhaber, M.L.; Holan, S.H.; Bryan, J.L.; Gladish, D.W.; Ellersieck, M.

2011-01-01

In 2003, the US Army Corps of Engineers initiated the Pallid Sturgeon Population Assessment Program (PSPAP) to monitor pallid sturgeon and the fish community of the Missouri River. The power analysis of PSPAP presented here was conducted to guide sampling design and effort decisions. The PSPAP sampling design has a nested structure with multiple gear subsamples within a river bend. Power analyses were based on a normal linear mixed model, using a mixed cell means approach, with variance estimates from the original data. It was found that, at current effort levels, at least 20 years for pallid and 10 years for shovelnose sturgeon is needed to detect a 5% annual decline. Modified bootstrap simulations suggest power estimates from the original data are conservative due to excessive zero fish counts. In general, the approach presented is applicable to a wide array of animal monitoring programs.

Core-power and decay-time limits for disabled automatic-actuation of LOFT ECCS

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

Hanson, G.H.

1978-06-05

The Emergency Core Cooling System (ECCS) for the LOFT reactor may need to be disabled for modifications or repairs of hardware or instrumentation or for component testing during periods when the reactor system is hot and pressurized, or it may be desirable to enable the ECCS to be disabled without the necessity of cooling down and depressurizing the reactor. LTR 113-47 has shown that the LOFT ECCS can be safely bypassed or disabled when the total core power does not exceed 25 kW. A modified policy involves disabling the automatic actuation of the LOFT ECCS, but still retaining the manualmore » activation capability. Disabling of the automatic actuation can be safely utilized, without subjecting the fuel cladding to unacceptable temperatures, when the LOFT power decays to 70 kW; this power level permits a maximum delay of 20 minutes following a LOCA for the manual actuation of ECCS.« less

Feeling High but Playing Low: Power, Need to Belong, and Submissive Behavior.

PubMed

Rios, Kimberly; Fast, Nathanael J; Gruenfeld, Deborah H

2015-08-01

Past research has demonstrated a causal relationship between power and dominant behavior, motivated in part by the desire to maintain the social distinctiveness created by one's position of power. In this article, we test the novel idea that some individuals respond to high-power roles by displaying not dominance but instead submissiveness. We theorize that high-power individuals who are also high in the need to belong experience the social distinctiveness associated with power as threatening, rather than as an arrangement to protect and maintain. We predict that such individuals will counter their feelings of threat with submissive behaviors to downplay their power and thereby reduce their distinctiveness. We found support for this hypothesis across three studies using different operationalizations of power, need to belong, and submissiveness. Furthermore, Study 3 illustrated the mediating role of fear of (positive) attention in the relationship between power, need to belong, and submissive behavior. © 2015 by the Society for Personality and Social Psychology, Inc.

Generalized SAMPLE SIZE Determination Formulas for Investigating Contextual Effects by a Three-Level Random Intercept Model.

PubMed

Usami, Satoshi

2017-03-01

Behavioral and psychological researchers have shown strong interests in investigating contextual effects (i.e., the influences of combinations of individual- and group-level predictors on individual-level outcomes). The present research provides generalized formulas for determining the sample size needed in investigating contextual effects according to the desired level of statistical power as well as width of confidence interval. These formulas are derived within a three-level random intercept model that includes one predictor/contextual variable at each level to simultaneously cover various kinds of contextual effects that researchers can show interest. The relative influences of indices included in the formulas on the standard errors of contextual effects estimates are investigated with the aim of further simplifying sample size determination procedures. In addition, simulation studies are performed to investigate finite sample behavior of calculated statistical power, showing that estimated sample sizes based on derived formulas can be both positively and negatively biased due to complex effects of unreliability of contextual variables, multicollinearity, and violation of assumption regarding the known variances. Thus, it is advisable to compare estimated sample sizes under various specifications of indices and to evaluate its potential bias, as illustrated in the example.

Comparisons of self-ratings on managerial competencies, research capability, time management, executive power, workload and work stress among nurse administrators.

PubMed

Kang, Chun-Mei; Chiu, Hsiao-Ting; Hu, Yi-Chun; Chen, Hsiao-Lien; Lee, Pi-Hsia; Chang, Wen-Yin

2012-10-01

To assess the level of and the differences in managerial competencies, research capability, time management, executive power, workload and work-stress ratings among nurse administrators (NAs), and to determine the best predictors of managerial competencies for NAs. Although NAs require multifaceted managerial competencies, research related to NAs' managerial competencies is limited. A cross-sectional survey was conducted with 330 NAs from 16 acute care hospitals. Managerial competencies were determined through a self-developed questionnaire. Data were collected in 2011. All NAs gave themselves the highest rating on integrity and the lowest on both financial/budgeting and business acumen. All scores for managerial competencies, research capability, time management and executive power showed a statistically significant correlation. The stepwise regression analysis revealed that age; having received NA training; having completed a nursing project independently; and scores for research capability, executive power and workload could explain 63.2% of the total variance in managerial competencies. The present study provides recommendations for future administrative training programmes to increase NAs' managerial competency in fulfilling their management roles and functions. The findings inform leaders of hospitals where NAs need to develop additional competencies concerning the type of training NAs need to function proficiently. © 2012 Blackwell Publishing Ltd.

Procedures and criteria for increasing the earthquake resistance level of electrical substations and special installations

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

Couch, R.W.; Deacon, R.J.

1973-09-30

This report defines a procedure and provides basic information needed to determine the modifications required to make electrical substations and special installations of the Bonneville Power Administration (BPA) more resistant to strong earthquake ground motion. It also provides a procedure for developing an effective plan for establishing the sequence, or priority, of providing the required modifications.

Sailing against the Wind. African Americans and Women in U.S. Education. SUNY Series, Frontiers in Education.

ERIC Educational Resources Information Center

Lomotey, Kofi, Ed.

This collection offer a much-needed and critical focus on African Americans and women in the United States. The politics of race, gender, and power influence education at every level as these chapters, written primarily from the perspectives of students, demonstrate. The following are included: (1) "What Does It Mean? Exploring the Myths of…

Alternative Fuels Data Center: DC Fast Charging at the Workplace:

Science.gov Websites

alleviate charging congestion when there are more PEV drivers than Level 1 or 2 charging at a worksite. DCFC can also be beneficial in emergencies or other situations when PEV drivers do not have time to charge electrical capacity for the DCFC's high power needs. There may also be additional costs to permitting or

Teaching Parents of Young Children: A Curriculum in 12 Sessions [and] Parent Power Pages.

ERIC Educational Resources Information Center

Wetzel, Laura L.

Based on the assumption that parents are increasingly aware of the high level of knowledge and skills needed to rear well-adjusted children, this parenting curriculum uses a developmental approach to help parents understand and relate appropriately to child behavior at different ages and at each stage. Part 1, "Before You Start," and the "Leader's…

A Hybrid Redox-Supercapacitor System with Anionic Catholyte and Cationic Anolyte

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

Wang, B; Macia-Agullo, JA; Prendiville, DG

A significant challenge for energy storage technologies is to realize battery-level energy density and capacitor-level durability and power density in one device. By introducing an electrolyte composed of an anionic catholyte and a cationic anolyte into a symmetric carbon-based supercapacitor configuration, a hybrid electrochemical battery-supercapacitor system using soluble redox species delivers significantly improved energy density from 20 to 42 W.h/kg (based on the electrode mass) and stable capacities for > 10(4) cycles. The ionic species formed in the electrolyte are studied by UV-Vis, Raman and mass spectroscopy to probe the energy storage mechanism. The strategy is general and may providemore » a route to critically-needed fast-charging devices with both high energy density and power. (C) 2014 The Electrochemical Society. All rights reserved.« less

Piezoelectric-based self-powered electronic adjustable impulse switches

NASA Astrophysics Data System (ADS)

Rastegar, Jahangir; Kwok, Philip

2018-03-01

Novel piezoelectric-based self-powered impulse detecting switches are presented. The switches are designed to detect shock loading events resulting in acceleration or deceleration above prescribed levels and durations. The prescribed acceleration level and duration thresholds are adjustable. They are provided with false trigger protection logic. The impulse switches are provided with electronic and logic circuitry to detect prescribed impulse events and reject events such as high amplitude but short duration shocks, and transportation vibration and similar low amplitude and relatively long duration events. They can be mounted directly onto electronics circuit boards, thereby significantly simplifying the electrical and electronic circuitry, simplifying the assembly process and total cost, significantly reducing the occupied volume, and in some applications eliminating the need for physical wiring to and from the impulse switches. The design of prototypes and testing under realistic conditions are presented.

Energy Beam Highways Through the Skies

NASA Technical Reports Server (NTRS)

Myrabo, Leik N.

1996-01-01

The emergence of Energy Beam Flight Transportation Systems could dramatically change the way we travel in the 21st Century. A framework for formulating 'Highways of Light' and the top level architectures that invoke radically new Space Power Grid infrastructure, are introduced. Basically, such flight systems, hereafter called Lightcraft, would employ off-board energy beam sources (either laser or microwave) to energize on-board dependent 'motors' -- instead of the traditional autonomous 'engines' with their on-board energy sources (e.g., chemical fuels). Extreme reductions in vehicle dry mass appear feasible with the use of off-board power and a high degree of on-board artificial intelligence. Such vehicles may no longer need airports for refueling (since they require no propellant), and could possibly pick up travelers at their homes -- before motoring over to one of many local boost stations, for the flight out. With off-board power, hyper-energetic acceleration performance and boost-glide trajectories become feasible. Hypersonic MS airbreathing propulsion can enable boosts up to twice escape velocity, which will cut trip times to the moon down to 5.5 hours. The predominant technological, environmental and social factors that will result from such transportation systems will be stressed. This presentation first introduces the remote source siting options for the space power system infrastructure, and then provides three representative laser/microwave Lightcraft options (derived from historical Case Studies): i.e., 'Acorn', 'Toy Top', and 'Disc.' Next the gamut of combined-cycle engine options developed for these Lightcraft are examined -- to illuminate the 'emerging technologies' that must be harnessed to produce flight hardware. Needed proof-of concept experiments are identified, along with the Macro-Level Issues that can springboard these revolutionary concepts into hardware reality.

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

Lawder, Matthew T.; Viswanathan, Vilayanur V.; Subramanian, Venkat R.

The growth of intermittent solar power has developed a need for energy storage systems in order to decouple generation and supply of energy. Microgrid (MG) systems comprising of solar arrays with battery energy storage studied in this paper desire high levels of autonomy, seeking to meet desired demand at all times. Large energy storage capacity is required for high levels of autonomy, but much of this expensive capacity goes unused for a majority of the year due to seasonal fluctuations of solar generation. In this paper, a model-based study of MGs comprised of solar generation and battery storage shows themore » relationship between system autonomy and battery utilization applied to multiple demand cases using a single particle battery model (SPM). The SPM allows for more accurate state-of-charge and utilization estimation of the battery than previous studies of renewably powered systems that have used empirical models. The increased accuracy of battery state estimation produces a better assessment of system performance. Battery utilization will depend on the amount of variation in solar insolation as well as the type of demand required by the MG. Consumers must balance autonomy and desired battery utilization of a system within the needs of their grid.« less

The Implementation and Validation of a Virtual Environment for Training Powered Wheelchair Manoeuvres.

PubMed

John, Nigel W; Pop, Serban R; Day, Thomas W; Ritsos, Panagiotis D; Headleand, Christopher J

2018-05-01

Navigating a powered wheelchair and avoiding collisions is often a daunting task for new wheelchair users. It takes time and practice to gain the coordination needed to become a competent driver and this can be even more of a challenge for someone with a disability. We present a cost-effective virtual reality (VR) application that takes advantage of consumer level VR hardware. The system can be easily deployed in an assessment centre or for home use, and does not depend on a specialized high-end virtual environment such as a Powerwall or CAVE. This paper reviews previous work that has used virtual environments technology for training tasks, particularly wheelchair simulation. We then describe the implementation of our own system and the first validation study carried out using thirty three able bodied volunteers. The study results indicate that at a significance level of 5 percent then there is an improvement in driving skills from the use of our VR system. We thus have the potential to develop the competency of a wheelchair user whilst avoiding the risks inherent to training in the real world. However, the occurrence of cybersickness is a particular problem in this application that will need to be addressed.

Tone Noise Predictions for a Spacecraft Cabin Ventilation Fan Ingesting Distorted Inflow and the Challenges of Validation

NASA Technical Reports Server (NTRS)

Koch, L. Danielle; Shook, Tony D.; Astler, Douglas T.; Bittinger, Samantha A.

2011-01-01

A fan tone noise prediction code has been developed at NASA Glenn Research Center that is capable of estimating duct mode sound power levels for a fan ingesting distorted inflow. This code was used to predict the circumferential and radial mode sound power levels in the inlet and exhaust duct of an axial spacecraft cabin ventilation fan. Noise predictions at fan design rotational speed were generated. Three fan inflow conditions were studied: an undistorted inflow, a circumferentially symmetric inflow distortion pattern (cylindrical rods inserted radially into the flowpath at 15deg, 135deg, and 255deg), and a circumferentially asymmetric inflow distortion pattern (rods located at 15deg, 52deg and 173deg). Noise predictions indicate that tones are produced for the distorted inflow cases that are not present when the fan operates with an undistorted inflow. Experimental data are needed to validate these acoustic predictions, as well as the aerodynamic performance predictions. Given the aerodynamic design of the spacecraft cabin ventilation fan, a mechanical and electrical conceptual design study was conducted. Design features of a fan suitable for obtaining detailed acoustic and aerodynamic measurements needed to validate predictions are discussed.

Tone Noise Predictions for a Spacecraft Cabin Ventilation Fan Ingesting Distorted Inflow and the Challenges of Validation

NASA Technical Reports Server (NTRS)

Koch, L. Danielle; Shook, Tony D.; Astler, Douglas T.; Bittinger, Samantha A.

2012-01-01

A fan tone noise prediction code has been developed at NASA Glenn Research Center that is capable of estimating duct mode sound power levels for a fan ingesting distorted inflow. This code was used to predict the circumferential and radial mode sound power levels in the inlet and exhaust duct of an axial spacecraft cabin ventilation fan. Noise predictions at fan design rotational speed were generated. Three fan inflow conditions were studied: an undistorted inflow, a circumferentially symmetric inflow distortion pattern (cylindrical rods inserted radially into the flowpath at 15deg, 135deg, and 255deg), and a circumferentially asymmetric inflow distortion pattern (rods located at 15deg, 52deg and 173deg). Noise predictions indicate that tones are produced for the distorted inflow cases that are not present when the fan operates with an undistorted inflow. Experimental data are needed to validate these acoustic predictions, as well as the aerodynamic performance predictions. Given the aerodynamic design of the spacecraft cabin ventilation fan, a mechanical and electrical conceptual design study was conducted. Design features of a fan suitable for obtaining detailed acoustic and aerodynamic measurements needed to validate predictions are discussed.

Incorporating environmental concerns into power sector decision-making: A case study of Sri Lanka. World Bank Environment Paper 6

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

Meier, P.; Munasinghe, M.; Team, S.L.S.

1994-04-01

Weighs Sri Lanka`s options for addressing environmental concerns during the planning stages of energy policymaking. Here is a holistic approach to analyzing the environmental impact of various power systems. Unlike standard impact studies that begin at the project level, this method calls for environmental assessments that start at the planning stage of a national framework for energy policymaking. The framework would take into account the energy needs of Sri Lanka`s total economy. It also would make it easier to incorporate environmental goals into power sector decisionmaking at the critical investment stage. Sri Lanka`s development options for the power sector aremore » reviewed in detail. Topics include alternative ways to assess the economic value of a power plant`s impact on biodiversity, human health, and air and water pollution. The study also assesses which energy planning options work best and recommends ways in which the Ceylon Electricity Board can improve its environmental policies.« less

Interference Effects Redress over Power-Efficient Wireless-Friendly Mesh Networks for Ubiquitous Sensor Communications across Smart Cities.

PubMed

Santana, Jose; Marrero, Domingo; Macías, Elsa; Mena, Vicente; Suárez, Álvaro

2017-07-21

Ubiquitous sensing allows smart cities to take control of many parameters (e.g., road traffic, air or noise pollution levels, etc.). An inexpensive Wireless Mesh Network can be used as an efficient way to transport sensed data. When that mesh is autonomously powered (e.g., solar powered), it constitutes an ideal portable network system which can be deployed when needed. Nevertheless, its power consumption must be restrained to extend its operational cycle and for preserving the environment. To this end, our strategy fosters wireless interface deactivation among nodes which do not participate in any route. As we show, this contributes to a significant power saving for the mesh. Furthermore, our strategy is wireless-friendly, meaning that it gives priority to deactivation of nodes receiving (and also causing) interferences from (to) the rest of the smart city. We also show that a routing protocol can adapt to this strategy in which certain nodes deactivate their own wireless interfaces.

Design of small Stirling dynamic isotope power system for robotic space missions

NASA Technical Reports Server (NTRS)

Bents, D. J.; Schreiber, J. G.; Withrow, C. A.; Mckissock, B. I.; Schmitz, P. C.

1992-01-01

Design of a multihundred-watt Dynamic Isotope Power System (DIPS) based on the U.S. Department of Energy (DOE) General Purpose Heat Source (GPHS) and small (multihundred-watt) free-piston Stirling engine (FPSE) technology is being pursued as a potential lower cost alternative to radioisotope thermoelectric generators (RTG's). The design is targeted at the power needs of future unmanned deep space and planetary surface exploration missions ranging from scientific probes to Space Exploration Initiative precursor missions. Power level for these missions is less than a kilowatt. Unlike previous DIPS designs which were based on turbomachinery conversion (e.g. Brayton), this small Stirling DIPS can be advantageously scaled down to multihundred-watt unit size while preserving size and mass competitiveness with RTG's. Preliminary characterization of units in the output power ranges 200-600 We indicate that on an electrical watt basis the GPHS/small Stirling DIPS will be roughly equivalent to an advanced RTG in size and mass but require less than a third of the isotope inventory.

Overcoming the Adoption Barrier to Electric Flight

NASA Technical Reports Server (NTRS)

Borer, Nicholas K.; Nickol, Craig L.; Jones, Frank P.; Yasky, Richard J.; Woodham, Kurt; Fell, Jared S.; Litherland, Brandon L.; Loyselle, Patricia L.; Provenza, Andrew J.; Kohlman, Lee W.;

Interference Effects Redress over Power-Efficient Wireless-Friendly Mesh Networks for Ubiquitous Sensor Communications across Smart Cities

PubMed Central

Marrero, Domingo; Macías, Elsa; Mena, Vicente

2017-01-01

Ubiquitous sensing allows smart cities to take control of many parameters (e.g., road traffic, air or noise pollution levels, etc.). An inexpensive Wireless Mesh Network can be used as an efficient way to transport sensed data. When that mesh is autonomously powered (e.g., solar powered), it constitutes an ideal portable network system which can be deployed when needed. Nevertheless, its power consumption must be restrained to extend its operational cycle and for preserving the environment. To this end, our strategy fosters wireless interface deactivation among nodes which do not participate in any route. As we show, this contributes to a significant power saving for the mesh. Furthermore, our strategy is wireless-friendly, meaning that it gives priority to deactivation of nodes receiving (and also causing) interferences from (to) the rest of the smart city. We also show that a routing protocol can adapt to this strategy in which certain nodes deactivate their own wireless interfaces. PMID:28754013

An Overview of Power Capability Requirements for Exploration Missions

NASA Technical Reports Server (NTRS)

Davis, Jose M.; Cataldo, Robert L.; Soeder, James F.; Manzo, Michelle A.; Hakimzadeh, Roshanak

2005-01-01

Advanced power is one of the key capabilities that will be needed to achieve NASA's missions of exploration and scientific advancement. Significant gaps exist in advanced power capabilities that are on the critical path to enabling human exploration beyond Earth orbit and advanced robotic exploration of the solar system. Focused studies and investment are needed to answer key development issues for all candidate technologies before down-selection. The viability of candidate power technology alternatives will be a major factor in determining what exploration mission architectures are possible. Achieving the capabilities needed to enable the CEV, Moon, and Mars missions is dependent on adequate funding. Focused investment in advanced power technologies for human and robotic exploration missions is imperative now to reduce risk and to make informed decisions on potential exploration mission decisions beginning in 2008. This investment would begin the long lead-time needed to develop capabilities for human exploration missions in the 2015 to 2030 timeframe. This paper identifies some of the key technologies that will be needed to fill these power capability gaps. Recommendations are offered to address capability gaps in advanced power for Crew Exploration Vehicle (CEV) power, surface nuclear power systems, surface mobile power systems, high efficiency power systems, and space transportation power systems. These capabilities fill gaps that are on the critical path to enabling robotic and human exploration missions. The recommendations address the following critical technology areas: Energy Conversion, Energy Storage, and Power Management and Distribution.

In vitro fragmentation efficiency of holmium: yttrium-aluminum-garnet (YAG) laser lithotripsy--a comprehensive study encompassing different frequencies, pulse energies, total power levels and laser fibre diameters.

PubMed

Kronenberg, Peter; Traxer, Olivier

2014-08-01

To assess the fragmentation (ablation) efficiency of laser lithotripsy along a wide range of pulse energies, frequencies, power settings and different laser fibres, in particular to compare high- with low-frequency lithotripsy using a dynamic and innovative testing procedure free from any human interaction bias. An automated laser fragmentation testing system was developed. The unmoving laser fibres fired at the surface of an artificial stone while the stone was moved past at a constant velocity, thus creating a fissure. The lithotripter settings were 0.2-1.2 J pulse energies, 5-40 Hz frequencies, 4-20 W power levels, and 200 and 550 μm core laser fibres. Fissure width, depth, and volume were analysed and comparisons between laser settings, fibres and ablation rates were made. Low frequency-high pulse energy (LoFr-HiPE) settings were (up to six times) more ablative than high frequency-low pulse energy (HiFr-LoPE) at the same power levels (P < 0.001), as they produced deeper (P < 0.01) and wider (P < 0.001) fissures. There were linear correlations between pulse energy and fragmentation volume, fissure width, and fissure depth (all P < 0.001). Total power did not correlate with fragmentation measurements. Laser fibre diameter did not affect fragmentation volume (P = 0.81), except at very low pulse energies (0.2 J), where the large fibre was less efficient (P = 0.015). At the same total power level, LoFr-HiPE lithotripsy was most efficient. Pulse energy was the key variable that drove fragmentation efficiency. Attention must be paid to prevent the formation of time-consuming bulky debris and adapt the lithotripter settings to one's needs. As fibre diameter did not affect fragmentation efficiency, small fibres are preferable due to better scope irrigation and manoeuvrability. © 2013 The Authors. BJU International © 2013 BJU International.

Equity in health in unequal societies: meeting health needs in contexts of social change.

PubMed

Bloom, G

2001-09-01

The paper explores the implications for health policy of the segmentation of society into social groups with very different levels of income and wealth. Discourses on equity in health are presently dominated by a debate between 'European' and 'American' models of health delivery. This has led to a focus on ideal outcomes rather than practical options for organising and financing health services in poor countries undergoing rapid change. The paper argues for a more explicit acknowledgement of the dynamic character of health development and the political nature of the negotiations regarding the use of government powers. Unregulated markets for health care are neither equitable nor efficient. Government must play a role in supporting the organisation of health services used by different social groups. Countries with low levels of inequality may be able to provide universal access to relatively sophisticated health services. Otherwise, governments need to operate within a segmented system. This means the negotiation of strategies to reduce the burden of sickness and premature death, whilst meeting the needs of different social groups. The discussion is organised in terms of the powers of government to require individuals and institutions to transfer resources for social uses, enforce regulations and generate and disseminate information. The paper concludes that governments committed to equity-enhancing health development need to increase their capacity to facilitate coalition building and manage change. It proposes an international public health legal framework that might include a definition of minimum standards for certain health services, to be underwritten by national and international financial commitments.

Energy Storage Project

NASA Technical Reports Server (NTRS)

Mercer, Carolyn R.; Jankovsky, Amy L.; Reid, Concha M.; Miller, Thomas B.; Hoberecht, Mark A.

2011-01-01

NASA's Exploration Technology Development Program funded the Energy Storage Project to develop battery and fuel cell technology to meet the expected energy storage needs of the Constellation Program for human exploration. Technology needs were determined by architecture studies and risk assessments conducted by the Constellation Program, focused on a mission for a long-duration lunar outpost. Critical energy storage needs were identified as batteries for EVA suits, surface mobility systems, and a lander ascent stage; fuel cells for the lander and mobility systems; and a regenerative fuel cell for surface power. To address these needs, the Energy Storage Project developed advanced lithium-ion battery technology, targeting cell-level safety and very high specific energy and energy density. Key accomplishments include the development of silicon composite anodes, lithiated-mixed-metal-oxide cathodes, low-flammability electrolytes, and cell-incorporated safety devices that promise to substantially improve battery performance while providing a high level of safety. The project also developed "non-flow-through" proton-exchange-membrane fuel cell stacks. The primary advantage of this technology set is the reduction of ancillary parts in the balance-of-plant--fewer pumps, separators and related components should result in fewer failure modes and hence a higher probability of achieving very reliable operation, and reduced parasitic power losses enable smaller reactant tanks and therefore systems with lower mass and volume. Key accomplishments include the fabrication and testing of several robust, small-scale nonflow-through fuel cell stacks that have demonstrated proof-of-concept. This report summarizes the project s goals, objectives, technical accomplishments, and risk assessments. A bibliography spanning the life of the project is also included.

P/N In(Al) GaAs multijunction laser power converters

NASA Technical Reports Server (NTRS)

Wojtczuk, Steven; Parados, Themis; Walker, Gilbert

1994-01-01

Eight In(AI)GaAs PN junctions grown epitaxially on the semi-insulating wafer were monolithically integrated in series to boost the approximately 0.4V photovoltage per typical In(Al)GaAs junction to over 3 volts for the 1 sq cm laser power converted (LPC) chip. Advantages of multijunction LCP designs include the need for less circuitry for power reconditioning and the potential for lower I(sup 2)R power loss. As an example, these LPC's have a responsivity of approximately 1 amp/watt. With a single junction LPC, 100 watts/sq cm incident power would lead to about 100 A/sq cm short-circuit current at approximately 0.4V open-cicuit voltage. One disadvantage is the large current would lead to a large I(sup 2)R loss which would lower the fill factor so that 40 watts/sq cm output would not be obtained. Another is that few circuits are designed to work at 0.4 volts, so DC-DC power conversion circuitry would be necessary to raise the voltage to a reasonable level. The multijunction LPC being developed in this program is a step toward solving these problems. In the above example, an eight-junction LPC would have eight times the voltage, approximately 3V, so that DC-DC power conversion may not be needed in many instances. In addition, the multijunction LPC would have 1/8 the current of a single-junction LPC, for only 1/64 the I(sup 2)R loss if the series resistance is the same. Working monolithic multijunction laser power converters (LPC's) were made in two different compositions of the In(x)Al(y)Ga(1-x-y)As semiconductor alloy, In(0.53)Ga(0.47)As (0.74 eV) and In(0.5)Al(0.1)Ga(0.4)As (0.87 eV). The final 0.8 sq cm LPC's had output voltages of about 3 volts and output currents up to about one-half amp. Maximum 1.3 micron power conversion efficiencies were approximately 22 percent. One key advantage of multijunction LPC's is that they have higher output voltages, so that less DC-DC power conversion circuitry is needed in applications.

Solar Array Power Conditioning for a Spinning Satellite

NASA Astrophysics Data System (ADS)

De Luca, Antonio; Chirulli, Giovanni

2008-09-01

The conditioning of the output power from a solar array can mainly be achieved by the adoption of DET or MPPT based architecture. There are several factors that can orientate the choice of the system designer towards one solution or the other; some of them maybe inherent to the mission derived requirements (Illumination levels, EMC cleanliness, etc.), others come directly from a careful assessment of performances and losses of both power conditioner and solar array.Definition of the criteria on which basis the final choice is justified is important as they have to guarantee a clear determination of the available versus the required power in all those mission conditions identifiable as design drivers for the overall satellite system both in terms of mass and costs.Such criteria cannot just be simple theoretical enunciations of principles; nor the meticulous definition of them on a case by case basis for different types of missions as neither option gives a guarantee of being conclusive.The aim of this paper is then to suggest assessment steps and guidelines that can be considered generically valid for any mission case, starting from the exposition of the trade off activity performed in order to choose the power conditioning solution for a spinning satellite having unregulated power bus architecture. Calculations and numerical simulations have been made in order to establish the needed solar array surface in case of adoption of a DET or MPPT solution, taking into account temperature and illumination levels on the solar cells, as well as power losses and inefficiencies from the solar generator to the main power bus, in different mission phases. Particular attention has been taken in order to correctly evaluate the thermal effects on the rest of the spacecraft as function of the adopted power system regulation.

Model depiction of the atmospheric flows of radioactive cesium emitted from the Fukushima Daiichi Nuclear Power Station accident

NASA Astrophysics Data System (ADS)

Nakajima, Teruyuki; Misawa, Shota; Morino, Yu; Tsuruta, Haruo; Goto, Daisuke; Uchida, Junya; Takemura, Toshihiko; Ohara, Toshimasa; Oura, Yasuji; Ebihara, Mitsuru; Satoh, Masaki

2017-12-01

In this study, a new method is proposed for the depiction of the atmospheric transportation of the 137Cs emitted from the Fukushima Daiichi Nuclear Power Station accident. This method employs a combination of the results of two aerosol model ensembles and the hourly observed atmospheric 137Cs concentration at surface level during 14-23 March 2011 at 90 sites in the suspended particulate matter monitoring network. The new method elucidates accurate transport routes and the distribution of the surface-level atmospheric 137Cs relevant to eight plume events that were previously identified. The model ensemble simulates the main features of the observed distribution of surface-level atmospheric 137Cs. However, significant differences were found in some cases, and this suggests the need to improve the modeling of the emission scenario, plume height, wet deposition process, and plume propagation in the Abukuma Mountain region. The contributions of these error sources differ in the early and dissipating phases of each event, depending on the meteorological conditions.

Effect of Bauxite addition on Adhesion Strength and Surface Roughness of Fly ash based Plasma Sprayed Coatings

NASA Astrophysics Data System (ADS)

Bhuyan, S. K.; Samal, S.; Pattnaik, D.; Sahu, A.; Swain, B.; Thiyagarajan, T. K.; Mishra, S. C.

2018-03-01

The environment is being contaminated with advancement of new technology, day by day. One of the primary sources for this contamination is the industrial waste. Industrialization is the prime reason behind the prosperity of any country to meet the materialistic demand. To run the industries, a huge amount of (electric) power is needed and hence need for thermal power plants to serve the purpose. In present scenario, coal fired thermal power plants are set up which generates a huge quantity of Fly ash. Consumption of industrial waste (Fly ash), continually a major concern for human race. In recent years, fly ash is being utilized for various purposes i.e. making bricks, mine reclamation, production of cements etc. The presence of Silica and Alumina in fly ash makes it useful for thermal barrier applications also. The plasma spray technology has the advantage of being able to process any types of metal/ceramic mineral, low-grade-ore minerals etc. to make value-added products and also to deposit ceramics, metals and a combination of these to deposit composite coatings with desired microstructure and required properties on a range of substrate materials. The present work focuses on utilization of fly ash mixing with bauxite (ore mineral) for a high valued application. Fly ash with 10 and 20% bauxite addition is used to deposit plasma spray overlay coatings at different power levels (10-20kW) on aluminum and mild steel substrates. Adhesion strength and surface roughness of the coatings are evaluated. Phase composition analysis of the coatings were done using X-ray diffraction analysis. Surface morphology of the coatings was studied using a scanning electron microscope (SEM). Maximum adhesion strength of 4.924 MPa is obtained for the composition fly ash and bauxite (10%), coated on mild steel at 16kW torch power level. The surface roughness (Ra) of the coatings is found to vary between 10.0102 to 17.2341 micron.

USE OF COAL DRYING TO REDUCE WATER CONSUMED IN PULVERIZED COAL POWER PLANTS

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

Edward Levy; Nenad Sarunac; Harun Bilirgen

2005-04-01

This is the ninth Quarterly Report for this project. The background and technical justification for the project are described, including potential benefits of reducing fuel moisture using power plant waste heat, prior to firing the coal in a pulverized coal boiler. During this last Quarter, comparative analyses were performed for lignite and PRB coals to determine how unit performance varies with coal product moisture. Results are given showing how the coal product moisture level and coal rank affect parameters such as boiler efficiency, station service power needed for fans and pulverizers and net unit heat rate. Results are also givenmore » for the effects of coal drying on cooling tower makeup water and comparisons are made between makeup water savings for various times of the year.« less

T55 power turbine rotor multiplane-multispeed balancing study

NASA Technical Reports Server (NTRS)

Martin, M. R.

1982-01-01

A rotordynamic analysis of the T55-L-11C engine was used to evaluate the balancing needs of the power turbine and to optimize the balancing procedure. As a result, recommendations were made for implementation of a multiplane-multispeed balancing plan. Precision collars for the attachment of trial weights to a slender rotor were designed enabling demonstration balancing on production hardware. The quality of the balance was then evaluated by installing a high speed balanced power turbine in an engine and running in a test cell at the Corpus Christi Army depot. The engine used had been tested prior to the turbine changeout and showed acceptable overall vibration levels for the engine were significantly reduced, demonstrating the ability of multiplane-multispeed balancing to control engine vibration.

Lighting: The Killer App of Village Power

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

NONE

1997-12-01

This paper looks at lighting systems as the major market for village level power generation. To the consumer it is something which is needed, could come from a much friendlier source, and the issues of affordability, convenience, and reliability are important. To the supplier lighting has an enormous range of potential customers, it opens the opportunity for other services, and even small demand can give big returns. Because the efficiency of the light source is critical to the number of lights which a fixed power supply can drive, it is important to pick the proper type of bulb to usemore » in this system. The paper discusses test results from an array of fluorescent and incadescent lamps, compared with a kerosene lamp. Low wattage fluorescents seem to perform the best.« less

Air Force space power and thermal management technology - Requirements for the early 21st century

NASA Astrophysics Data System (ADS)

Herrera, Ernest D.; Kuck, Inara

Typical projections for military space power and thermal management technologies have posited requirements for high powered and highly survivable systems. Recent changes in defense needs, however, will require spacecraft that are smaller, lower powered, less survivable, and highly proliferated. Technologies will be developed to provide low cost, ultra-light, high power density, 'smart' conventional power systems. Compact nuclear power systems will also be developed to meet higher power needs.

A Compound Algorithm for Maximum Power Point Tracking Used in Laser Power Beaming

NASA Astrophysics Data System (ADS)

Chen, Cheng; Liu, Qiang; Gao, Shan; Teng, Yun; Cheng, Lin; Yu, Chengtao; Peng, Kai

2018-03-01

With the high voltage intelligent substation developing in a pretty high speed, more and more artificial intelligent techniques have been incorporated into the power devices to meet the automation needs. For the sake of the line maintenance staff’s safety, the high voltage isolating switch draws great attention among the most important power devices because of its capability of connecting and disconnecting the high voltage circuit. However, due to the very high level voltage of the high voltage isolating switch’s working environment, the power supply system of the surveillance devices could suffer from great electromagnetic interference. Laser power beaming exhibits its merits in such situation because it can provide steady power from a distance despite the day or the night. Then the energy conversion efficiency arises as a new concern. To make as much use of the laser power as possible, our work mainly focuses on extracting maximum power from the photovoltaic (PV) panel. In this paper, we proposed a neural network based algorithm which relates both the intrinsic and the extrinsic features of the PV panel to the proportion of the voltage at the maximum power point (MPP) to the open circuit voltage of the PV panel. Simulations and experiments were carried out to verify the validness of our algorithm.

Power, effects, confidence, and significance: an investigation of statistical practices in nursing research.

PubMed

Gaskin, Cadeyrn J; Happell, Brenda

2014-05-01

To (a) assess the statistical power of nursing research to detect small, medium, and large effect sizes; (b) estimate the experiment-wise Type I error rate in these studies; and (c) assess the extent to which (i) a priori power analyses, (ii) effect sizes (and interpretations thereof), and (iii) confidence intervals were reported. Statistical review. Papers published in the 2011 volumes of the 10 highest ranked nursing journals, based on their 5-year impact factors. Papers were assessed for statistical power, control of experiment-wise Type I error, reporting of a priori power analyses, reporting and interpretation of effect sizes, and reporting of confidence intervals. The analyses were based on 333 papers, from which 10,337 inferential statistics were identified. The median power to detect small, medium, and large effect sizes was .40 (interquartile range [IQR]=.24-.71), .98 (IQR=.85-1.00), and 1.00 (IQR=1.00-1.00), respectively. The median experiment-wise Type I error rate was .54 (IQR=.26-.80). A priori power analyses were reported in 28% of papers. Effect sizes were routinely reported for Spearman's rank correlations (100% of papers in which this test was used), Poisson regressions (100%), odds ratios (100%), Kendall's tau correlations (100%), Pearson's correlations (99%), logistic regressions (98%), structural equation modelling/confirmatory factor analyses/path analyses (97%), and linear regressions (83%), but were reported less often for two-proportion z tests (50%), analyses of variance/analyses of covariance/multivariate analyses of variance (18%), t tests (8%), Wilcoxon's tests (8%), Chi-squared tests (8%), and Fisher's exact tests (7%), and not reported for sign tests, Friedman's tests, McNemar's tests, multi-level models, and Kruskal-Wallis tests. Effect sizes were infrequently interpreted. Confidence intervals were reported in 28% of papers. The use, reporting, and interpretation of inferential statistics in nursing research need substantial improvement. Most importantly, researchers should abandon the misleading practice of interpreting the results from inferential tests based solely on whether they are statistically significant (or not) and, instead, focus on reporting and interpreting effect sizes, confidence intervals, and significance levels. Nursing researchers also need to conduct and report a priori power analyses, and to address the issue of Type I experiment-wise error inflation in their studies. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Millimeterwave Space Power Grid architecture development 2012

NASA Astrophysics Data System (ADS)

Komerath, Narayanan; Dessanti, Brendan; Shah, Shaan

This is an update of the Space Power Grid architecture for space-based solar power with an improved design of the collector/converter link, the primary heater and the radiator of the active thermal control system. The Space Power Grid offers an evolutionary approach towards TeraWatt-level Space-based solar power. The use of millimeter wave frequencies (around 220GHz) and Low-Mid Earth Orbits shrinks the size of the space and ground infrastructure to manageable levels. In prior work we showed that using Brayton cycle conversion of solar power allows large economies of scale compared to the linear mass-power relationship of photovoltaic conversion. With high-temperature materials permitting 3600 K temperature in the primary heater, over 80 percent cycle efficiency was shown with a closed helium cycle for the 1GW converter satellite which formed the core element of the architecture. Work done since the last IEEE conference has shown that the use of waveguides incorporated into lighter-than-air antenna platforms, can overcome the difficulties in transmitting millimeter wave power through the moist, dense lower atmosphere. A graphene-based radiator design conservatively meets the mass budget for the waste heat rejection system needed for the compressor inlet temperature. Placing the ultralight Mirasol collectors in lower orbits overcomes the solar beam spot size problem of high-orbit collection. The architecture begins by establishing a power exchange with terrestrial renewable energy plants, creating an early revenue generation approach with low investment. The approach allows for technology development and demonstration of high power millimeter wave technology. A multinational experiment using the International Space Station and another power exchange satellite is proposed to gather required data and experience, thus reducing the technical and policy risks. The full-scale architecture deploys pairs of Mirasol sunlight collectors and Girasol 1 GW converter satellites t- ramp up space solar power level to over 5.6 TeraWatts by year 50 from project start. Runway-based launch and landing are required to achieve the launch productivity as well as the cost reductions to enable such a large deployment on schedule. Advancements in the certainty of millimeter wave conversion technology and runway-based space access, are seen to be the outstanding issues in proceeding to full-scale Space Solar Power.

Quantification of Hungry Horse Reservoir Water Levels Needed to Maintain or Enhance Reservoir Fisheries; Methods and Data, 1983-1987 Summary Report.

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

May, Bruce; Michael, Gary; Wachsmuth, John

1988-06-01

The Hungry Horse Reservoir study is part of the Northwest Power Planning Council's resident fish and wildlife plan. The plan is responsible for mitigating damages to the fish and wildlife resources caused by hydroelectric development in the Columbia River Basin. The major goal of our study is to quantify seasonal water levels needed to maintain or enhance the reservoir fishery. This study began in May, 1983, and the initial phase will be completed July, 1988. This report summarizes limnological, fish abundance, fish distribution and fish food habits data collected from 1983 to 1988. The effect of reservoir operation upon fishmore » habitat, fish food organisms and fish growth is discussed. 71 refs., 36 figs., 46 tabs.« less

Real-time UNIX in HEP data acquisition

NASA Astrophysics Data System (ADS)

Buono, S.; Gaponenko, I.; Jones, R.; Mapelli, L.; Mornacchi, G.; Prigent, D.; Sanchez-Corral, E.; Skiadelli, M.; Toppers, A.; Duval, P. Y.; Ferrato, D.; Le Van Suu, A.; Qian, Z.; Rondot, C.; Ambrosini, G.; Fumagalli, G.; Aguer, M.; Huet, M.

1994-12-01

Today's experimentation in high energy physics is characterized by an increasing need for sensitivity to rare phenomena and complex physics signatures, which require the use of huge and sophisticated detectors and consequently a high performance readout and data acquisition. Multi-level triggering, hierarchical data collection and an always increasing amount of processing power, distributed throughout the data acquisition layers, will impose a number of features on the software environment, especially the need for a high level of standardization. Real-time UNIX seems, today, the best solution for the platform independence, operating system interface standards and real-time features necessary for data acquisition in HEP experiments. We present the results of the evaluation, in a realistic application environment, of a Real-Time UNIX operating system: the EP/LX real-time UNIX system.

Digital Architecture Planning Model

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

Oxstrand, Johanna Helene; Al Rashdan, Ahmad Yahya Mohammad; Bly, Aaron Douglas

As part of the U.S. Department of Energy’s Light Water Reactor Sustainability Program, the Digital Architecture (DA) Project focuses on providing a model that nuclear utilities can refer to when planning deployment of advanced technologies. The digital architecture planning model (DAPM) is the methodology for mapping power plant operational and support activities into a DA that unifies all data sources needed by the utilities to operate their plants. The DA is defined as a collection of information technology capabilities needed to support and integrate a wide spectrum of real-time digital capabilities for performance improvements of nuclear power plants. DA canmore » be thought of as integration of the separate instrumentation and control and information systems already in place in nuclear power plants, which are brought together for the purpose of creating new levels of automation in plant work activities. A major objective in DAPM development was to survey all key areas that needed to be reviewed in order for a utility to make knowledgeable decisions regarding needs and plans to implement a DA at the plant. The development was done in two steps. First, researchers surveyed the nuclear industry in order to learn their near-term plans for adopting new advanced capabilities and implementing a network (i.e., wireless and wire) infrastructure throughout the plant, including the power block. Secondly, a literature review covering regulatory documents, industry standards, and technical research reports and articles was conducted. The objective of the review was to identify key areas to be covered by the DAPM, which included the following: 1. The need for a DA and its benefits to the plant 2. Resources required to implement the DA 3. Challenges that need to be addressed and resolved to implement the DA 4. Roles and responsibilities of the DA implementation plan. The DAPM was developed based on results from the survey and the literature review. Model development, including the survey results and conclusions made about the key areas during the literature review, are described in this report.« less

High-Power, High-Thrust Ion Thruster (HPHTion)

NASA Technical Reports Server (NTRS)

Peterson, Peter Y.

2015-01-01

Advances in high-power photovoltaic technology have enabled the possibility of reasonably sized, high-specific power solar arrays. At high specific powers, power levels ranging from 50 to several hundred kilowatts are feasible. Ion thrusters offer long life and overall high efficiency (typically greater than 70 percent efficiency). In Phase I, the team at ElectroDynamic Applications, Inc., built a 25-kW, 50-cm ion thruster discharge chamber and fabricated a laboratory model. This was in response to the need for a single, high-powered engine to fill the gulf between the 7-kW NASA's Evolutionary Xenon Thruster (NEXT) system and a notional 25-kW engine. The Phase II project matured the laboratory model into a protoengineering model ion thruster. This involved the evolution of the discharge chamber to a high-performance thruster by performance testing and characterization via simulated and full beam extraction testing. Through such testing, the team optimized the design and built a protoengineering model thruster. Coupled with gridded ion thruster technology, this technology can enable a wide range of missions, including ambitious near-Earth NASA missions, Department of Defense missions, and commercial satellite activities.

PMU-Aided Voltage Security Assessment for a Wind Power Plant

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

Jiang, Huaiguang; Zhang, Yingchen; Zhang, Jun Jason

2015-10-05

Because wind power penetration levels in electric power systems are continuously increasing, voltage stability is a critical issue for maintaining power system security and operation. The traditional methods to analyze voltage stability can be classified into two categories: dynamic and steady-state. Dynamic analysis relies on time-domain simulations of faults at different locations; however, this method needs to exhaust faults at all locations to find the security region for voltage at a single bus. With the widely located phasor measurement units (PMUs), the Thevenin equivalent matrix can be calculated by the voltage and current information collected by the PMUs. This papermore » proposes a method based on a Thevenin equivalent matrix to identify system locations that will have the greatest impact on the voltage at the wind power plant's point of interconnection. The number of dynamic voltage stability analysis runs is greatly reduced by using the proposed method. The numerical results demonstrate the feasibility, effectiveness, and robustness of the proposed approach for voltage security assessment for a wind power plant.« less

A SiC MOSFET Based Inverter for Wireless Power Transfer Applications

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

Onar, Omer C; Chinthavali, Madhu Sudhan; Campbell, Steven L

2014-01-01

In a wireless power transfer (WPT) system, efficiency of the power conversion stages is crucial so that the WPT technology can compete with the conventional conductive charging systems. Since there are 5 or 6 power conversion stages, each stage needs to be as efficient as possible. SiC inverters are crucial in this case; they can handle high frequency operation and they can operate at relatively higher temperatures resulting in reduces cost and size for the cooling components. This study presents the detailed power module design, development, and fabrication of a SiC inverter. The proposed inverter has been tested at threemore » center frequencies that are considered for the WPT standardization. Performance of the inverter at the same target power transfer level is analyzed along with the other system components. In addition, another SiC inverter has been built in authors laboratory by using the ORNL designed and developed SiC modules. It is shown that the inverter with ORNL packaged SiC modules performs simular to that of the inverter having commercially available SiC modules.« less

Advanced Radioisotope Power Systems Segmented Thermoelectric Research

NASA Technical Reports Server (NTRS)

Caillat, Thierry

2004-01-01

Flight times are long; - Need power systems with >15 years life. Mass is at an absolute premium; - Need power systems with high specific power and scalability. 3 orders of magnitude reduction in solar irradiance from Earth to Pluto. Nuclear power sources preferable. The Overall objective is to develop low mass, high efficiency, low-cost Advanced Radioisotope Power System with double the Specific Power and Efficiency over state-of-the-art Radioisotope Thermoelectric Generators (RTGs).

Tightly Coupled Inertial Navigation System/Global Positioning System (TCMIG)

NASA Technical Reports Server (NTRS)

Watson, Michael D.; Jackson, Kurt (Technical Monitor)

2002-01-01

Many NASA applications planned for execution later this decade are seeking high performance, miniaturized, low power Inertial Management Units (IMU). Much research has gone into Micro-Electro-Mechanical System (MEMS) over the past decade as a solution to these needs. While MEMS devices have proven to provide high accuracy acceleration measurements, they have not yet proven to have the accuracy required by many NASA missions in rotational measurements. Therefore, a new solution has been formulated integrating the best of all IMU technologies to address these mid-term needs in the form of a Tightly Coupled Micro Inertial Navigation System (INS)/Global Positioning System (GPS) (TCMIG). The TCMIG consists of an INS and a GPS tightly coupled by a Kalman filter executing on an embedded Field Programmable Gate Array (FPGA) processor. The INS consists of a highly integrated Interferometric Fiber Optic Gyroscope (IFOG) and a MEMS accelerometer. The IFOG utilizes a tightly wound fiber coil to reduce volume and the high level of integration and advanced optical components to reduce power. The MEMS accelerometer utilizes a newly developed deep etch process to increase the proof mass and yield a highly accurate accelerometer. The GPS receiver consists of a low power miniaturized version of the Blackjack receiver. Such an IMU configuration is ideal to meet the mid-term needs of the NASA Science Enterprises and the new launch vehicles being developed for the Space Launch Initiative (SLI).

Changes in speed distribution: Applying aggregated safety effect models to individual vehicle speeds.

PubMed

Vadeby, Anna; Forsman, Åsa

2017-06-01

This study investigated the effect of applying two aggregated models (the Power model and the Exponential model) to individual vehicle speeds instead of mean speeds. This is of particular interest when the measure introduced affects different parts of the speed distribution differently. The aim was to examine how the estimated overall risk was affected when assuming the models are valid on an individual vehicle level. Speed data from two applications of speed measurements were used in the study: an evaluation of movable speed cameras and a national evaluation of new speed limits in Sweden. The results showed that when applied on individual vehicle speed level compared with aggregated level, there was essentially no difference between these for the Power model in the case of injury accidents. However, for fatalities the difference was greater, especially for roads with new cameras where those driving fastest reduced their speed the most. For the case with new speed limits, the individual approach estimated a somewhat smaller effect, reflecting that changes in the 15th percentile (P15) were somewhat larger than changes in P85 in this case. For the Exponential model there was also a clear, although small, difference between applying the model to mean speed changes and individual vehicle speed changes when speed cameras were used. This applied both for injury accidents and fatalities. There were also larger effects for the Exponential model than for the Power model, especially for injury accidents. In conclusion, applying the Power or Exponential model to individual vehicle speeds is an alternative that provides reasonable results in relation to the original Power and Exponential models, but more research is needed to clarify the shape of the individual risk curve. It is not surprising that the impact on severe traffic crashes was larger in situations where those driving fastest reduced their speed the most. Further investigations on use of the Power and/or the Exponential model at individual vehicle level would require more data on the individual level from a range of international studies. Copyright © 2017 Elsevier Ltd. All rights reserved.

Salt Lake City Area Integrated Projects Electric Power Marketing. Draft environmental impact statement: Volume 4, Appendixes B-D

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

Not Available

1994-02-01

The Salt Lake City Area Office of the Western Area Power Administration (Western) markets electricity produced at hydroelectric facilities operated by the Bureau of Reclamation. The facilities are known collectively as the Salt Lake City Area Integrated Projects (SLCA/IP) and include dams equipped for power generation on the Green, Gunnison, Rio Grande, and Colorado rivers and on Deer and Plateau creeks in the states of Wyoming, Utah, Colorado, Arizona, and New Mexico. Of these facilities, only the Glen Canyon Unit, the Flaming Gorge Unit, and the Aspinall Unit (which includes Blue Mesa, Morrow Point, and Crystal dams;) are influenced bymore » Western power scheduling and transmission decisions. The EIS alternatives, called commitment-level alternatives, reflect combinations of capacity and energy that would feasibly and reasonably fulfill Westerns firm power marketing responsibilities, needs, and statutory obligations. The viability of these alternatives relates directly to the combination of generation capability of the SLCA/IP with energy purchases and interchange. The economic and natural resource assessments in this environmental impact statement (EIS) include an analysis of commitment-level alternatives. Impacts of the no-action alternative are also assessed. Supply options, which include combinations of electrical power purchases and hydropower operational scenarios reflecting different operations of the dams, are also assessed. The EIS evaluates the impacts of these scenarios relative to socioeconomics, air resources, water resources, ecological resources, cultural resources, land use, recreation, and visual resources.« less

Salt Lake City Area Integrated Projects Electric Power Marketing. Draft environmental impact statement: Volume 2, Sections 1-16

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

Not Available

The Salt Lake City Area Office of the Western Area Power Administration (Western) markets electricity produced at hydroelectric facilities operated by the Bureau of Reclamation. The facilities are known collectively as the Salt Lake City Area Integrated Projects (SLCA/IP) and include dams equipped for power generation on the Green, Gunnison, Rio Grande, and Colorado rivers and on Deer and Plateau creeks in the states of Wyoming, Utah, Colorado, Arizona, and New Mexico. Of these facilities, only the Glen Canyon Unit, the Flaming Gorge Unit, and the Aspinall Unit (which includes Blue Mesa, Morrow Point, and Crystal dams;) are influenced bymore » Western power scheduling and transmission decisions. The EIS alternatives, called commitment-level alternatives, reflect combinations of capacity and energy that would feasibly and reasonably fulfill Westerns firm power marketing responsibilities, needs, and statutory obligations. The viability of these alternatives relates directly to the combination of generation capability of the SLCA/IP with energy purchases and interchange. The economic and natural resource assessments in this environmental impact statement (EIS) include an analysis of commitment-level alternatives. Impacts of the no-action alternative are also assessed. Supply options, which include combinations of electrical power purchases and hydropower operational scenarios reflecting different operations of the dams, are also assessed. The EIS evaluates the impacts of these scenarios relative to socioeconomics, air resources, water resources, ecological resources, cultural resources, land use, recreation, and visual resources.« less

Electronic Equipment Proposal to Improve the Photovoltaic Systems Efficiency

NASA Astrophysics Data System (ADS)

Flores-Mena, J. E.; Juárez Morán, L. A.; Díaz Reyes, J.

2011-05-01

This paper reports a new technique proposal to improve the photovoltaic systems. It was made to design and implement an electronic system that will detect, capture, and transfer the maximum power of the photovoltaic (PV) panel to optimize the supplied power of a solar panel. The electronic system works on base technical proposal of electrical sweeping of electric characteristics using capacitive impedance. The maximum power is transformed and the solar panel energy is sent to an automotive battery. This electronic system reduces the energy lost originated when the solar radiation level decreases or the PV panel temperature is increased. This electronic system tracks, captures, and stores the PV module's maximum power into a capacitor. After, a higher voltage level step-up circuit was designed to increase the voltage of the PV module's maximum power and then its current can be sent to a battery. The experimental results show that the developed electronic system has 95% efficiency. The measurement was made to 50 W, the electronic system works rightly with solar radiation rate from 100 to 1,000 W m - 2 and the PV panel temperature rate changed from 1 to 75°C. The main advantage of this electronic system compared with conventional methods is the elimination of microprocessors, computers, and sophisticated numerical approximations, and it does not need any small electrical signals to track the maximum power. The proposed method is simple, fast, and it is also cheaper.

Prospects for development of wind turbines with orthogonal rotor

NASA Astrophysics Data System (ADS)

Gorelov, D. N.; Krivospitsky, V. P.

2008-03-01

The experimental data obtained previously on the investigation of power characteristics and the possibility of the self-start of the Darrieus rotor are anlysed. These results are used at the design of new two-tier wind turbines with straight blades. The full-scale tests of two design variants showed the prospects for the development of wind turbines with the Darrieus rotor. At a reasonable design, they do not need any devices for the rotor orientation and start-up, are little sensitive to wind gusts and can have a high level of power characteristics, which is not inferior to the best samples of the units of propeller type.

Chimeric antigen receptor T cells: power tools to wipe out leukemia and lymphoma.

PubMed

Riet, Tobias; Abken, Hinrich

2015-08-01

Adoptive cell therapy for malignant diseases is showing promise in recent early-phase trials in the treatment of B cell leukemia/lymphoma. Genetically engineered with a tumor-specific chimeric antigen receptor, patient's T cells produce lasting and complete leukemia regression. However, treatment is associated with some toxicity which needs our attention and the field still faces some hurdles at the scientific, technologic and clinical levels. Surmounting these obstacles will establish chimeric antigen receptor T cell therapy as a powerful approach to cure hematologic malignancies, paving the way for the treatment of other common types of cancer in the future.

Design of micro bending deformer for optical fiber weight sensor

NASA Astrophysics Data System (ADS)

Ula, R. K.; Hanto, D.; Waluyo, T. B.; Adinanta, H.; Widiyatmoko, B.

2017-04-01

The road damage due to excessive load is one of the causes of accidents on the road. A device to measure weight of the passing vehicles needs to be planted in the road structure. Thus, a weight sensor for the passing vehicles is required. In this study, we designed a weight sensor for a static load based on a power loss due to a micro bending on the optical fiber flanked on a board. The following main components are used i.e. LED 1310 nm as a light source, a multimode fiber optic as a transmission media and a power meter for measuring power loss. This works focuses on obtaining a suitable deformer design for weight sensor. Experimental results show that deformer design with 1.5 mm single side has level of accuracy as 4.32% while the design with 1.5 mm double side has level of accuracy as 98.77%. Increasing deformer length to 2.5 mm gives 71.18% level of accuracy for single side, and 76.94% level of accuracy for double side. Micro bending design with 1.5 mm double side has a high sensitivity and it is also capable of measuring load up to 100 kg. The sensor designed has been tested for measuring the weight of motor cycle, and it can be upgraded for measuring heavy vehicles.

Optical Injection Locking of a VCSEL in an OEO

NASA Technical Reports Server (NTRS)

Strekalov, Dmitry; Matsko, Andrey; Savchenkov, Anatoliy; Yu, Nan; Maleki, Lute

2009-01-01

Optical injection locking has been demonstrated to be effective as a means of stabilizing the wavelength of light emitted by a vertical-cavity surface- emitting laser (VCSEL) that is an active element in the frequency-control loop of an opto-electronic oscillator (OEO) designed to implement an atomic clock based on an electromagnetically- induced-transparency resonance. This particular optical-injection- locking scheme is expected to enable the development of small, low-power, high-stability atomic clocks that would be suitable for use in applications involving precise navigation and/or communication. In one essential aspect of operation of an OEO of the type described above, a microwave modulation signal is coupled into the VCSEL. Heretofore, it has been well known that the wavelength of light emitted by a VCSEL depends on its temperature and drive current, necessitating thorough stabilization of these operational parameters. Recently, it was discovered that the wavelength also depends on the microwave power coupled into the VCSEL. Inasmuch as the microwave power circulating in the frequency-control loop is a dynamic frequency-control variable (and, hence, cannot be stabilized), there arises a need for another means of stabilizing the wavelength. The present optical-injection-locking scheme satisfies the need for a means to stabilize the wavelength against microwave- power fluctuations. It is also expected to afford stabilization against temperature and current fluctuations. In an experiment performed to demonstrate this scheme, wavelength locking was observed when about 200 W of the output power of a commercial tunable diode laser was injected into a commercial VCSEL, designed to operate in the wavelength range of 795+/-3 nm, that was generating about 200 microW of optical power. (The use of relatively high injection power levels is a usual practice in injection locking of VCSELs.)

Sizing Dynamic Wireless Charging for Light-Duty Electric Vehicles in Roadway Applications

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

Foote, Andrew P; Ozpineci, Burak; Chinthavali, Madhu Sudhan

Dynamic wireless charging is a possible cure for the range limitations seen in electric vehicles (EVs) once implemented in highways or city streets. The contribution of this paper is the use of experimental data to show that the expected energy gain from a dynamic wireless power transfer (WPT) system is largely a function of average speed, which allows the power level and number of coils per mile of a dynamic WPT system to be sized for the sustained operation of an EV. First, data from dynamometer testing is used to determine the instantaneous energy requirements of a light-duty EV. Then,more » experimental data is applied to determine the theoretical energy gained by passing over a coil as a function of velocity and power level. Related simulations are performed to explore possible methods of placing WPT coils within roadways with comparisons to the constant velocity case. Analyses with these cases demonstrate what system ratings are needed to meet the energy requirements of the EV. The simulations are also used to determine onboard energy storage requirements for each driving cycle.« less

Concern that "EMF" magnetic fields from power lines cause cancer.

PubMed

Repacholi, Michael

2012-06-01

In 2002, the International Agency for Research on Cancer (IARC, 2002) categorized extremely low frequency (ELF) (including the power frequencies of 50 and 60 Hz) magnetic fields as "possibly carcinogenic to humans." That was based on pooled analyses of epidemiological research that reported an association between exposure to low-level magnetic fields and childhood leukemia. In 2007 a task group of scientific experts convened by the World Health Organization (WHO) acknowledged the IARC categorization but found that the laboratory studies and other research results did not support the association. Taking all evidence into account WHO reported that it could not confirm the existence of any health consequences from exposure to low-level magnetic fields. There remains continuing concern by some people that exposure to power frequency magnetic fields may cause adverse health effects, particularly childhood leukemia. Public health authorities need to fully understand the reasons for that ongoing concern and effective ways to address it. This paper describes what drives the concern, including how people perceive risks, how WHO and other public health authorities assess scientific research to determine whether health risks exist and the conclusions they have reached about power frequency magnetic fields. This paper also addresses the scientific basis of international exposure guidelines for power frequency magnetic fields and what precautionary measures are warranted to address the concern. Copyright © 2012. Published by Elsevier B.V.

A Theory of Human Needs Should Be Human-Centered, Not Animal-Centered: Commentary on Kenrick et al. (2010).

PubMed

Kesebir, Selin; Graham, Jesse; Oishi, Shigehiro

2010-05-01

Kenrick et al. (2010, this issue) make an important contribution by presenting a theory of human needs within an evolutionary framework. In our opinion, however, this framework bypasses the human uniqueness that Maslow intended to capture in his theory. We comment on the unique power of culture in shaping human motivation at the phylogenetic, ontogenetic, and proximate levels. We note that culture-gene coevolution may be a more promising lead to a theory of human motivation than a mammalcentric evolutionary perspective. © The Author(s) 2010.

Human factors aspects of control room design

NASA Technical Reports Server (NTRS)

Jenkins, J. P.

1983-01-01

A plan for the design and analysis of a multistation control room is reviewed. It is found that acceptance of the computer based information system by the uses in the control room is mandatory for mission and system success. Criteria to improve computer/user interface include: match of system input/output with user; reliability, compatibility and maintainability; easy to learn and little training needed; self descriptive system; system under user control; transparent language, format and organization; corresponds to user expectations; adaptable to user experience level; fault tolerant; dialog capability user communications needs reflected in flexibility, complexity, power and information load; integrated system; and documentation.

The Cycle of Reciprocity: A Social Capital Intervention Strategy for SSTR Operations

DTIC Science & Technology

2007-06-01

of Hope, Harvest Initiative, social capital, reciprocity, SSTR, Maslow , intervention, KFOR, game theory , prisoner’s dilemma, civil affairs...power beyond the personal level. Abraham Maslow’s theory is based on a seemingly intuitive prioritization of human needs progressing with 56 the...simply introducing unconditional aid. 57 Figure 4. Maslow’s Hierarchy as a Societal Template88 88 A. H. Maslow , "A Theory

One Sound Is Worth a Thousand Words: Using and Understanding Audio Files

ERIC Educational Resources Information Center

Frantiska, Joseph J., Jr.

2008-01-01

In the past few years, there has been an increased emphasis for teachers to become more adept at multimedia-based skills. Whether it's creating PowerPoint[R] slides, MPEG movies, image files, or a host of other tasks, today's K-12 teacher needs to have an appropriate level of expertise in multimedia development. One aspect of this skill set that…

Wartime Roles and Capabilities for the Unified Logistic Staffs

DTIC Science & Technology

1989-02-01

standard Army ammunition system SAPO Subarea Petroleum Office SCP service control point (fuels) SHAPE Supreme Headquarters, Allied Powers Europe SIDATH... SAPOs ). Communication exists between the operations and logistic staffs within the unified, component, Service, and JS levels. But between...daily. The JPOs/ SAPOs receive the short-term requirements and consoli- date them for resupply by submitting slates (how much, when, and where needed

You Can Lead Students to the Classroom, and You Can Make Them Think: Ten Brain-Based Strategies for College Teaching and Learning Success

ERIC Educational Resources Information Center

Freeman, Greta G.; Wash, Pamela D.

2013-01-01

Teaching in the digital age has become increasingly challenging for college and university faculty. Application, relevance, and active engagement rather than traditional PowerPoint slide show lectures are what our technology-savvy, socially networked students crave and need to keep their attention and interest levels high. Using a combination of…

Fuel cell technology for lunar surface operations

NASA Technical Reports Server (NTRS)

Deronck, Henry J.

1992-01-01

Hydrogen-oxygen fuel cells have been shown, in several NASA and contractor studies, to be an enabling technology for providing electrical power for lunar bases, outposts, and vehicles. The fuel cell, in conjunction with similar electrolysis cells, comprises a closed regenerative energy storage system, commonly referred to as a regenerative fuel cell (RFC). For stationary applications, energy densities of 1,000 watt-hours per kilograms an order of magnitude over the best rechargeable batteries, have been projected. In this RFC, the coupled fuel cell and electrolyzer act as an ultra-light battery. Electrical energy from solar arrays 'charges' the system by electrolyzing water into hydrogen and oxygen. When an electrical load is applied, the fuel cell reacts the hydrogen and oxygen to 'discharge' usable power. Several concepts for utilizing RFC's, with varying degrees of integration, have been proposed, including both primary and backup roles. For mobile power needs, such as rovers, an effective configuration may be to have only the fuel cell located on the vehicle, and to use a central electrolysis 'gas station'. Two fuel cell technologies are prime candidates for lunar power system concepts: alkaline electrolyte and proton exchange membrane. Alkaline fuel cells have been developed to a mature production power unit in NASA's Space Shuttle Orbiter. Recent advances in materials offer to significantly improve durability to the level needed for extended lunar operations. Proton exchange membrane fuel cells are receiving considerable support for hydrospace and terrestrial transportation applications. This technology promises durability, simplicity, and flexibility.

Enhancing the versatility of wireless biopotential acquisition for myoelectric prosthetic control

NASA Astrophysics Data System (ADS)

Bercich, Rebecca A.; Wang, Zhi; Mei, Henry; Hammer, Lauren H.; Seburn, Kevin L.; Hargrove, Levi J.; Irazoqui, Pedro P.

2016-08-01

Objective. A significant challenge in rehabilitating upper-limb amputees with sophisticated, electric-powered prostheses is sourcing reliable and independent channels of motor control information sufficient to precisely direct multiple degrees of freedom simultaneously. Approach. In response to the expressed needs of clinicians, we have developed a miniature, batteryless recording device that utilizes emerging integrated circuit technology and optimal impedance matching for magnetic resonantly coupled (MRC) wireless power transfer to improve the performance and versatility of wireless electrode interfaces with muscle. Main results. In this work we describe the fabrication and performance of a fully wireless and batteryless EMG recording system and use of this system to direct virtual and electric-powered limbs in real-time. The advantage of using MRC to optimize power transfer to a network of wireless devices is exhibited by EMG collected from an array of eight devices placed circumferentially around a human subject’s forearm. Significance. This is a comprehensive, low-cost, and non-proprietary solution that provides unprecedented versatility of configuration to direct myoelectric prostheses without wired connections to the body. The amenability of MRC to varied coil geometries and arrangements has the potential to improve the efficiency and robustness of wireless power transfer links at all levels of upper-limb amputation. Additionally, the wireless recording device’s programmable flash memory and selectable features will grant clinicians the unique ability to adapt and personalize the recording system’s functional protocol for patient- or algorithm-specific needs.

An autonomous structural health monitoring solution

NASA Astrophysics Data System (ADS)

Featherston, Carol A.; Holford, Karen M.; Pullin, Rhys; Lees, Jonathan; Eaton, Mark; Pearson, Matthew

2013-05-01

Combining advanced sensor technologies, with optimised data acquisition and diagnostic and prognostic capability, structural health monitoring (SHM) systems provide real-time assessment of the integrity of bridges, buildings, aircraft, wind turbines, oil pipelines and ships, leading to improved safety and reliability and reduced inspection and maintenance costs. The implementation of power harvesting, using energy scavenged from ambient sources such as thermal gradients and sources of vibration in conjunction with wireless transmission enables truly autonomous systems, reducing the need for batteries and associated maintenance in often inaccessible locations, alongside bulky and expensive wiring looms. The design and implementation of such a system however presents numerous challenges. A suitable energy source or multiple sources capable of meeting the power requirements of the system, over the entire monitoring period, in a location close to the sensor must be identified. Efficient power management techniques must be used to condition the power and deliver it, as required, to enable appropriate measurements to be taken. Energy storage may be necessary, to match a continuously changing supply and demand for a range of different monitoring states including sleep, record and transmit. An appropriate monitoring technique, capable of detecting, locating and characterising damage and delivering reliable information, whilst minimising power consumption, must be selected. Finally a wireless protocol capable of transmitting the levels of information generated at the rate needed in the required operating environment must be chosen. This paper considers solutions to some of these challenges, and in particular examines SHM in the context of the aircraft environment.

Fuel cell technology for lunar surface operations

NASA Astrophysics Data System (ADS)

Deronck, Henry J.

1992-02-01

Hydrogen-oxygen fuel cells have been shown, in several NASA and contractor studies, to be an enabling technology for providing electrical power for lunar bases, outposts, and vehicles. The fuel cell, in conjunction with similar electrolysis cells, comprises a closed regenerative energy storage system, commonly referred to as a regenerative fuel cell (RFC). For stationary applications, energy densities of 1,000 watt-hours per kilograms an order of magnitude over the best rechargeable batteries, have been projected. In this RFC, the coupled fuel cell and electrolyzer act as an ultra-light battery. Electrical energy from solar arrays 'charges' the system by electrolyzing water into hydrogen and oxygen. When an electrical load is applied, the fuel cell reacts the hydrogen and oxygen to 'discharge' usable power. Several concepts for utilizing RFC's, with varying degrees of integration, have been proposed, including both primary and backup roles. For mobile power needs, such as rovers, an effective configuration may be to have only the fuel cell located on the vehicle, and to use a central electrolysis 'gas station'. Two fuel cell technologies are prime candidates for lunar power system concepts: alkaline electrolyte and proton exchange membrane. Alkaline fuel cells have been developed to a mature production power unit in NASA's Space Shuttle Orbiter. Recent advances in materials offer to significantly improve durability to the level needed for extended lunar operations. Proton exchange membrane fuel cells are receiving considerable support for hydrospace and terrestrial transportation applications. This technology promises durability, simplicity, and flexibility.

High Power Broadband Millimeter Wave TWTs

NASA Astrophysics Data System (ADS)

James, Bill G.

1998-04-01

In the early 1980's the requirement for high power broadband millimeter wave sources encouraged the development of microwave vacuum device amplifiers for radar and communication systems. Many government funded programs were implemented for the development of high power broadband millimeter wave amplifiers that would meet the needs of the high power community. The tube design capable of meeting these goals was the slow wave coupled cavity traveling wave device, which had a proven technology base at the lower frequencies (X Band). However scaling this technology to the millimeter frequencies had severe shortcomings in both thermal and manufacturing design. These shortcomings were overcome with the development of the Ladder Circuit technology. In conjunction with the circuit development high power electron beam systems had to be developed for the generation of high rf powers. These beam systems had to be capable of many megawatts of beam power density and high current densities. The cathode technology required to be capable of operating at current densities of 10 amperes per square centimeter at long pulse lengths and high duty cycle. Since the introduction of the Ladder Circuit technology a number of high power broadband millimeter wave amplifiers have been developed and deployed in operating radar and communication systems. Broadband millimeter wave sources have been manufactured in the frequency range from 27 GHz to 100 GHz with power levels ranging from 100 watts CW to 10 kilowatts Peak at W band over a 2 GHz bandwidth. Also a 50 kW peak power and 10 kW average power device at Ka band with 2 GHz bandwidth has been developed. Today the power levels achieved by these devices are nearing the limits of this technology; therefore to gain a significant increase in power at the millimeter wave frequencies, other technologies will have to be considered, particularly fast wave devices. This paper will briefly review the ladder circuit technology and present the designs of a number of broadband high power devices developed at Ka and W band. The discussion will include the beam systems employed in these devices which are the highest power density linear beams generated to date. In conclusion the limits of the power generating capability of this technology will be presented.

Advanced electrical power system technology for the all electric aircraft

NASA Technical Reports Server (NTRS)

Finke, R. C.; Sundberg, G. R.

1983-01-01

The application of advanced electric power system technology to an all electric airplane results in an estimated reduction of the total takeoff gross weight of over 23,000 pounds for a large airplane. This will result in a 5 to 10 percent reduction in direct operating costs (DOC). Critical to this savings is the basic electrical power system component technology. These advanced electrical power components will provide a solid foundation for the materials, devices, circuits, and subsystems needed to satisfy the unique requirements of advanced all electric aircraft power systems. The program for the development of advanced electrical power component technology is described. The program is divided into five generic areas: semiconductor devices (transistors, thyristors, and diodes); conductors (materials and transmission lines); dielectrics; magnetic devices; and load management devices. Examples of progress in each of the five areas are discussed. Bipolar power transistors up to 1000 V at 100 A with a gain of 10 and a 0.5 microsec rise and fall time are presented. A class of semiconductor devices with a possibility of switching up to 100 kV is described. Solid state power controllers for load management at 120 to 1000 V and power levels to 25 kW were developed along with a 25 kW, 20 kHz transformer weighing only 3.2 kg.

Power and Integrated Health Care: Shifting from Governance to Governmentality

PubMed Central

Rau, Asta; Fourie, Pieter; Bracke, Piet

2016-01-01

Integrated care occurs within micro, meso and macro levels of governance structures, which are shaped by complex power dynamics. Yet theoretically-led notions of power, and scrutiny of its meanings and its functioning, are neglected in the literature on integrated care. We explore an alternative approach. Following a discussion on governance, two streams of theorising power are presented: mainstream and second-stream. Mainstream concepts are based on the notion of power-as-capacity, of one agent having the capacity to influence another—so the overall idea is ‘power over?’. Studies on integrated care typically employ mainstream ideas, which yield rather limited analyses. Second-stream concepts focus on strategies and relations of power—how it is channelled, negotiated and (re)produced. These notions align well with the contemporary shift away from the idea that power is centralised, towards more fluid ideas of power as dispersed and (re)negotiated throughout a range of societal structures, networks and actors. Accompanying this shift, the notion of governance is slowly being eclipsed by that of governmentality. We propose governmentality as a valuable perspective for analysing and understanding power in integrated care. Our contribution aims to address the need for more finely tuned theoretical frameworks that can be used to guide empirical work. PMID:28435425

POWER for reproductive health: results from a social marketing campaign promoting female and male condoms.

PubMed

Bull, Sheana S; Posner, Samuel F; Ortiz, Charlene; Beaty, Brenda; Benton, Kathryn; Lin, Lillian; Pals, Sherri L; Evans, Tom

2008-07-01

To evaluate effects of a 6-month social marketing campaign on awareness of, attitudes toward and use of female as well as male condoms for 15-25 year-old-women. Using a time-space sampling methodology, we conducted a cross-sectional survey of 3407 women at pre-campaign in 12 western U.S. neighborhoods on female and male condom awareness, attitudes, and use. Six of the 12 study neighborhoods were randomly selected to receive the POWER social marketing campaign designed to impact condom knowledge, attitudes, and use. The campaign was followed with another cross-sectional survey of 3,003 women in all 12 study neighborhoods on condom knowledge, attitudes, use and awareness of POWER materials. We compared pre-and post-campaign surveys to determine the efficacy of POWER and conducted post hoc analyses on post-campaign data to determine if exposure to POWER was related to higher levels of positive condom attitudes and norms and condom use. We found no differences between neighborhoods with and without the POWER campaign with regard to our primary outcomes. To diagnose reasons for this null effect, we examined outcomes post hoc examining the influence of POWER exposure. Post hoc analyses show some evidence that exposure to POWER was associated with condom use. In the context of the nested trial, this raises concerns that post test only evaluations are limited. Establishing the efficacy of a social marketing campaign is challenging. This group randomized trial showed a null effect. Social marketing campaigns may need to have more media channels and saturation before they can show behavioral effects. Using a nested design with randomization at the community level and probability sampling introduces rigor not commonly seen in evaluations of social marketing campaigns.

SunShot solar power reduces costs and uncertainty in future low-carbon electricity systems.

PubMed

Mileva, Ana; Nelson, James H; Johnston, Josiah; Kammen, Daniel M

2013-08-20

The United States Department of Energy's SunShot Initiative has set cost-reduction targets of $1/watt for central-station solar technologies. We use SWITCH, a high-resolution electricity system planning model, to study the implications of achieving these targets for technology deployment and electricity costs in western North America, focusing on scenarios limiting carbon emissions to 80% below 1990 levels by 2050. We find that achieving the SunShot target for solar photovoltaics would allow this technology to provide more than a third of electric power in the region, displacing natural gas in the medium term and reducing the need for nuclear and carbon capture and sequestration (CCS) technologies, which face technological and cost uncertainties, by 2050. We demonstrate that a diverse portfolio of technological options can help integrate high levels of solar generation successfully and cost-effectively. The deployment of GW-scale storage plays a central role in facilitating solar deployment and the availability of flexible loads could increase the solar penetration level further. In the scenarios investigated, achieving the SunShot target can substantially mitigate the cost of implementing a carbon cap, decreasing power costs by up to 14% and saving up to $20 billion ($2010) annually by 2050 relative to scenarios with Reference solar costs.

Probing the Complexities of Structural Changes in Layered Oxide Cathode Materials for Li-Ion Batteries during Fast Charge–Discharge Cycling and Heating

DOE PAGES

Hu, Enyuan; Wang, Xuelong; Yu, Xiqian; ...

2018-01-19

The rechargeable lithium-ion battery (LIB) is the most promising energy storage system to power electric vehicles with high energy density and long cycling life. However, in order to meet customers’ demands for fast charging, the power performances of current LIBs need to be improved. From the cathode aspect, layer-structured cathode materials are widely used in today’s market and will continue to play important roles in the near future. The high rate capability of layered cathode materials during charging and discharging is critical to the power performance of the whole cell and the thermal stability is closely related to the safetymore » issues. Therefore, the in-depth understanding of structural changes of layered cathode materials during high rate charging/discharging and the thermal stability during heating are essential in developing new materials and improving current materials. Since structural changes take place from the atomic level to the whole electrode level, combination of characterization techniques covering multilength scales is quite important. Finally, in many cases, this means using comprehensive tools involving diffraction, spectroscopy, and imaging to differentiate the surface from the bulk and to obtain structural/chemical information with different levels of spatial resolution.« less

Modular uncooled video engines based on a DSP processor

NASA Astrophysics Data System (ADS)

Schapiro, F.; Milstain, Y.; Aharon, A.; Neboshchik, A.; Ben-Simon, Y.; Kogan, I.; Lerman, I.; Mizrahi, U.; Maayani, S.; Amsterdam, A.; Vaserman, I.; Duman, O.; Gazit, R.

2011-06-01

The market demand for low SWaP (Size, Weight and Power) uncooled engines keeps growing. Low SWaP is especially critical in battery-operated applications such as goggles and Thermal Weapon Sights. A new approach for the design of the engines was implemented by SCD to optimize size and power consumption at system level. The new approach described in the paper, consists of: 1. A modular hardware design that allows the user to define the exact level of integration needed for his system 2. An "open architecture" based on the OMAPTM530 DSP that allows the integrator to take advantage of unused hardware (FPGA) and software (DSP) resources, for implementation of additional algorithms or functionality. The approach was successfully implemented on the first generation of 25μm pitch BIRD detectors, and more recently on the new, 640 x480, 17 μm pitch detector.

GRIN planar waveguide concentrator used with a single axis tracker.

PubMed

Bouchard, Sébastien; Thibault, Simon

2014-03-10

It is generally accepted that small to medium level concentrators could be used as cost-competitive replacements for tracked solar panels. The objective is to design a system that can reach a good level of sun concentration with only one sun-tracking axis and is cheap to fabricate. As the most critical parameter for all concentrator designs, optical efficiency needed improvement to reduce the cost of power produced by our system. By using a graded-index planar waveguide with an index profile similar to SELFOC fiber, the ray's path can be controlled. Also, the concentrator can be fabricated in a single block, which reduces Fresnel reflections. Overall, the optical efficiency can be improved by as much as 33% compared to the same system made with a homogeneous waveguide. Furthermore, the ability to cost-effectively fabricate the concentrator by molding can be preserved, making it possible to reduce the cost of the solar power produced.

GRIN planar waveguide concentrator used with a single axis tracker.

PubMed

Bouchard, Sébastien; Thibault, Simon

2014-03-10

It is generally accepted that small to medium level concentrators could be used as cost-competitive replacements for tracked solar panels. The objective is to design a system that can reach a good level of sun concentration with only one sun-tracking axis and is cheap to fabricate. As the most critical parameter for all concentrator designs, optical efficiency needed improvement to reduce the cost of power produced by our system. By using a graded-index planar waveguide with an index profile similar to SELFOC fiber, the ray’s path can be controlled. Also, the concentrator can be fabricated in a single block, which reduces Fresnel reflections. Overall, the optical efficiency can be improved by as much as 33% compared to the same system made with a homogeneous waveguide. Furthermore, the ability to cost-effectively fabricate the concentrator by molding can be preserved, making it possible to reduce the cost of the solar power produced.

Electric power from sugar cane in Costa Rica. A technical and economic analysis

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

Tugwell, F.; Gowen, M.; Kenda, W.

1988-07-01

A team of specialists visited Costa Rica in May 1988 to analyze the potential for production and sale of electricity by the sugar-cane industry. Focusing on three sugar mills, the team made technical projections at four levels of investment, ranging from the simplest sale of surplus power to the installation of new turbogenerator systems. For each level, capital costs, electricity production and sales, and fuel options were estimated. Associated risks were assessed through sensitivity analyses to demonstrate the possible impacts of varying interest rates, fuel costs, and electricity sales prices. The team concluded that production and sale of electricity formore » the national grid could be an excellent investment opportunity for the sugar industry and would provide important economic benefits, including creation of additional jobs in rural areas, diversification of the sugar industry, and (in the short term) displacement of the need for imported fuels.« less

Novel Space-based Solar Power Technologies and Architectures for Earth and Beyond

NASA Technical Reports Server (NTRS)

Howell, Joe T.; Fikes, John C.; O'Neill, Mark J.

2005-01-01

Research, development and studies of novel space-based solar power systems, technologies and architectures for Earth and beyond are needed to reduce the cost of clean electrical power for terrestrial use and to provide a stepping stone for providing an abundance of power in space, i.e., manufacturing facilities, tourist facilities, delivery of power between objects in space, and between space and surface sites. The architectures, technologies and systems needed for space to Earth applications may also be used for in-space applications. Advances in key technologies, i.e., power generation, power management and distribution, power beaming and conversion of beamed power are needed to achieve the objectives of both terrestrial and extraterrestrial applications. Power beaming or wireless power transmission (WPT) can involve lasers or microwaves along with the associated power interfaces. Microwave and laser transmission techniques have been studied with several promising approaches to safe and efficient WPT identified. These investigations have included microwave phased array transmitters, as well as laser transmission and associated optics. There is a need to produce "proof-of-concept" validation of critical WPT technologies for both the near-term, as well as far-term applications. Investments may be harvested in near-term beam safe demonstrations of commercial WPT applications. Receiving sites (users) include ground-based stations for terrestrial electrical power, orbital sites to provide power for satellites and other platforms, future space elevator systems, space vehicle propulsion, and space to surface sites. This paper briefly discusses achieving a promising approach to the solar power generation and beamed power conversion. The approach is based on a unique high-power solar concentrator array called Stretched Lens Array (SLA) for both solar power generation and beamed power conversion. Since both versions (solar and laser) of SLA use many identical components (only the photovoltaic cells need to be different), economies of manufacturing and scale may be realized by using SLA on both ends of the laser power beaming system in a space solar power application. Near-term uses of this SLA-laser-SLA system may include terrestrial and space exploration in near Earth space. Later uses may include beamed power for bases or vehicles on Mars.

Towards a theoretical model on medicines as a health need.

PubMed

Vargas-Peláez, Claudia Marcela; Soares, Luciano; Rover, Marina Raijche Mattozo; Blatt, Carine Raquel; Mantel-Teeuwisse, Aukje; Rossi Buenaventura, Francisco Augusto; Restrepo, Luis Guillermo; Latorre, María Cristina; López, José Julián; Bürgin, María Teresa; Silva, Consuelo; Leite, Silvana Nair; Mareni Rocha, Farias

2017-04-01

Medicines are considered one of the main tools of western medicine to resolve health problems. Currently, medicines represent an important share of the countries' healthcare budget. In the Latin America region, access to essential medicines is still a challenge, although countries have established some measures in the last years in order to guarantee equitable access to medicines. A theoretical model is proposed for analysing the social, political, and economic factors that modulate the role of medicines as a health need and their influence on the accessibility and access to medicines. The model was built based on a narrative review about health needs, and followed the conceptual modelling methodology for theory-building. The theoretical model considers elements (stakeholders, policies) that modulate the perception towards medicines as a health need from two perspectives - health and market - at three levels: international, national and local levels. The perception towards medicines as a health need is described according to Bradshaw's categories: felt need, normative need, comparative need and expressed need. When those different categories applied to medicines coincide, the patients get access to the medicines they perceive as a need, but when the categories do not coincide, barriers to access to medicines are created. Our theoretical model, which holds a broader view about the access to medicines, emphasises how power structures, interests, interdependencies, values and principles of the stakeholders could influence the perception towards medicines as a health need and the access to medicines in Latin American countries. Copyright © 2017 Elsevier Ltd. All rights reserved.

When Power Shapes Interpersonal Behavior: Low Relationship Power Predicts Men’s Aggressive Responses to Low Situational Power

PubMed Central

Overall, Nickola C.; Hammond, Matthew D.; McNulty, James K.; Finkel, Eli J.

2016-01-01

When does power in intimate relationships shape important interpersonal behaviors, such as psychological aggression? Five studies tested whether possessing low relationship power was associated with aggressive responses, but (1) only within power-relevant relationship interactions when situational power was low, and (2) only by men because masculinity (but not femininity) involves the possession and demonstration of power. In Studies 1 and 2, men lower in relationship power exhibited greater aggressive communication during couples’ observed conflict discussions, but only when they experienced low situational power because they were unable to influence their partner. In Study 3, men lower in relationship power reported greater daily aggressive responses toward their partner, but only on days when they experienced low situational power because they were either (a) unable to influence their partner or (b) dependent on their partner for support. In Study 4, men who possessed lower relationship power exhibited greater aggressive responses during couples’ support-relevant discussions, but only when they had low situational power because they needed high levels of support. Study 5 provided evidence for the theoretical mechanism underlying men’s aggressive responses to low relationship power. Men who possessed lower relationship power felt less manly on days they faced low situational power because their partner was unwilling to change to resolve relationship problems, which in turn predicted greater aggressive responses to their partner. These results demonstrate that fully understanding when and why power is associated with interpersonal behavior requires differentiating between relationship and situational power. PMID:27442766

When power shapes interpersonal behavior: Low relationship power predicts men's aggressive responses to low situational power.

PubMed

Overall, Nickola C; Hammond, Matthew D; McNulty, James K; Finkel, Eli J

2016-08-01

When does power in intimate relationships shape important interpersonal behaviors, such as psychological aggression? Five studies tested whether possessing low relationship power was associated with aggressive responses, but (a) only within power-relevant relationship interactions when situational power was low, and (b) only by men because masculinity (but not femininity) involves the possession and demonstration of power. In Studies 1 and 2, men lower in relationship power exhibited greater aggressive communication during couples' observed conflict discussions, but only when they experienced low situational power because they were unable to influence their partner. In Study 3, men lower in relationship power reported greater daily aggressive responses toward their partner, but only on days when they experienced low situational power because they were either (a) unable to influence their partner or (b) dependent on their partner for support. In Study 4, men who possessed lower relationship power exhibited greater aggressive responses during couples' support-relevant discussions, but only when they had low situational power because they needed high levels of support. Study 5 provided evidence for the theoretical mechanism underlying men's aggressive responses to low relationship power. Men who possessed lower relationship power felt less manly on days they faced low situational power because their partner was unwilling to change to resolve relationship problems, which in turn predicted greater aggressive behavior toward their partner. These results demonstrate that fully understanding when and why power is associated with interpersonal behavior requires differentiating between relationship and situational power. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Estimates of power requirements for a Manned Mars Rover powered by a nuclear reactor

NASA Technical Reports Server (NTRS)

Morley, Nicholas J.; El-Genk, Mohamed S.; Cataldo, Robert; Bloomfield, Harvey

1991-01-01

This paper assesses the power requirement for a Manned Mars Rover vehicle. Auxiliary power needs are fulfilled using a hybrid solar photovoltaic/regenerative fuel cell system, while the primary power needs are meet using an SP-100 type reactor. The primary electric power needs, which include 30-kW(e) net user power, depend on the reactor thermal power and the efficiency of the power conversion system. Results show that an SP-100 type reactor coupled to a Free Piston Stirling Engine yields the lowest total vehicle mass and lowest specific mass for the power system. The second lowest mass was for a SP-100 reactor coupled to a Closed Brayton Cycle using He/Xe as the working fluid. The specific mass of the nuclear reactor power system, including a man-rated radiation shield, ranged from 150-kg/kW(e) to 190-kg/KW(e) and the total mass of the Rover vehicle varied depend upon the cruising speed.

Federal Geothermal Research Program Update Fiscal Year 2003

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

Not Available

2004-03-01

The Department of Energy (DOE) and its predecessors have conducted research and development (R&D) in geothermal energy since 1971. To develop the technology needed to harness the Nation's vast geothermal resources, DOE's Office of Geothermal Technologies oversees a network of national laboratories, industrial contractors, universities, and their subcontractors. The following mission and goal statements guide the overall activities of the Office. The goals are: (1) Reduce the levelized cost of generating geothermal power to 3-5 cents per kWh by 2007; (2) Double the number of States with geothermal electric power facilities to eight by 2006; and (3) Supply the electricalmore » power or heat energy needs of 7 million homes and businesses in the United States by 2010. This Federal Geothermal Program Research Update reviews the accomplishments of DOE's Geothermal Program for Federal Fiscal Year (FY) 2003. The information contained in this Research Update illustrates how the mission and goals of the Office of Geothermal Technologies are reflected in each R&D activity. The Geothermal Program, from its guiding principles to the most detailed research activities, is focused on expanding the use of geothermal energy. balanced strategy for the Geothermal Program.« less

High-Capacity Communications from Martian Distances

NASA Technical Reports Server (NTRS)

Williams, W. Dan; Collins, Michael; Hodges, Richard; Orr, Richard S.; Sands, O. Scott; Schuchman, Leonard; Vyas, Hemali

2007-01-01

High capacity communications from Martian distances, required for the envisioned human exploration and desirable for data-intensive science missions, is challenging. NASA s Deep Space Network currently requires large antennas to close RF telemetry links operating at kilobit-per-second data rates. To accommodate higher rate communications, NASA is considering means to achieve greater effective aperture at its ground stations. This report, focusing on the return link from Mars to Earth, demonstrates that without excessive research and development expenditure, operational Mars-to-Earth RF communications systems can achieve data rates up to 1 Gbps by 2020 using technology that today is at technology readiness level (TRL) 4-5. Advanced technology to achieve the needed increase in spacecraft power and transmit aperture is feasible at an only moderate increase in spacecraft mass and technology risk. In addition, both power-efficient, near-capacity coding and modulation and greater aperture from the DSN array will be required. In accord with these results and conclusions, investment in the following technologies is recommended:(1) lightweight (1 kg/sq m density) spacecraft antenna systems; (2) a Ka-band receive ground array consisting of relatively small (10-15 m) antennas; (3) coding and modulation technology that reduces spacecraft power by at least 3 dB; and (4) efficient generation of kilowatt-level spacecraft RF power.

Space-based solar power generation using a distributed network of satellites and methods for efficient space power transmission

NASA Astrophysics Data System (ADS)

McLinko, Ryan M.; Sagar, Basant V.

2009-12-01

Space-based solar power (SSP) generation is being touted as a solution to our ever-increasing energy consumption and dependence on fossil fuels. Satellites in Earth's orbit can capture solar energy through photovoltaic cells and transmit that power to ground based stations. Solar cells in orbit are not hindered by weather, clouds, or night. The energy generated by this process is clean and pollution-free. Although the concept of space-based solar power was initially proposed nearly 40 years ago, the level of technology in photovoltaics, power transmission, materials, and efficient satellite design has finally reached a level of maturity that makes solar power from space a feasible prospect. Furthermore, new strategies in methods for solar energy acquisition and transmission can lead to simplifications in design, reductions in cost and reduced risk. This paper proposes using a distributed array of small satellites to collect power from the Sun, as compared to the more traditional SSP design that consists of one monolithic satellite. This concept mitigates some of SSP's most troublesome historic constraints, such as the requirement for heavy lift launch vehicles and the need for significant assembly in space. Instead, a larger number of smaller satellites designed to collect solar energy are launched independently. A high frequency beam will be used to aggregate collected power into a series of transmission antennas, which beam the energy to Earth's surface at a lower frequency. Due to the smaller power expectations of each satellite and the relatively short distance of travel from low earth orbit, such satellites can be designed with smaller arrays. The inter-satellite rectenna devices can also be smaller and lighter in weight. Our paper suggests how SSP satellites can be designed small enough to fit within ESPA standards and therefore use rideshare to achieve orbit. Alternatively, larger versions could be launched on Falcon 9s or on Falcon 1s with booster stages. The only satellites that are constrained to a significant mass are the beam-down satellites, which still require significant transmission arrays to sufficiently focus the beams targeting corresponding ground stations. With robust design and inherent redundancy built-in, power generation and transmission will not be interrupted in the event of mishaps like space debris collision. Furthermore, the "plug and play" nature of this system significantly reduces the cost, complexity, and risk of upgrading the system. The distributed nature of smallsat clusters maximizes the use of economies of scale. This approach retains some problems of older designs and introduces additional ones. Mitigations will be explored further. For example, the distributed nature of the system requires very precise coordination between and among satellites and a mature attitude control and determination system. Such a design incorporates multiple beaming stages, which has the potential to reduce overall system efficiency. Although this design eliminates the need for space assembly, it retains the challenge of significant on-orbit deployment of solar and transmission arrays. Space power "beaming" is a three step process that involves: 1) conversion of dc power generated by solar cells on the satellite into an electromagnetic wave of suitable frequency, 2) transmission of that wave to power stations on ground, and 3) conversion of the radio waves back into dc power. A great deal of research has been done on the use of microwaves for this purpose. Various factors that affect efficient power generation and transmission will be analyzed in this paper. Based on relevant theory and performance and optimization models, the paper proposes solutions that will help make space-based solar power generation a practical and viable option for addressing the world's growing energy needs.

41 CFR 102-75.375 - What happens once a State, or political subdivision, certifies that it needs a surplus power...

Code of Federal Regulations, 2010 CFR

2010-07-01

... State, or political subdivision, certifies that it needs a surplus power transmission line and the right... political subdivision, certifies that it needs a surplus power transmission line and the right-of-way... right-of-way, the disposal agency may sell the property to the state, or political subdivision thereof...

Solar-powered drip irrigation enhances food security in the Sudano–Sahel

PubMed Central

Burney, Jennifer; Woltering, Lennart; Burke, Marshall; Naylor, Rosamond; Pasternak, Dov

2010-01-01

Meeting the food needs of Africa’s growing population over the next half-century will require technologies that significantly improve rural livelihoods at minimal environmental cost. These technologies will likely be distinct from those of the Green Revolution, which had relatively little impact in sub-Saharan Africa; consequently, few such interventions have been rigorously evaluated. This paper analyzes solar-powered drip irrigation as a strategy for enhancing food security in the rural Sudano–Sahel region of West Africa. Using a matched-pair comparison of villages in northern Benin (two treatment villages, two comparison villages), and household survey and field-level data through the first year of harvest in those villages, we find that solar-powered drip irrigation significantly augments both household income and nutritional intake, particularly during the dry season, and is cost effective compared to alternative technologies. PMID:20080616

Consumption Behavior Analytics-Aided Energy Forecasting and Dispatch

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

Zhang, Yingchen; Yang, Rui; Jiang, Huaiguang

For decades, electricity customers have been treated as mere recipients of electricity in vertically integrated power systems. However, as customers have widely adopted distributed energy resources and other forms of customer participation in active dispatch (such as demand response) have taken shape, the value of mining knowledge from customer behavior patterns and using it for power system operation is increasing. Further, the variability of renewable energy resources has been considered a liability to the grid. However, electricity consumption has shown the same level of variability and uncertainty, and this is sometimes overlooked. This article investigates data analytics and forecasting methodsmore » to identify correlations between electricity consumption behavior and distributed photovoltaic (PV) output. The forecasting results feed into a predictive energy management system that optimizes energy consumption in the near future to balance customer demand and power system needs.« less

Wind Energy Management System EMS Integration Project: Incorporating Wind Generation and Load Forecast Uncertainties into Power Grid Operations

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

Makarov, Yuri V.; Huang, Zhenyu; Etingov, Pavel V.

2010-01-01

The power system balancing process, which includes the scheduling, real time dispatch (load following) and regulation processes, is traditionally based on deterministic models. Since the conventional generation needs time to be committed and dispatched to a desired megawatt level, the scheduling and load following processes use load and wind and solar power production forecasts to achieve future balance between the conventional generation and energy storage on the one side, and system load, intermittent resources (such as wind and solar generation), and scheduled interchange on the other side. Although in real life the forecasting procedures imply some uncertainty around the loadmore » and wind/solar forecasts (caused by forecast errors), only their mean values are actually used in the generation dispatch and commitment procedures. Since the actual load and intermittent generation can deviate from their forecasts, it becomes increasingly unclear (especially, with the increasing penetration of renewable resources) whether the system would be actually able to meet the conventional generation requirements within the look-ahead horizon, what the additional balancing efforts would be needed as we get closer to the real time, and what additional costs would be incurred by those needs. To improve the system control performance characteristics, maintain system reliability, and minimize expenses related to the system balancing functions, it becomes necessary to incorporate the predicted uncertainty ranges into the scheduling, load following, and, in some extent, into the regulation processes. It is also important to address the uncertainty problem comprehensively by including all sources of uncertainty (load, intermittent generation, generators’ forced outages, etc.) into consideration. All aspects of uncertainty such as the imbalance size (which is the same as capacity needed to mitigate the imbalance) and generation ramping requirement must be taken into account. The latter unique features make this work a significant step forward toward the objective of incorporating of wind, solar, load, and other uncertainties into power system operations. Currently, uncertainties associated with wind and load forecasts, as well as uncertainties associated with random generator outages and unexpected disconnection of supply lines, are not taken into account in power grid operation. Thus, operators have little means to weigh the likelihood and magnitude of upcoming events of power imbalance. In this project, funded by the U.S. Department of Energy (DOE), a framework has been developed for incorporating uncertainties associated with wind and load forecast errors, unpredicted ramps, and forced generation disconnections into the energy management system (EMS) as well as generation dispatch and commitment applications. A new approach to evaluate the uncertainty ranges for the required generation performance envelope including balancing capacity, ramping capability, and ramp duration has been proposed. The approach includes three stages: forecast and actual data acquisition, statistical analysis of retrospective information, and prediction of future grid balancing requirements for specified time horizons and confidence levels. Assessment of the capacity and ramping requirements is performed using a specially developed probabilistic algorithm based on a histogram analysis, incorporating all sources of uncertainties of both continuous (wind and load forecast errors) and discrete (forced generator outages and start-up failures) nature. A new method called the “flying brick” technique has been developed to evaluate the look-ahead required generation performance envelope for the worst case scenario within a user-specified confidence level. A self-validation algorithm has been developed to validate the accuracy of the confidence intervals.« less

Synchronous orbit power technology needs

NASA Technical Reports Server (NTRS)

Slifer, L. W., Jr.; Billerbeck, W. J.

1979-01-01

The needs are defined for future geosynchronous orbit spacecraft power subsystem components, including power generation, energy storage, and power processing. A review of the rapid expansion of the satellite communications field provides a basis for projection into the future. Three projected models, a mission model, an orbit transfer vehicle model, and a mass model for power subsystem components are used to define power requirements and mass limitations for future spacecraft. Based upon these three models, the power subsystems for a 10 kw, 10 year life, dedicated spacecraft and for a 20 kw, 20 year life, multi-mission platform are analyzed in further detail to establish power density requirements for the generation, storage and processing components of power subsystems as related to orbit transfer vehicle capabilities. Comparison of these requirements to state of the art design values shows that major improvements, by a factor of 2 or more, are needed to accomplish the near term missions. However, with the advent of large transfer vehicles, these requirements are significantly reduced, leaving the long lifetime requirement, associated with reliability and/or refurbishment, as the primary development need. A few technology advances, currently under development, are noted with regard to their impacts on future capability.

Relationship Factors and Trajectories of Intimate Partner Violence among South African Women during Pregnancy and the Postpartum Period

PubMed Central

Groves, Allison K.; McNaughton-Reyes, H. Luz; Foshee, Vangie A.; Moodley, Dhayendre; Maman, Suzanne

2014-01-01

Intimate partner violence (IPV) is a significant public health problem in South Africa. However, there is limited research on whether and how IPV changes during pregnancy and the postpartum period and on the factors that might affect women's risk during this time. In this study, we describe the mean trajectories of physical and psychological IPV during pregnancy and the postpartum period and examine whether relationship power, partner social support, and relationship stress are associated with women's trajectories of IPV. Data come from a longitudinal study with 1,480 women recruited during pregnancy between May 2008 and June 2010 at a public clinic in Durban. Women completed behavioral assessments at their first antenatal visit, at fourteen weeks and at nine months postpartum. Women's experiences of IPV were measured at all three time points and relationship power, partner social support and relationship stress were each measured at the baseline assessment. We used multilevel random coefficients growth modeling to build our models. The mean trajectory for both types of IPV was flat which means that, on average, there was not significant change in levels of IPV over pregnancy and the postpartum period. However, there was significant individual variability in trajectories of IPV over the study period. Women who had higher relationship power had lower levels of physical and psychological IPV over time than women with lower relationship power. Additionally, women with higher relationship stress and lower partner support had higher levels of psychological IPV at pregnancy. Interventions that maximize women's relationship power and partner social support and minimize relationship stress during this transformative time are needed. PMID:25268363

The case for increasing the statistical power of eddy covariance ecosystem studies: why, where and how?

PubMed

Hill, Timothy; Chocholek, Melanie; Clement, Robert

2017-06-01

Eddy covariance (EC) continues to provide invaluable insights into the dynamics of Earth's surface processes. However, despite its many strengths, spatial replication of EC at the ecosystem scale is rare. High equipment costs are likely to be partially responsible. This contributes to the low sampling, and even lower replication, of ecoregions in Africa, Oceania (excluding Australia) and South America. The level of replication matters as it directly affects statistical power. While the ergodicity of turbulence and temporal replication allow an EC tower to provide statistically robust flux estimates for its footprint, these principles do not extend to larger ecosystem scales. Despite the challenge of spatially replicating EC, it is clearly of interest to be able to use EC to provide statistically robust flux estimates for larger areas. We ask: How much spatial replication of EC is required for statistical confidence in our flux estimates of an ecosystem? We provide the reader with tools to estimate the number of EC towers needed to achieve a given statistical power. We show that for a typical ecosystem, around four EC towers are needed to have 95% statistical confidence that the annual flux of an ecosystem is nonzero. Furthermore, if the true flux is small relative to instrument noise and spatial variability, the number of towers needed can rise dramatically. We discuss approaches for improving statistical power and describe one solution: an inexpensive EC system that could help by making spatial replication more affordable. However, we note that diverting limited resources from other key measurements in order to allow spatial replication may not be optimal, and a balance needs to be struck. While individual EC towers are well suited to providing fluxes from the flux footprint, we emphasize that spatial replication is essential for statistically robust fluxes if a wider ecosystem is being studied. © 2016 The Authors Global Change Biology Published by John Wiley & Sons Ltd.

High power broadband millimeter wave TWTs

NASA Astrophysics Data System (ADS)

James, Bill G.

1999-05-01

In the early 1980's the requirement for high power broadband millimeter wave sources encouraged the development of microwave vacuum device amplifiers for radar and communication systems. Many government funded programs were implemented for the development of high power broadband millimeter wave amplifiers that would meet the needs of the high power community. The tube design capable of meeting these goals was the slow wave coupled cavity traveling wave device, which had a proven technology base at the lower frequencies (X Band). However scaling this technology to the millimeter frequencies had severe shortcomings in both thermal and manufacturing design. These shortcomings were overcome with the development of the Ladder Circuit technology. In conjunction with the circuit development high power electron beam systems had to be developed for the generation of high rf powers. These beam systems had to be capable of many megawatts of beam power density and high current densities. The cathode technology required to be capable of operating at current densities of 10 amperes per square centimeter at long pulse lengths and high duty cycle. Since the introduction of the Ladder Circuit technology a number of high power broadband millimeter wave amplifiers have been developed using this technology, and have been deployed in operating radar and communication systems. Broadband millimeter wave sources have been manufactured in the frequency range from 27 GHz to 100 GHz with power levels ranging from 100 watts to 50 kilowatts. Today the power levels achieved by these devices are nearing the limits of this technology; therefore to gain a significant increase in power at the millimeter wave frequencies other technologies will have to be considered particularly fast wave devices. This paper will briefly review the ladder circuit technology and present the designs of a number of broadband high power devices developed at Ka and W band. The discussion will include the beam systems employed in these devices which are the highest power density linear beams generated to date. In conclusion the limits of the power generating capability of this technology will be presented.

Comparison of Prime Movers Suitable for USMC Expeditionary Power Sources

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

Theiss, T J; Conklin, J. C.; Thomas, John F.

2000-04-18

This report documents the results of the ORNL investigation into prime movers that would be desirable for the construction of a power system suitable for the United States Marine Corps (USMC) expeditionary forces under Operational Maneuvers From The Sea (OMFTS) doctrine. Discrete power levels of {approx}1, 5, 15, and 30 kW are considered. The only requirement is that the prime mover consumes diesel fuel. A brief description is given for the prime movers to describe their basic scientific foundations and relative advantages and disadvantages. A list of key attributes developed by ORNL has been weighted by the USMC to indicatemore » the level of importance. A total of 14 different prime movers were scored by ORNL personnel in four size ranges (1,5, 15, & 30 kW) for their relative strength in each attribute area. The resulting weighted analysis was used to indicate which prime movers are likely to be suitable for USMC needs. No single engine or prime mover emerged as the clear-cut favorite but several engines scored as well or better than the diesel engine. At the higher load levels (15 & 30 kW), the results indicate that the open Brayton (gas turbine) is a relatively mature technology and likely a suitable choice to meet USMC needs. At the lower power levels, the situation is more difficult and the market alone is not likely to provide an optimum solution in the time frame desired (2010). Several prime movers should be considered for future developments and may be satisfactory; specifically, the Atkinson cycle, the open Brayton cycle (gas turbine), the 2-stroke diesel. The rotary diesel and the solid oxide fuel cell should be backup candidates. Of all these prime movers, the Atkinson cycle may well be the most suitable for this application but is an immature technology. Additional demonstrations of this engine will be conducted at ORNL. If this analysis is positive, then the performance of a generator set using this engine, the open Brayton and the 2-stroke diesel should be estimated to evaluate its potential suitability for expeditionary forces. The overriding conclusion of this effort is that we feel a suitable prime mover can be found but that the development will be technically challenging and trade-offs will be made before an optimum solution is found.« less

Variable speed wind turbine generator with zero-sequence filter

DOEpatents

Muljadi, Eduard

1998-01-01

A variable speed wind turbine generator system to convert mechanical power into electrical power or energy and to recover the electrical power or energy in the form of three phase alternating current and return the power or energy to a utility or other load with single phase sinusoidal waveform at sixty (60) hertz and unity power factor includes an excitation controller for generating three phase commanded current, a generator, and a zero sequence filter. Each commanded current signal includes two components: a positive sequence variable frequency current signal to provide the balanced three phase excitation currents required in the stator windings of the generator to generate the rotating magnetic field needed to recover an optimum level of real power from the generator; and a zero frequency sixty (60) hertz current signal to allow the real power generated by the generator to be supplied to the utility. The positive sequence current signals are balanced three phase signals and are prevented from entering the utility by the zero sequence filter. The zero sequence current signals have zero phase displacement from each other and are prevented from entering the generator by the star connected stator windings. The zero sequence filter allows the zero sequence current signals to pass through to deliver power to the utility.

Variable Speed Wind Turbine Generator with Zero-sequence Filter

DOEpatents

Muljadi, Eduard

1998-08-25

A variable speed wind turbine generator system to convert mechanical power into electrical power or energy and to recover the electrical power or energy in the form of three phase alternating current and return the power or energy to a utility or other load with single phase sinusoidal waveform at sixty (60) hertz and unity power factor includes an excitation controller for generating three phase commanded current, a generator, and a zero sequence filter. Each commanded current signal includes two components: a positive sequence variable frequency current signal to provide the balanced three phase excitation currents required in the stator windings of the generator to generate the rotating magnetic field needed to recover an optimum level of real power from the generator; and a zero frequency sixty (60) hertz current signal to allow the real power generated by the generator to be supplied to the utility. The positive sequence current signals are balanced three phase signals and are prevented from entering the utility by the zero sequence filter. The zero sequence current signals have zero phase displacement from each other and are prevented from entering the generator by the star connected stator windings. The zero sequence filter allows the zero sequence current signals to pass through to deliver power to the utility.

Variable speed wind turbine generator with zero-sequence filter

DOEpatents

Muljadi, E.

1998-08-25

A variable speed wind turbine generator system to convert mechanical power into electrical power or energy and to recover the electrical power or energy in the form of three phase alternating current and return the power or energy to a utility or other load with single phase sinusoidal waveform at sixty (60) hertz and unity power factor includes an excitation controller for generating three phase commanded current, a generator, and a zero sequence filter. Each commanded current signal includes two components: a positive sequence variable frequency current signal to provide the balanced three phase excitation currents required in the stator windings of the generator to generate the rotating magnetic field needed to recover an optimum level of real power from the generator; and a zero frequency sixty (60) hertz current signal to allow the real power generated by the generator to be supplied to the utility. The positive sequence current signals are balanced three phase signals and are prevented from entering the utility by the zero sequence filter. The zero sequence current signals have zero phase displacement from each other and are prevented from entering the generator by the star connected stator windings. The zero sequence filter allows the zero sequence current signals to pass through to deliver power to the utility. 14 figs.

20--500 watt AMTEC auxiliary electric power system

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

Ivanenok, J.F. III; Sievers, R.K.

1996-12-31

Numerous design studies have been completed on Alkali Metal Thermal to Electric Converter (AMTEC) power systems for space applications demonstrating their substantial increase in performance. Recently design studies have been initiated to couple AMTEC power conversion with fossil fueled combustion systems. This paper describes the results of a Phase 1 SBIR effort to design an innovative, efficient, reliable, long life AMTEC Auxiliary Electric Power System (AEPS) for remote site applications (20--500 watts). The concept uses high voltage AMTEC cells, each containing 7 to 9 small electrolyte tubes, integrated with a combustor and recuperator. These multi-tube AMTEC cells are low cost,more » reliable, long life static converters. AMTEC technology is ideal for auxiliary electric power supplies that must operate reliably over a broad range of temperatures, fuel sources, power levels, and operational specifications. The simplicity, efficiency (20% systems) and modularity of this technology allow it to fill applications as varied as light-weight backpacks, remote site power supplies, and military base power. Phase 1 demonstrated the feasibility of a 20% system design, and showed that the development needs to focus on identifying long life AMTEC cell components, determining the AMTEC cell and system reliability, and demonstrating that a 20 watt AMTEC system is 3--5 times more efficient than existing systems for the same application.« less

Geothermal power, policy, and design: Using levelized cost of energy and sensitivity analysis to target improved policy incentives for the U.S. geothermal market

NASA Astrophysics Data System (ADS)

Richard, Christopher L.

At the core of the geothermal industry is a need to identify how policy incentives can better be applied for optimal return. Literature from Bloomquist (1999), Doris et al. (2009), and McIlveen (2011) suggest that a more tailored approach to crafting geothermal policy is warranted. In this research the guiding theory is based on those suggestions and is structured to represent a policy analysis approach using analytical methods. The methods being used are focus on qualitative and quantitative results. To address the qualitative sections of this research an extensive review of contemporary literature is used to identify the frequency of use for specific barriers, and is followed upon with an industry survey to determine existing gaps. As a result there is support for certain barriers and justification for expanding those barriers found within the literature. This method of inquiry is an initial point for structuring modeling tools to further quantify the research results as part of the theoretical framework. Analytical modeling utilizes the levelized cost of energy as a foundation for comparative assessment of policy incentives. Model parameters use assumptions to draw conclusions from literature and survey results to reflect unique attributes held by geothermal power technologies. Further testing by policy option provides an opportunity to assess the sensitivity of each variable with respect to applied policy. Master limited partnerships, feed in tariffs, RD&D, and categorical exclusions all result as viable options for mitigating specific barriers associated to developing geothermal power. The results show reductions of levelized cost based upon the model's exclusive parameters. These results are also compared to contemporary policy options highlighting the need for tailored policy, as discussed by Bloomquist (1999), Doris et al. (2009), and McIlveen (2011). It is the intent of this research to provide the reader with a descriptive understanding of the role of geothermal power in the United States, and to recognize that not all policy or energy technology is created equal. Further study options are provide to expand the scope and granularity of this research design to better support a growing market.

Electricity market liberalization under the power of customer value evaluation and service model

NASA Astrophysics Data System (ADS)

Bai, Hong Kun; Wang, Jiang Bo; Song, Da Wei

2018-06-01

After the power reform No. 9 was released in March 2015, the state officially released the Opinions on the Implementation of the Reform on the Power Sales Side. From this document, we can see that the openness of sales of social capital to the electricity business, the sales side of the market competition through multiple ways to train the main competitors, the result is more users have the right to choose, sales service quality and user energy levels will significantly improve. With the gradual promotion of the electricity sales market, the national electricity sales companies have been established one after another. In addition to power grid outside the power generation companies, energy-saving service companies and distributed power companies may become the main selling power, while industrial parks, commercial complex, large residential area, industrial and commercial users, large industrial users in the new electricity demand appearing The new changes, some power customers have also self-built distributed power supply, installation of energy storage devices or equipment to participate in the transformation of the electricity market. The main body of the electricity sales market has gradually evolved from the traditional electricity generation main body to the multi-unit main body and emerged new value points. Therefore, the electricity sales companies need to establish a power customer value evaluation method and service mode to adapt to the new electricity reform, Provide supportive decision support.

Analysis of chitin particle size on maximum power generation, power longevity, and Coulombic efficiency in solid-substrate microbial fuel cells

NASA Astrophysics Data System (ADS)

Rezaei, Farzaneh; Richard, Tom L.; Logan, Bruce E.

Microbial fuel cells (MFCs) produce bioelectricity from a wide variety of organic and inorganic substrates. Chitin can be used as a slowly degrading substrate in MFCs and thus as a long-term fuel to sustain power by these devices in remote locations. However, little is known about the effects of particle size on power density and length of the power cycle (longevity). We therefore examined power generation from chitin particles sieved to produce three average particle sizes (0.28, 0.46 and 0.78 mm). The longevity increased from 9 to 33 days with an increase in the particle diameter from 0.28 to 0.78 mm. Coulombic efficiency also increased with particle size from 18% to 56%. The maximum power density was lower for the largest (0.78 mm) particles (176 mW m -2), with higher power densities for the 0.28 mm (272 mW m -2) and 0.46 mm (252 mW m -2) particle sizes. The measured lifetimes of these particles scaled with particle diameter to the 1.3 power. Application of a fractal dissolution model indicates chitin particles had a three-dimensional fractal dimension between 2 and 2.3. These results demonstrate particles can be used as a sustainable fuel in MFCs, but that particle sizes will need to be controlled to achieve desired power levels.

ONRASIA Scientific Information Bulletin. Volume 17, Number 4, October-December 1992

DTIC Science & Technology

1992-12-01

Corporate Software Planning Oki’s Software Improvement Environment and Engineering Div. Strategy - Effective Management - Improvement of Informa- Mr...a CCITT-supported implementation phase. -- David K fore we have effectively implemented ISO Standard high-level language Kahaner, ONRASIA them...power with a system fo- putation) Result cused on their specific needs. Result Effective speed should be (Readers can write to me or to 150 times VP-400

Hybrid lean premixing catalytic combustion system for gas turbines

DOEpatents

Critchley, Ian L.

2003-12-09

A system and method of combusting a hydrocarbon fuel is disclosed. The system combines the accuracy and controllability of an air staging system with the ultra-low emissions achieved by catalytic combustion systems without the need for a pre-heater. The result is a system and method that is mechanically simple and offers ultra-low emissions over a wide range of power levels, fuel properties and ambient operating conditions.

Vaporization Would Cool Primary Battery

NASA Technical Reports Server (NTRS)

Bhandari, Pradeep; Miyake, Robert N.

1991-01-01

Temperature of discharging high-power-density primary battery maintained below specified level by evaporation of suitable liquid from jacket surrounding battery, according to proposal. Pressure-relief valve regulates pressure and boiling temperature of liquid. Less material needed in cooling by vaporization than in cooling by melting. Technique used to cool batteries in situations in which engineering constraints on volume, mass, and location prevent attachment of cooling fins, heat pipes, or like.

On the Path to SunShot. The Environmental and Public Health Benefits of Achieving High Solar Penetrations in the United States

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

Wiser, Ryan; Mai, Trieu; Millstein, Dev

Compared with fossil fuel generators, photovoltaics (PV) and concentrating solar power (CSP) produce far lower lifecycle levels of greenhouse gas (GHG) emissions and harmful pollutants including fine particular matter (PM2.5), sulfur dioxide (SO 2), and nitrogen oxides (NO x). In this report, we monetize the emission reductions from achieving the U.S. Department of Energy's SunShot deployment goals: 14% of U.S. electricity demand met by solar in 2030 and 27% in 2050. We estimate that achieving these goals could reduce cumulative power-sector GHG emissions by 10% between 2015 and 2050, resulting in savings of $238-$252 billion. This is equivalent to 2.0-2.2more » cents per kilowatt-hour of solar installed (cents/kWh-solar). Similarly, realizing these levels of solar deployment could reduce cumulative power-sector emissions of PM2.5 by 8%, SO 2 by 9%, and NOx by 11% between 2015 and 2050. This could produce $167 billion in savings from lower future health and environmental damages, or 1.4 cents/kWh-solar--while also preventing 25,000-59,000 premature deaths. To put this in perspective, this estimated combined benefit of 3.5 cents/kWh-solar due to SunShot-level solar deployment is approximately equal to the additional levelized cost of electricity reduction needed to make unsubsidized utility-scale solar competitive with conventional generators today. In addition, the analysis shows that achieving the SunShot goals could save 4% of total power-sector water withdrawals and 9% of total power-sector water consumption over the 2015-2050 period--a particularly important consideration for arid states where substantial solar will be deployed. These results have potential implications for policy innovation and the economic competitiveness of solar and other generation technologies.« less

Investigation into the absorptivity change in metals with increased laser power

NASA Astrophysics Data System (ADS)

Blidegn, M. Sc. K.; Olsen, Flemming O.

1997-04-01

At first glance the low absorptivity of metals in the infrared (IR) makes the use of YAG or carbon-dioxide lasers in metal processing very inefficient. However, it has been demonstrated that the absorptivity can reach significantly higher levels during the high power laser interaction. An increase which cannot be explained by the increase in temperature only. The interaction between laser light and metals is a major physical phenomena in laser material processing and when modeling processes the Drude free electron model or simplifications, such as the Hagen-Rubens relation, have often been used. This paper discusses the need to extend the Drude model taking into account interband transitions and anormal skin effect at low light intensities and a multiphoton absorption model in order to describe the increase in the absorptivity at high intensities. The model is compared with experimental results carried out at low power, and tested on experimental absorptivity measurements at high power YAG laser pulses, found in literature.

Si--Au Schottky barrier nuclear battery

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

Tse, Anthony N.

1972-11-01

A long-life, high-power-density, high-reliability, compact microwatt battery is needed in many applications. In the field of medicine, for example, such a battery could power an artificial pacemaker which would greatly extend the residence time of the device. Various alternatives are analyzed and discussed. Betavoltaic conversion systems with Si-Au Schottky barrier cells coupled with 147Pm metal foil were selected for investigation. Characterization experiments were performed to obtain optimized silicon resistivity and promethium metal foil thickness. Radiation dose rates were measured and the safety aspects of the battery were analyzed. A prototype battery was assembled and tested. The economics of the batterymore » were demonstrated for special applications. It is concluded that a microwatt nuclear battery can be built with a conversion efficiency of 1 to 2%, a power density of 60 to 300 pW/cm 3 depending on the power level, and a useful life of 5 to 10 years. Further research areas are recommended.« less

Temperature Effects in Varactors and Multipliers

NASA Technical Reports Server (NTRS)

East, J.; Mehdi, Imran

2001-01-01

Varactor diode multipliers are a critical part of many THz measurement systems. The power and efficiencies of these devices limit the available power for THz sources. Varactor operation is determined by the physics of the varactor device and a careful doping profile design is needed to optimize the performance. Higher doped devices are limited by junction breakdown and lower doped structures are limited by current saturation. Higher doped structures typically have higher efficiencies and lower doped structures typically have higher powers at the same operating frequency and impedance level. However, the device material properties are also a function of the operating temperature. Recent experimental evidence has shown that the power output of a multiplier can be improved by cooling the device. We have used a particle Monte Carlo simulation to investigate the temperature dependent velocity vs. electric field in GaAs. This information was then included in a nonlinear device circuit simulator to predict multiplier performance for various temperatures and device designs. This paper will describe the results of this analysis of temperature dependent multiplier operation.

An All-Digital Fast Tracking Switching Converter with a Programmable Order Loop Controller for Envelope Tracking RF Power Amplifiers

PubMed Central

Anabtawi, Nijad; Ferzli, Rony; Harmanani, Haidar M.

2017-01-01

This paper presents a step down, switched mode power converter for use in multi-standard envelope tracking radio frequency power amplifiers (RFPA). The converter is based on a programmable order sigma delta modulator that can be configured to operate with either 1st, 2nd, 3rd or 4th order loop filters, eliminating the need for a bulky passive output filter. Output ripple, sideband noise and spectral emission requirements of different wireless standards can be met by configuring the modulator’s filter order and converter’s sampling frequency. The proposed converter is entirely digital and is implemented in 14nm bulk CMOS process for post layout verification. For an input voltage of 3.3V, the converter’s output can be regulated to any voltage level from 0.5V to 2.5V, at a nominal switching frequency of 150MHz. It achieves a maximum efficiency of 94% at 1.5 W output power. PMID:28919657

Advanced microgrid design and analysis for forward operating bases

NASA Astrophysics Data System (ADS)

Reasoner, Jonathan

This thesis takes a holistic approach in creating an improved electric power generation system for a forward operating base (FOB) in the future through the design of an isolated microgrid. After an extensive literature search, this thesis found a need for drastic improvement of the FOB power system. A thorough design process analyzed FOB demand, researched demand side management improvements, evaluated various generation sources and energy storage options, and performed a HOMERRTM discrete optimization to determine the best microgrid design. Further sensitivity analysis was performed to see how changing parameters would affect the outcome. Lastly, this research also looks at some of the challenges which are associated with incorporating a design which relies heavily on inverter-based generation sources, and gives possible solutions to help make a renewable energy powered microgrid a reality. While this thesis uses a FOB as the case study, the process and discussion can be adapted to aide in the design of an off-grid small-scale power grid which utilizes high-penetration levels of renewable energy.

Master Logic Diagram: An Approach to Identify Initiating Events of HTGRs

NASA Astrophysics Data System (ADS)

Purba, J. H.

2018-02-01

Initiating events of a nuclear power plant being evaluated need to be firstly identified prior to applying probabilistic safety assessment on that plant. Various types of master logic diagrams (MLDs) have been proposedforsearching initiating events of the next generation of nuclear power plants, which have limited data and operating experiences. Those MLDs are different in the number of steps or levels and different in the basis for developing them. This study proposed another type of MLD approach to find high temperature gas cooled reactor (HTGR) initiating events. It consists of five functional steps starting from the top event representing the final objective of the safety functions to the basic event representing the goal of the MLD development, which is an initiating event. The application of the proposed approach to search for two HTGR initiating events, i.e. power turbine generator trip and loss of offsite power, is provided. The results confirmed that the proposed MLD is feasiblefor finding HTGR initiating events.

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

Shahidehpour, Mohammad

Starting in October 2008, Illinois Institute of Technology (IIT), in collaboration with over 20 participating members, led an extensive effort to develop, demonstrate, promote, and commercialize a microgrid system and offer supporting technologies that will achieve Perfect Power at the main campus of IIT. A Perfect Power system, as defined by the Galvin Electricity Initiative (GEI), is a system that cannot fail to meet the electric needs of the individual end-user. The Principle Investigator of this Perfect Power project was Dr. Mohammad Shahidehpour, Director of the Robert W. Galvin Center for Electricity Innovation at IIT. There were six overall objectivesmore » of the Perfect Power project: (1) Demonstrate the higher reliability introduced by the microgrid system at IIT; (2) Demonstrate the economics of microgrid operations; (3) Allow for a decrease of fifty percent (50%) of grid electricity load; (4) Create a permanent twenty percent (20%) decrease in peak load from 2007 level; (5) Defer planned substation through load reduction; (6) Offer a distribution system design that can be replicated in urban communities.« less

System-level view of geospace dynamics: Challenges for high-latitude ground-based observations

NASA Astrophysics Data System (ADS)

Donovan, E.

2014-12-01

Increasingly, research programs including GEM, CEDAR, GEMSIS, GO Canada, and others are focusing on how geospace works as a system. Coupling sits at the heart of system level dynamics. In all cases, coupling is accomplished via fundamental processes such as reconnection and plasma waves, and can be between regions, energy ranges, species, scales, and energy reservoirs. Three views of geospace are required to attack system level questions. First, we must observe the fundamental processes that accomplish the coupling. This "observatory view" requires in situ measurements by satellite-borne instruments or remote sensing from powerful well-instrumented ground-based observatories organized around, for example, Incoherent Scatter Radars. Second, we need to see how this coupling is controlled and what it accomplishes. This demands quantitative observations of the system elements that are being coupled. This "multi-scale view" is accomplished by networks of ground-based instruments, and by global imaging from space. Third, if we take geospace as a whole, the system is too complicated, so at the top level we need time series of simple quantities such as indices that capture important aspects of the system level dynamics. This requires a "key parameter view" that is typically provided through indices such as AE and DsT. With the launch of MMS, and ongoing missions such as THEMIS, Cluster, Swarm, RBSP, and ePOP, we are entering a-once-in-a-lifetime epoch with a remarkable fleet of satellites probing processes at key regions throughout geospace, so the observatory view is secure. With a few exceptions, our key parameter view provides what we need. The multi-scale view, however, is compromised by space/time scales that are important but under-sampled, combined extent of coverage and resolution that falls short of what we need, and inadequate conjugate observations. In this talk, I present an overview of what we need for taking system level research to its next level, and how high latitude ground based observations can address these challenges.

The East Asian age-friendly cities promotion - Taiwan's experience and the need for an oriental paradigm.

PubMed

Chao, Tzuyuan Stessa; Huang, Huiwen

2016-03-01

It is the consensus that the rapid increase of the ageing population has become a global phenomenon. In 2007, the World Health Organization (WHO) advanced a handbook called Global Age-friendly Cities: A Guide The core concept of the age-friendly cities (AFC) movement is 'active ageing'. Taiwan became one of the few Asian countries that initially responded to the WHO AFC movement in 2010. Following the guidance set by the WHO, Taiwan began its promotion at a national level, and with local authorities. However, during the advocacy process, the fundamental differences between Eastern and Western cultures in terms of family values and deep-rooted respect for the elderly have raised an awareness of the need for an oriental paradigm. This paper identifies three key elements for AFC promotion in East Asian countries based on an analysis of Taiwan's experience: during needs assessment take collectivism into consideration, during action plans at the community level community leaders' views will be more important (particularism), and when promoting AFC at the institutional level a top-down approach will be more acceptable (high power distance concept). © The Author(s) 2016.

Politics or Technocracy - What Next for Global Health? Comment on "Navigating Between Stealth Advocacy and Unconscious Dogmatism: The Challenge of Researching the Norms, Politics and Power of Global Health".

PubMed

Kickbusch, Ilona

2015-12-12

Politics play a central part in determining health and development outcomes as Gorik Ooms highlights in his recent commentary. As health becomes more global and more politicized the need grows to better understand the inherently political processes at all levels of governance, such as ideological positions, ideas, value judgments, and power. I agree that global health research should strengthen its contribution to generating such knowledge by drawing more on political science, such research is gaining ground. Even more important is - as Ooms indicates - that global health scholars better understand their own role in the political process. It is time to acknowledge that expert-based technocratic approaches are no less political. We will need to reflect and analyse the role of experts in global health governance to a greater extent and in that context explore the links between politics, expertise and democracy. © 2016 by Kerman University of Medical Sciences.

Thermo-economic analysis of a trigeneration HCPVT power plant

NASA Astrophysics Data System (ADS)

Selviaridis, Angelos; Burg, Brian R.; Wallerand, Anna Sophia; Maréchal, François; Michel, Bruno

2015-09-01

The increasing need for electricity and heat in a growing global economy must be combined with CO2 emissions reduction, in order to limit the human influence on the environment. This calls for energy-efficient and cost-competitive renewable energy systems that are able to satisfy both pressing needs. A High-Concentration Photovoltaic Thermal (HCPVT) system is a cogeneration concept that shows promising potential in delivering electricity and heat in an efficient and cost-competitive manner. This study investigates the transient behavior of the HCPVT system and presents a thermo-economic analysis of a MW-scale trigeneration (electricity, heating and cooling) power plant. Transient simulations show a fast dynamic response of the system which results in short heat-up intervals, maximizing heat recuperation throughout the day. Despite suboptimal coupling between demand and supply, partial heat utilization throughout the year and low COP of commercially available devices for the conversion of heat into cooling, the thermo-economic analysis shows promising economic behavior, with a levelized cost of electricity close to current retail prices.

Variability in effective radiating area and output power of new ultrasound transducers at 3 MHz.

PubMed

Johns, Lennart D; Straub, Stephen J; Howard, Samuel M

2007-01-01

Spatial average intensity (SAI) is often used by clinicians to gauge therapeutic ultrasound dosage, yet SAI measures are not directly regulated by US Food and Drug Administration (FDA) standards. Current FDA guidelines permit a possible 50% to 150% minimum to maximum range of SAI values, potentially contributing to variability in clinical outcomes. To measure clinical values that describe ultrasound transducers and to determine the degree of intramanufacturer and intermanufacturer variability in effective radiating area, power, and SAI when the transducer is functioning at 3 MHz. A descriptive and interferential approach was taken to this quasi-experimental design. Measurement laboratory. Sixty-six 5-cm(2) ultrasound transducers were purchased from 6 different manufacturers. All transducers were calibrated and then assessed using standardized measurement techniques; SAI was normalized to account for variability in effective radiating area, resulting in an nSAI. Effective radiating area, power, and nSAI. All manufacturers with the exception of Omnisound (P = .534) showed a difference between the reported and measured effective radiating area values (P < .001). All transducers were within FDA guidelines for power (+/-20%). Chattanooga (0.85 +/- 0.05 W/cm(2)) had a lower nSAI (P < .05) than all other manufacturers functioning at 3 MHz. Intramanufacturer variability in SAI ranged from 16% to 35%, and intermanufacturer variability ranged from 22% to 61%. Clinicians should consider treatment values of each individual transducer, regardless of the manufacturer. In addition, clinicians should scrutinize the power calibration and recalibration record of the transducer and adjust clinical settings as needed for the desired level of heating. Our data may aid in explaining the reported heating differences among transducers from different manufacturers. Stricter FDA standards regarding effective radiating area and total power are needed, and standards regulating SAI should be established.

Nuclear power systems for lunar and Mars exploration

NASA Technical Reports Server (NTRS)

Sovie, R. J.; Bozek, J. M.

1990-01-01

Initial studies of a variety of mission scenarios for the new Space Exploration Initiative, and the technologies necessary to enable or significantly enhance them, have identified the development of advanced space power systems whether solar, chemical or nuclear to be of prime importance. Lightweight, compact, reliable power systems for planetary rovers and a variety of surface vehicles, utility surface power, and power for advanced propulsion systems have been identified as critical needs for these missions. These mission scenarios, the concomitant power system requirements, and power system options considered are discussed. The significant potential benefits of nuclear power are identified for meeting the power needs of the above applications.

On verifying a high-level design. [cost and error analysis

NASA Technical Reports Server (NTRS)

Mathew, Ben; Wehbeh, Jalal A.; Saab, Daniel G.

1993-01-01

An overview of design verification techniques is presented, and some of the current research in high-level design verification is described. Formal hardware description languages that are capable of adequately expressing the design specifications have been developed, but some time will be required before they can have the expressive power needed to be used in real applications. Simulation-based approaches are more useful in finding errors in designs than they are in proving the correctness of a certain design. Hybrid approaches that combine simulation with other formal design verification techniques are argued to be the most promising over the short term.

Space Power Free-Piston Stirling Engine Scaling Study

NASA Technical Reports Server (NTRS)

Jones, D.

1989-01-01

The design feasibility study is documented of a single cylinder, free piston Stirling engine/linear alternator (FPSE/LA) power module generating 150 kW-electric (kW sub e), and the determination of the module's maximum feasible power level. The power module configuration was specified to be a single cylinder (single piston, single displacer) FPSE/LA, with tuning capacitors if required. The design requirements were as follows: (1) Maximum electrical power output; (2) Power module thermal efficiency equal to or greater than 20 percent at a specific mass of 5 to 8 kg/kW(sub e); (3) Heater wall temperature/cooler wall temperature = 1050 K/525 K; (4) Sodium heat-pipe heat transport system, pumped loop NaK (sodium-potassium eutectic mixture) rejection system; (5) Maximum power module vibration amplitude = 0.0038 cm; and (6) Design life = 7 years (60,000 hr). The results show that a single cylinder FPSE/LA is capable of meeting program goals and has attractive scaling attributes over the power range from 25 to 150 kW(sub e). Scaling beyond the 150 kW(sub e) power level, the power module efficiency falls and the power module specific mass reaches 10 kg/kW(sub e) at a power output of 500 kW(sub e). A discussion of scaling rules for the engine, alternator, and heat transport systems is presented, along with a detailed description of the conceptual design of a 150 kW(sub e) power module that meets the requirements. Included is a discussion of the design of a dynamic balance system. A parametric study of power module performance conducted over the power output range of 25 to 150 kW(sub e) for temperature ratios of 1.7, 2.0, 2.5, and 3.0 is presented and discussed. The results show that as the temperature ratio decreases, the efficiency falls and specific mass increases. At a temperature ratio of 1.7, the 150 kW(sub e) power module cannot satisfy both efficiency and specific mass goals. As the power level increases from 25 to 150 kW(sub e) at a fixed temperature ratio, power module efficiency is seen to increase slightly, but at the expense of increased specific mass. An empirical equation relating power module thermal efficiency as a function of power module specific mass, power output, and temperature ratio is developed. Alternative configurations to the single cylinder, direct coupled linear alternator approach are also evaluated, but are shown to have technical drawbacks that lessen their attractiveness. The dynamic balance assembly mass (moving mass and structure) represents 20 to 30 percent of the total single cylinder power module mass. Joining two modules in a balanced opposed configuration eliminates the need for the balancer, and a hot end junction can be made without significant addition of structural mass. Recommendations are made for evaluation of advanced heat pipe concepts, tests of radial flow heat exchangers, and evaluation of high temperature alternator materials.

Venus Mobile Explorer with RPS for Active Cooling: A Feasibility Study

NASA Technical Reports Server (NTRS)

Leifer, Stephanie D.; Green, Jacklyn R.; Balint, Tibor S.; Manvi, Ram

2009-01-01

We present our findings from a study to evaluate the feasibility of a radioisotope power system (RPS) combined with active cooling to enable a long-duration Venus surface mission. On-board power with active cooling technology featured prominently in both the National Research Council's Decadal Survey and in the 2006 NASA Solar System Exploration Roadmap as mission-enabling for the exploration of Venus. Power and cooling system options were reviewed and the most promising concepts modeled to develop an assessment tool for Venus mission planners considering a variety of future potential missions to Venus, including a Venus Mobile Explorer (either a balloon or rover concept), a long-lived Venus static lander, or a Venus Geophysical Network. The concepts modeled were based on the integration of General Purpose Heat Source (GPHS) modules with different types of Stirling cycle heat engines for power and cooling. Unlike prior investigations which reported on single point design concepts, this assessment tool allows the user to generate either a point design or parametric curves of approximate power and cooling system mass, power level, and number of GPHS modules needed for a "black box" payload housed in a spherical pressure vessel.

Nurse managers don't get the corner office.

PubMed

Paliadelis, Penny

2013-03-01

To provide an original perspective on the power and status of first-line nurse managers by observing their working environment. The role of first-line nurse managers includes clinical, administrative and managerial components, with their responsibilities not always reflected in their level of organizational power. The business literature suggests that an appropriately resourced workspace is not merely functional, it also confers power and status. Twenty Australian rural nurse managers' workspaces were observed, as part of a larger qualitative study that explored their role and organizational power using semi-structured interviews. The observational data consisted of detailed researcher notes that were analysed thematically. The nurse managers' workspaces were suboptimal and did not provide sufficient physical space or resources for the participants' to manage tasks effectively. These results were considered using Kanter's theory of organizational power. The findings support those reported in the business literature that inadequate physical workspaces are counterproductive in terms of both functionality and organizational power. Suggestions are made regarding the workspace needs of first-line nurse managers, based on a closer alignment between the work environment and their role responsibilities. These findings have implications for decisions regarding organizational support of first-line nurse managers. © 2012 Blackwell Publishing Ltd.

Re-scheduling as a tool for the power management on board a spacecraft

NASA Technical Reports Server (NTRS)

Albasheer, Omar; Momoh, James A.

1995-01-01

The scheduling of events on board a spacecraft is based on forecast energy levels. The real time values of energy may not coincide with the forecast values; consequently, a dynamic revising to the allocation of power is needed. The re-scheduling is also needed for other reasons on board a spacecraft like the addition of new event which must be scheduled, or a failure of an event due to many different contingencies. This need of rescheduling is very important to the survivability of the spacecraft. In this presentation, a re-scheduling tool will be presented as a part of an overall scheme for the power management on board a spacecraft from the allocation of energy point of view. The overall scheme is based on the optimal use of energy available on board a spacecraft using expert systems combined with linear optimization techniques. The system will be able to schedule maximum number of events utilizing most energy available. The outcome is more events scheduled to share the operation cost of that spacecraft. The system will also be able to re-schedule in case of a contingency with minimal time and minimal disturbance of the original schedule. The end product is a fully integrated planning system capable of producing the right decisions in short time with less human error. The overall system will be presented with the re-scheduling algorithm discussed in detail, then the tests and results will be presented for validations.

Measurement and analysis of radiofrequency radiations from some mobile phone base stations in Ghana.

PubMed

Amoako, J K; Fletcher, J J; Darko, E O

2009-08-01

A survey of the radiofrequency electromagnetic radiation at public access points in the vicinity of 50 cellular phone base stations has been carried out. The primary objective was to measure and analyse the electromagnetic field strength levels emitted by antennae installed and operated by the Ghana Telecommunications Company. On all the sites measurements were made using a hand-held spectrum analyser to determine the electric field level with the 900 and 1800 MHz frequency bands. The results indicated that power densities at public access points varied from as low as 0.01 microW m(-2) to as high as 10 microW m(-2) for the frequency of 900 MHz. At a transmission frequency of 1800 MHz, the variation of power densities is from 0.01 to 100 microW m(-2). The results were found to be in compliant with the International Commission on Non-ionizing Radiological Protection guidance level but were 20 times higher than the results generally obtained for such a practice elsewhere. There is therefore a need to re-assess the situation to ensure reduction in the present level as an increase in mobile phone usage is envisaged within the next few years.

Considerations for an Obesity Policy Research Agenda

PubMed Central

McKinnon, Robin A.; Orleans, C. Tracy; Kumanyika, Shiriki K.; Haire-Joshu, Debra; Krebs-Smith, Susan M.; Finkelstein, Eric A.; Brownell, Kelly D.; Thompson, Joseph W.; Ballard-Barbash, Rachel

2010-01-01

The rise in obesity levels in the U.S. in the past several decades has been dramatic, with serious implications for public health and the economy. Experiences in tobacco control and other public health initiatives have shown that public policy may be a powerful tool to effect structural change to alter population-level behavior. In 2007, the National Cancer Institute convened a meeting to discuss priorities for a research agenda to inform obesity policy. Issues considered were how to define obesity policy research, key challenges and key partners in formulating/implementing an obesity policy research agenda, criteria by which to set research priorities, and specific research needs and questions. Themes that emerged were: (1) the embryonic nature of obesity policy research, (2) the need to study “natural experiments” resulting from policy-based efforts to address the obesity epidemic, (3) the importance of research focused beyond individual-level behavior change, (4) the need for economic research across several relevant policy areas, and (5) the overall urgency of taking action in the policy arena. Moving forward, timely evaluation of natural experiments is of especially high priority. A variety of policies intended to promote healthy weight in children and adults are being implemented in communities and at the state and national levels. Although some of these policies are supported by the findings of intervention research, additional research is needed to evaluate the implementation and quantify the impact of new policies designed to address obesity. PMID:19211215

Need for Affiliation as a Motivational Add-On for Leadership Behaviors and Managerial Success

PubMed Central

Steinmann, Barbara; Ötting, Sonja K.; Maier, Günter W.

2016-01-01

In a sample of 70 leader-follower dyads, this study examines the separate and interactive effects of the leaders’ implicit needs for power, achievement, and affiliation on leadership behaviors and outcomes. Results show that whereas the need for achievement was marginally associated with follower-rated passive leadership, the need for affiliation was significantly related to ratings of the leaders’ concern for the needs of their followers. Analyzing motive combinations in terms of interactive effects and accounting for the growing evidence on the value of affiliative concerns in leadership, we assumed the need for affiliation would channel the interplay among the needs for power and achievement in such a way that the leaders would become more effective in leading others. As expected, based on high need for achievement, the followers were more satisfied with their jobs and with their leaders and perceived more transformational leadership behavior if power-motivated leaders equally had a high need for affiliation. Moreover, the leaders indicated higher career success when this was the case. However, in indicators of followers’ performance, the three-way interaction among the needs for power, achievement, and affiliation did not account for additional variance. PMID:28066295

Need for Affiliation as a Motivational Add-On for Leadership Behaviors and Managerial Success.

PubMed

Steinmann, Barbara; Ötting, Sonja K; Maier, Günter W

2016-01-01

In a sample of 70 leader-follower dyads, this study examines the separate and interactive effects of the leaders' implicit needs for power, achievement, and affiliation on leadership behaviors and outcomes. Results show that whereas the need for achievement was marginally associated with follower-rated passive leadership, the need for affiliation was significantly related to ratings of the leaders' concern for the needs of their followers. Analyzing motive combinations in terms of interactive effects and accounting for the growing evidence on the value of affiliative concerns in leadership, we assumed the need for affiliation would channel the interplay among the needs for power and achievement in such a way that the leaders would become more effective in leading others. As expected, based on high need for achievement, the followers were more satisfied with their jobs and with their leaders and perceived more transformational leadership behavior if power-motivated leaders equally had a high need for affiliation. Moreover, the leaders indicated higher career success when this was the case. However, in indicators of followers' performance, the three-way interaction among the needs for power, achievement, and affiliation did not account for additional variance.

Selective harmonic elimination strategy in eleven level inverter for PV system with unbalanced DC sources

NASA Astrophysics Data System (ADS)

Ghoudelbourk, Sihem.; Dib, D.; Meghni, B.; Zouli, M.

2017-02-01

The paper deals with the multilevel converters control strategy for photovoltaic system integrated in distribution grids. The objective of the proposed work is to design multilevel inverters for solar energy applications so as to reduce the Total Harmonic Distortion (THD) and to improve the power quality. The multilevel inverter power structure plays a vital role in every aspect of the power system. It is easier to produce a high-power, high-voltage inverter with the multilevel structure. The topologies of multilevel inverter have several advantages such as high output voltage, lower total harmonic distortion (THD) and reduction of voltage ratings of the power semiconductor switching devices. The proposed control strategy ensures an implementation of selective harmonic elimination (SHE) modulation for eleven levels. SHE is a very important and efficient strategy of eliminating selected harmonics by judicious selection of the firing angles of the inverter. Harmonics elimination technique eliminates the need of the expensive low pass filters in the system. Previous research considered that constant and equal DC sources with invariant behavior; however, this research extends earlier work to include variant DC sources, which are typical of lead-acid batteries when used in system PV. This Study also investigates methods to minimize the total harmonic distortion of the synthesized multilevel waveform and to help balance the battery voltage. The harmonic elimination method was used to eliminate selected lower dominant harmonics resulting from the inverter switching action.

A SOCIO-ECONOMIST LOOKS AT THE CURRENT VALUES AND CHANGING NEEDS OF YOUTH. FINAL DRAFT.

ERIC Educational Resources Information Center

THEOBALD, ROBERT

MAN HAS ACHIEVED THE POWER TO CREATE AN ENVIRONMENT SUITED TO HIS NEEDS. THIS POWER COMES FROM DEVELOPMENTS IN THE UTILIZATION OF ENERGY, ADVANCEMENTS IN CHEMISTRY, AN INCREASE IN SCIENTIFIC PROBLEM SOLVING ABILITY AND COMPUTER TECHNOLOGY. THESE SOURCES OF POWER RESULT IN THE DRIVE TOWARD THE DEVELOPMENT OF DESTRUCTIVE POWER, THE CAPABILITY OF…

Intelligent trend analysis for a solar thermal energy collector field

NASA Astrophysics Data System (ADS)

Juuso, E. K.

2018-03-01

Solar thermal power plants collect available solar energy in a usable form at a temperature range which is adapted to the irradiation levels and seasonal variations. Solar energy can be collected only when the irradiation is high enough to produce the required temperatures. During the operation, a trade-off of the temperature and the flow is needed to achieve a good level for the collected power. The scaling approach brings temporal analysis to all measurements and features: trend indices are calculated by comparing the averages in the long and short time windows, a weighted sum of the trend index and its derivative detects the trend episodes and severity of the trend is estimated by including also the variable level in the sum. The trend index, trend episodes and especially, the deviation index reveal early evolving changes in the operating conditions, including cloudiness and load disturbances. The solution is highly compact: all variables, features and indices are transformed to the range [-2, 2] and represented in natural language which is important in integrating data-driven solutions with domain expertise. The special situations detected during the test campaigns are explained well.

Towards an implantable bio-sensor platform for continuous real-time monitoring of anti-epileptic drugs.

PubMed

Hammoud, Abbas; Chamseddine, Ahmad; Nguyen, Dang K; Sawan, Mohamad

2016-08-01

The need of continuous real-time monitoring device for in-vivo drug level detection has been widely articulated lately. Such monitoring could guide drug posology and timing of intake, detect low or high drug levels, in order to take adequate measures, and give clinicians a valuable window into patients' health and their response to therapeutics. This paper presents a novel implantable bio-sensor based on impedance measurement capable of continuously monitoring various antiepileptic drug levels. This portable point-of-care microsystem replaces large and stationary conventional macrosystems, and is a one of a kind system designed with an array of electrodes to monitor various anti-epileptic drugs rather than one drug. The micro-system consists of (i) the front-end circuit including an inductive coil to receive energy from an external base station, and to exchange data with the latter; (ii) the power management block; (iii) the readout and control block; and (iv) the biosensor array. The electrical circuitry was designed using the 0.18-um CMOS process technology intended to be miniature and consume ultra-low power.

A Wireless Fluid-Level Measurement Technique

NASA Technical Reports Server (NTRS)

Woodard, Stanley E.; Taylor, Bryant D.

2006-01-01

This paper presents the application of a recently developed wireless measurement acquisition system to fluid-level measurement. This type of fluid-level measurement system alleviates many shortcomings of fluid-level measurement methods currently being used, including limited applicability of any one fluid-level sensor design. Measurement acquisition shortcomings include the necessity for power to be supplied to each sensor and for the measurement to be extracted from each sensor via a physical connection to the sensor. Another shortcoming is existing measurement systems require that a data channel and signal conditioning electronics be dedicated to each sensor. Use of wires results in other shortcomings such as logistics needed to add or replace sensors, weight, potential for electrical arcing and wire degradations. The fluid level sensor design is a simple passive inductor-capacitor circuit that is not subject to mechanical failure that is possible when float and lever-arm systems are used. Methods are presented for using the sensor in caustic, acidic or cryogenic fluids. Oscillating magnetic fields are used to power the sensor. Once electrically excited, the sensor produces a magnetic field response. The response frequency corresponds to the amount to fluid within the capacitor s electric field. The sensor design can be modified for measuring the level of any fluid or fluent substance that can be stored in a non-conductive reservoir. The interrogation method for discerning changes in the sensor response frequency is also presented.

Spatial distribution of nymphs of Scaphoideus titanus (Homoptera: Cicadellidae) in grapes, and evaluation of sequential sampling plans.

PubMed

Lessio, Federico; Alma, Alberto

2006-04-01

The spatial distribution of the nymphs of Scaphoideus titanus Ball (Homoptera Cicadellidae), the vector of grapevine flavescence dorée (Candidatus Phytoplasma vitis, 16Sr-V), was studied by applying Taylor's power law. Studies were conducted from 2002 to 2005, in organic and conventional vineyards of Piedmont, northern Italy. Minimum sample size and fixed precision level stop lines were calculated to develop appropriate sampling plans. Model validation was performed, using independent field data, by means of Resampling Validation of Sample Plans (RVSP) resampling software. The nymphal distribution, analyzed via Taylor's power law, was aggregated, with b = 1.49. A sample of 32 plants was adequate at low pest densities with a precision level of D0 = 0.30; but for a more accurate estimate (D0 = 0.10), the required sample size needs to be 292 plants. Green's fixed precision level stop lines seem to be more suitable for field sampling: RVSP simulations of this sampling plan showed precision levels very close to the desired levels. However, at a prefixed precision level of 0.10, sampling would become too time-consuming, whereas a precision level of 0.25 is easily achievable. How these results could influence the correct application of the compulsory control of S. titanus and Flavescence dorée in Italy is discussed.

Mentoring--Who Needs It? A Comparison of Proteges' and Nonproteges' Needs for Power, Achievement, Affiliation, and Autonomy.

ERIC Educational Resources Information Center

Fagenson, Ellen A.

1992-01-01

Responses from 46 proteges (46 percent of sample) and 54 nonproteges (54 percent) in high technology service companies revealed that proteges have significantly higher needs for power and achievement. No differences appeared in need for autonomy or affiliation. Proteges' gender was not a significant factor. (SK)

Advanced electrical power system technology for the all electric aircraft

NASA Technical Reports Server (NTRS)

Finke, R. C.; Sundberg, G. R.

1983-01-01

The application of advanced electric power system technology to an all electric airplane results in an estimated reduction of the total takeoff gross weight of over 23,000 pounds for a large airplane. This will result in a 5 to 10 percent reduction in direct operating costs (DOC). Critical to this savings is the basic electrical power system component technology. These advanced electrical power components will provide a solid foundation for the materials, devices, circuits, and subsystems needed to satisfy the unique requirements of advanced all electric aircraft power systems. The program for the development of advanced electrical power component technology is described. The program is divided into five generic areas: semiconductor devices (transistors, thyristors, and diodes); conductors (materials and transmission lines); dielectrics; magnetic devices; and load management devices. Examples of progress in each of the five areas are discussed. Bipolar power transistors up to 1000 V at 100 A with a gain of 10 and a 0.5 microsec rise and fall time are presented. A class of semiconductor devices with a possibility of switching up to 100 kV is described. Solid state power controllers for load management at 120 to 1000 V and power levels to 25 kW were developed along with a 25 kW, 20 kHz transformer weighing only 3.2 kg. Previously announced in STAR as N83-24764

National Maglev initiative: California line electric utility power system requirements

NASA Technical Reports Server (NTRS)

Save, Phil

1994-01-01

The electrical utility power system requirements were determined for a Maglev line from San Diego to San Francisco and Sacramento with a maximum capacity of 12,000 passengers an hour in each direction at a speed of 300 miles per hour, or one train every 30 seconds in each direction. Basically the Maglev line requires one 50-MVA substation every 12.5 miles. The need for new power lines to serve these substations and their voltage levels are based not only on equipment loading criteria but also on limitations due to voltage flicker and harmonics created by the Maglev system. The resulting power system requirements and their costs depend mostly on the geographical area, urban or suburban with 'strong' power systems, or mountains and rural areas with 'weak' power systems. A reliability evaluation indicated that emergency power sources, such as a 10-MW battery at each substation, were not justified if sufficient redundancy is provided in the design of the substations and the power lines serving them. With a cost of $5.6 M per mile, the power system requirements, including the 12-kV DC cables and the inverters along the Maglev line, were found to be the second largest cost component of the Maglev system, after the cost of the guideway system ($9.1 M per mile), out of a total cost of $23 M per mile.

Ultra-low-power conversion and management techniques for thermoelectric energy harvesting applications

NASA Astrophysics Data System (ADS)

Fleming, Jerry W.

2010-04-01

Thermoelectric energy harvesting has increasingly gained acceptance as a potential power source that can be used for numerous commercial and military applications. However, power electronic designers have struggled to incorporate energy harvesting methods into their designs due to the relatively small voltage levels available from many harvesting device technologies. In order to bridge this gap, an ultra-low input voltage power conversion method is needed to convert small amounts of scavenged energy into a usable form of electricity. Such a method would be an enabler for new and improved medical devices, sensor systems, and other portable electronic products. This paper addresses the technical challenges involved in ultra-low-voltage power conversion by providing a solution utilizing novel power conversion techniques and applied technologies. Our solution utilizes intelligent power management techniques to control unknown startup conditions. The load and supply management functionality is also controlled in a deterministic manner. The DC to DC converter input operating voltage is 20mV with a conversion efficiency of 90% or more. The output voltage is stored into a storage device such as an ultra-capacitor or lithium-ion battery for use during brown-out or unfavorable harvesting conditions. Applications requiring modular, low power, extended maintenance cycles, such as wireless instrumentation would significantly benefit from the novel power conversion and harvesting techniques outlined in this paper.

Determination of the needed power of an electric motor on the basis of acceleration time of the electric car

NASA Astrophysics Data System (ADS)

Sapundzhiev, M.; Evtimov, I.; Ivanov, R.

2017-10-01

The paper presents an upgraded methodology for determination of the electric motor power considering the time for acceleration. The influence of the speed factor of electric motor on the value of needed power at same acceleration time is studied. Some calculations on the basis of real vehicle were made. The numeric and graphical results are given. They show a decrease of needed power with the increase of the speed factor of motor, because the high speed factor allows the use of a larger range of the characteristic with the maximum power of the motor. An experimental verification of methodology was done.

Utilizing Solar Power Technologies for On-Orbit Propellant Production

NASA Technical Reports Server (NTRS)

Fikes, John C.; Howell, Joe T.; Henley, Mark W.

2006-01-01

The cost of access to space beyond low Earth orbit may be reduced if vehicles can refuel in orbit. The cost of access to low Earth orbit may also be reduced by launching oxygen and hydrogen propellants in the form of water. To achieve this reduction in costs of access to low Earth orbit and beyond, a propellant depot is considered that electrolyzes water in orbit, then condenses and stores cryogenic oxygen and hydrogen. Power requirements for such a depot require Solar Power Satellite technologies. A propellant depot utilizing solar power technologies is discussed in this paper. The depot will be deployed in a 400 km circular equatorial orbit. It receives tanks of water launched into a lower orbit from Earth, converts the water to liquid hydrogen and oxygen, and stores up to 500 metric tons of cryogenic propellants. This requires a power system that is comparable to a large Solar Power Satellite capable of several 100 kW of energy. Power is supplied by a pair of solar arrays mounted perpendicular to the orbital plane, which rotates once per orbit to track the Sun. The majority of the power is used to run the electrolysis system. Thermal control is maintained by body-mounted radiators; these also provide some shielding against orbital debris. The propellant stored in the depot can support transportation from low Earth orbit to geostationary Earth orbit, the Moon, LaGrange points, Mars, etc. Emphasis is placed on the Water-Ice to Cryogen propellant production facility. A very high power system is required for cracking (electrolyzing) the water and condensing and refrigerating the resulting oxygen and hydrogen. For a propellant production rate of 500 metric tons (1,100,000 pounds) per year, an average electrical power supply of 100 s of kW is required. To make the most efficient use of space solar power, electrolysis is performed only during the portion of the orbit that the Depot is in sunlight, so roughly twice this power level is needed for operations in sunlight (slightly over half of the time). This power level mandates large solar arrays, using advanced Space Solar Power technology. A significant amount of the power has to be dissipated as heat, through large radiators. This paper briefly describes the propellant production facility and the requirements for a high power system capability. The Solar Power technologies required for such an endeavor are discussed.

A Comprehensive Program for Measurement of Military Aircraft Emissions

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

Cheng, Mengdawn

2009-11-01

Emissions of gases and particulate matter by military aircraft were characterized inplume by 'extractive' and 'optical remote-sensing (ORS)' technologies. Non-volatile particle size distribution, number and mass concentrations were measured with good precision and reproducibly. Time-integrated particulate filter samples were collected and analyzed for smoke number, elemental composition, carbon contents, and sulfate. Observed at EEP the geometric mean diameter (as measured by the mobility diameter) generally increased as the engine power setting increased, which is consistent with downstream observations. The modal diameters at the downstream locations are larger than that at EEP at the same engine power level. The results indicatemore » that engine particles were processed by condensation, for example, leading to particle growth in-plume. Elemental analysis indicated little metals were present in the exhaust, while most of the exhaust materials in the particulate phase were carbon and sulfate (in the JP-8 fuel). CO, CO{sub 2}, NO, NO{sub 2}, SO{sub 2}, HCHO, ethylene, acetylene, propylene, and alkanes were measured. The last five species were most noticeable under engine idle condition. The levels of hydrocarbons emitted at high engine power level were generally below the detection limits. ORS techniques yielded real-time gaseous measurement, but the same techniques could not be extended directly to ultrafine particles found in all engine exhausts. The results validated sampling methodology and measurement techniques used for non-volatile particulate aircraft emissions, which also highlighted the needs for further research on sampling and measurement for volatile particulate matter and semi-volatile species in the engine exhaust especially at the low engine power setting.« less

The nuclear energy outlook--a new book from the OECD nuclear energy agency.

PubMed

Yoshimura, Uichiro

2011-01-01

This paper summarizes the key points of a report titled Nuclear Energy Outlook, published in 2008 by the Nuclear Energy Agency of the Organization for Economic Cooperation and Development, which has 30 member nations. The report discusses the commitment of many nations to increase nuclear power generating capacity and the potential rate of building new electricity-generating nuclear plants by 2030 to 2050. The resulting decrease in carbon dioxide emissions from fossil fuel combustion resulting from an increase in nuclear power sources is described. Other topics that are discussed include the need to develop non-proliferative nuclear fuels, the importance of developing geological disposal facilities or reprocessing capabilities for spent nuclear fuel and high-level radioactive waste materials, and the requirements for a larger nuclear workforce and greater cost competitiveness for nuclear power generation. Copyright © 2010 Health Physics Society

Characterization of the differences in strength and power between different levels of competition in rugby union athletes.

PubMed

Argus, Christos K; Gill, Nicholas D; Keogh, Justin W L

2012-10-01

Levels of strength and power have been used to effectively discriminate between different levels of competition; however, there is limited literature in rugby union athletes. To assess the difference in strength and power between levels of competition, 112 rugby union players, including 43 professionals, 19 semiprofessionals, 32 academy level, and 18 high school level athletes, were assessed for bench press and box squat strength, and bench throw, and jump squat power. High school athletes were not assessed for jump squat power. Raw data along with data normalized to body mass with a derived power exponent were log transformed and analyzed. With the exception of box squat and bench press strength between professional and semiprofessional athletes, higher level athletes produced greater absolute and relative strength and power outputs than did lower level athletes (4-51%; small to very large effect sizes). Lower level athletes should strive to attain greater levels of strength and power in an attempt to reach or to be physically prepared for the next level of competition. Furthermore, the ability to produce high levels of power, rather than strength, may be a better determinate of playing ability between professional and semiprofessional athletes.

Analysis of modified SMI method for adaptive array weight control

NASA Technical Reports Server (NTRS)

Dilsavor, R. L.; Moses, R. L.

1989-01-01

An adaptive array is applied to the problem of receiving a desired signal in the presence of weak interference signals which need to be suppressed. A modification, suggested by Gupta, of the sample matrix inversion (SMI) algorithm controls the array weights. In the modified SMI algorithm, interference suppression is increased by subtracting a fraction F of the noise power from the diagonal elements of the estimated covariance matrix. Given the true covariance matrix and the desired signal direction, the modified algorithm is shown to maximize a well-defined, intuitive output power ratio criterion. Expressions are derived for the expected value and variance of the array weights and output powers as a function of the fraction F and the number of snapshots used in the covariance matrix estimate. These expressions are compared with computer simulation and good agreement is found. A trade-off is found to exist between the desired level of interference suppression and the number of snapshots required in order to achieve that level with some certainty. The removal of noise eigenvectors from the covariance matrix inverse is also discussed with respect to this application. Finally, the type and severity of errors which occur in the covariance matrix estimate are characterized through simulation.

3 μm CW lasers for myringotomy and microsurgery.

PubMed

Linden, Kurt J; Pfeffer, Christian P; Sousa, John Gary; D'Alleva, Nicholas; Aslani, Arash; Gorski, Grzegorz; Kenna, Margaret; Poe, Dennis S

2013-03-08

This paper describes the development and implementation of 3 μm lasers for myringotomy and microsurgery. Two different lasers were investigated. The first, an Er-doped, CW zirconate glass fiber laser optically pumped by a 970 nm diode laser, emitted > 1 W of CW power at 2.76 μm with concomitant green incoherent emission that served as a convenient visible illumination beam. The second, a 1 W CW Er:YAG solid-state laser also optically pumped by a 970 nm diode laser, emitted > 1 W of CW power at 2.94 μm, coincident with the strongest infrared water absorption peak. Running CW, both lasers are expected to avoid the loud acoustical shocks associated with pulsed lasers. Myringotomies were carried out with the Er:YAG laser on anaesthetized guinea pigs and the effects of the laser were documented. Laser ablated samples of tympanic membrane, soft tissue and bone were histologically examined. Histology results indicated that the CW Er:YAG laser is a potential candidate for a new myringotomy tool and possibly for otologic microsurgery, but deliverable power levels need to be increased to the 2 W (or higher) level. This work was funded under NIH SBIR Grant No. 5R44DC004899.

3-μm CW lasers for myringotomy and microsurgery

NASA Astrophysics Data System (ADS)

Linden, Kurt J.; Pfeffer, Christian P.; Sousa, John Gary; D'Alleva, Nicholas; Aslani, Arash; Gorski, Grzegorz; Kenna, Margaret; Poe, Dennis S.

2013-03-01

This paper describes the development and implementation of 3 μm lasers for myringotomy and microsurgery. Two different lasers were investigated. The first, an Er-doped, CW zirconate glass fiber laser optically pumped by a 970 nm diode laser, emitted > 1 W of CW power at 2.76 μm with concomitant green incoherent emission that served as a convenient visible illumination beam. The second, a 1 W CW Er:YAG solid-state laser also optically pumped by a 970 nm diode laser, emitted > 1 W of CW power at 2.94 μm, coincident with the strongest infrared water absorption peak. Running CW, both lasers are expected to avoid the loud acoustical shocks associated with pulsed lasers. Myringotomies were carried out with the Er:YAG laser on anaesthetized guinea pigs and the effects of the laser were documented. Laser ablated samples of tympanic membrane, soft tissue and bone were histologically examined. Histology results indicated that the CW Er:YAG laser is a potential candidate for a new myringotomy tool and possibly for otologic microsurgery, but deliverable power levels need to be increased to the 2 W (or higher) level. This work was funded under NIH SBIR Grant No. 5R44DC004899.

3 μm CW lasers for myringotomy and microsurgery

PubMed Central

Linden, Kurt J.; Pfeffer, Christian P.; Sousa, John Gary; D’Alleva, Nicholas; Aslani, Arash; Gorski, Grzegorz; Kenna, Margaret; Poe, Dennis S.

2013-01-01

This paper describes the development and implementation of 3 μm lasers for myringotomy and microsurgery. Two different lasers were investigated. The first, an Er-doped, CW zirconate glass fiber laser optically pumped by a 970 nm diode laser, emitted > 1 W of CW power at 2.76 μm with concomitant green incoherent emission that served as a convenient visible illumination beam. The second, a 1 W CW Er:YAG solid-state laser also optically pumped by a 970 nm diode laser, emitted > 1 W of CW power at 2.94 μm, coincident with the strongest infrared water absorption peak. Running CW, both lasers are expected to avoid the loud acoustical shocks associated with pulsed lasers. Myringotomies were carried out with the Er:YAG laser on anaesthetized guinea pigs and the effects of the laser were documented. Laser ablated samples of tympanic membrane, soft tissue and bone were histologically examined. Histology results indicated that the CW Er:YAG laser is a potential candidate for a new myringotomy tool and possibly for otologic microsurgery, but deliverable power levels need to be increased to the 2 W (or higher) level. This work was funded under NIH SBIR Grant No. 5R44DC004899. PMID:24382990

Varying ultrasound power level to distinguish surgical instruments and tissue.

PubMed

Ren, Hongliang; Anuraj, Banani; Dupont, Pierre E

2018-03-01

We investigate a new framework of surgical instrument detection based on power-varying ultrasound images with simple and efficient pixel-wise intensity processing. Without using complicated feature extraction methods, we identified the instrument with an estimated optimal power level and by comparing pixel values of varying transducer power level images. The proposed framework exploits the physics of ultrasound imaging system by varying the transducer power level to effectively distinguish metallic surgical instruments from tissue. This power-varying image-guidance is motivated from our observations that ultrasound imaging at different power levels exhibit different contrast enhancement capabilities between tissue and instruments in ultrasound-guided robotic beating-heart surgery. Using lower transducer power levels (ranging from 40 to 75% of the rated lowest ultrasound power levels of the two tested ultrasound scanners) can effectively suppress the strong imaging artifacts from metallic instruments and thus, can be utilized together with the images from normal transducer power levels to enhance the separability between instrument and tissue, improving intraoperative instrument tracking accuracy from the acquired noisy ultrasound volumetric images. We performed experiments in phantoms and ex vivo hearts in water tank environments. The proposed multi-level power-varying ultrasound imaging approach can identify robotic instruments of high acoustic impedance from low-signal-to-noise-ratio ultrasound images by power adjustments.

International Nursing: How Much Power Do Nurse Managers Have?

PubMed

Trus, Marija; Martinkenas, Arvydas; Suominen, Tarja

This study was conducted to explore issues of nurse managers' power and empowerment. Data were collected from nurse managers by way of a questionnaire consisting of background factors, work-related questions, and power-related questions at the unit and organization levels. The degree of empowerment was evaluated using 2 established instruments (CWEQ-II and Work Empowerment Questionnaire). The overall level of managers' personal power within their own units was relatively high. Nurse managers' perception of their power at an organizational level was found to be at a moderate level. Several factors related to an individual's professional background were correlated to power issues, both at the unit and organizational levels. Structural and psychological empowerment correlated with the overall level of power at a unit level and the overall level of power at an organizational level. Nurse managers self-reported their own general power at a unit level as high, which offers them possibilities to lead the development of nursing care in their units. Organizations may benefit more from nurse managers' leadership by more fully integrating them in the development processes of the entire organization.

Medium and Short Wave RF Energy Harvester for Powering Wireless Sensor Networks

PubMed Central

Leon-Gil, Jesus A.; Cortes-Loredo, Agustin; Fabian-Mijangos, Angel; Martinez-Flores, Javier J.; Tovar-Padilla, Marco; Cardona-Castro, M. Antonia; Alvarez-Quintana, Jaime

2018-01-01

Internet of Things (IoT) is an emerging platform in which every day physical objects provided with unique identifiers are connected to the Internet without requiring human interaction. The possibilities of such a connected world enables new forms of automation to make our lives easier and safer. Evidently, in order to keep billions of these communicating devices powered long-term, a self-sustainable operation is a key point for realization of such a complex network. In this sense, energy-harvesting technologies combined with low power consumption ICs eliminate the need for batteries, removing an obstacle to the success of the IoT. In this work, a Radio Frequency (RF) energy harvester tuned at AM broadcast has been developed for low consumption power devices. The AM signals from ambient are detected via a high-performance antenna-free LC circuit with an efficiency of 3.2%. To maximize energy scavenging, the RF-DC conversion stage is based on a full-wave Cockcroft–Walton voltage multiplier (CWVM) with efficiency up to 90%. System performance is evaluated by rating the maximum power delivered into the load via its output impedance, which is around 62 μW, although power level seems to be low, it is able to power up low consumption devices such as Leds, portable calculators and weather monitoring stations. PMID:29510482

Medium and Short Wave RF Energy Harvester for Powering Wireless Sensor Networks.

PubMed

Leon-Gil, Jesus A; Cortes-Loredo, Agustin; Fabian-Mijangos, Angel; Martinez-Flores, Javier J; Tovar-Padilla, Marco; Cardona-Castro, M Antonia; Morales-Sánchez, Alfredo; Alvarez-Quintana, Jaime

2018-03-03

Internet of Things (IoT) is an emerging platform in which every day physical objects provided with unique identifiers are connected to the Internet without requiring human interaction. The possibilities of such a connected world enables new forms of automation to make our lives easier and safer. Evidently, in order to keep billions of these communicating devices powered long-term, a self-sustainable operation is a key point for realization of such a complex network. In this sense, energy-harvesting technologies combined with low power consumption ICs eliminate the need for batteries, removing an obstacle to the success of the IoT. In this work, a Radio Frequency (RF) energy harvester tuned at AM broadcast has been developed for low consumption power devices. The AM signals from ambient are detected via a high-performance antenna-free LC circuit with an efficiency of 3.2%. To maximize energy scavenging, the RF-DC conversion stage is based on a full-wave Cockcroft-Walton voltage multiplier (CWVM) with efficiency up to 90%. System performance is evaluated by rating the maximum power delivered into the load via its output impedance, which is around 62 μW, although power level seems to be low, it is able to power up low consumption devices such as Leds, portable calculators and weather monitoring stations.

The interdependence of Ca2+ activation, sarcomere length, and power output in the heart.

PubMed

McDonald, Kerry S

2011-07-01

Myocardium generates power to perform external work on the circulation; yet, many questions regarding intermolecular mechanisms regulating power output remain unresolved. Power output equals force × shortening velocity, and some interesting new observations regarding control of these two factors have arisen. While it is well established that sarcomere length tightly controls myocyte force, sarcomere length-tension relationships also appear to be markedly modulated by PKA-mediated phosphorylation of myofibrillar proteins. Concerning loaded shortening, historical models predict independent cross-bridge mechanics; however, it seems that the mechanical state of one population of cross-bridges affects the activity of other cross-bridges by, for example, recruitment of cross-bridges from the non-cycling pool to the cycling force-generating pool during submaximal Ca(2+) activation. This is supported by the findings that Ca(2+) activation levels, myofilament phosphorylation, and sarcomere length are all modulators of loaded shortening and power output independent of their effects on force. This fine tuning of power output probably helps optimize myocardial energetics and to match ventricular supply with peripheral demand; yet, the discernment of the chemo-mechanical signals that modulate loaded shortening needs further clarification since power output may be a key convergent point and feedback regulator of cytoskeleton and cellular signals that control myocyte growth and survival.

Micro/Nano Fabricated Solid-State Thermoelectric Generator Devices for Integrated High Voltage Power Sources

NASA Astrophysics Data System (ADS)

Fleurial, J.-P.; Ryan, M. A.; Snyder, G. J.; Huang, C.-K.; Whitacre, J. F.; Patel, J.; Lim, J.; Borshchevsky, A.

2002-01-01

Deep space missions have a strong need for compact, high power density, reliable and long life electrical power generation and storage under extreme temperature conditions. Except for electrochemical batteries and solar cells, there are currently no available miniaturized power sources. Conventional power generators devices become inefficient in extreme environments (such as encountered in Mars, Venus or outer planet missions) and rechargeable energy storage devices can only be operated in a narrow temperature range thereby limiting mission duration. The planned development of much smaller spacecrafts incorporating a variety of micro/nanodevices and miniature vehicles will require novel, reliable power technologies. It is also expected that such micro power sources could have a wide range of terrestrial applications, in particular when the limited lifetime and environmental limitations of batteries are key factors. Advanced solid-state thermoelectric combined with radioisotope or waste heat sources and low profile energy storage devices are ideally suited for these applications. The Jet Propulsion Laboratory has been actively pursuing the development of thermoelectric micro/nanodevices that can be fabricated using a combination of electrochemical deposition and integrated circuit processing techniques. Some of the technical challenges associated with these micro/nanodevice concepts, their expected level of performance and experimental fabrication and testing results to date are presented and discussed.

Key issues in space nuclear power challenges for the future

NASA Technical Reports Server (NTRS)

Brandhorst, Henry W., Jr.

1991-01-01

The future appears rich in missions that will extend the frontiers of knowledge, human presence in space, and opportunities for profitable commerce. Key to the success of these ventures is the availability of plentiful, cost effective electric power and assured, low cost access to space. While forecasts of space power needs are problematic, an assessment of future needs based on terrestrial experience has been made. These needs fall into three broad categories: survival, self sufficiency, and industrialization. The cost of delivering payloads to orbital locations from LEO to Mars has been determined and future launch cost reductions projected. From these factors, then, projections of the performance necessary for future solar and nuclear space power options has been made. These goals are largely dependent upon orbital location and energy storage needs. Finally the cost of present space power systems has been determined and projections made for future systems.

Key issues in space nuclear power

NASA Technical Reports Server (NTRS)

Brandhorst, Henry W.

1991-01-01

The future appears rich in missions that will extend the frontiers of knowledge, human presence in space, and opportunities for profitable commerce. Key to the success of these ventures is the availability of plentiful, cost effective electric power and assured, low cost access to space. While forecasts of space power needs are problematic, an assessment of future needs based on terrestrial experience has been made. These needs fall into three broad categories: survival, self sufficiency, and industrialization. The cost of delivering payloads to orbital locations from LEO to Mars has been determined and future launch cost reductions projected. From these factors, then, projections of the performance necessary for future solar and nuclear space power options has been made. These goals are largely dependent upon orbital location and energy storage needs. Finally the cost of present space power systems has been determined and projections made for future systems.

Seismic Hazard to the Diablo Canyon Nuclear Power Plant, Coastal Central California; a Realistic Assessment Needed

NASA Astrophysics Data System (ADS)

Hamilton, D. H.

2014-12-01

SourceURL:file://localhost/Users/joycehamilton/Desktop/Hamilton%20AGU%20abstractREV8-2-14.doc A recent issue of EOS featured the article "Active Faults and Nuclear Power Plants" (Chapman et.al., 2014). Although this article mainly reports on evaluations of fault hazard issues at Japan's Tsuruga NPP, it also includes a section on how the owner of the Diablo Canyon Nuclear Power Plant (DCNPP) in California, Pacific Gas and Electric Company (PG&E), is successfully responding to the evolving needs of seismic hazard assessment for that project. However, a review of the history of such assessment for the DCNPP project reveals a less benign situation, of which there is no hint in the EOS article. This history shows a long term pattern of collaborative efforts by PG&E and its operations and safety regulator, the US NRC, to maintain the operation of DCNPP using stratagems of non-recognition or non-acknowledgment of hazardous conditions, or of minimizing the postulated effects of such conditions by combinations of discovering new means of estimating ever lower levels of potential vibratory ground motions, and feeding the results into logic trees for a PRA which calculates the hazard down to levels acceptable to the NRC for the plant's continued operation. Such a result, however, can be made only if the geologic and seismologic reality of a very high level of seismic hazard to the facility is side stepped, down played, or dismissed. The actual pattern of late Quaternary—including contemporary—tectonism beneath and surrounding the DCNPP site, as shown on a realistic portrayal of geologic structures and active seismicity, is clearly at odds with such a conclusion, and with the statement in the EOS article that PG&E's Long Term Seismic Program "…has provided increased confidence that earthquakes occurring in central California are not likely to produce surprising or conflicting data."

Steady state security assessment in deregulated power systems

NASA Astrophysics Data System (ADS)

Manjure, Durgesh Padmakar

Power system operations are undergoing changes, brought about primarily due to deregulation and subsequent restructuring of the power industry. The primary intention of the introduction of deregulation in power systems was to bring about competition and improved customer focus. The underlying motive was increased economic benefit. Present day power system analysis is much different than what it was earlier, essentially due to the transformation of the power industry from being cost-based to one that is price-based and due to open access of transmission networks to the various market participants. Power is now treated as a commodity and is traded in an open market. The resultant interdependence of the technical criteria and the economic considerations has only accentuated the need for accurate analysis in power systems. The main impetus in security analysis studies is on efficient assessment of the post-contingency status of the system, accuracy being of secondary consideration. In most cases, given the time frame involved, it is not feasible to run a complete AC load flow for determining the post-contingency state of the system. Quite often, it is not warranted as well, as an indication of the state of the system is desired rather than the exact quantification of the various state variables. With the inception of deregulation, transmission networks are subjected to a host of multilateral transactions, which would influence physical system quantities like real power flows, security margins and voltage levels. For efficient asset utilization and maximization of the revenue, more often than not, transmission networks are operated under stressed conditions, close to security limits. Therefore, a quantitative assessment of the extent to which each transaction adversely affects the transmission network is required. This needs to be done accurately as the feasibility of the power transactions and subsequent decisions (execution, curtailment, pricing) would depend upon the outcome of the analysis. Also considering the large number of transactions occurring in the power market, and the massive sizes of transmission networks, the need for efficient analysis techniques is further highlighted. Thus on the whole, for present-day power systems, security assessment has acquired predominant importance. The primary emphasis of the work done in this dissertation is on development of techniques for fast assessment of the state of the transmission network following credible contingencies in traditional and deregulated power systems. In addition, methodologies for optimal correction strategies in the event of violation of security limits are also proposed. The work done can be enumerated as: (1) development of fast methods to assess the state of the transmission network from the point of view of loading margin and power flows, following increased loading conditions and line outages; (2) development of a comprehensive scheme to assess the impact of bilateral transactions on the operating state of the network; (3) optimal rescheduling of generation and curtailable loads for relieving the system of congestion and simultaneously maximizing the security margins.

PFP Emergency Lighting Study

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

BUSCH, M.S.

2000-02-02

NFPA 101, section 5-9 mandates that, where required by building classification, all designated emergency egress routes be provided with adequate emergency lighting in the event of a normal lighting outage. Emergency lighting is to be arranged so that egress routes are illuminated to an average of 1.0 footcandle with a minimum at any point of 0.1 footcandle, as measured at floor level. These levels are permitted to drop to 60% of their original value over the required 90 minute emergency lighting duration after a power outage. The Plutonium Finishing Plant (PFP) has two designations for battery powered egress lights ''Emergencymore » Lights'' are those battery powered lights required by NFPA 101 to provide lighting along officially designated egress routes in those buildings meeting the correct occupancy requirements. Emergency Lights are maintained on a monthly basis by procedure ZSR-12N-001. ''Backup Lights'' are battery powered lights not required by NFPA, but installed in areas where additional light may be needed. The Backup Light locations were identified by PFP Safety and Engineering based on several factors. (1) General occupancy and type of work in the area. Areas occupied briefly during a shiftly surveillance do not require backup lighting while a room occupied fairly frequently or for significant lengths of time will need one or two Backup lights to provide general illumination of the egress points. (2) Complexity of the egress routes. Office spaces with a standard hallway/room configuration will not require Backup Lights while a large room with several subdivisions or irregularly placed rooms, doors, and equipment will require Backup Lights to make egress safer. (3) Reasonable balance between the safety benefits of additional lighting and the man-hours/exposure required for periodic light maintenance. In some plant areas such as building 236-Z, the additional maintenance time and risk of contamination do not warrant having Backup Lights installed in all rooms. Sufficient light for egress is provided by existing lights located in the hallways.« less

Health-Related Physical Fitness, BMI, physical activity and time spent at a computer screen in 6 and 7-year-old children from rural areas in Poland.

PubMed

Cieśla, Elżbieta; Mleczko, Edward; Bergier, Józef; Markowska, Małgorzata; Nowak-Starz, Grażyna

2014-01-01

The objective of the study was determination of the effect of various forms of physical activity, BMI, and time devoted to computer games on the level of Health-Related Physical Fitness (H-RF) in 6-7-year-old children from Polish rural areas. The study covered 25,816 children aged 6-7: 12,693 girls and 13,123 boys. The evaluations included body height and weight, and 4 H-RF fitness components (trunk strength, explosive leg power, arm strength and flexibility). The BMI was calculated for each child. The Questionnaire directed to parents was designed to collect information concerning the time devoted by children to computer games, spontaneous and additional physical activity. The strength of the relationships between dependent and independent variables was determined using the Spearman's rank correlation (RSp), and the relationship by using the regression analysis. The BMI negatively affected the level of all the H-RF components analysed (p=0.000). The negative effect of computer games revealed itself only with respect to flexibility (p=0.000), explosive leg power (p=0.000) and trunk muscle strength (p=0.000). A positive effect of spontaneous activity was observed for flexibility (p=0.047), explosive leg power (p=0.000), and arm strength (p=0.000). Additional activity showed a positive relationship with trunk muscles strength (p=0.000), and explosive leg power (p=0.000). The results of studies suggest that it is necessary to pay attention to the prevention of diseases related with the risk of obesity and overweight among Polish rural children as early as at pre-school age. There is also a need during education for shaping in these children the awareness of concern about own body, and the need for active participation in various forms of physical activity.

A Review of Materials for Gas Turbines Firing Syngas Fuels

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

Gibbons, Thomas; Wright, Ian G

2009-05-01

Following the extensive development work carried out in the 1990's, gas turbine combined-cycle (GTCC) systems burning natural gas represent a reliable and efficient power generation technology widely used in many parts of the world. A critical factor was that, in order to operate at the high turbine entry temperatures required for high efficiency operation, aero-engine technology, i.e., single-crystal blades, thermal barrier coatings, and sophisticated cooling techniques had to be rapidly scaled up and introduced into these large gas turbines. The problems with reliability that resulted have been largely overcome, so that the high-efficiency GTCC power generation system is now amore » mature technology, capable of achieving high levels of availability. The high price of natural gas and concern about emission of greenhouse gases has focused attention on the desirability of replacing natural gas with gas derived from coal (syngas) in these gas turbine systems, since typical systems analyses indicate that IGCC plants have some potential to fulfil the requirement for a zero-emissions power generation system. In this review, the current status of materials for the critical hot gas path parts in large gas turbines is briefly considered in the context of the need to burn syngas. A critical factor is that the syngas is a low-Btu fuel, and the higher mass flow compared to natural gas will tend to increase the power output of the engine. However, modifications to the turbine and to the combustion system also will be necessary. It will be shown that many of the materials used in current engines will also be applicable to units burning syngas but, since the combustion environment will contain a greater level of impurities (especially sulfur, water vapor, and particulates), the durability of some components may be prejudiced. Consequently, some effort will be needed to develop improved coatings to resist attack by sulfur-containing compounds, and also erosion.« less

Integrated Cost Analysis Teams: How ICATs Support Better Buying Power 2.0

DTIC Science & Technology

2014-06-01

and its procuring contracting officer ( PCO ) with a supportable and sustainable starting position for negotiation. The ICAT can deliver full pricing...proposals as well, arming the PCO with an all-encompassing report. Requesting DCMA assistance is straightforward. The cus- tomer receives a proposal in...any level of support needed to assist the PCO . Conversely, if the schedule is the determining factor, the ICAT can tailor the scope to meet the

Greater Commitment Needed to Solve Continuing Problems at Three Mile Island.

DTIC Science & Technology

1981-08-26

respon- sibility for assuring the reliability of electric bulk power supply throughout the United States. The basic authority for Federal regulation of...and support FERC on ratemaking and cost of service matters, (2) intervene in regulatory cases at botn State and Federal levels on national energy policy...of the GPU operating companies. Through the ratemaking process, State regulators may review a utility’s expenses, set the amount of revenues the

Space Shuttle Main Engine Off-Nominal Low Power Level Operation

NASA Technical Reports Server (NTRS)

Bradley, Michael

1997-01-01

This paper describes Rocketdyne's successful analysis and demonstration of the Space Shuttle Main Engine (SSME) operation at off-nominal power levels during Reusable Launch Vehicle (RLV) evaluation tests. The nominal power level range for the SSME is from 65% rated power level (RPL) to 109% RPL. Off-nominal power levels incrementally demonstrated were: 17% RPL, 22% RPL, 27% RPL, 40% RPL, 45% RPL, and 50% RPL. Additional achievements during low power operation included: use of a hydrostatic bearing High Pressure Oxidizer Turbopump (HPOTP), nominal High Pressure Fuel Turbopump (HPFTP) first rotor critical speed operation, combustion stability at low power levels, and refined definition of nozzle flow separation heat loads.

Rapid deceleration mode evaluation

NASA Technical Reports Server (NTRS)

Conners, Timothy R.; Nobbs, Steven G.; Orme, John S.

1995-01-01

Aircraft with flight capability above 1.4 normally have an RPM lockup or similar feature to prevent inlet buzz that would occur at low engine airflows. This RPM lockup has the effect of holding the engine thrust level at the intermediate power (maximum non-afterburning). For aircraft such as military fighters or supersonic transports, the need exists to be able to rapidly slow from supersonic to subsonic speeds. For example, a supersonic transport that experiences a cabin decompression needs to be able to slow/descend rapidly, and this requirement may size the cabin environmental control system. For a fighter, there may be a desire to slow/descend rapidly, and while doing so to minimize fuel usage and engine exhaust temperature. Both of these needs can be aided by achieving the minimum possible overall net propulsive force. As the intermediate power thrust levels of engines increase, it becomes even more difficult to slow rapidly from supersonic speeds. Therefore, a mode of the performance seeking control (PSC) system to minimize overall propulsion system thrust has been developed and tested. The rapid deceleration mode reduces the engine airflow consistent with avoiding inlet buzz. The engine controls are trimmed to minimize the thrust produced by this reduced airflow, and moves the inlet geometry to degrade the inlet performance. As in the case of the other PSC modes, the best overall performance (in this case the least net propulsive force) requires an integrated optimization of inlet, engine, and nozzle variables. This paper presents the predicted and measured results for the supersonic minimum thrust mode, including the overall effects on aircraft deceleration.

7 CFR 1710.101 - Types of eligible borrowers.

Code of Federal Regulations, 2010 CFR

2010-01-01

... provide: (1) The retail electric service needs of rural areas, or (2) The power supply needs of distribution borrowers under the terms of power supply arrangements satisfactory to RUS. (b) In making loans... the power supply borrower and RUS. (d) For the purpose of determining the eligibility of a...

7 CFR 1710.101 - Types of eligible borrowers.

Code of Federal Regulations, 2011 CFR

2011-01-01

... provide: (1) The retail electric service needs of rural areas, or (2) The power supply needs of distribution borrowers under the terms of power supply arrangements satisfactory to RUS. (b) In making loans... the power supply borrower and RUS. (d) For the purpose of determining the eligibility of a...

Orthorectification by Using Gpgpu Method

NASA Astrophysics Data System (ADS)

Sahin, H.; Kulur, S.

2012-07-01

Thanks to the nature of the graphics processing, the newly released products offer highly parallel processing units with high-memory bandwidth and computational power of more than teraflops per second. The modern GPUs are not only powerful graphic engines but also they are high level parallel programmable processors with very fast computing capabilities and high-memory bandwidth speed compared to central processing units (CPU). Data-parallel computations can be shortly described as mapping data elements to parallel processing threads. The rapid development of GPUs programmability and capabilities attracted the attentions of researchers dealing with complex problems which need high level calculations. This interest has revealed the concepts of "General Purpose Computation on Graphics Processing Units (GPGPU)" and "stream processing". The graphic processors are powerful hardware which is really cheap and affordable. So the graphic processors became an alternative to computer processors. The graphic chips which were standard application hardware have been transformed into modern, powerful and programmable processors to meet the overall needs. Especially in recent years, the phenomenon of the usage of graphics processing units in general purpose computation has led the researchers and developers to this point. The biggest problem is that the graphics processing units use different programming models unlike current programming methods. Therefore, an efficient GPU programming requires re-coding of the current program algorithm by considering the limitations and the structure of the graphics hardware. Currently, multi-core processors can not be programmed by using traditional programming methods. Event procedure programming method can not be used for programming the multi-core processors. GPUs are especially effective in finding solution for repetition of the computing steps for many data elements when high accuracy is needed. Thus, it provides the computing process more quickly and accurately. Compared to the GPUs, CPUs which perform just one computing in a time according to the flow control are slower in performance. This structure can be evaluated for various applications of computer technology. In this study covers how general purpose parallel programming and computational power of the GPUs can be used in photogrammetric applications especially direct georeferencing. The direct georeferencing algorithm is coded by using GPGPU method and CUDA (Compute Unified Device Architecture) programming language. Results provided by this method were compared with the traditional CPU programming. In the other application the projective rectification is coded by using GPGPU method and CUDA programming language. Sample images of various sizes, as compared to the results of the program were evaluated. GPGPU method can be used especially in repetition of same computations on highly dense data, thus finding the solution quickly.

Experimental study on parasitic mode suppression using FeSiAl in relativistic klystron amplifier

NASA Astrophysics Data System (ADS)

Zhang, Zehai

2015-03-01

Experimental study of parasitic mode suppression using electromagnetic attenuate material FeSiAl in an S-band Relativistic Klystron Amplifier (RKA) is presented in this paper. The FeSiAl powder is coated and sintered onto the inner surface of a drift tube which locates between the input and the middle cavity of the RKA. Cold tests show that the attenuate rate of the tube against parasitic mode TE11 is about 50%. Experiments carried out on the Torch-01 accelerator present that the tube is effective in suppressing the parasitic mode. Two typical outputs are obtained. When the diode voltage is on a moderate level, the RKA operates well and the parasitic mode is totally suppressed. The pulse length of the High Power Microwave (HPM) almost equals the electron beam pulse length and the HPM average output power is about 300 MW, with a power efficiency of 10%. When the diode voltage is on a higher level, the output power and efficiency rise but the parasitic mode oscillation occurred and the pulse length is shortened. By contrast, the parasitic mode oscillation is too strong for the RKA to operate normally with un-sintered drift tube. The experimental study implies that FeSiAl is effective in suppressing the parasitic mode oscillation in a certain extent. However, total suppression needs a deeper attenuate rate and further investigation.

Experimental study on parasitic mode suppression using FeSiAl in Relativistic Klystron Amplifier.

PubMed

Zhang, Zehai

2015-03-01

Experimental study of parasitic mode suppression using electromagnetic attenuate material FeSiAl in an S-band Relativistic Klystron Amplifier (RKA) is presented in this paper. The FeSiAl powder is coated and sintered onto the inner surface of a drift tube which locates between the input and the middle cavity of the RKA. Cold tests show that the attenuate rate of the tube against parasitic mode TE11 is about 50%. Experiments carried out on the Torch-01 accelerator present that the tube is effective in suppressing the parasitic mode. Two typical outputs are obtained. When the diode voltage is on a moderate level, the RKA operates well and the parasitic mode is totally suppressed. The pulse length of the High Power Microwave (HPM) almost equals the electron beam pulse length and the HPM average output power is about 300 MW, with a power efficiency of 10%. When the diode voltage is on a higher level, the output power and efficiency rise but the parasitic mode oscillation occurred and the pulse length is shortened. By contrast, the parasitic mode oscillation is too strong for the RKA to operate normally with un-sintered drift tube. The experimental study implies that FeSiAl is effective in suppressing the parasitic mode oscillation in a certain extent. However, total suppression needs a deeper attenuate rate and further investigation.

Using the sound of nuclear energy

DOE PAGES

Garrett, Steven; Smith, James; Smith, Robert; ...

2016-08-01

The generation of sound by heat has been documented as an “acoustical curiosity” since a Buddhist monk reported the loud tone generated by a ceremonial rice-cooker in his diary, in 1568. Over the last four decades, significant progress has been made in understanding “thermoacoustic processes,” enabling the design of thermoacoustic engines and refrigerators. Motivated by the Fukushima nuclear reactor disaster, we have developed and tested a thermoacoustic engine that exploits the energy-rich conditions in the core of a nuclear reactor to provide core condition information to the operators without a need for external electrical power. The heat engine is self-poweredmore » and can wirelessly transmit the temperature and reactor power level by generation of a pure tone which can be detected outside the reactor. We report here the first use of a fission-powered thermoacoustic engine capable of serving as a performance and safety sensor in the core of a research reactor and present data from the hydrophones in the coolant (far from the core) and an accelerometer attached to a structure outside the reactor. These measurements confirmed that the frequency of the sound produced indicates the reactor’s coolant temperature and that the amplitude (above an onset threshold) is related to the reactor’s operating power level. Furthermore, these signals can be detected even in the presence of substantial background noise generated by the reactor’s fluid pumps.« less

Using the sound of nuclear energy

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

Garrett, Steven; Smith, James; Smith, Robert

The generation of sound by heat has been documented as an “acoustical curiosity” since a Buddhist monk reported the loud tone generated by a ceremonial rice-cooker in his diary, in 1568. Over the last four decades, significant progress has been made in understanding “thermoacoustic processes,” enabling the design of thermoacoustic engines and refrigerators. Motivated by the Fukushima nuclear reactor disaster, we have developed and tested a thermoacoustic engine that exploits the energy-rich conditions in the core of a nuclear reactor to provide core condition information to the operators without a need for external electrical power. The heat engine is self-poweredmore » and can wirelessly transmit the temperature and reactor power level by generation of a pure tone which can be detected outside the reactor. We report here the first use of a fission-powered thermoacoustic engine capable of serving as a performance and safety sensor in the core of a research reactor and present data from the hydrophones in the coolant (far from the core) and an accelerometer attached to a structure outside the reactor. These measurements confirmed that the frequency of the sound produced indicates the reactor’s coolant temperature and that the amplitude (above an onset threshold) is related to the reactor’s operating power level. Furthermore, these signals can be detected even in the presence of substantial background noise generated by the reactor’s fluid pumps.« less

Development of micro-heaters with optimized temperature compensation design for gas sensors.

PubMed

Hwang, Woo-Jin; Shin, Kyu-Sik; Roh, Ji-Hyoung; Lee, Dae-Sung; Choa, Sung-Hoon

2011-01-01

One of the key components of a chemical gas sensor is a MEMS micro-heater. Micro-heaters are used in both semiconductor gas sensors and NDIR gas sensors; however they each require different heat dissipation characteristics. For the semiconductor gas sensors, a uniform temperature is required over a wide area of the heater. On the other hand, for the NDIR gas sensor, the micro-heater needs high levels of infrared radiation in order to increase sensitivity. In this study, a novel design of a poly-Si micro-heater is proposed to improve the uniformity of heat dissipation on the heating plate. Temperature uniformity of the micro-heater is achieved by compensating for the variation in power consumption around the perimeter of the heater. With the power compensated design, the uniform heating area is increased by 2.5 times and the average temperature goes up by 40 °C. Therefore, this power compensated micro-heater design is suitable for a semiconductor gas sensor. Meanwhile, the poly-Si micro-heater without compensation shows a higher level of infrared radiation under equal power consumption conditions. This indicates that the micro-heater without compensation is more suitable for a NDIR gas sensor. Furthermore, the micro-heater shows a short response time of less than 20 ms, indicating a very high efficiency of pulse driving.

Induction Bonding of Prepreg Tape and Titanium Foil

NASA Technical Reports Server (NTRS)

Messier, Bernadette C.; Hinkley, Jeffrey A.; Johnston, Norman J.

1998-01-01

Hybrid structural laminates made of titanium foil and carbon fiber reinforced polymer composite offer a potential for improved performance in aircraft structural applications. To obtain information needed for the automated fabrication of hybrid laminates, a series of bench scale tests were conducted of the magnetic induction bonding of titanium foil and thermoplastic prepreg tape. Foil and prepreg specimens were placed in the gap of a toroid magnet mounted in a bench press. Several magnet power supplies were used to study power at levels from 0.5 to 1.75 kW and frequencies from 50 to 120 kHz. Sol-gel surface-treated titanium foil, 0.0125 cm thick, and PIXA/IM7 prepreg tape were used in several lay-up configurations. Data were obtained on wedge peel bond strength, heating rate, and temperature ramp over a range of magnet power levels and frequencies at different "power-on" times for several magnet gap dimensions. These data will be utilized in assessing the potential for automated processing. Peel strengths of foil-tape bonds depended on the maximum temperature reached during heating and on the applied pressure. Maximum peel strengths were achieved at 1.25kW and 8OkHz. Induction heating of the foil appears to be capable of good bonding up to 10 plies of tape. Heat transfer calculations indicate that a 20-40 C temperature difference exists across the tape thickness during heat-up.

Space power technology 21: Photovoltaics

NASA Astrophysics Data System (ADS)

Wise, Joseph

1989-04-01

The Space Power needs for the 21st Century and the program in photovoltaics needed to achieve it are discussed. Workshops were conducted in eight different power disciplines involving industry and other government agencies. The Photovoltaics Workshop was conducted at Aerospace Corporation in June 1987. The major findings and recommended program from this workshop are discussed. The major finding is that a survivable solar power capability is needed in photovoltaics for critical Department of Defense missions including Air Force and Strategic Defense Initiative. The tasks needed to realize this capability are described in technical, not financial, terms. The second finding is the need for lightweight, moderately survivable planar solar arrays. High efficiency thin III-V solar cells can meet some of these requirements. Higher efficiency, longer life solar cells are needed for application to both future planar and concentrator arrays with usable life up to 10 years. Increasing threats are also anticipated and means for avoiding prolonged exposure, retraction, maneuvering and autonomous operation are discussed.

The generic task toolset: High level languages for the construction of planning and problem solving systems

NASA Technical Reports Server (NTRS)

Chandrasekaran, B.; Josephson, J.; Herman, D.

1987-01-01

The current generation of languages for the construction of knowledge-based systems as being at too low a level of abstraction is criticized, and the need for higher level languages for building problem solving systems is advanced. A notion of generic information processing tasks in knowledge-based problem solving is introduced. A toolset which can be used to build expert systems in a way that enhances intelligibility and productivity in knowledge acquistion and system construction is described. The power of these ideas is illustrated by paying special attention to a high level language called DSPL. A description is given of how it was used in the construction of a system called MPA, which assists with planning in the domain of offensive counter air missions.

Motivational profiles of retired cosmonauts

NASA Astrophysics Data System (ADS)

Suedfeld, Peter; Johnson, Phyllis J.; Gushin, Vadim; Brcic, Jelena

2018-05-01

Motivational patterns have been shown to be related to outcomes such as occupational success and satisfaction, innovation, aggressiveness, cooperation, and conformity. They are likely to be important in adaptation to the demands of flying in a space crew. Autobiographical interviews with 20 retired long-duration male cosmonauts were scored for references to three core motives: the needs for Achievement, Power, and Affiliation. Overall, the cosmonauts mentioned need for Affiliation most often, followed by need for Achievement, with need for Power the least frequently mentioned. However, need for Power increased between reminiscences of one's pre-flight career to those concerning the in-flight and post-flight periods. Imagery related to both other needs decreased. Cosmonauts who had spent less than a year in space mentioned need for Achievement significantly more frequently than those who had spent more than a year. Other space-experience and demographic variables, and changes across pairs of career phases, were not significant. The high scores for need for Affiliation indicate the importance of selecting compatible teams and fostering friendship and cooperation during training and deployment. A relatively flat hierarchical organization would be harmonious with low Power motivation; but the increase during missions indicates a desire for autonomy. After retirement from spaceflight, former space crews should be afforded opportunities for leadership and decision-making to satisfy continuing need for Power. Comparison is made to the same measures applied to a sample of ISS crewmembers, and to the ISS vs. veteran data for 8 cosmonauts who were included in both sets of data.

Analysis of power gating in different hierarchical levels of 2MB cache, considering variation

NASA Astrophysics Data System (ADS)

Jafari, Mohsen; Imani, Mohsen; Fathipour, Morteza

2015-09-01

This article reintroduces power gating technique in different hierarchical levels of static random-access memory (SRAM) design including cell, row, bank and entire cache memory in 16 nm Fin field effect transistor. Different structures of SRAM cells such as 6T, 8T, 9T and 10T are used in design of 2MB cache memory. The power reduction of the entire cache memory employing cell-level optimisation is 99.7% with the expense of area and other stability overheads. The power saving of the cell-level optimisation is 3× (1.2×) higher than power gating in cache (bank) level due to its superior selectivity. The access delay times are allowed to increase by 4% in the same energy delay product to achieve the best power reduction for each supply voltages and optimisation levels. The results show the row-level power gating is the best for optimising the power of the entire cache with lowest drawbacks. Comparisons of cells show that the cells whose bodies have higher power consumption are the best candidates for power gating technique in row-level optimisation. The technique has the lowest percentage of saving in minimum energy point (MEP) of the design. The power gating also improves the variation of power in all structures by at least 70%.

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

Adaptation and Re-Use of Spacecraft Power System Models for the Constellation Program

NASA Technical Reports Server (NTRS)

Hojnicki, Jeffrey S.; Kerslake, Thomas W.; Ayres, Mark; Han, Augustina H.; Adamson, Adrian M.

2008-01-01

NASA's Constellation Program is embarking on a new era of space exploration, returning to the Moon and beyond. The Constellation architecture will consist of a number of new spacecraft elements, including the Orion crew exploration vehicle, the Altair lunar lander, and the Ares family of launch vehicles. Each of these new spacecraft elements will need an electric power system, and those power systems will need to be designed to fulfill unique mission objectives and to survive the unique environments encountered on a lunar exploration mission. As with any new spacecraft power system development, preliminary design work will rely heavily on analysis to select the proper power technologies, size the power system components, and predict the system performance throughout the required mission profile. Constellation projects have the advantage of leveraging power system modeling developments from other recent programs such as the International Space Station (ISS) and the Mars Exploration Program. These programs have developed mature power system modeling tools, which can be quickly modified to meet the unique needs of Constellation, and thus provide a rapid capability for detailed power system modeling that otherwise would not exist.

Infrastructure for thulium-170 isotope power systems for autonomous underwater vehicle fleets

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

Walter, C.E.

1991-07-01

The radioisotope thulium-170 is a safe and environmentally benign heat source for providing the high endurance and energy densities needed by advanced power systems for autonomous underwater vehicles (AUV). Thulium Isotope Power (TIP) systems have an endurance of {approximately}3000 h, and gravimetric and volumetric energy densities of 3 {times} 10{sup 4} Wh/kg and 3 {times} 10{sup 8} Wh/m{sup 3}, respectively. These energy densities are more than 200 times higher than those currently provided by Ag-Zn battery technology. In order to capitalize on these performance levels with about one hundred AUVs in continuous use, it will be necessary to establish anmore » infrastructure for isotope production and heat-source refurbishment. The infrastructure cost is not trivial, and studies are needed to determine its optimum configuration. The major component of the projected infrastructure is the nuclear reactor used to produce Tm- 170 by neutron absorption in Tm-169. The reactor design should ideally be optimized for TM-170 production. Using the byproduct waste'' heat beneficially would help defray the cost of isotope production. However, generating electric power with the reactor would compromise both the cost of electricity and the isotope production capacity. A coastal location for the reactor would be most convenient from end-use considerations, and the waste'' heat could be used to desalinate seawater in water-thirsty states. 13 refs., 6 figs., 2 tabs.« less

The Abacus/Reflector and Integrated Symmetrical Concentrator: Concepts for Space Solar Power Collection and Transmission

NASA Technical Reports Server (NTRS)

Carrington, Connie; Fikes, John; Gerry, Mark; Perkinson, Don

2000-01-01

New energy sources are vital for the development of emerging nations, and the growth of industry in developed economies. Also vital is the need for these energy sources to be clean and renewable. For the past several years, NASA has been taking a new look at collecting solar energy in space and transmitting it to Earth, to planetary surfaces, and to orbiting spacecraft. Several innovative concepts are being studied for the space segment component of solar power beaming. One is the Abacus/Reflector, a large sun-oriented array structure fixed to the transmitter, and a rotating RF reflector that tracks a receiving rectenna on Earth. This concept eliminates the need for power-conducting slip rings in rotating joints between the solar collectors and the transmitter. Another concept is the Integrated Symmetrical Concentrator (ISC), composed of two very large segmented reflectors which rotate to collect and reflect the incident sunlight onto two centrally-located photovoltaic arrays. Adjacent to the PV arrays is the RF transmitter, which as a unit track the receiving rectenna, again eliminating power-conducting joints, and in addition reducing the cable lengths between the arrays and transmitter. The metering structure to maintain the position of the reflectors is a long mast, oriented perpendicular to the equatorial orbit plane. This paper presents a status of ongoing systems studies and configurations for the Abacus/Reflector and the ISC concepts, and a top-level study of packaging for launch and assembly.

A HUMAN AUTOMATION INTERACTION CONCEPT FOR A SMALL MODULAR REACTOR CONTROL ROOM

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

Le Blanc, Katya; Spielman, Zach; Hill, Rachael

Many advanced nuclear power plant (NPP) designs incorporate higher degrees of automation than the existing fleet of NPPs. Automation is being introduced or proposed in NPPs through a wide variety of systems and technologies, such as advanced displays, computer-based procedures, advanced alarm systems, and computerized operator support systems. Additionally, many new reactor concepts, both full scale and small modular reactors, are proposing increased automation and reduced staffing as part of their concept of operations. However, research consistently finds that there is a fundamental tradeoff between system performance with increased automation and reduced human performance. There is a need to addressmore » the question of how to achieve high performance and efficiency of high levels of automation without degrading human performance. One example of a new NPP concept that will utilize greater degrees of automation is the SMR concept from NuScale Power. The NuScale Power design requires 12 modular units to be operated in one single control room, which leads to a need for higher degrees of automation in the control room. Idaho National Laboratory (INL) researchers and NuScale Power human factors and operations staff are working on a collaborative project to address the human performance challenges of increased automation and to determine the principles that lead to optimal performance in highly automated systems. This paper will describe this concept in detail and will describe an experimental test of the concept. The benefits and challenges of the approach will be discussed.« less

Testing in Support of Fission Surface Power System Qualification

NASA Technical Reports Server (NTRS)

Houts, Mike; Bragg-Sitton, Shannon; Godfroy, Tom; Martin, Jim; Pearson, Boise; VanDyke, Melissa

2007-01-01

The strategy for qualifying a FSP system could have a significant programmatic impact. The US has not qualified a space fission power system since launch of the SNAP-10A in 1965. This paper explores cost-effective options for obtaining data that would be needed for flight qualification of a fission system. Qualification data could be obtained from both nuclear and non-nuclear testing. The ability to perform highly realistic nonnuclear testing has advanced significantly throughout the past four decades. Instrumented thermal simulators were developed during the 1970s and 1980s to assist in the development, operation, and assessment of terrestrial fission systems. Instrumented thermal simulators optimized for assisting in the development, operation, and assessment of modern FSP systems have been under development (and utilized) since 1998. These thermal simulators enable heat from fission to be closely mimicked (axial power profile, radial power profile, temperature, heat flux, etc.) and extensive data to be taken from the core region. For transient testing, pin power during a transient is calculated based on the reactivity feedback that would occur given measured values of test article temperature and/or dimensional changes. The reactivity feedback coefficients needed for the test are either calculated or measured using cold/warm zero-power criticals. In this way non-nuclear testing can be used to provide very realistic information related to nuclear operation. Non-nuclear testing can be used at all levels, including component, subsystem, and integrated system testing. FSP fuels and materials are typically chosen to ensure very high confidence in operation at design burnups, fluences, and temperatures. However, facilities exist (e.g. ATR, HFIR) for affordably performing in-pile fuel and materials irradiations, if such testing is desired. Ex-core materials and components (such as alternator materials, control drum drives, etc.) could be irradiated in university or DOE reactors to ensure adequate radiation resistance. Facilities also exist for performing warm and cold zero-power criticals.

Solar Flight on Mars and Venus

NASA Technical Reports Server (NTRS)

Landis, Geoffrey A.; LaMarre, Christopher; Colozza, Anthony

2002-01-01

Solar powered aircraft are of interest for exploring both Mars and Venus. The thin atmosphere of Mars presents a difficult environment for flying. It is clear that a new approach is needed. By making a totally solar airplane, we can eliminate many of the heavy components, and make an airplane that can fly without fuel. Using high efficiency solar cells, we can succeed with an airplane design that can fly for up to 6 hours in near-equatorial regions of Mars (4 hours of level flight, plus two hours of slow descent), and potentially fly for many days in the polar regions. By designing an airplane for a single day flight. In particular, this change means that we no longer have to cope with the weight of the energy storage system that made previous solar powered airplanes for Mars impractical). The new airplane concept is designed to fly only under the optimal conditions: near equatorial flight, at the subsolar point, near noon. We baseline an 8 kg airplane, with 2 kg margin. Science instruments will be selected with the primary criterion of low mass. Solar-powered aircraft are also quite interesting for the exploration of Venus. Venus provides several advantages for flying a solar-powered aircraft. At the top of the cloud level, the solar intensity is comparable to or greater than terrestrial solar intensities. The atmospheric pressure makes flight much easier than on planets such as Mars. The atmospheric pressure on Venus is presented. From an altitude of approximately 45 km (pressure = 2 bar), to approximately 60 km (pressure = 0.2 bar), terrestrial airplane experience can be easily applied to a Venus airplane design. At these flight altitudes, the temperature varies from 80 C at 45 km, decreasing to -35 C at 60 km. Also, the slow rotation of Venus allows an airplane to be designed for flight within continuous sunlight, eliminating the need for energy storage for nighttime flight. These factors make Venus a prime choice for a long-duration solar-powered aircraft. Fleets of solar-powered aircraft could provide an architecture for efficient and low-cost comprehensive coverage for a variety of scientific missions. Exploratory planetary mapping and atmospheric sampling can lead to a greater understanding of the greenhouse effect not only on Venus but on Earth as well.

Simulation and Performance Analysis of Lithium Battery Bank Mounted on the Hybrid Power System for Mobile Public Health Center

NASA Astrophysics Data System (ADS)

Busono, Pratondo; Kartini, Evvy

2013-07-01

Mobile medical clinic has been proposed to serve homeless people, people in the disaster area or in the remote area where no health service exist. At that site, a number of essential services such as primary health care, general health screening, medical treatment and emergency/rescue operations are required. Such services usually requires on board electrical equipments such as refrigerators, komputer, power tools and medical equipments. To supply such electrical equipments, it needs extra auxiliary power sources, in addition of standard automotive power supply. The auxiliary power source specifically design to supply non automotive load which may have similar configuration, but usually uses high power alternator rated and larger deep cycle on board battery bank. This study covers the modeling and dynamic simulation of auxiliary power source/battery to supply the medical equipment and other electrical equipments on board. It consists a variable speed diesel generator set, photovoltaic (PV) generator mounted on the roof of the car, a rechargable battery bank. As an initial step in the system design, a simulation study was performed. The simulation is conducted in the system level. Simulation results shows that dynamical behaviour by means of current density, voltage and power plot over a chosen time range, and functional behaviour such as charging and discharging characteristic of the battery bank can be obtained.

A space-to-space microwave wireless power transmission experiential mission using small satellites

NASA Astrophysics Data System (ADS)

Bergsrud, Corey; Straub, Jeremy

2014-10-01

A space solar microwave power transfer system (SSMPTS) may represent a paradigm shift to how space missions in Earth orbit are designed. A SSMPTS may allow a smaller receiving surface to be utilized on the receiving craft due to the higher-density power transfer (compared to direct solar flux) from a SSMPTS supplier craft; the receiving system is also more efficient and requires less mass and volume. The SSMPTS approach also increases mission lifetime, as antenna systems do not degrade nearly as quickly as solar panels. The SSMPTS supplier craft (instead) can be replaced as its solar panels degrade, a mechanism for replacing panels can be utilized or the SSMPTS can be maneuvered closer to a subset of consumer spacecraft. SSMPTS can also be utilized to supply power to spacecraft in eclipse and to supply variable amounts of power, based on current mission needs, to power the craft or augment other power systems. A minimal level of orbital demonstrations of SSP technologies have occurred. A mission is planned to demonstrate and characterize the efficacy of space-to-space microwave wireless power transfer. This paper presents an overview of this prospective mission. It then discusses the spacecraft system (comprised of an ESPA/SmallSat-class spacecraft and a 1-U CubeSat), launch options, mission operations and the process of evaluating mission outcomes.

Magnetic storm effects in electric power systems and prediction needs

NASA Technical Reports Server (NTRS)

Albertson, V. D.; Kappenman, J. G.

1979-01-01

Geomagnetic field fluctuations produce spurious currents in electric power systems. These currents enter and exit through points remote from each other. The fundamental period of these currents is on the order of several minutes which is quasi-dc compared to the normal 60 Hz or 50 Hz power system frequency. Nearly all of the power systems problems caused by the geomagnetically induced currents result from the half-cycle saturation of power transformers due to simultaneous ac and dc excitation. The effects produced in power systems are presented, current research activity is discussed, and magnetic storm prediction needs of the power industry are listed.

Application of photovoltaic electric power to the rural education/communication needs of developing countries

NASA Technical Reports Server (NTRS)

Cabraal, A.; Delansanta, D.; Burrill, G.

1982-01-01

The suitability (i.e., cost competitiveness and reliability) of photovoltaic (PV) power systems for rural applications in developing countries is considered. Potential application sectors include health delivery, education and communication where small amounts of electricity are needed to meet critical needs.

Challenges for future space power systems

NASA Technical Reports Server (NTRS)

Brandhorst, Henry W., Jr.

1989-01-01

The future appears rich in missions that will extend the frontiers of knowledge, human presence in space, and opportunities for profitable commerce. The key to success of these ventures is the availability of plentiful, cost effective electric power and assured, low cost access to space. While forecasts of space power needs are problematic, an assessment of future needs based on terrestrial experience was made. These needs fall into three broad categories-survival, self sufficiency and industrialization. The cost of delivering payloads to orbital locations from low earth orbit (LEO) to Mars was determined and future launch cost reductions projected. From these factors, then, projections of the performance necessary for future solar and nuclear space power options were made. These goals are largely dependent upon orbital location and energy storage needs.

The history, genotoxicity and carcinogenicity of carbon-based fuels and their emissions: part 4 - alternative fuels.

PubMed

Claxton, Larry D

2015-01-01

Much progress has been made in reducing the pollutants emitted from various combustors (including diesel engines and power plants) by the use of alternative fuels; however, much more progress is needed. Not only must researchers improve fuels and combustors, but also there is a need to improve the toxicology testing and analytical chemistry methods associated with these complex mixtures. Emissions from many alternative carbonaceous fuels are mutagenic and carcinogenic. Depending on their source and derivation, alternative carbonaceous fuels before combustion may or may not be genotoxic; however, in order to know their genotoxicity, appropriate chemical analysis and/or bioassay must be performed. Newly developed fuels and combustors must be tested to determine if they provide a public health advantage over existing technologies - including what tradeoffs can be expected (e.g., decreasing levels of PAHs versus increasing levels of NOx and possibly nitroarenes in ambient air). Another need is to improve exposure estimations which presently are a weak link in doing risk analyses. Copyright © 2014 Elsevier B.V. All rights reserved.

The Environmental Impact of Electrical Power Generation: Nuclear and Fossil.

ERIC Educational Resources Information Center

Pennsylvania State Dept. of Education, Harrisburg.

This text was written to accompany a course concerning the need, environmental costs, and benefits of electrical power generation. It was compiled and written by a committee drawn from educators, health physicists, members of industry and conservation groups, and environmental scientists. Topics include: the increasing need for electrical power,…