Analysis of impact of “strong DC and weak AC” on receiving-end power system

NASA Astrophysics Data System (ADS)

Wang, Qiang; Li, Tianran; Yang, Pengcheng

2018-02-01

The rapid development of UHVDC transmission project has brought abundant power supply to the receiving-end power system area, but also many security and stability problems. This paper summarizes four elements that affect the strength of AC system, and then simulates the most basic two-terminal single-pole UHV transmission system by MATLAB/Simulink. It analyses the impact of receiving-end AC power system strength on real-time power, frequency and voltage. Finally, in view of operation risk of “strong DC and weak AC”, this paper puts forward three countermeasures.

Analysis of chaos in high-dimensional wind power system.

PubMed

Wang, Cong; Zhang, Hongli; Fan, Wenhui; Ma, Ping

2018-01-01

A comprehensive analysis on the chaos of a high-dimensional wind power system is performed in this study. A high-dimensional wind power system is more complex than most power systems. An 11-dimensional wind power system proposed by Huang, which has not been analyzed in previous studies, is investigated. When the systems are affected by external disturbances including single parameter and periodic disturbance, or its parameters changed, chaotic dynamics of the wind power system is analyzed and chaotic parameters ranges are obtained. Chaos existence is confirmed by calculation and analysis of all state variables' Lyapunov exponents and the state variable sequence diagram. Theoretical analysis and numerical simulations show that the wind power system chaos will occur when parameter variations and external disturbances change to a certain degree.

Active Power Control by Wind Power | Grid Modernization | NREL

Science.gov Websites

of conventional generators. How this will affect the system at different wind power penetration levels is not well understood. To gain insight, NREL researchers conducted simulations of different

Grid-connected wind and photovoltaic system

NASA Astrophysics Data System (ADS)

Devabakthuni, Sindhuja

The objective of this thesis is to design a grid connected wind and photovoltaic system. A new model of converter control was designed which maintains the voltage of the bus to grid as constant when combined system of solar and wind is connected to AC bus. The model is designed to track maximum power at each point irrespective of changes in irradiance, temperature and wind speed which affects the power supplied to grid. Solar power from the sun is not constant as it is affected by changes in irradiances and temperature. Even the wind power is affected by wind speed. A MPPT controller was designed for both systems. A boost converter is designed which uses the pulses from MPPT controller to boost the output. Wind system consists of wind turbine block from the MATLAB with a pitch angle controller to maintain optimum pitch angle. The output from wind turbine is connected to a permanent magnet synchronous generator. The unregulated DC output from the photovoltaic system is directly given to boost converter. The AC output from the wind system is given to an uncontrolled rectifier to get a unregulated DC output. The unregulated DC output goes to the boost converter. A voltage source inverter was designed which converts the rectified DC output from the boost converter to AC power. The inverter is designed to maintain constant AC bus voltage irrespective of the disturbances in the power supply. Photovoltaic and wind systems are individually designed for 5KW each in MATLAB-Simulink environment. In this thesis, the models were subjected to changes in irradiance, temperature and wind speed and the results were interpreted. The model was successful in tracking maximum at every instant and the AC bus voltage was maintained constant throughout the simulation.

The wind power prediction research based on mind evolutionary algorithm

NASA Astrophysics Data System (ADS)

Zhuang, Ling; Zhao, Xinjian; Ji, Tianming; Miao, Jingwen; Cui, Haina

2018-04-01

When the wind power is connected to the power grid, its characteristics of fluctuation, intermittent and randomness will affect the stability of the power system. The wind power prediction can guarantee the power quality and reduce the operating cost of power system. There were some limitations in several traditional wind power prediction methods. On the basis, the wind power prediction method based on Mind Evolutionary Algorithm (MEA) is put forward and a prediction model is provided. The experimental results demonstrate that MEA performs efficiently in term of the wind power prediction. The MEA method has broad prospect of engineering application.

Power-law Exponent in Multiplicative Langevin Equation with Temporally Correlated Noise

NASA Astrophysics Data System (ADS)

Morita, Satoru

2018-05-01

Power-law distributions are ubiquitous in nature. Random multiplicative processes are a basic model for the generation of power-law distributions. For discrete-time systems, the power-law exponent is known to decrease as the autocorrelation time of the multiplier increases. However, for continuous-time systems, it is not yet clear how the temporal correlation affects the power-law behavior. Herein, we analytically investigated a multiplicative Langevin equation with colored noise. We show that the power-law exponent depends on the details of the multiplicative noise, in contrast to the case of discrete-time systems.

Analysis of economic benefit of wind power based on system dynamics

NASA Astrophysics Data System (ADS)

Zhao, Weibo; Han, Yaru; Niu, Dongxiao

2018-04-01

The scale of renewable power generation, such as wind power, has increased gradually in recent years. Considering that the economic benefits of wind farms are affected by many dynamic factors. The dynamic simulation model of wind power economic benefit system is established based on the system dynamics method. By comparing the economic benefits of wind farms under different setting scenarios through this model, the impact of different factors on the economic benefits of wind farms can be reflected.

Design of a hybrid power system based on solar cell and vibration energy harvester

NASA Astrophysics Data System (ADS)

Zhang, Bin; Li, Mingxue; Zhong, Shaoxuan; He, Zhichao; Zhang, Yufeng

2018-03-01

Power source has become a serious restriction of wireless sensor network. High efficiency, self-energized and long-life renewable source is the optimum solution for unmanned sensor network applications. However, single renewable power source can be easily affected by ambient environment, which influences stability of the system. In this work, a hybrid power system consists of a solar panel, a vibration energy harvester and a lithium battery is demonstrated. The system is able to harvest multiple types of ambient energy, which extends its applicability and feasibility. Experiments have been conducted to verify performance of the system.

Evaluation of Potential Energy Loss Reduction and Savings for U. S. Army Electrical Distribution Systems

DTIC Science & Technology

1993-09-01

Different Size Transformers (Per Transformer ) 41 15 Additional Energy Losses for Mis-Sized Transformers (Per Transformer ) 42 16 Power System ...directly affects the amount of neutral line power loss in the system . Since most Army three-phase loads are distribution transformers spread out over a...61 Balancing Three-Phase Loads Balancing Feeder Circuit Loads Power Factor Correction Optimal Transformer Sizing Conductor Sizing Combined

Assessment of economic factors affecting the satellite power system. Volume 2: The systems implications of rectenna siting issues

NASA Technical Reports Server (NTRS)

Chapman, P. K.; Bugos, B. J.; Csigi, K. I.; Glaser, P. E.; Schimke, G. R.; Thomas, R. G.

1979-01-01

The feasibility was evaluated of finding potential sites for Solar Power Satellite (SPS) receiving antennas (rectennas) in the continental United States, in sufficient numbers to permit the SPS to make a major contribution to U.S. generating facilities, and to give statistical validity to an assessment of the characteristics of such sites and their implications for the design of the SPS system. It is found that the cost-optimum power output of the SPS does not depend on the particular value assigned to the cost per unit area of a rectenna and its site, as long as it is independent of rectenna area. Many characteristics of the sites chosen affect the optimum design of the rectenna itself.

Fault diagnosis of power transformer based on fault-tree analysis (FTA)

NASA Astrophysics Data System (ADS)

Wang, Yongliang; Li, Xiaoqiang; Ma, Jianwei; Li, SuoYu

2017-05-01

Power transformers is an important equipment in power plants and substations, power distribution transmission link is made an important hub of power systems. Its performance directly affects the quality and health of the power system reliability and stability. This paper summarizes the five parts according to the fault type power transformers, then from the time dimension divided into three stages of power transformer fault, use DGA routine analysis and infrared diagnostics criterion set power transformer running state, finally, according to the needs of power transformer fault diagnosis, by the general to the section by stepwise refinement of dendritic tree constructed power transformer fault

Issues and status of power distribution options for space exploration

NASA Technical Reports Server (NTRS)

Bercaw, Robert W.; Cull, Ronald C.; Kenny, Barbara H.

1991-01-01

The Space Exploration Initiative (SEI) will need a wide variety of manned systems with requirements significantly different than those for existing systems. The concept of a space power utility is discussed and the impact of this concept on the engineering of space power systems is examined. Almost all existing space power systems use low voltage direct current. Although they have been very succesful, increasing power system requirements in recent years have exposed their inherent limitations and led to the proposal of a number of alternatives including high voltage DC and AC at various frequencies. Drawing on the experience gained from Space Station Freedom and SEI systems studies, factors that may affect the choice of frequency standards on which to build such a space power utility are discussed.

The Principle and the Application of Self-cleaning Anti-pollution Coating in Power System

NASA Astrophysics Data System (ADS)

Zhao, Y. J.; Zhang, Z. B.; Liu, Y.; Wang, J. H.; Teng, J. L.; Wu, L. S.; Zhang, Y. L.

2017-11-01

The common problem existed in power system is analyzed in this paper. The main reason for the affection of the safe and stable operation to power equipment is flash-over caused by dirt and discharge. Using the self-cleaning anti-pollution coating in the power equipment surface is the key to solve the problem. In the work, the research progress and design principle about the self-cleaning anti-pollution coating was summarized. Furthermore, the preparation technology was also studied. Finally, the application prospect of hard self-cleaning anti-pollution coating in power system was forecast.

Qualitative Description of Electric Power System Future States

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

Hardy, Trevor D.; Corbin, Charles D.

The simulation and evaluation of transactive systems depends to a large extent on the context in which those efforts are performed. Assumptions regarding the composition of the electric power system, the regulatory and policy environment, the distribution of renewable and other distributed energy resources (DERs), technological advances, and consumer engagement all contribute to, and affect, the evaluation of any given transactive system, regardless of its design. It is our position that the assumptions made about the state of the future power grid will determine, to some extent, the systems ultimately deployed, and that the transactive system itself may play anmore » important role in the evolution of the power system.« less

EMC and power quality standards for 20-kHz power distribution

NASA Technical Reports Server (NTRS)

Hansen, Irving G.

1987-01-01

The Space Station Power Distribution System has been baselined as a sinusoidal single phase, 440 VRMS system. This system has certain unique characteristics directly affecting its application. In particular, existing systematic description and control documents were modified to reflect the high operating frequency. This paper will discuss amendments made on Mil STD 704 (Electrical Power Characteristics), and Mil STD 461-B (Electromagnetic Emission and Susceptibility Requirements for the Control of Electromagnetic Interference). In some cases these amendments reflect changes of several orders of magnitude. Implications and impacts of these changes are discussed.

The Role of Demand Response in Reducing Water-Related Power Plant Vulnerabilities

NASA Astrophysics Data System (ADS)

Macknick, J.; Brinkman, G.; Zhou, E.; O'Connell, M.; Newmark, R. L.; Miara, A.; Cohen, S. M.

2015-12-01

The electric sector depends on readily available water supplies for reliable and efficient operation. Elevated water temperatures or low water levels can trigger regulatory or plant-level decisions to curtail power generation, which can affect system cost and reliability. In the past decade, dozens of power plants in the U.S. have curtailed generation due to water temperatures and water shortages. Curtailments occur during the summer, when temperatures are highest and there is greatest demand for electricity. Climate change could alter the availability and temperature of water resources, exacerbating these issues. Constructing alternative cooling systems to address vulnerabilities can be capital intensive and can also affect power plant efficiencies. Demand response programs are being implemented by electric system planners and operators to reduce and shift electricity demands from peak usage periods to other times of the day. Demand response programs can also play a role in reducing water-related power sector vulnerabilities during summer months. Traditionally, production cost modeling and demand response analyses do not include water resources. In this effort, we integrate an electricity production cost modeling framework with water-related impacts on power plants in a test system to evaluate the impacts of demand response measures on power system costs and reliability. Specifically, we i) quantify the cost and reliability implications of incorporating water resources into production cost modeling, ii) evaluate the impacts of demand response measures on reducing system costs and vulnerabilities, and iii) consider sensitivity analyses with cooling systems to highlight a range of potential benefits of demand response measures. Impacts from climate change on power plant performance and water resources are discussed. Results provide key insights to policymakers and practitioners for reducing water-related power plant vulnerabilities via lower cost methods.

Optimization of output power and transmission efficiency of magnetically coupled resonance wireless power transfer system

NASA Astrophysics Data System (ADS)

Yan, Rongge; Guo, Xiaoting; Cao, Shaoqing; Zhang, Changgeng

2018-05-01

Magnetically coupled resonance (MCR) wireless power transfer (WPT) system is a promising technology in electric energy transmission. But, if its system parameters are designed unreasonably, output power and transmission efficiency will be low. Therefore, optimized parameters design of MCR WPT has important research value. In the MCR WPT system with designated coil structure, the main parameters affecting output power and transmission efficiency are the distance between the coils, the resonance frequency and the resistance of the load. Based on the established mathematical model and the differential evolution algorithm, the change of output power and transmission efficiency with parameters can be simulated. From the simulation results, it can be seen that output power and transmission efficiency of the two-coil MCR WPT system and four-coil one with designated coil structure are improved. The simulation results confirm the validity of the optimization method for MCR WPT system with designated coil structure.

The Design of Power System Stability Controller Based on the PCH Theory and Improved Genetic Algorithm

NASA Astrophysics Data System (ADS)

Liu, Zhijian; Yin, Donghui; Yan, Jun

2017-05-01

Low frequency oscillation is still frequently happened in the power system and it affects the safety and stability of power system directly. With the continuously expending of the interconnection scale of power grid, the risk of low frequency oscillation becomes more and more noticeable. Firstly, the basic theory of port-controlled Hamilton (PCH) and its application is analyzed. Secondly, based on the PCH theory and the dynamic model of system, from the viewpoint of energy, the nonlinear stability controller of power system is designed. By the improved genetic algorithm, the parameters of the PCH model are optimized. Finally, a simulation model with PCH is built to vary the effectiveness of the method proposed in this paper.

Impacts of Rising Air Temperatures and Emissions Mitigation on Electricity Demand and Supply in the United States. A Multi-Model Comparison

DOE PAGES

McFarland, James; Zhou, Yuyu; Clarke, Leon; ...

2015-06-10

The electric power sector both affects and is affected by climate change. Numerous studies highlight the potential of the power sector to reduce greenhouse gas emissions. Fewer studies have explored the physical impacts of climate change on the power sector. Our present analysis examines how projected rising temperatures affect the demand for and supply of electricity. We apply a common set of temperature projections to three well-known electric sector models in the United States: the US version of the Global Change Assessment Model (GCAM-USA), the Regional Electricity Deployment System model (ReEDS), and the Integrated Planning Model (IPM®). Incorporating the effectsmore » of rising temperatures from a control scenario without emission mitigation into the models raises electricity demand by 1.6 to 6.5 % in 2050 with similar changes in emissions. Moreover, the increase in system costs in the reference scenario to meet this additional demand is comparable to the change in system costs associated with decreasing power sector emissions by approximately 50 % in 2050. This result underscores the importance of adequately incorporating the effects of long-run temperature change in climate policy analysis.« less

Satellite Power System (SPS). State and local regulations as applied to satellite power system microwave receiving antenna facilities

NASA Technical Reports Server (NTRS)

Kotin, A. D.

1978-01-01

State and local regulation of power plant construction and operation of solar power satellite (SPS) receiving stations is presented. Each receiving antenna station occupies a land area 100-200 km square, receives microwave transmissions from the solar power satellite, and converts them into electricity for transmission to the power grid. The long lead time associated with the SPS and the changing status of state and local regulation dictated emphasis on: generic classification of the types of regulation, and identification of regulatory vectors which affect rectenna facilities.

Effect of distributed generation installation on power loss using genetic algorithm method

NASA Astrophysics Data System (ADS)

Hasibuan, A.; Masri, S.; Othman, W. A. F. W. B.

2018-02-01

Injection of the generator distributed in the distribution network can affect the power system significantly. The effect that occurs depends on the allocation of DG on each part of the distribution network. Implementation of this approach has been made to the IEEE 30 bus standard and shows the optimum location and size of the DG which shows a decrease in power losses in the system. This paper aims to show the impact of distributed generation on the distribution system losses. The main purpose of installing DG on a distribution system is to reduce power losses on the power system.Some problems in power systems that can be solved with the installation of DG, one of which will be explored in the use of DG in this study is to reduce the power loss in the transmission line. Simulation results from case studies on the IEEE 30 bus standard system show that the system power loss decreased from 5.7781 MW to 1,5757 MW or just 27,27%. The simulated DG is injected to the bus with the lowest voltage drop on the bus number 8.

Design and realization of temperature measurement system based on optical fiber temperature sensor for wireless power transfer

NASA Astrophysics Data System (ADS)

Chen, Xi; Zeng, Shuang; Liu, Xiulan; Jin, Yuan; Li, Xianglong; Wang, Xiaochen

2018-02-01

The electric vehicles (EV) have become accepted by increasing numbers of people for the environmental-friendly advantages. A novel way to charge the electric vehicles is through wireless power transfer (WPT). The wireless power transfer is a high power transfer system. The high currents flowing through the transmitter and receiver coils increasing temperature affects the safety of person and charging equipment. As a result, temperature measurement for wireless power transfer is needed. In this paper, a temperature measurement system based on optical fiber temperature sensors for electric vehicle wireless power transfer is proposed. Initially, the thermal characteristics of the wireless power transfer system are studied and the advantages of optical fiber sensors are analyzed. Then the temperature measurement system based on optical fiber temperature sensor is designed. The system consists of optical subsystem, data acquisition subsystem and data processing subsystem. Finally, the system is tested and the experiment result shows that the system can realize 1°C precision and can acquire real-time temperature distribution of the coils, which can meet the requirement of the temperature measuring for wireless power transfer.

Dynamics of Complex Systems Built as Coupled Physical, Communication and Decision Layers

PubMed Central

Kühnlenz, Florian; Nardelli, Pedro H. J.

2016-01-01

This paper proposes a simple model to capture the complexity of multilayer systems where their constituent layers affect, and are affected by, each other. The physical layer is a circuit composed by a power source and resistors in parallel. Every individual agent aims at maximizing its own delivered power by adding, removing or keeping the resistors it has; the delivered power is in turn a non-linear function that depends on the other agents’ behavior, its own internal state, its global state perception, the information received from its neighbors via the communication network and a randomized selfishness. We develop an agent-based simulation to analyze the effects of number of agents (system size), communication network topology, communication errors and the minimum power gain that triggers a behavioral change on the system dynamic. Our results show that a wave-like behavior at macro-level (caused by individual changes in the decision layer) can only emerge for a specific system size. The ratio between cooperators and defectors depends on the minimum gain assumed—lower minimal gains lead to less cooperation, and vice-versa. Different communication network topologies imply different levels of power utilization and fairness at the physical layer, and a certain level of error in the communication layer induces more cooperation. PMID:26730590

Power enhancement of heat engines via correlated thermalization in a three-level "working fluid".

PubMed

Gelbwaser-Klimovsky, David; Niedenzu, Wolfgang; Brumer, Paul; Kurizki, Gershon

2015-09-23

We explore means of maximizing the power output of a heat engine based on a periodically-driven quantum system that is constantly coupled to hot and cold baths. It is shown that the maximal power output of such a heat engine whose "working fluid" is a degenerate V-type three-level system is that generated by two independent two-level systems. Hence, level degeneracy is a thermodynamic resource that may effectively double the power output. The efficiency, however, is not affected. We find that coherence is not an essential asset in such multilevel-based heat engines. The existence of two thermalization pathways sharing a common ground state suffices for power enhancement.

The changing sensitivity of power systems to meteorological drivers: a case study of Great Britain

NASA Astrophysics Data System (ADS)

Bloomfield, H. C.; Brayshaw, D. J.; Shaffrey, L. C.; Coker, P. J.; Thornton, H. E.

2018-05-01

The increasing use of intermittent renewable generation (such as wind) is increasing the exposure of national power systems to meteorological variability. This study identifies how the integration of wind power in one particular country (Great Britain, GB) is affecting the overall sensitivity of the power system to weather using three key metrics: total annual energy requirement, peak residual load (from sources other than wind) and wind power curtailment. The present-day level of wind power capacity (approximately 15 GW) is shown to have already changed the power system’s overall sensitivity to weather in terms of the total annual energy requirement, from a temperature- to a wind-dominated regime (which occurred with 6GW of installed wind power capacity). Peak residual load from sources other than wind also shows a similar shift. The associated changes in the synoptic- and large-scale meteorological drivers associated with each metric are identified and discussed. In a period where power systems are changing rapidly, it is therefore argued that past experience of the weather impacts on the GB power system may not be a good guide for the impact on the present or near-future power system.

Airworthiness criteria development for powered-lift aircraft: A program summary

NASA Technical Reports Server (NTRS)

Heffley, R. K.; Stapleford, R. L.; Rumold, R. C.

1977-01-01

A four-year simulation program to develop airworthiness criteria for powered-lift aircraft is summarized. All flight phases affected by use of powered lift (approach, landing, takeoff) are treated with regard to airworthiness problem areas (limiting flight conditions and safety margins: stability, control, and performance; and systems failure). The general features of powered-lift aircraft are compared to conventional aircraft.

Satellite Power System (SPS) military implications

NASA Technical Reports Server (NTRS)

Bain, C. N.

1978-01-01

The military implications of the reference satellite power system (SPS) were examined is well as important military related study tasks. Primary areas of investigation were the potential of the SPS as a weapon, for supporting U.S. military preparedness, and for affecting international relations. In addition, the SPS's relative vulnerability to overt military action, terrorist attacks, and sabotage was considered.

HOMER: The Micropower Optimization Model

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

Not Available

2004-03-01

HOMER, the micropower optimization model, helps users to design micropower systems for off-grid and grid-connected power applications. HOMER models micropower systems with one or more power sources including wind turbines, photovoltaics, biomass power, hydropower, cogeneration, diesel engines, cogeneration, batteries, fuel cells, and electrolyzers. Users can explore a range of design questions such as which technologies are most effective, what size should components be, how project economics are affected by changes in loads or costs, and is the renewable resource adequate.

Power quality improvement by using STATCOM control scheme in wind energy generation interface to grid

NASA Astrophysics Data System (ADS)

Kirmani, Sheeraz; Kumar, Brijesh

2018-01-01

“Electric Power Quality (EPQ) is a term that refers to maintaining the near sinusoidal waveform of power distribution bus voltages and currents at rated magnitude and frequency”. Today customers are more aware of the seriousness that the power quality possesses, this prompt the utilities to assure good quality of power to their customer. The power quality is basically customer centric. Increased focus of utilities toward maintaining reliable power supply by employing power quality improvement tools has reduced the power outages and black out considerably. Good power quality is the characteristic of reliable power supply. Low power factor, harmonic pollution, load imbalance, fast voltage variations are some common parameters which are used to define the power quality. If the power quality issues are not checked i.e. the parameters that define power quality doesn't fall within the predefined standards than it will lead into high electricity bill, high running cost in industries, malfunctioning of equipments, challenges in connecting renewable. Capacitor banks, FACTS devices, harmonic filters, SVC’s (static voltage compensators), STATCOM (Static-Compensator) are the solutions to achieve the power quality. The performance of Wind turbine generators is affected by poor quality power, at the same time these wind power generating plant affects the power quality negatively. This paper presents the STATCOM-BESS (battery energy storage system) system and studies its impact on the power quality in a system which consists of wind turbine generator, non linear load, hysteresis controller for controlling the operation of STATCOM and grid. The model is simulated in the MATLAB/Simulink. This scheme mitigates the power quality issues, improves voltage profile and also reduces harmonic distortion of the waveforms. BESS level out the imbalances caused in real power due to intermittent nature of wind power available due to varying wind speeds.

Power System Simulation for Policymaking and Making Policymakers

NASA Astrophysics Data System (ADS)

Cohen, Michael Ari

Power system simulation is a vital tool for anticipating, planning for and ultimately addressing future conditions on the power grid, especially in light of contemporary shifts in power generation, transmission and use that are being driven by a desire to utilize more environmentally responsible energy sources. This dissertation leverages power system simulation and engineering-economic analysis to provide initial answers to one open question about future power systems: how will high penetrations of distributed (rooftop) solar power affect the physical and economic operation of distribution feeders? We find that the overall impacts of distributed solar power (both positive and negative) on the feeders we modeled are minor compared to the overall cost of energy, but that there is on average a small net benefit provided by distributed generation. We then describe an effort to make similar analyses more accessible to a non-engineering (high school) audience by developing an educational video game called "Griddle" that is based on the same power system simulation techniques used in the first study. We describe the design and evaluation of Griddle and find that it demonstrates potential to provide students with insights about key power system learning objectives.

Guidelines for traffic signal energy back\\0x2010up systems : final report.

DOT National Transportation Integrated Search

2009-07-01

Power outages affect traffic signalized intersections, leading to potentially serious problems. Current practices of responding to power failures are very basic, ranging from do nothing to installing portable generators. The purpose of this res...

Complex systems analysis of series of blackouts: cascading failure, critical points, and self-organization.

PubMed

Dobson, Ian; Carreras, Benjamin A; Lynch, Vickie E; Newman, David E

2007-06-01

We give an overview of a complex systems approach to large blackouts of electric power transmission systems caused by cascading failure. Instead of looking at the details of particular blackouts, we study the statistics and dynamics of series of blackouts with approximate global models. Blackout data from several countries suggest that the frequency of large blackouts is governed by a power law. The power law makes the risk of large blackouts consequential and is consistent with the power system being a complex system designed and operated near a critical point. Power system overall loading or stress relative to operating limits is a key factor affecting the risk of cascading failure. Power system blackout models and abstract models of cascading failure show critical points with power law behavior as load is increased. To explain why the power system is operated near these critical points and inspired by concepts from self-organized criticality, we suggest that power system operating margins evolve slowly to near a critical point and confirm this idea using a power system model. The slow evolution of the power system is driven by a steady increase in electric loading, economic pressures to maximize the use of the grid, and the engineering responses to blackouts that upgrade the system. Mitigation of blackout risk should account for dynamical effects in complex self-organized critical systems. For example, some methods of suppressing small blackouts could ultimately increase the risk of large blackouts.

Power enhancement of heat engines via correlated thermalization in a three-level “working fluid”

PubMed Central

Gelbwaser-Klimovsky, David; Niedenzu, Wolfgang; Brumer, Paul; Kurizki, Gershon

2015-01-01

We explore means of maximizing the power output of a heat engine based on a periodically-driven quantum system that is constantly coupled to hot and cold baths. It is shown that the maximal power output of such a heat engine whose “working fluid” is a degenerate V-type three-level system is that generated by two independent two-level systems. Hence, level degeneracy is a thermodynamic resource that may effectively double the power output. The efficiency, however, is not affected. We find that coherence is not an essential asset in such multilevel-based heat engines. The existence of two thermalization pathways sharing a common ground state suffices for power enhancement. PMID:26394838

The construction of power grid operation index system considering the risk of maintenance

NASA Astrophysics Data System (ADS)

Tang, Jihong; Wang, Canlin; Jiang, Xinfan; Ye, Jianhui; Pan, Feilai

2018-02-01

In recent years, large-scale blackout occurred at home and abroad caused widespread concern about the operation of the grid in the world, and the maintenance risk is an important indicator of grid safety. The barrier operation of the circuit breaker exists in the process of overhaul of the power grid. The operation of the different barrier is of great significance to the change of the power flow, thus affecting the safe operation of the system. Most of the grid operating status evaluation index system did not consider the risk of maintenance, to this end, this paper from the security, economy, quality and cleanliness of the four angles, build the power grid operation index system considering the risk of maintenance.

The interaction of spacecraft high voltage power systems with the space plasma environment

NASA Technical Reports Server (NTRS)

Domitz, S.; Grier, N. T.

1974-01-01

Research work has shown that the interaction of a spacecraft and its high voltage power systems with the space plasma environment can result in harmful power loss and damage to insulators and metal surfaces. Insulator and solar panel tests were performed and flight tests are planned. High voltage power processing equipment was shown to be affected by power loss, and by transients due to plasma interactions. Power loss was determined to be roughly proportional to the square of the voltage and increases approximately as the square root of the area. Kapton, Teflon, and glass were found to be satisfactory insulating materials and it is concluded that for large space power stations should consider the effect of large pinhole currents.

A Three-Stage Enhanced Reactive Power and Voltage Optimization Method for High Penetration of Solar

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

Ke, Xinda; Huang, Renke; Vallem, Mallikarjuna R.

This paper presents a three-stage enhanced volt/var optimization method to stabilize voltage fluctuations in transmission networks by optimizing the usage of reactive power control devices. In contrast with existing volt/var optimization algorithms, the proposed method optimizes the voltage profiles of the system, while keeping the voltage and real power output of the generators as close to the original scheduling values as possible. This allows the method to accommodate realistic power system operation and market scenarios, in which the original generation dispatch schedule will not be affected. The proposed method was tested and validated on a modified IEEE 118-bus system withmore » photovoltaic data.« less

Model and Study on Cascade Control System Based on IGBT Chopping Control

NASA Astrophysics Data System (ADS)

Niu, Yuxin; Chen, Liangqiao; Wang, Shuwen

2018-01-01

Thyristor cascade control system has a wide range of applications in the industrial field, but the traditional cascade control system has some shortcomings, such as a low power factor, serious harmonic pollution. In this paper, not only analyzing its system structure and working principle, but also discussing the two main factors affecting the power factor. Chopping-control cascade control system, adopted a new power switching device IGBT, which could overcome traditional cascade control system’s two main drawbacks efficiently. The basic principle of this cascade control system is discussed in this paper and the model of speed control system is built by using MATLAB/Simulink software. Finally, the simulation results of the system shows that the system works efficiently. This system is worthy to be spread widely in engineering application.

Composite turbine blade design options for Claude (open) cycle OTEC power systems

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

Penney, T R

1985-11-01

Small-scale turbine rotors made from composites offer several technical advantages for a Claude (open) cycle ocean thermal energy conversion (OTEC) power system. Westinghouse Electric Corporation has designed a composite turbine rotor/disk using state-of-the-art analysis methods for large-scale (100-MW/sub e/) open cycle OTEC applications. Near-term demonstrations using conventional low-pressure turbine blade shapes with composite material would achieve feasibility and modern credibility of the open cycle OTEC power system. Application of composite blades for low-pressure turbo-machinery potentially improves the reliability of conventional metal blades affected by stress corrosion.

Scheduling lessons learned from the Autonomous Power System

NASA Technical Reports Server (NTRS)

Ringer, Mark J.

1992-01-01

The Autonomous Power System (APS) project at NASA LeRC is designed to demonstrate the applications of integrated intelligent diagnosis, control, and scheduling techniques to space power distribution systems. The project consists of three elements: the Autonomous Power Expert System (APEX) for Fault Diagnosis, Isolation, and Recovery (FDIR); the Autonomous Intelligent Power Scheduler (AIPS) to efficiently assign activities start times and resources; and power hardware (Brassboard) to emulate a space-based power system. The AIPS scheduler was tested within the APS system. This scheduler is able to efficiently assign available power to the requesting activities and share this information with other software agents within the APS system in order to implement the generated schedule. The AIPS scheduler is also able to cooperatively recover from fault situations by rescheduling the affected loads on the Brassboard in conjunction with the APEX FDIR system. AIPS served as a learning tool and an initial scheduling testbed for the integration of FDIR and automated scheduling systems. Many lessons were learned from the AIPS scheduler and are now being integrated into a new scheduler called SCRAP (Scheduler for Continuous Resource Allocation and Planning). This paper will service three purposes: an overview of the AIPS implementation, lessons learned from the AIPS scheduler, and a brief section on how these lessons are being applied to the new SCRAP scheduler.

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.

Wind Power Ramping Product for Increasing Power System Flexibility

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

Cui, Mingjian; Zhang, Jie; Wu, Hongyu

With increasing penetrations of wind power, system operators are concerned about a potential lack of system flexibility and ramping capacity in real-time dispatch stages. In this paper, a modified dispatch formulation is proposed considering the wind power ramping product (WPRP). A swinging door algorithm (SDA) and dynamic programming are combined and used to detect WPRPs in the next scheduling periods. The detected WPRPs are included in the unit commitment (UC) formulation considering ramping capacity limits, active power limits, and flexible ramping requirements. The modified formulation is solved by mixed integer linear programming. Numerical simulations on a modified PJM 5-bus Systemmore » show the effectiveness of the model considering WPRP, which not only reduces the production cost but also does not affect the generation schedules of thermal units.« less

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

Kar, Durga P.; Nayak, Praveen P.; Bhuyan, Satyanarayan

In order to power or charge electronic devices wirelessly, a bi-directional wireless power transfer method has been proposed and experimentally investigated. In the proposed design, two receiving coils are used on both sides of a transmitting coil along its central axis to receive the power wirelessly from the generated magnetic fields through strongly coupled magnetic resonance. It has been observed experimentally that the maximum power transfer occurs at the operating resonant frequency for optimum electric load connected across the receiving coils on both side. The optimum wireless power transfer efficiency is 88% for the bi-directional power transfer technique compared 84%more » in the one side receiver system. By adopting the developed bi-directional power transfer method, two electronic devices can be powered up or charged simultaneously instead of a single device through usual one side receiver system without affecting the optimum power transfer efficiency.« less

Performance Issues for a Changing Electric Power Industry

EIA Publications

1995-01-01

Provides an overview of some of the factors affecting reliability within the electric bulk power system. Historical and projected data related to reliability issues are discussed on a national and regional basis. Current research on economic considerations associated with reliability levels is also reviewed.

Recent Trend of New Type Power Delivery System and its Demonstrative Project in Japan

NASA Astrophysics Data System (ADS)

Morozumi, Satoshi; Nara, Koichi

Recently many such distributed generating systems as co-generation, photovoltaic, wind, fuel cells etc. are introduced into power distribution system, and the power system must cope with the situation with distributed generators. Moreover, such industries as IT request reliable and high quality power to preserve their businesses, and some other electric energy based industries request less reliable but cheaper electricity. From these backgrounds, several new type power delivery systems are emerging where lots of distributed generators (DGs) can be connected and many benefits offered by DGs can be realized without affecting the existing power system. They are referred to various names. In U.S.A., Microgrid, Power Park and Virtual Utilities, etc. are proposed. In Europe, DISPOWER or Smart Grid is under developing. In Japan, FRIENDS and Demand Area Network System etc. are proposed and tested in real sites. In this paper, first, general concepts of such new type power delivery systems and new businesses expected to be created by using DGs are introduced. Then, recent research activities in this area in Japan are introduced so as to stimulate new business opportunities. In the later part of this paper, related NEDO's demonstrative projects are introduced. NEDO is the largest public R&D management organization and promoting several projects regarding grid connecting issues on the power system. Those projects were planned to solve several problems on the power system where distributed renewable energy resources are installed.

Space shuttle engineering and operations support. Orbiter to spacelab electrical power interface. Avionics system engineering

NASA Technical Reports Server (NTRS)

Emmons, T. E.

1976-01-01

The results are presented of an investigation of the factors which affect the determination of Spacelab (S/L) minimum interface main dc voltage and available power from the orbiter. The dedicated fuel cell mode of powering the S/L is examined along with the minimum S/L interface voltage and available power using the predicted fuel cell power plant performance curves. The values obtained are slightly lower than current estimates and represent a more marginal operating condition than previously estimated.

Cost Analysis of the Discrete Address Beacon System for the Low-Performance General Aviation Aircraft Community.

DTIC Science & Technology

1981-09-01

power supplies of the transponder to pro - vide a maximum 23.5 dBW power output. Tables 3-5 and 3-6 present the cost development for this configuration...configurations studied the cavity oscillator tube provides the necessary output characteristics for proper operation of the DABS transponder. Power supplies ...however, are affected by each configuration. The power supply was designed to provide 141 watts peak power at the antenna and sufficient capacity in

Kaman 40 kW wind turbine generator - control system dynamics

NASA Technical Reports Server (NTRS)

Perley, R.

1981-01-01

The generator design incorporates an induction generator for application where a utility line is present and a synchronous generator for standalone applications. A combination of feed forward and feedback control is used to achieve synchronous speed prior to connecting the generator to the load, and to control the power level once the generator is connected. The dynamics of the drive train affect several aspects of the system operation. These were analyzed to arrive at the required shaft stiffness. The rotor parameters that affect the stability of the feedback control loop vary considerably over the wind speed range encountered. Therefore, the controller gain was made a function of wind speed in order to maintain consistent operation over the whole wind speed range. The velocity requirement for the pitch control mechanism is related to the nature of the wind gusts to be encountered, the dynamics of the system, and the acceptable power fluctuations and generator dropout rate. A model was developed that allows the probable dropout rate to be determined from a statistical model of wind gusts and the various system parameters, including the acceptable power fluctuation.

Scenarios for low carbon and low water electric power plant ...

EPA Pesticide Factsheets

In the water-energy nexus, water use for the electric power sector is critical. Currently, the operational phase of electric power production dominates the electric sector's life cycle withdrawal and consumption of fresh water resources. Water use associated with the fuel cycle and power plant equipment manufacturing phase is substantially lower on a life cycle basis. An outstanding question is: how do regional shifts to lower carbon electric power mixes affect the relative contribution of the upstream life cycle water use? To test this, we examine a range of scenarios comparing a baseline with scenarios of carbon reduction and water use constraints using the MARKet ALlocation (MARKAL) energy systems model with ORD's 2014 U.S. 9-region database (EPAUS9r). The results suggest that moving toward a low carbon and low water electric power mix may increase the non-operational water use. In particular, power plant manufacturing water use for concentrating solar power, and fuel cycle water use for biomass feedstock, could see sharp increases under scenarios of high deployment of these low carbon options. Our analysis addresses the following questions. First, how does moving to a lower carbon electricity generation mix affect the overall regional electric power water use from a life cycle perspective? Second, how does constraining the operational water use for power plants affect the mix, if at all? Third, how does the life cycle water use differ among regions under

Experimental study on an S-band near-field microwave magnetron power transmission system on hundred-watt level

NASA Astrophysics Data System (ADS)

Zhang, Biao; Jiang, Wan; Yang, Yang; Yu, Chengyang; Huang, Kama; Liu, Changjun

2015-11-01

A multi-magnetron microwave source, a metamaterial transmitting antenna, and a large power rectenna array are presented to build a near-field 2.45 GHz microwave power transmission system. The square 1 m2 rectenna array consists of sixteen rectennas with 2048 Schottky diodes for large power microwave rectifying. It receives microwave power and converts them into DC power. The design, structure, and measured performance of a unit rectenna as well as the entail rectenna array are presented in detail. The multi-magnetron microwave power source switches between half and full output power levels, i.e. the half-wave and full-wave modes. The transmission antenna is formed by a double-layer metallic hole array, which is applied to combine the output power of each magnetron. The rectenna array DC output power reaches 67.3 W on a 1.2 Ω DC load at a distance of 5.5 m from the transmission antenna. DC output power is affected by the distance, DC load, and the mode of microwave power source. It shows that conventional low power Schottky diodes can be applied to a microwave power transmission system with simple magnetrons to realise large power microwave rectifying.

Femtosecond Laser Eyewear Protection: Measurements and Precautions

PubMed Central

Stromberg, Christopher J.; Hadler, Joshua A.; Alberding, Brian G.; Heilweil, Edwin J.

2018-01-01

Ultrafast laser systems are becoming more widespread throughout the research and industrial communities yet eye protection for these high power, bright pulsed sources still require scrupulous characterization and testing before use. Femtosecond lasers, with pulses naturally possessing broad-bandwidth and high average power with variable repetition rate, can exhibit spectral side-bands and subtly changing center wavelengths, which may unknowingly affect eyewear safety protection. Pulse spectral characterization and power diagnostics are presented for a 80 MHz, Ti+3:Sapphire, ≈ 800 nm, ≈40 femtosecond oscillator system. Power and spectral transmission for 22 test samples are measured to determine whether they fall within manufacturer specifications. PMID:29353984

Femtosecond Laser Eyewear Protection: Measurements and Precautions.

PubMed

Stromberg, Christopher J; Hadler, Joshua A; Alberding, Brian G; Heilweil, Edwin J

2017-11-01

Ultrafast laser systems are becoming more widespread throughout the research and industrial communities yet eye protection for these high power, bright pulsed sources still require scrupulous characterization and testing before use. Femtosecond lasers, with pulses naturally possessing broad-bandwidth and high average power with variable repetition rate, can exhibit spectral side-bands and subtly changing center wavelengths, which may unknowingly affect eyewear safety protection. Pulse spectral characterization and power diagnostics are presented for a 80 MHz, Ti +3 :Sapphire, ≈ 800 nm, ≈40 femtosecond oscillator system. Power and spectral transmission for 22 test samples are measured to determine whether they fall within manufacturer specifications.

Time-varying causal network of the Korean financial system based on firm-specific risk premiums

NASA Astrophysics Data System (ADS)

Song, Jae Wook; Ko, Bonggyun; Cho, Poongjin; Chang, Woojin

2016-09-01

The aim of this paper is to investigate the Korean financial system based on time-varying causal network. We discover many stylized facts by utilizing the firm-specific risk premiums for measuring the causality direction from a firm to firm. At first, we discover that the interconnectedness of causal network is affected by the outbreak of financial events; the co-movement of firm-specific risk premium is strengthened after each positive event, and vice versa. Secondly, we find that the major sector of the Korean financial system is the Depositories, and the financial reform in June-2011 achieves its purpose by weakening the power of risk-spillovers of Broker-Dealers. Thirdly, we identify that the causal network is a small-world network with scale-free topology where the power-law exponents of out-Degree and negative event are more significant than those of in-Degree and positive event. Lastly, we discuss that the current aspects of causal network are closely related to the long-term future scenario of the KOSPI Composite index where the direction and stability are significantly affected by the power of risk-spillovers and the power-law exponents of degree distributions, respectively.

Received optical power calculations for optical communications link performance analysis

NASA Technical Reports Server (NTRS)

Marshall, W. K.; Burk, B. D.

1986-01-01

The factors affecting optical communication link performance differ substantially from those at microwave frequencies, due to the drastically differing technologies, modulation formats, and effects of quantum noise in optical communications. In addition detailed design control table calculations for optical systems are less well developed than corresponding microwave system techniques, reflecting the relatively less mature state of development of optical communications. Described below are detailed calculations of received optical signal and background power in optical communication systems, with emphasis on analytic models for accurately predicting transmitter and receiver system losses.

High power laser-mechanical drilling bit and methods of use

DOEpatents

Grubb, Daryl L.; Kolachalam, Sharath K.; Faircloth, Brian O.; Rinzler, Charles C.; Allen, Erik C.; Underwood, Lance D.; Zediker, Mark S.

2017-02-07

An apparatus with a high power laser-mechanical bit for use with a laser drilling system and a method for advancing a borehole. The laser-mechanical bit has a beam path and mechanical removal devices that provide for the removal of laser-affected rock to advance a borehole.

Affective Neuronal Selection: The Nature of the Primordial Emotion Systems

PubMed Central

Toronchuk, Judith A.; Ellis, George F. R.

2013-01-01

Based on studies in affective neuroscience and evolutionary psychiatry, a tentative new proposal is made here as to the nature and identification of primordial emotional systems. Our model stresses phylogenetic origins of emotional systems, which we believe is necessary for a full understanding of the functions of emotions and additionally suggests that emotional organizing systems play a role in sculpting the brain during ontogeny. Nascent emotional systems thus affect cognitive development. A second proposal concerns two additions to the affective systems identified by Panksepp. We suggest there is substantial evidence for a primary emotional organizing program dealing with power, rank, dominance, and subordination which instantiates competitive and territorial behavior and is an evolutionary contributor to self-esteem in humans. A program underlying disgust reactions which originally functioned in ancient vertebrates to protect against infection and toxins is also suggested. PMID:23316177

Design and Implementation of RF Energy Harvesting System for Low-Power Electronic Devices

NASA Astrophysics Data System (ADS)

Uzun, Yunus

2016-08-01

Radio frequency (RF) energy harvester systems are a good alternative for energizing of low-power electronics devices. In this work, an RF energy harvester is presented to obtain energy from Global System for Mobile Communications (GSM) 900 MHz signals. The energy harvester, consisting of a two-stage Dickson voltage multiplier circuit and L-type impedance matching circuits, was designed, simulated, fabricated and tested experimentally in terms of its performance. Simulation and experimental works were carried out for various input power levels, load resistances and input frequencies. Both simulation and experimental works have been carried out for this frequency band. An efficiency of 45% is obtained from the system at 0 dBm input power level using the impedance matching circuit. This corresponds to the power of 450 μW and this value is sufficient for many low-power devices. The most important parameters affecting the efficiency of the RF energy harvester are the input power level, frequency band, impedance matching and voltage multiplier circuits, load resistance and the selection of diodes. RF energy harvester designs should be optimized in terms of these parameters.

Investigating power capping toward energy-efficient scientific applications: Investigating Power Capping toward Energy-Efficient Scientific Applications

DOE PAGES

Haidar, Azzam; Jagode, Heike; Vaccaro, Phil; ...

2018-03-22

The emergence of power efficiency as a primary constraint in processor and system design poses new challenges concerning power and energy awareness for numerical libraries and scientific applications. Power consumption also plays a major role in the design of data centers, which may house petascale or exascale-level computing systems. At these extreme scales, understanding and improving the energy efficiency of numerical libraries and their related applications becomes a crucial part of the successful implementation and operation of the computing system. In this paper, we study and investigate the practice of controlling a compute system's power usage, and we explore howmore » different power caps affect the performance of numerical algorithms with different computational intensities. Further, we determine the impact, in terms of performance and energy usage, that these caps have on a system running scientific applications. This analysis will enable us to characterize the types of algorithms that benefit most from these power management schemes. Our experiments are performed using a set of representative kernels and several popular scientific benchmarks. Lastly, we quantify a number of power and performance measurements and draw observations and conclusions that can be viewed as a roadmap to achieving energy efficiency in the design and execution of scientific algorithms.« less

Investigating power capping toward energy-efficient scientific applications: Investigating Power Capping toward Energy-Efficient Scientific Applications

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

Haidar, Azzam; Jagode, Heike; Vaccaro, Phil

The emergence of power efficiency as a primary constraint in processor and system design poses new challenges concerning power and energy awareness for numerical libraries and scientific applications. Power consumption also plays a major role in the design of data centers, which may house petascale or exascale-level computing systems. At these extreme scales, understanding and improving the energy efficiency of numerical libraries and their related applications becomes a crucial part of the successful implementation and operation of the computing system. In this paper, we study and investigate the practice of controlling a compute system's power usage, and we explore howmore » different power caps affect the performance of numerical algorithms with different computational intensities. Further, we determine the impact, in terms of performance and energy usage, that these caps have on a system running scientific applications. This analysis will enable us to characterize the types of algorithms that benefit most from these power management schemes. Our experiments are performed using a set of representative kernels and several popular scientific benchmarks. Lastly, we quantify a number of power and performance measurements and draw observations and conclusions that can be viewed as a roadmap to achieving energy efficiency in the design and execution of scientific algorithms.« less

Globalization of Access to Higher Education: Lessons for Nigeria

ERIC Educational Resources Information Center

Uchendu, C. C.

2013-01-01

Education is such a powerful instrument for national transformation and development such that anything that affects an educational system negatively affects the national development. This study investigated the extent to which access to higher education is globalized and the implications for Nigeria. An ex-post facto research design was adopted…

Water-Related Power Plant Curtailments: An Overview of Incidents and Contributing Factors

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

McCall, James; Macknick, Jordan; Macknick, Jordan

Water temperatures and water availability can affect the reliable operations of power plants in the United States. Data on water-related impacts on the energy sector are not consolidated and are reported by multiple agencies. This study provides an overview of historical incidents where water resources have affected power plant operations, discusses the various data sources providing information, and creates a publicly available and open access database that contains consolidated information about water-related power plant curtailment and shut-down incidents. Power plants can be affected by water resources if incoming water temperatures are too high, water discharge temperatures are too high, ormore » if there is not enough water available to operate. Changes in climate have the potential to exacerbate uncertainty over water resource availability and temperature. Power plant impacts from water resources include curtailment of generation, plant shut-downs, and requests for regulatory variances. In addition, many power plants have developed adaptation approaches to reducing the potential risks of water-related issues by investing in new technologies or developing and implementing plans to undertake during droughts or heatwaves. This study identifies 42 incidents of water-related power plant issues from 2000-2015, drawing from a variety of different datasets. These incidents occur throughout the U.S., and affect coal and nuclear plants that use once-through, recirculating, and pond cooling systems. In addition, water temperature violations reported to the Environmental Protection Agency are also considered, with 35 temperature violations noted from 2012-2015. In addition to providing some background information on incidents, this effort has also created an open access database on the Open Energy Information platform that contains information about water-related power plant issues that can be updated by users.« less

Effect of loading on peak power of the bar, body, and system during power cleans, squats, and jump squats.

PubMed

McBride, Jeffrey M; Haines, Tracie L; Kirby, Tyler J

2011-08-01

Nine males (age 24.7 ± 2.1 years, height 175.3 ± 5.5 cm, body mass 80.8 ± 7.2 kg, power clean 1-RM 97.1 ± 6.36 kg, squat 1-RM = 138.3 ± 20.9 kg) participated in this study. On day 1, the participants performed a one-repetition maximum (1-RM) in the power clean and the squat. On days 2, 3, and 4, participants performed the power clean, squat or jump squat. Loading for the power clean ranged from 30% to 90% of the participant's power clean 1-RM and loading for the squat and jump squat ranged from 0% to 90% of the participant's squat 1-RM, all at 10% increments. Peak force, velocity, and power were calculated for the bar, body, and system (bar + body) for all power clean, squat, and jump squat trials. Results indicate that peak power for the bar, body, and system is differentially affected by load and movement pattern. When using the power clean, squat or jump squat for training, the optimal load in each exercise may vary. Throwing athletes or weightlifters may be most concerned with bar power, but jumpers or sprinters may be more concerned with body or system power. Thus, the exercise type and load vary according to the desired stimulus.

75 FR 33220 - Unlicensed Personal Communications Services Devices in the 1920-1930 MHz Band

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-11

... required minimum number of channels and transmit on the channels with the lowest power. According to DECT... interference to adjacent-band Advanced Wireless Service (AWS) and PCS services. 3. DECT claims that its... with the lowest power and an alternative approach suggested by DECT--could require affected systems to...

Lead/acid batteries in systems to improve power quality

NASA Astrophysics Data System (ADS)

Taylor, P.; Butler, P.; Nerbun, W.

Increasing dependence on computer technology is driving needs for extremely high-quality power to prevent loss of information, material, and workers' time that represent billions of dollars annually. This cost has motivated commercial and Federal research and development of energy storage systems that detect and respond to power-quality failures in milliseconds. Electrochemical batteries are among the storage media under investigation for these systems. Battery energy storage systems that employ either flooded lead/acid or valve-regulated lead/acid battery technologies are becoming commercially available to capture a share of this emerging market. Cooperative research and development between the US Department of Energy and private industry have led to installations of lead/acid-based battery energy storage systems to improve power quality at utility and industrial sites and commercial development of fully integrated, modular battery energy storage system products for power quality. One such system by AC Battery Corporation, called the PQ2000, is installed at a test site at Pacific Gas and Electric Company (San Ramon, CA, USA) and at a customer site at Oglethorpe Power Corporation (Tucker, GA, USA). The PQ2000 employs off-the-shelf power electronics in an integrated methodology to control the factors that affect the performance and service life of production-model, low-maintenance, flooded lead/acid batteries. This system, and other members of this first generation of lead/acid-based energy storage systems, will need to compete vigorously for a share of an expanding, yet very aggressive, power quality market.

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

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

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

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

Investigation of load current feed-forward control strategy for wind power grid connected inverter through VSC-HVDC

NASA Astrophysics Data System (ADS)

Liu, Hongbo; Liu, Haihan; Liu, Sitong; Peng, Huanhuan

2018-06-01

The VSC-HVDC connection system will be the effective transmission method for the large scale and long distance integrated wind farm. Because of the fluctuating power, the DC voltage will be over-voltage or under-voltage in transmission line which will affect the steady operation of the wind power integrating system. In order to mitigate the DC voltage variation of the grid-connected inverter on the grid side and improve the dynamic response of the system, a load current feed-forward control scheme is put forward. Firstly, this paper analyses stability of a system without additional feed-forward control based on double close loop. Secondly, the load current which can indicate the power changes is introduced to counteract the fluctuation of DC voltage in the improvement control scheme. By simulating the results show that the proposed control strategy can improve the dynamic response performance and mitigate the fluctuation of the active power output of the wind farm.

Nuclear reactor power for a space-based radar. SP-100 project

NASA Technical Reports Server (NTRS)

Bloomfield, Harvey; Heller, Jack; Jaffe, Leonard; Beatty, Richard; Bhandari, Pradeep; Chow, Edwin; Deininger, William; Ewell, Richard; Fujita, Toshio; Grossman, Merlin

1986-01-01

A space-based radar mission and spacecraft, using a 300 kWe nuclear reactor power system, has been examined, with emphasis on aspects affecting the power system. The radar antenna is a horizontal planar array, 32 X 64 m. The orbit is at 61 deg, 1088 km. The mass of the antenna with support structure is 42,000 kg; of the nuclear reactor power system, 8,300 kg; of the whole spacecraft about 51,000 kg, necessitating multiple launches and orbital assembly. The assembly orbit is at 57 deg, 400 km, high enough to provide the orbital lifetime needed for orbital assembly. The selected scenario uses six Shuttle launches to bring the spacecraft and a Centaur G upper-stage vehicle to assembly orbit. After assembly, the Centaur places the spacecraft in operational orbit, where it is deployed on radio command, the power system started, and the spacecraft becomes operational. Electric propulsion is an alternative and allows deployment in assembly orbit, but introduces a question of nuclear safety.

Water and Climate Impacts on Power System Operations: The Importance of Cooling Systems and Demand Response Measures

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

Macknick, Jordan; Zhou, Ella; O'Connell, Matthew

The U.S. electricity sector is highly dependent upon water resources; changes in water temperatures and water availability can affect operational costs and the reliability of power systems. Despite the importance of water for power system operations, the effects of changes in water characteristics on multiple generators in a system are generally not modeled. Moreover, demand response measures, which can change the magnitude and timing of loads and can have beneficial impacts on power system operations, have not yet been evaluated in the context of water-related power vulnerabilities. This effort provides a first comprehensive vulnerability and cost analysis of water-related impactsmore » on a modeled power system and the potential for demand response measures to address vulnerability and cost concerns. This study uniquely combines outputs and inputs of a water and power plant system model, production cost, model, and relative capacity value model to look at variations in cooling systems, policy-related thermal curtailments, and demand response measures to characterize costs and vulnerability for a test system. Twenty-five scenarios over the course of one year are considered: a baseline scenario as well as a suite of scenarios to evaluate six cooling system combinations, the inclusion or exclusion of policy-related thermal curtailments, and the inclusion or exclusion of demand response measures. A water and power plant system model is utilized to identify changes in power plant efficiencies resulting from ambient conditions, a production cost model operating at an hourly scale is used to calculate generation technology dispatch and costs, and a relative capacity value model is used to evaluate expected loss of carrying capacity for the test system.« less

Anomalous TWTA output power spikes and their effect on a digital satellite communications system

NASA Technical Reports Server (NTRS)

May, Brian D.; Kerczewski, Robert J.; Svoboda, James S.

1992-01-01

Several 30 GHz, 60 W traveling wave tube amplifiers (TWTA) were manufactured for the NASA Lewis Research Center's High Burst Rate Link Evaluation Terminal Project. An unusual operating problem characterized by anomalous nonperiodic output power spikes, common to all of the TWTAs proved during testing to significantly affect the performance of a digitally-modulated data transmission test system. Modifications made to the TWTAs significantly curtailed the problem and allowed acceptable system performance to be obtained. This paper presents a discussion of the TWTA output power spike problem, possible causes of the problem, and the solutions implemented by the manufacturer which improved the TWTA performance to an acceptable level. The results of the testing done at NASA Lewis on the TWTAs both before and after the improvement made by Hughes are presented, and the effects of the output power spikes on the performance of the test system are discussed.

Study on the flow in the pipelines of the support system of circulating fluidized bed

NASA Astrophysics Data System (ADS)

Meng, L.; Yang, J.; Zhou, L. J.; Wang, Z. W.; Zhuang, X. H.

2013-12-01

In the support system of Circulating Fluidized Bed (Below referred to as CFB) of thermal power plant, the pipelines of primary wind are used for transporting the cold air to the boiler, which is important in controlling and combustion effect. The pipeline design will greatly affect the energy loss of the system, and accordingly affect the thermal power plant economic benefits and production environment. Three-dimensional numerical simulation is carried out for the pipeline internal flow field of a thermal power plant in this paper. Firstly three turbulence models were compared and the results showed that the SST k-ω model converged better and the energy losses predicted were closer to the experimental results. The influence of the pipeline design form on the flow characteristics are analysed, then the optimization designs of the pipeline are proposed according to the energy loss distribution of the flow field, in order to reduce energy loss and improve the efficiency of tunnel. The optimization plan turned out to be efficacious; about 36% of the pressure loss is reduced.

14 CFR 27.923 - Rotor drive system and control mechanism tests.

Code of Federal Regulations, 2011 CFR

2011-01-01

... purpose of this paragraph, an affected power input includes all parts of the rotor drive system which can... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Rotor drive system and control mechanism... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Rotor Drive System § 27...

14 CFR 27.923 - Rotor drive system and control mechanism tests.

Code of Federal Regulations, 2013 CFR

2013-01-01

... purpose of this paragraph, an affected power input includes all parts of the rotor drive system which can... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Rotor drive system and control mechanism... TRANSPORTATION AIRCRAFT AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT Powerplant Rotor Drive System § 27...

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

Static power reduction for midpoint-terminated busses

DOEpatents

Coteus, Paul W [Yorktown Heights, NY; Takken, Todd [Brewster, NY

2011-01-18

A memory system is disclosed which is comprised of a memory controller and addressable memory devices such as DRAMs. The invention provides a programmable register to control the high vs. low drive state of each bit of a memory system address and control bus during periods of bus inactivity. In this way, termination voltage supply current can be minimized, while permitting selected bus bits to be driven to a required state. This minimizes termination power dissipation while not affecting memory system performance. The technique can be extended to work for other high-speed busses as well.

On variable hydrostatic transmission for road vehicles, powered by supply of fluid at constant pressure

NASA Technical Reports Server (NTRS)

Magi, M.; Freivald, A.; Andersson, I.; Ericsson, U.

1981-01-01

Various hydrostatic power transmission systems for automotive applications with power supply at constant pressure and unrestricted flow and with a Volvo Flygmotor variable displacement motor as the principal unit were investigated. Two most promising concepts were analyzed in detail and their main components optimized for minimum power loss at the EPA Urban Driving Cycle. The best fuel consumption is less than 10 lit. per 100 kM for a 1542 kG vehicle with a hydrostatic motor and a two speed gear box in series (braking power not recovered). Realistic system pressure affects the fuel consumption just slightly, but the package volume/weight drastically. Back pressure increases losses significantly. Special attention was paid to description of the behavior and modeling of the losses of variable displacement hydrostatic machines.

Data centers as dispatchable loads to harness stranded power

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

Kim, Kibaek; Yang, Fan; Zavala, Victor M.

Here, we analyze how traditional data center placement and optimal placement of dispatchable data centers affect power grid efficiency. We use detailed network models, stochastic optimization formulations, and diverse renewable generation scenarios to perform our analysis. Our results reveal that significant spillage and stranded power will persist in power grids as wind power levels are increased. A counter-intuitive finding is that collocating data centers with inflexible loads next to wind farms has limited impacts on renewable portfolio standard (RPS) goals because it provides limited system-level flexibility. Such an approach can, in fact, increase stranded power and fossil-fueled generation. In contrast,more » optimally placing data centers that are dispatchable provides system-wide flexibility, reduces stranded power, and improves efficiency. In short, optimally placed dispatchable computing loads can enable better scaling to high RPS. In our case study, we find that these dispatchable computing loads are powered to 60-80% of their requested capacity, indicating that there are significant economic incentives provided by stranded power.« less

Data centers as dispatchable loads to harness stranded power

DOE PAGES

Kim, Kibaek; Yang, Fan; Zavala, Victor M.; ...

2016-07-20

Here, we analyze how traditional data center placement and optimal placement of dispatchable data centers affect power grid efficiency. We use detailed network models, stochastic optimization formulations, and diverse renewable generation scenarios to perform our analysis. Our results reveal that significant spillage and stranded power will persist in power grids as wind power levels are increased. A counter-intuitive finding is that collocating data centers with inflexible loads next to wind farms has limited impacts on renewable portfolio standard (RPS) goals because it provides limited system-level flexibility. Such an approach can, in fact, increase stranded power and fossil-fueled generation. In contrast,more » optimally placing data centers that are dispatchable provides system-wide flexibility, reduces stranded power, and improves efficiency. In short, optimally placed dispatchable computing loads can enable better scaling to high RPS. In our case study, we find that these dispatchable computing loads are powered to 60-80% of their requested capacity, indicating that there are significant economic incentives provided by stranded power.« less

Invited Article: Visualisation of extreme value events in optical communications

NASA Astrophysics Data System (ADS)

Derevyanko, Stanislav; Redyuk, Alexey; Vergeles, Sergey; Turitsyn, Sergei

2018-06-01

Fluctuations of a temporal signal propagating along long-haul transoceanic scale fiber links can be visualised in the spatio-temporal domain drawing visual analogy with ocean waves. Substantial overlapping of information symbols or use of multi-frequency signals leads to strong statistical deviations of local peak power from an average signal power level. We consider long-haul optical communication systems from this unusual angle, treating them as physical systems with a huge number of random statistical events, including extreme value fluctuations that potentially might affect the quality of data transmission. We apply the well-established concepts of adaptive wavefront shaping used in imaging through turbid medium to detect the detrimental phase modulated sequences in optical communications that can cause extreme power outages (rare optical waves of ultra-high amplitude) during propagation down the ultra-long fiber line. We illustrate the concept by a theoretical analysis of rare events of high-intensity fluctuations—optical freak waves, taking as an example an increasingly popular optical frequency division multiplexing data format where the problem of high peak to average power ratio is the most acute. We also show how such short living extreme value spikes in the optical data streams are affected by nonlinearity and demonstrate the negative impact of such events on the system performance.

Music Attenuated a Decrease in Parasympathetic Nervous System Activity after Exercise.

PubMed

Jia, Tiantian; Ogawa, Yoshiko; Miura, Misa; Ito, Osamu; Kohzuki, Masahiro

2016-01-01

Music and exercise can both affect autonomic nervous system activity. However, the effects of the combination of music and exercise on autonomic activity are poorly understood. Additionally, it remains unknown whether music affects post-exercise orthostatic tolerance. The aim of this study was to evaluate the effects of music on autonomic nervous system activity in orthostatic tolerance after exercise. Twenty-six healthy graduate students participated in four sessions in a random order on four separate days: a sedentary session, a music session, a bicycling session, and a bicycling with music session. Participants were asked to listen to their favorite music and to exercise on a cycle ergometer. We evaluated autonomic nervous system activity before and after each session using frequency analysis of heart rate variability. High frequency power, an index of parasympathetic nervous system activity, was significantly increased in the music session. Heart rate was increased, and high frequency power was decreased, in the bicycling session. There was no significant difference in high frequency power before and after the bicycling with music session, although heart rate was significantly increased. Additionally, both music and exercise did not significantly affect heart rate, systolic blood pressure or also heart rate variability indices in the orthostatic test. These data suggest that music increased parasympathetic activity and attenuated the exercise-induced decrease in parasympathetic activity without altering the orthostatic tolerance after exercise. Therefore, music may be an effective approach for improving post-exercise parasympathetic reactivation, resulting in a faster recovery and a reduction in cardiac stress after exercise.

Integration of Variable Speed Pumped Hydro Storage in Automatic Generation Control Systems

NASA Astrophysics Data System (ADS)

Fulgêncio, N.; Moreira, C.; Silva, B.

2017-04-01

Pumped storage power (PSP) plants are expected to be an important player in modern electrical power systems when dealing with increasing shares of new renewable energies (NRE) such as solar or wind power. The massive penetration of NRE and consequent replacement of conventional synchronous units will significantly affect the controllability of the system. In order to evaluate the capability of variable speed PSP plants participation in the frequency restoration reserve (FRR) provision, taking into account the expected performance in terms of improved ramp response capability, a comparison with conventional hydro units is presented. In order to address this issue, a three area test network was considered, as well as the corresponding automatic generation control (AGC) systems, being responsible for re-dispatching the generation units to re-establish power interchange between areas as well as the system nominal frequency. The main issue under analysis in this paper is related to the benefits of the fast response of variable speed PSP with respect to its capability of providing fast power balancing in a control area.

Performance study on the effect of filter curve in CWDM System for the access network

NASA Astrophysics Data System (ADS)

Ali, N.; Rahman, N. A.; Hambali, N. A. M. Ahmad; Rashidi, C. B. M.

2017-11-01

This paper presents the study on the effect of filter variation on the coarse wavelength division multiplexing (CWDM) system. The filter curve will affect the performance of the CWDM system due to changes of received power lever and isolation of the signal. The significant impact on the received power level and isolation can be found when the required signal is isolated from unwanted signal by the steep curve of filter. As a result, BER of 1.0x 10-12 was obtained corresponding to receive power level of -24.27 dBm with isolation of 23.22 dB. When the wavelength spacing is reduced to 1nm, the isolation is only 11.30 dB and BER increased to 5.49x10-7 with a received power of -15.39 dBm.

A modular electric power system test bed for small spacecraft

NASA Technical Reports Server (NTRS)

Button, Robert M.; Baez, Anastacio N.

1994-01-01

In the new climate of smaller, faster, and cheaper space science satellites, a new power system topology has been developed at the NASA Lewis Research Center. This new topology is based on a series connected boost converter (SCBC) and can greatly affect the size, weight, fault tolerance, and cost of any small spacecraft using photovoltaic solar arrays. The paper presents electric power system design factors and requirements as background information. The series connected boost converter topology is discussed and several advantages over existing technologies are illustrated. Besides being small, lightweight, and efficient, this topology has the added benefit of inherent fault tolerance. A positive ground power system test bed has been developed for the TROPIX spacecraft program. Performance of the SCBC in the test bed is described in detail. SCBC efficiencies of 95 percent to 98 percent have been measured. Finally, a modular, photovoltaic regulator 'kit' concept is presented. Two SCBC's are used to regulate solar array charging of batteries and to provide 'utilitytype' power to the user loads. The kit's modularity will allow a spacecraft electric power system to be built from off-the-shelf hardware; resulting in smaller, faster, and cheaper spacecraft.

Comprehensive evaluation of power grid projects' investment benefits under the reform of transmission and distribution price

NASA Astrophysics Data System (ADS)

Wang, Yongli; Wang, Gang; Zuo, Yi; Fan, Lisha; Ling, Yunpeng

2017-03-01

On March 15, 2015, the Central Office issued the "Opinions on Further Deepening the Reform of Electric Power System" (Zhong Fa No. 9). This policy marks the central government officially opened a new round of electricity reform. As a programmatic document under the new situation to comprehensively promote the reform of the power system, No. 9 document will be approved as a separate transmission and distribution of electricity prices, which is the first task of promoting the reform of the power system. Grid tariff reform is not only the transmission and distribution price of a separate approval, more of the grid company input-output relationship and many other aspects of deep-level adjustments. Under the background of the reform of the transmission and distribution price, the main factors affecting the input-output relationship, such as the main business, electricity pricing, and investment approval, financial accounting and so on, have changed significantly. The paper designed the comprehensive evaluation index system of power grid projects' investment benefits under the reform of transmission and distribution price to improve the investment efficiency of power grid projects after the power reform in China.

Engineering of beam direct conversion for a 120-kV, 1-MW ion beam

NASA Technical Reports Server (NTRS)

Barr, W. L.; Doggett, J. N.; Hamilton, G. W.; Kinney, J. D.; Moir, R. W.

1977-01-01

Practical systems for beam direct conversion are required to recover the energy from ion beams at high efficiency and at very high beam power densities in the environment of a high-power neutral-injection system. Such an experiment is now in progress using a 120-kV beam with a maximum total current of 20 A. After neutralization, the H(+) component to be recovered will have a power of approximately 1 MW. A system testing these concepts has been designed and tested at 15 kV, 2 kW in preparation for the full-power tests. The engineering problems involved in the full-power tests affect electron suppression, gas pumping, voltage holding, diagnostics, and measurement conditions. Planning for future experiments at higher power includes the use of cryopumping and electron suppression by a magnetic field rather than by an electrostatic field. Beam direct conversion for large fusion experiments and reactors will save millions of dollars in the cost of power supplies and electricity and will dispose of the charged beam under conditions that may not be possible by other techniques.

Lessons unlearned in Japan before 2011: Effects of the 2004 Indian Ocean tsunami on a nuclear plant in India

NASA Astrophysics Data System (ADS)

Sugimoto, M.

2015-12-01

The 2004 Indian Ocean tsunami killed around 220,000 people and startled the world. North of Chennai (Madras), the Indian plant nearly affected by tsunami in 2004. The local residents really did not get any warning in India. "On December 26, the Madras Atomic Power Station looked like a desolate place with no power, no phones, no water, no security arrangement and no hindrance whatsoever for outsiders to enter any part of the plant," said S.P. Udaykumar of SACCER. Nuclear issues hide behind such big tsunami damaged. Few media reported outside India. As for US, San Francisco Chronicle reported scientists had to rethink about nuclear power plants by the 2004 tsunami in 11th July 2005. Few tsunami scientsts did not pay attention to nucler power plants nearly affected by tsunami in US. On the other hand, US government noticed the Indian plant nearly affected in 2004. US Goverment supported nucler disaster management in several countries. As for Japan, Japanese goverment mainly concentrated reconstrucation in affected areas and tsunami early warning system. I worked in Japanese embassy in Jakarta Indonesia at that time. I did not receive the information about the Indian plant nearly affected by tsunami and US supported nucler safety to the other coutries. The 2011 Tohoku earthquake and tsunami damaged society and nuclear power stations. The Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident resulted in the largest release of radioactive material since the 1986 Chernobyl accident. Why did not Japanese tsunami scientists learn from warning signs from the nuclear plant in India by the 2004 Indian Ocean tsunami to the 2011 Fukushima accident? I would like to clarify the reason few tsunami scientist notice this point in my presentation.

An innovative integrated system utilizing solar energy as power for the treatment of decentralized wastewater.

PubMed

Han, Changfu; Liu, Junxin; Liang, Hanwen; Guo, Xuesong; Li, Lin

2013-02-01

This article reports an innovative integrated system utilizing solar energy as power for decentralized wastewater treatment, which consists of an oxidation ditch with double channels and a photovoltaic (PV) system without a storage battery. Because the system operates without a storage battery, which can reduce the cost of the PV system, the solar radiation intensity affects the amount of power output from the PV system. To ensure that the power output is sufficient in all different weather conditions, the solar radiation intensity of 78 W/m2 with 95% confidence interval was defined as a threshold of power output for the PV system according to the monitoring results in this study, and a step power output mode was used to utilize the solar energy as well as possible. The oxidation ditch driven by the PV system without storage battery ran during the day and stopped at night. Therefore, anaerobic, anoxic and aerobic conditions could periodically appear in the oxidation ditch, which was favorable to nitrogen and phosphate removal from the wastewater. The experimental results showed that the system was efficient, achieving average removal efficiencies of 88% COD, 98% NH4+-N, 70% TN and 83% TP, under the loading rates of 140 mg COD/(g MLSS x day), 32 mg NH4+-N/(g MLSS x day), 44 mg TN/(g MLSS x day) and 5 mg TP/(g MLSS x day).

I Like the Way This Feels: Using Classroom Response System Technology to Enhance Tactile Learners' Introductory American Government Experience

ERIC Educational Resources Information Center

Ulbig, Stacy G.

2016-01-01

Do individual-level student learning styles affect appreciation for and benefit from the use of classroom response system technology? This research investigates the benefit of in-class electronic classroom response systems ("classroom clickers"). With these systems, students answer questions posed to them in a PowerPoint presentation…

Electric power - Photovoltaic or solar dynamic?

NASA Technical Reports Server (NTRS)

Thomas, R. L.; Hallinan, G. J.; Hieatt, J. L.

1985-01-01

The design of the power system for supplying the Space Station with insolation-generated electricity is the main Phase B task at NASA-Lewis Center. The advantages and limitations of two types of power systems, the photovoltaic arrays (PV) and the solar dynamic system (SD), are discussed from the points of view of cost, overall systems integration, and growth. Subsystems of each of these options are described, and a sketch of a projected SD system is shown. The PV technology is well developed and proven, but its low efficiency calls for solar arrays of large areas, which affect station dynamics, control, and drag compensation. The SD systems would be less costly to operate than VP, and are more efficient, needing less deployed area. The major drawback of the SD is its infancy. The conservative and forgiving designs for some of its components must still be created and tested, and the development risks assessed.

Flight experience of Solar Mesosphere Explorer's two nickel-cadmium batteries

NASA Technical Reports Server (NTRS)

Faber, J.

1985-01-01

The performance of the power system on the solar mesosphere explorer (SME) since launch is discussed. Predictions for continued operation for the rest of the project mission are also discussed. The SME satellite's power system was characterized by both insufficient loading and excessive battery charging during the first year of the mission. These conditions affected battery performance and jeopardized the long-term mission. Increased loading on selected orbits has improved battery performance. Long term projections indicate steadily increasing temperatures for the remainder of the mission.

Conditional quantum entropy power inequality for d-level quantum systems

NASA Astrophysics Data System (ADS)

Jeong, Kabgyun; Lee, Soojoon; Jeong, Hyunseok

2018-04-01

We propose an extension of the quantum entropy power inequality for finite dimensional quantum systems, and prove a conditional quantum entropy power inequality by using the majorization relation as well as the concavity of entropic functions also given by Audenaert et al (2016 J. Math. Phys. 57 052202). Here, we make particular use of the fact that a specific local measurement after a partial swap operation (or partial swap quantum channel) acting only on finite dimensional bipartite subsystems does not affect the majorization relation for the conditional output states when a separable ancillary subsystem is involved. We expect our conditional quantum entropy power inequality to be useful, and applicable in bounding and analyzing several capacity problems for quantum channels.

Design considerations for space radiators based on the liquid sheet (LSR) concept

NASA Technical Reports Server (NTRS)

Juhasz, Albert J.; Chubb, Donald L.

1991-01-01

This study is directed at performing a comparative examination of LSR characteristics as they affect the basic design of low earth orbit solar dynamic conversion systems. The power systems considered were based on the closed Brayton (CBC) and the free piston Stirling (FPS) cycles, each with a power output of 2 kWe and using previously tested silicone oil (Dow-Corning Me2) as the radiator working fluid. Conclusions indicate that, due to its ability for direct cold end cooling, an LSR based heat rejection subsystem is far more compatible with a Stirling space power system than with a CBC, which requires LSR coupling by means of an intermediate gas/liquid heat exchanger and adjustment of cycle operating conditions.

Neutron and gamma irradiation effects on power semiconductor switches

NASA Technical Reports Server (NTRS)

Schwarze, G. E.; Frasca, A. J.

1990-01-01

The performance characteristics of high-power semiconductor switches subjected to high levels of neutron fluence and gamma dose must be known by the designer of the power conditioning, control and transmission subsystem of space nuclear power systems. Location and the allowable shielding mass budget will determine the level of radiation tolerance required by the switches to meet performance and reliability requirements. Neutron and gamma ray interactions with semiconductor materials and how these interactions affect the electrical and switching characteristics of solid state power switches is discussed. The experimental measurement system and radiation facilities are described. Experimental data showing the effects of neutron and gamma irradiation on the performance characteristics are given for power-type NPN Bipolar Junction Transistors (BJTs), and Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs). BJTs show a rapid decrease in gain, blocking voltage, and storage time for neutron irradiation, and MOSFETs show a rapid decrease in the gate threshold voltage for gamma irradiation.

Neutron and gamma irradiation effects on power semiconductor switches

NASA Technical Reports Server (NTRS)

Schwarze, G. E.; Frasca, A. J.

1990-01-01

The performance characteristics of high power semiconductor switches subjected to high levels of neutron fluence and gamma dose must be known by the designer of the power conditioning, control and transmission subsystem of space nuclear power systems. Location and the allowable shielding mass budget will determine the level of radiation tolerance required by the switches to meet performance and reliability requirements. Neutron and gamma ray interactions with semiconductor materials and how these interactions affect the electrical and switching characteristics of solid state power switches is discussed. The experimental measurement system and radiation facilities are described. Experimental data showing the effects of neutron and gamma irradiation on the performance characteristics are given for power-type NPN Bipolar Junction Transistors (BJTs), and Metal-Oxide-Semiconductor Field Effect Transistors (MOSFETs). BJTs show a rapid decrease in gain, blocking voltage, and storage time for neutron irradiation, and MOSFETs show a rapid decrease in the gate threshold voltage for gamma irradiation.

Bidirectional peripheral nerve interface and applications.

PubMed

Thakor, Nitish V; Qihong Wang; Greenwald, Elliot

2016-08-01

Peripheral nerves, due to their small size and complex innervation to organs and complex physiology, pose particularly significant challenges towards interfacing electrodes and electronics to enable neuromodulation. Here, we present a review of the technology for building such interface, including recording and stimulating electrodes and low power electronics, as well as powering. Of particular advantage to building a miniature implanted device is a "bidirectional" system that both senses from the nerves or surrogate organs and stimulates the nerves to affect the organ function. This review and presentation will cover a range of electrodes, electronics, wireless power and data schemes and system integration, and will end with some examples and applications.

Hydrogen Storage for Aircraft Applications Overview

NASA Technical Reports Server (NTRS)

Colozza, Anthony J.; Kohout, Lisa (Technical Monitor)

2002-01-01

Advances in fuel cell technology have brought about their consideration as sources of power for aircraft. This power can be utilized to run aircraft systems or even provide propulsion power. One of the key obstacles to utilizing fuel cells on aircraft is the storage of hydrogen. An overview of the potential methods of hydrogen storage was compiled. This overview identifies various methods of hydrogen storage and points out their advantages and disadvantages relative to aircraft applications. Minimizing weight and volume are the key aspects to storing hydrogen within an aircraft. An analysis was performed to show how changes in certain parameters of a given storage system affect its mass and volume.

Optimization of hydraulic turbine governor parameters based on WPA

NASA Astrophysics Data System (ADS)

Gao, Chunyang; Yu, Xiangyang; Zhu, Yong; Feng, Baohao

2018-01-01

The parameters of hydraulic turbine governor directly affect the dynamic characteristics of the hydraulic unit, thus affecting the regulation capacity and the power quality of power grid. The governor of conventional hydropower unit is mainly PID governor with three adjustable parameters, which are difficult to set up. In order to optimize the hydraulic turbine governor, this paper proposes wolf pack algorithm (WPA) for intelligent tuning since the good global optimization capability of WPA. Compared with the traditional optimization method and PSO algorithm, the results show that the PID controller designed by WPA achieves a dynamic quality of hydraulic system and inhibits overshoot.

Thermal pollution consequences of the implementation of the president's energy message on increased coal utilization.

PubMed Central

Parker, F L

1979-01-01

The thermal consequences of coal utilization are most meaningfully assessed in comparison with the form of power generation replaced by coal which is most likely nuclear. The different effects are influenced by siting decisions and the intrinsic thermal efficiencies of the two fuel systems. Nuclear power plants discharge 50% more waste Rheat to the atmosphere through cooling towers or to a water body than coal-fired plants. Coal-fired plants require about 2/3 as much water as nuclear power plants. Nearly every property of water is affected nonlinearly by temperature, and biological effects may amplify these changes because protein denaturation takes place more rapidly above 30 degrees C and these high temperatures affect bactericidal and viricidal activity of chlorine compounds. Usually algal populations change from a dominance of diatoms and green algae to dominance by blue-green algae. All organisms experience elevated metabolic rates at higher temperatures which may affect total energy needs, foraging ability, reproduction, migration and susceptibility to disease. Intake structures inevitably draw many organisms into the cooling system of a power plant, but the number and kind are influenced by its location, configuration, and mode of operation. Use of water recirculation systems reduces water use and with it, the number of organisms entrained. Mechanical damage in the cooling system to small organisms is generally low, but fish and their larvae and eggs may be seriously damaged. Discharge effects may also be severe but are generally local. The near field, where there are strong shear velocities and rapid temperature changes are particularly stressful to fish, and stringent limitations on the timing and strength of discharges may be required to reduce these stresses to nondamaging levels. Off-stream cooling systems may increase cloudiness, ground fog, precipitation, temperature and local winds, but these effects generally extend no further than 1000 m even in winter. There is considerable potential for using condenser cooling water for agricultural and aquacultural purposes such as irrigation, frost protection, undersoil heating, greenhouse heating and climate control. However, over the next few decades little of this waste heat is likely to be used creatively. The thermal consequences of implementing NEP are locally serious but do not pose regional problems. Creative use of the waste heat for aquaculture, agriculture, cogeneration, and power for energy intensive industries can be a powerful means of mitigating undesirable effects. PMID:540623

Solar energy/utility interface - The technical issues

NASA Astrophysics Data System (ADS)

Tabors, R. D.; White, D. C.

1982-01-01

The technical and economic factors affecting an interface between solar/wind power sources and utilities are examined. Photovoltaic, solar thermal, and wind powered systems are subject to stochastic local climatic variations and as such may require full back-up services from utilities, which are then in a position of having reserve generating power and power lines and equipment which are used only part time. The low reliability which has degraded some economies of scale formerly associated with large, centralized power plants, and the lowered rate of the increase in electricity usage is taken to commend the inclusion of power sources with a modular nature such as is available from solar derived electrical generation. Technical issues for maintaining the quality of grid power and also effectively metering purchased and supplied back-up power as part of a homeostatic system of energy control are discussed. It is concluded that economic considerations, rather than technical issues, bear the most difficulty in integrating solar technologies into the utility network.

Electromagnetic interference in electrical systems of motor vehicles

NASA Astrophysics Data System (ADS)

Dziubiński, M.; Drozd, A.; Adamiec, M.; Siemionek, E.

2016-09-01

Electronic ignition system affects the electronic equipment of the vehicle by electric and magnetic fields. The measurement of radio electromagnetic interference originating from the ignition system affecting the audiovisual test bench was carried out with a variable speed of the ignition system. The paper presents measurements of radio electromagnetic interference in automobiles. In order to determine the level of electromagnetic interference, the audiovisual test bench was equipped with a set of meters for power consumption and assessment of the level of electromagnetic interference. Measurements of the electromagnetic interference level within the audiovisual system were performed on an experimental test bench consisting of the ignition system, starting system and charging system with an alternator and regulator.

Probabilistic performance assessment of complex energy process systems - The case of a self-sustained sanitation system.

PubMed

Kolios, Athanasios; Jiang, Ying; Somorin, Tosin; Sowale, Ayodeji; Anastasopoulou, Aikaterini; Anthony, Edward J; Fidalgo, Beatriz; Parker, Alison; McAdam, Ewan; Williams, Leon; Collins, Matt; Tyrrel, Sean

2018-05-01

A probabilistic modelling approach was developed and applied to investigate the energy and environmental performance of an innovative sanitation system, the "Nano-membrane Toilet" (NMT). The system treats human excreta via an advanced energy and water recovery island with the aim of addressing current and future sanitation demands. Due to the complex design and inherent characteristics of the system's input material, there are a number of stochastic variables which may significantly affect the system's performance. The non-intrusive probabilistic approach adopted in this study combines a finite number of deterministic thermodynamic process simulations with an artificial neural network (ANN) approximation model and Monte Carlo simulations (MCS) to assess the effect of system uncertainties on the predicted performance of the NMT system. The joint probability distributions of the process performance indicators suggest a Stirling Engine (SE) power output in the range of 61.5-73 W with a high confidence interval (CI) of 95%. In addition, there is high probability (with 95% CI) that the NMT system can achieve positive net power output between 15.8 and 35 W. A sensitivity study reveals the system power performance is mostly affected by SE heater temperature. Investigation into the environmental performance of the NMT design, including water recovery and CO 2 /NO x emissions, suggests significant environmental benefits compared to conventional systems. Results of the probabilistic analysis can better inform future improvements on the system design and operational strategy and this probabilistic assessment framework can also be applied to similar complex engineering systems.

76 FR 52871 - Pseudomonas fluorescens Strain CL145A; Exemption From the Requirement of a Tolerance

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-24

..., hydroelectric power facility operator or water supply system operator. Potentially affected entities may include... (NAICS code 221111). Water supply and irrigation systems (NAICS code 221310). This listing is not... treatment areas are limited to completely enclosed pipe or water conveyance systems or concrete chambers...

46 CFR 58.30-5 - Design requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 2 2010-10-01 2010-10-01 false Design requirements. 58.30-5 Section 58.30-5 Shipping... AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-5 Design requirements. (a) The.... (b) The system shall be so designed that proper functioning of any unit shall not be affected by the...

46 CFR 58.30-5 - Design requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 46 Shipping 2 2011-10-01 2011-10-01 false Design requirements. 58.30-5 Section 58.30-5 Shipping... AND RELATED SYSTEMS Fluid Power and Control Systems § 58.30-5 Design requirements. (a) The.... (b) The system shall be so designed that proper functioning of any unit shall not be affected by the...

Low power multi-camera system and algorithms for automated threat detection

NASA Astrophysics Data System (ADS)

Huber, David J.; Khosla, Deepak; Chen, Yang; Van Buer, Darrel J.; Martin, Kevin

2013-05-01

A key to any robust automated surveillance system is continuous, wide field-of-view sensor coverage and high accuracy target detection algorithms. Newer systems typically employ an array of multiple fixed cameras that provide individual data streams, each of which is managed by its own processor. This array can continuously capture the entire field of view, but collecting all the data and back-end detection algorithm consumes additional power and increases the size, weight, and power (SWaP) of the package. This is often unacceptable, as many potential surveillance applications have strict system SWaP requirements. This paper describes a wide field-of-view video system that employs multiple fixed cameras and exhibits low SWaP without compromising the target detection rate. We cycle through the sensors, fetch a fixed number of frames, and process them through a modified target detection algorithm. During this time, the other sensors remain powered-down, which reduces the required hardware and power consumption of the system. We show that the resulting gaps in coverage and irregular frame rate do not affect the detection accuracy of the underlying algorithms. This reduces the power of an N-camera system by up to approximately N-fold compared to the baseline normal operation. This work was applied to Phase 2 of DARPA Cognitive Technology Threat Warning System (CT2WS) program and used during field testing.

Photovoltaic utility/customer interface study

NASA Astrophysics Data System (ADS)

Eichler, C. H.; Hayes, T. P.; Matthews, M. M.; Wilraker, V. F.

1980-12-01

The technical, economic, and legal and regulatory issues of interconnecting small, privately-owned, on-site photovoltaic generating systems to an electric utility are addressed. Baseline residential, commercial and industrial class photovoltaic systems were developed. Technical issues of concern affecting this interconnection were identified and included fault protection, undervoltage protection, lamp flicker, revenue metering, loss of synchromism, electrical safety, prevention of backfeeding a de-energized utility feeder, effects of on-site generation on utility relaying schemes, effects of power conditioner harmonic distortion on the electric utility, system isolation, electromagnetic interference and site power factor as seen by the utility. Typical interconnection wiring diagrams were developed for interconnecting each class of baseline photovoltaic generating system.

The Effect of Mitigation Policy on Regional Climate Impacts on the U.S. Electric Sector

NASA Astrophysics Data System (ADS)

Cohen, S. M.; Sun, Y.; Strzepek, K.; McFarland, J.; Boehlert, B.; Fant, C.

2017-12-01

Climate change can influence the U.S. electricity sector in many ways, the nature of which can be shaped by energy and environmental policy choices. Changing temperatures affect electricity demand largely through heating and cooling needs, and temperatures also affect generation and transmission system performance. Altered precipitation patterns affect the regional and seasonal distribution of surface water runoff, which changes hydropower operation and thermal cooling water availability. The extent to which these stimuli influence U.S. power sector operation and planning will depend to some extent on whether or not proactive policies are enacted to mitigate these impacts. Mitigation policies such as CO2 emissions limits or technology restrictions can change the makeup of the electricity system while reducing the extent of climate change itself. We use the National Renewable Energy Laboratory's Regional Energy Deployment System (ReEDS), a U.S. electric sector capacity expansion model, to explore electric sector evolution through 2050 under alternative climate and policy assumptions. The model endogenously represents climate impacts on load, power system performance, cooling water availability, and hydropower, allowing internally consistent system responses to climate change along with projected technology, market, and policy conditions. We compare climate impacts across 5 global circulation models for a 8.5 W/m2 representative concentration pathway (RCP) without a climate mitigation policy and a 4.5 W/m2 RCP with climate mitigation. Climate drivers affect the capacity and generation mix at the national and regional levels, with relative growth of wind, solar, and natural gas-based technologies depending on local electricity system characteristics. These differences affect regional economic impacts, measured here as changes to electricity price and system costs. Mitigation policy reduces the economic and system impacts of climate change largely by moderating temperature-induced load but also by lessening water- and temperature-based performance constraints. Policy impacts are nuanced and region-specific, and this analysis underscores the importance of climate mitigation policy to regional electricity system planning decisions.

How to do (or not to do)… gender analysis in health systems research.

PubMed

Morgan, Rosemary; George, Asha; Ssali, Sarah; Hawkins, Kate; Molyneux, Sassy; Theobald, Sally

2016-10-01

Gender-the socially constructed roles, behaviours, activities and attributes that a given society considers appropriate for males, females and other genders-affects how people live, work and relate to each other at all levels, including in relation to the health system. Health systems research (HSR) aims to inform more strategic, effective and equitable health systems interventions, programs and policies; and the inclusion of gender analysis into HSR is a core part of that endeavour. We outline what gender analysis is and how gender analysis can be incorporated into HSR content, process and outcomes Starting with HSR content, i.e. the substantive focus of HSR, we recommend exploring whether and how gender power relations affect females and males in health systems through the use of sex disaggregated data, gender frameworks and questions. Sex disaggregation flags female-male differences or similarities that warrant further analysis; and further analysis is guided by gender frameworks and questions to understand how gender power relations are constituted and negotiated in health systems. Critical aspects of understanding gender power relations include examining who has what (access to resources); who does what (the division of labour and everyday practices); how values are defined (social norms) and who decides (rules and decision-making). Secondly, we examine gender in HSR process by reflecting on how the research process itself is imbued with power relations. We focus on data collection and analysis by reviewing who participates as respondents; when data is collected and where; who is present; who collects data and who analyses data. Thirdly, we consider gender and HSR outcomes by considering who is empowered and disempowered as a result of HSR, including the extent to which HSR outcomes progressively transform gender power relations in health systems, or at least do not further exacerbate them. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Solar Dynamic Power System Stability Analysis and Control

NASA Technical Reports Server (NTRS)

Momoh, James A.; Wang, Yanchun

1996-01-01

The objective of this research is to conduct dynamic analysis, control design, and control performance test of solar power system. Solar power system consists of generation system and distribution network system. A bench mark system is used in this research, which includes a generator with excitation system and governor, an ac/dc converter, six DDCU's and forty-eight loads. A detailed model is used for modeling generator. Excitation system is represented by a third order model. DDCU is represented by a seventh order system. The load is modeled by the combination of constant power and constant impedance. Eigen-analysis and eigen-sensitivity analysis are used for system dynamic analysis. The effects of excitation system, governor, ac/dc converter control, and the type of load on system stability are discussed. In order to improve system transient stability, nonlinear ac/dc converter control is introduced. The direct linearization method is used for control design. The dynamic analysis results show that these controls affect system stability in different ways. The parameter coordination of controllers are recommended based on the dynamic analysis. It is concluded from the present studies that system stability is improved by the coordination of control parameters and the nonlinear ac/dc converter control stabilize system oscillation caused by the load change and system fault efficiently.

The Power of Their Voice: Promoting Equal Respect and Redistributing Power in Hierarchically Differentiated Groups

ERIC Educational Resources Information Center

Sanchez-Griego, Karen

2010-01-01

Todos Juntos New Mexico was a collaborative made possible through a multimillion dollar grant awarded by the Fellows Foundation to empower the community, students, and educators in New Mexico to affect positive change in our public educational system, leading to increased student success, not just for Hispanics, but for all students. Of particular…

Review Of Laser Lightcraft Propulsion System

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

Davis, Eric W.; Mead, Franklin B. Jr

Laser-powered 'Lightcraft' systems that deliver nano-satellites to LEO have been studied for the Air Force Research Laboratory (AFRL). The study was built on the extensive Lightcraft laser propulsion technology already developed by theoretical and experimental work by the AFRL's Propulsion Directorate at Edwards AFB, CA. Here we review the history and engineering-physics of the laser Lightcraft system and its propulsive performance. We will also review the effectiveness and cost of a Lightcraft vehicle powered by a high-energy laser beam. One result of this study is the significant influence of laser wavelength on the power lost during laser beam propagation throughmore » Earth's atmosphere and in space. It was discovered that energy and power losses in the laser beam are extremely sensitive to wavelength for Earth-To-Orbit missions, and this significantly affects the amount of mass that can be placed into orbit for a given maximum amount of radiated power from a ground-based laser.« less

Degradation and ESR Failures in MnO2 Chip Tantalum Capacitors

NASA Technical Reports Server (NTRS)

Teverovsky, Alexander A.

2017-01-01

Equivalent series resistance (ESR) of chip tantalum capacitors determines the rate of energy delivery and power dissipation thus affecting temperature and reliability of the parts. Employment of advanced capacitors with reduced ESR decreases power losses and improves efficiency in power systems. Stability of ESR is essential for correct operations of power units and might cause malfunctioning and failures when ESR becomes too high or too low. Several cases with ESR values in CWR29 capacitors exceeding the specified limit that were observed recently raised concerns regarding environmental factors affecting ESR and the adequacy of the existing screening and qualification testing. In this work, results of stress testing of various types of military and commercial capacitors obtained over years by GSFC test lab and NEPP projects that involved ESR measurements are described. Environmental stress tests include testing in humidity and vacuum chambers, temperature cycling, long-term storage at high temperatures, and various soldering simulation tests. Note that in many cases parts failed due to excessive leakage currents or reduced breakdown voltages. However, only ESR-related degradation and failures are discussed. Mechanisms of moisture effect are discussed and recommendations to improve screening and qualification system are suggested.

14 CFR 23.1203 - Fire detector system.

Code of Federal Regulations, 2011 CFR

2011-01-01

... in— (1) An engine compartment of— (i) Multiengine turbine powered airplanes; (ii) Multiengine... may be subjected in operation. (c) No fire detector may be affected by any oil, water, other fluids...

14 CFR 23.1203 - Fire detector system.

Code of Federal Regulations, 2010 CFR

2010-01-01

... in— (1) An engine compartment of— (i) Multiengine turbine powered airplanes; (ii) Multiengine... may be subjected in operation. (c) No fire detector may be affected by any oil, water, other fluids...

14 CFR 23.1203 - Fire detector system.

Code of Federal Regulations, 2014 CFR

2014-01-01

... in— (1) An engine compartment of— (i) Multiengine turbine powered airplanes; (ii) Multiengine... may be subjected in operation. (c) No fire detector may be affected by any oil, water, other fluids...

14 CFR 23.1203 - Fire detector system.

Code of Federal Regulations, 2013 CFR

2013-01-01

... in— (1) An engine compartment of— (i) Multiengine turbine powered airplanes; (ii) Multiengine... may be subjected in operation. (c) No fire detector may be affected by any oil, water, other fluids...

14 CFR 23.1203 - Fire detector system.

Code of Federal Regulations, 2012 CFR

2012-01-01

... in— (1) An engine compartment of— (i) Multiengine turbine powered airplanes; (ii) Multiengine... may be subjected in operation. (c) No fire detector may be affected by any oil, water, other fluids...

Analysis of a utility-interactive wind-photovoltaic hybrid system with battery storage using neural network

NASA Astrophysics Data System (ADS)

Giraud, Francois

1999-10-01

This dissertation investigates the application of neural network theory to the analysis of a 4-kW Utility-interactive Wind-Photovoltaic System (WPS) with battery storage. The hybrid system comprises a 2.5-kW photovoltaic generator and a 1.5-kW wind turbine. The wind power generator produces power at variable speed and variable frequency (VSVF). The wind energy is converted into dc power by a controlled, tree-phase, full-wave, bridge rectifier. The PV power is maximized by a Maximum Power Point Tracker (MPPT), a dc-to-dc chopper, switching at a frequency of 45 kHz. The whole dc power of both subsystems is stored in the battery bank or conditioned by a single-phase self-commutated inverter to be sold to the utility at a predetermined amount. First, the PV is modeled using Artificial Neural Network (ANN). To reduce model uncertainty, the open-circuit voltage VOC and the short-circuit current ISC of the PV are chosen as model input variables of the ANN. These input variables have the advantage of incorporating the effects of the quantifiable and non-quantifiable environmental variants affecting the PV power. Then, a simplified way to predict accurately the dynamic responses of the grid-linked WPS to gusty winds using a Recurrent Neural Network (RNN) is investigated. The RNN is a single-output feedforward backpropagation network with external feedback, which allows past responses to be fed back to the network input. In the third step, a Radial Basis Functions (RBF) Network is used to analyze the effects of clouds on the Utility-Interactive WPS. Using the irradiance as input signal, the network models the effects of random cloud movement on the output current, the output voltage, the output power of the PV system, as well as the electrical output variables of the grid-linked inverter. Fourthly, using RNN, the combined effects of a random cloud and a wind gusts on the system are analyzed. For short period intervals, the wind speed and the solar radiation are considered as the sole sources of power, whose variations influence the system variables. Since both subsystems have different dynamics, their respective responses are expected to impact differently the whole system behavior. The dispatchability of the battery-supported system as well as its stability and reliability during gusts and/or cloud passage is also discussed. In the fifth step, the goal is to determine to what extent the overall power quality of the grid would be affected by a proliferation of Utility-interactive hybrid system and whether recourse to bulky or individual filtering and voltage controller is necessary. The final stage of the research includes a steady-state analysis of two-year operation (May 96--Apr 98) of the system, with a discussion on system reliability, on any loss of supply probability, and on the effects of the randomness in the wind and solar radiation upon the system design optimization.

Advanced nickel-hydrogen cell configuration study

NASA Technical Reports Server (NTRS)

1983-01-01

Long-term trends in the evolution of space power technology point toward increased payload power demand which in turn translates into both higher battery system charge storage capability and higher operating voltages. State of the art nickel-hydrogen cells of the 50 to 60 Wh size, packaged in individual pressure vessels, are capable of meeting the required cycle life for a wide range of anticipated operating conditions; however, they provided several drawbacks to battery system integrated efforts. Because of size, high voltage/high power systems require integrating hundreds of cells into the operating system. Packaging related weight and volume inefficiencies degrade the energy density and specific energy of individual cells currently at 30 Wh/cudm and 40 Wh/kg respectively. In addition, the increased parts count and associated handling significantly affect the overall battery related costs. Spacecraft battery systems designers within industry and Government realize that to reduce weight, volume, and cost requires increases in the capacity of nickel-hydrogen cells.

Multiple Solutions for Reconfiguration to Address Partial Shading Losses in Solar Photovoltaic Arrays

NASA Astrophysics Data System (ADS)

Sharma, Nikesh; Pareek, Smita; Chaturvedi, Nitin; Dahiya, Ratna

2018-03-01

Solar photovoltaic (SPV) systems are steadily rising and considered as the best alternatives to meet the rising demand of energy. In developing countries like India, SPV’s contribution being a clean energy is the most favourable. However, experiences have shown that produced power of these systems is usually affected due to day, night, seasonal variations, insolation, partial shading conditions etc. Among these parameters, partial shading causes a huge reduction in output power of PV systems. This results in lack of confidence for this technology among users. Thus, it is important and a major challenge in PV systems to minimize the effect of partial shading on their energy production. The work in this paper aims to propose solutions for reconfiguration of solar photovoltaic arrays in order to reduce partial shading losses and thus to enhance power generation.

Low power infrared laser modifies the morphology of lung affected with acute injury induced by sepsis

NASA Astrophysics Data System (ADS)

Sergio, L. P. S.; Trajano, L. A. S. N.; Thomé, A. M. C.; Mencalha, A. L.; Paoli, F.; Fonseca, A. S.

2018-06-01

Acute lung injury (ALI) is a potentially fatal disease characterized by uncontrolled hyperinflammatory responses in the lungs as a consequence of sepsis. ALI is divided into two sequential and time-dependent phases, exudative and fibroproliferative phases, with increased permeability of the alveolar barrier, causing edema and inflammation. However, there are no specific treatments for ALI. Low-power lasers have been successfully used in the resolution of acute inflammatory processes. The aim of this study was to evaluate the effects of low-power infrared laser exposure on alveolus and interalveolar septa of Wistar rats affected by ALI-induced by sepsis. Laser fluences, power, and the emission mode were those used in clinical protocols for the treatment of acute inflammation. Adult male Wistar rats were randomized into six groups: control, 10 J cm‑2, 20 J cm‑2, ALI, ALI  +  10 J cm‑2, and ALI  +  20 J cm‑2. ALI was induced by intraperitoneal Escherichia coli lipopolysaccharide (LPS). Lungs were removed and processed for hematoxylin–eosin staining. Morphological alterations induced by LPS in lung tissue were quantified by morphometry with a 32-point cyclic arcs test system in Stepanizer. Data showed that exposure to low-power infrared laser in both fluences reduced the thickening of interalveolar septa in lungs affected by ALI, increasing the alveolar space; however, inflammatory infiltrate was still observed. Our research showed that exposure to low-power infrared laser improves the lung parenchyma in Wistar rats affected by ALI, which could be an alternative approach for treatment of inflammatory lung injuries.

Illustration of distributed generation effects on protection system coordination

NASA Astrophysics Data System (ADS)

Alawami, Hussain Adnan

Environmental concerns, market forces, and emergence of new technologies have recently resulted in restructuring electric utility from vertically integrated networks to competitive deregulated entities. Distributed generation (DG) is playing a major role in such deregulated markets. When they are installed in small amounts and small sizes, their impacts on the system may be negligible. When their penetration levels increase as well as their sizes, however, they may start affecting the system performance from more than one aspect. Power system protection needs to be re-assessed after the emergence of DG. This thesis attempts to illustrate the impact of DG on the power system protection coordination. It will study the operation of the impedance relays, fuses, reclosers and overcurrent relays when a DG is added to the distribution network. Different DG sizes, distances from the network and locations within the distribution system will be considered. Power system protection coordination is very sensitive to the DG size where it is not for the DG distance. DG location has direct impact on the operation of the protective devices especially when it is inserted in the middle point of the distribution system. Key Words, Distributed Generation, Impedance relay, fuses, reclosers, overcurrent relays, power system protection coordination.

Integrating plug-in electric vehicles into the electric power system

NASA Astrophysics Data System (ADS)

Wu, Di

This dissertation contributes to our understanding of how plug-in hybrid electric vehicles (PHEVs) and plug-in battery-only electric vehicles (EVs)---collectively termed plug-in electric vehicles (PEVs)---could be successfully integrated with the electric power system. The research addresses issues at a diverse range of levels pertaining to light-duty vehicles, which account for the majority of highway vehicle miles traveled, energy consumed by highway travel modes, and carbon dioxide emissions from on-road sources. Specifically, the following topics are investigated: (i) On-board power electronics topologies for bidirectional vehicle-to-grid and grid-to-vehicle power transfer; (ii) The estimation of the electric energy and power consumption by fleets of light-duty PEVs; (iii) An operating framework for the scheduling and dispatch of electric power by PEV aggregators; (iv) The pricing of electricity by PHEV aggregators and how it affects the decision-making process of a cost-conscious PHEV owner; (v) The impacts on distribution systems from PEVs under aggregator control; (vi) The modeling of light-duty PEVs for long-term energy and transportation planning at a national scale.

Rich-burn, flame-assisted fuel cell, quick-mix, lean-burn (RFQL) combustor and power generation

NASA Astrophysics Data System (ADS)

Milcarek, Ryan J.; Ahn, Jeongmin

2018-03-01

Micro-tubular flame-assisted fuel cells (mT-FFC) were recently proposed as a modified version of the direct flame fuel cell (DFFC) operating in a dual chamber configuration. In this work, a rich-burn, quick-mix, lean-burn (RQL) combustor is combined with a micro-tubular solid oxide fuel cell (mT-SOFC) stack to create a rich-burn, flame-assisted fuel cell, quick-mix, lean-burn (RFQL) combustor and power generation system. The system is tested for rapid startup and achieves peak power densities after only 35 min of testing. The mT-FFC power density and voltage are affected by changes in the fuel-lean and fuel-rich combustion equivalence ratio. Optimal mT-FFC performance favors high fuel-rich equivalence ratios and a fuel-lean combustion equivalence ratio around 0.80. The electrical efficiency increases by 150% by using an intermediate temperature cathode material and improving the insulation. The RFQL combustor and power generation system achieves rapid startup, a simplified balance of plant and may have applications for reduced NOx formation and combined heat and power.

Drying kinetics and characteristics of combined infrared-vacuum drying of button mushroom slices

NASA Astrophysics Data System (ADS)

Salehi, Fakhreddin; Kashaninejad, Mahdi; Jafarianlari, Ali

2017-05-01

Infrared-vacuum drying characteristics of button mushroom ( Agaricus bisporus) were evaluated in a combined dryer system. The effects of drying parameters, including infrared radiation power (150-375 W), system pressure (5-15 kPa) and time (0-160 min) on the drying kinetics and characteristics of button mushroom slices were investigated. Both the infrared lamp power and vacuum pressure influenced the drying time of button mushroom slices. The rate constants of the nine different kinetic's models for thin layer drying were established by nonlinear regression analysis of the experimental data which were found to be affected mainly by the infrared power level while system pressure had a little effect on the moisture ratios. The regression results showed that the Page model satisfactorily described the drying behavior of button mushroom slices with highest R value and lowest SE values. The effective moisture diffusivity increases as power increases and range between 0.83 and 2.33 × 10-9 m2/s. The rise in infrared power has a negative effect on the ΔE and with increasing in infrared radiation power it was increased.

Hybrid inverter for HVDC/weak AC system interconnection

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

Tam, K.S.

1985-01-01

The concept of the hybrid converter is introduced. By independently controlling a naturally commutated converter (NCC) and an artificially commutated converter (ACC), real power and reactive power can be controlled independently. Alternatively, the ac bus voltage can be regulated without affecting the real power transfer. Independent control is feasible only within certain operating boundaries. Twelve pulse operation, sequential control, and complementary circuits may be viewed as variations of the hybrid converter. The concept of the hybrid converter is demonstrated by digital simulation. At the current state of technology, the NCC is best implemented by a 6-pulse bridge using thyristors asmore » the switching elements. A survey of power electronics applicable to HVDC applications reveals that the capacitively commutated current-sourced converters are either technically or economically better than the other alternatives for the implementation of the ACC. The digital simulation results show that the problems of operating an HVDC system into a weak ac system can be solved by using a hybrid inverter. A new control scheme, the zero Q control, is developed. With no reactive power interaction between the dc system and the ac system, the stability of the HVDC/weak ac system operation is significantly improved. System start-up and fault recovery is fast and stable.« less

Effectiveness of an audience response system in teaching pharmacology to baccalaureate nursing students.

PubMed

Vana, Kimberly D; Silva, Graciela E; Muzyka, Diann; Hirani, Lorraine M

2011-06-01

It has been proposed that students' use of an audience response system, commonly called clickers, may promote comprehension and retention of didactic material. Whether this method actually improves students' grades, however, is still not determined. The purpose of this study was to evaluate whether a lecture format utilizing multiple-choice PowerPoint slides and an audience response system was more effective than a lecture format using only multiple-choice PowerPoint slides in the comprehension and retention of pharmacological knowledge in baccalaureate nursing students. The study also assessed whether the additional use of clickers positively affected students' satisfaction with their learning. Results from 78 students who attended lecture classes with multiple-choice PowerPoint slides plus clickers were compared with those of 55 students who utilized multiple-choice PowerPoint slides only. Test scores between these two groups were not significantly different. A satisfaction questionnaire showed that 72.2% of the control students did not desire the opportunity to use clickers. Of the group utilizing the clickers, 92.3% recommend the use of this system in future courses. The use of multiple-choice PowerPoint slides and an audience response system did not seem to improve the students' comprehension or retention of pharmacological knowledge as compared with those who used solely multiple-choice PowerPoint slides.

Addressing Impacts of Geomagnetic Disturbances on the North American Bulk Power System

NASA Astrophysics Data System (ADS)

Rollison, Eric; Moura, John; Lauby, Mark

2011-08-01

In a joint report issued in June 2010, the North American Electric Reliability Corporation (NERC) and the U.S. Department of Energy (DOE) identified geomagnetic disturbances as a high-impact, low-frequency (HILF) event risk to bulk power system reliability. The potential impact of geomagnetic disturbance events has gained renewed attention as recent studies have suggested that solar storms may be more severe and reach lower geographic latitudes than formerly expected and can affect bulk power system reliability. The most well known power system experience with geomagnetic disturbances in North America was the 13-14 March 1989 storm, which led to the collapse of the Hydro-Québec system in the early morning hours of 13 March 1989, lasting approximately 9 hours. NERC is actively addressing a range of HILF event risks to bulk power system reliability through the efforts of four of its task forces: Geomagnetic Disturbance, Spare Equipment Database, Cyber and Physical Attack, and Severe Impact Resilience. These task forces operate under the direction of three NERC committees: Planning, Operating, and Critical Infrastructure Protection. The NERC Geomagnetic Disturbance Task Force (GMDTF), which was established in September 2010, is charged with investigating the implications of geomagnetic disturbances to the reliability of bulk power systems and developing solutions to help mitigate these risks. The objective of these efforts is to develop models to better understand the nature and effects of coronal mass ejections (CMEs), the vulnerabilities of equipment, bulk power system design considerations, our ability to reduce the operational and real-time impacts of geomagnetic disturbances on the bulk power system, and restoration methods, as well as to inventory long-lead-time equipment. For more information on the current activities of the GMDTF, please visit: www.nerc.com/filez/gmdtf.html

10 CFR 73.55 - Requirements for physical protection of licensed activities in nuclear power reactors against...

Code of Federal Regulations, 2011 CFR

2011-01-01

... integration of systems, technologies, programs, equipment, supporting processes, and implementing procedures...-in-depth methodologies to minimize the potential for an insider to adversely affect, either directly... protection of digital computer and communication systems and networks. (ii) Site-specific conditions that...

14 CFR 29.1203 - Fire detector systems.

Code of Federal Regulations, 2010 CFR

2010-01-01

... detector systems. (a) For each turbine engine powered rotorcraft and Category A reciprocating engine... fire zones and in the combustor, turbine, and tailpipe sections of turbine installations (whether or... affected by any oil, water, other fluids, or fumes that might be present. (d) There must be means to allow...

14 CFR 29.1203 - Fire detector systems.

Code of Federal Regulations, 2012 CFR

2012-01-01

... detector systems. (a) For each turbine engine powered rotorcraft and Category A reciprocating engine... fire zones and in the combustor, turbine, and tailpipe sections of turbine installations (whether or... affected by any oil, water, other fluids, or fumes that might be present. (d) There must be means to allow...

14 CFR 29.1203 - Fire detector systems.

Code of Federal Regulations, 2013 CFR

2013-01-01

... detector systems. (a) For each turbine engine powered rotorcraft and Category A reciprocating engine... fire zones and in the combustor, turbine, and tailpipe sections of turbine installations (whether or... affected by any oil, water, other fluids, or fumes that might be present. (d) There must be means to allow...

14 CFR 29.1203 - Fire detector systems.

Code of Federal Regulations, 2011 CFR

2011-01-01

... detector systems. (a) For each turbine engine powered rotorcraft and Category A reciprocating engine... fire zones and in the combustor, turbine, and tailpipe sections of turbine installations (whether or... affected by any oil, water, other fluids, or fumes that might be present. (d) There must be means to allow...

14 CFR 29.1203 - Fire detector systems.

Code of Federal Regulations, 2014 CFR

2014-01-01

... detector systems. (a) For each turbine engine powered rotorcraft and Category A reciprocating engine... fire zones and in the combustor, turbine, and tailpipe sections of turbine installations (whether or... affected by any oil, water, other fluids, or fumes that might be present. (d) There must be means to allow...

Loss of Load Probability Calculation for West Java Power System with Nuclear Power Plant Scenario

NASA Astrophysics Data System (ADS)

Azizah, I. D.; Abdullah, A. G.; Purnama, W.; Nandiyanto, A. B. D.; Shafii, M. A.

2017-03-01

Loss of Load Probability (LOLP) index showing the quality and performance of an electrical system. LOLP value is affected by load growth, the load duration curve, forced outage rate of the plant, number and capacity of generating units. This reliability index calculation begins with load forecasting to 2018 using multiple regression method. Scenario 1 with compositions of conventional plants produce the largest LOLP in 2017 amounted to 71.609 days / year. While the best reliability index generated in scenario 2 with the NPP amounted to 6.941 days / year in 2015. Improved reliability of systems using nuclear power more efficiently when compared to conventional plants because it also has advantages such as emission-free, inexpensive fuel costs, as well as high level of plant availability.

Power control and management of the grid containing largescale wind power systems

NASA Astrophysics Data System (ADS)

Aula, Fadhil Toufick

The ever increasing demand for electricity has driven many countries toward the installation of new generation facilities. However, concerns such as environmental pollution and global warming issues, clean energy sources, high costs associated with installation of new conventional power plants, and fossil fuels depletion have created many interests in finding alternatives to conventional fossil fuels for generating electricity. Wind energy is one of the most rapidly growing renewable power sources and wind power generations have been increasingly demanded as an alternative to the conventional fossil fuels. However, wind power fluctuates due to variation of wind speed. Therefore, large-scale integration of wind energy conversion systems is a threat to the stability and reliability of utility grids containing these systems. They disturb the balance between power generation and consumption, affect the quality of the electricity, and complicate load sharing and load distribution managing and planning. Overall, wind power systems do not help in providing any services such as operating and regulating reserves to the power grid. In order to resolve these issues, research has been conducted in utilizing weather forecasting data to improve the performance of the wind power system, reduce the influence of the fluctuations, and plan power management of the grid containing large-scale wind power systems which consist of doubly-fed induction generator based energy conversion system. The aims of this research, my dissertation, are to provide new methods for: smoothing the output power of the wind power systems and reducing the influence of their fluctuations, power managing and planning of a grid containing these systems and other conventional power plants, and providing a new structure of implementing of latest microprocessor technology for controlling and managing the operation of the wind power system. In this research, in order to reduce and smooth the fluctuations, two methods are presented. The first method is based on a de-loaded technique while the other method is based on utilizing multiple storage facilities. The de-loaded technique is based on characteristics of the power of a wind turbine and estimation of the generated power according to weather forecasting data. The technique provides a reference power by which the wind power system will operate and generate a smooth power. In contrast, utilizing storage facilities will allow the wind power system to operate at its maximum tracking power points' strategy. Two types of energy storages are considered in this research, battery energy storage system (BESS) and pumped-hydropower storage system (PHSS), to suppress the output fluctuations and to support the wind power system to follow the system load demands. Furthermore, this method provides the ability to store energy when there is a surplus of the generated power and to reuse it when there is a shortage of power generation from wind power systems. Both methods are new in terms of utilizing of the techniques and wind speed data. A microprocessor embedded system using an IntelRTM Atom(TM) processor is presented for controlling the wind power system and for providing the remote communication for enhancing the operation of the individual wind power system in a wind farm. The embedded system helps the wind power system to respond and to follow the commands of the central control of the power system. Moreover, it enhances the performance of the wind power system through self-managing, self-functioning, and self-correcting. Finally, a method of system power management and planning is modeled and studied for a grid containing large-scale wind power systems. The method is based on a new technique through constructing a new load demand curve (NLDC) from merging the estimation of generated power from wind power systems and forecasting of the load. To summarize, the methods and their results presented in this dissertation, enhance the operation of the large-scale wind power systems and reduce their drawbacks on the operation of the power grid.

The Observation of Manual Grasp Actions Affects the Control of Speech: A Combined Behavioral and Transcranial Magnetic Stimulation Study

ERIC Educational Resources Information Center

Gentilucci, Maurizio; Campione, Giovanna Cristina; Volta, Riccardo Dalla; Bernardis, Paolo

2009-01-01

Does the mirror system affect the control of speech? This issue was addressed in behavioral and Transcranial Magnetic Stimulation (TMS) experiments. In behavioral experiment 1, participants pronounced the syllable /da/ while observing (1) a hand grasping large and small objects with power and precision grasps, respectively, (2) a foot interacting…

Design considerations for a Mars solar energy system

NASA Technical Reports Server (NTRS)

Atkinson, David H.; Gwynne, Owen

1992-01-01

The supply, collection and demand for solar power needed for a ten person base on Mars are examined. A detailed discussion is presented for the estimation of the amount of usable solar energy than can reach the surface of Mars. The irradiance is determined for high, middle and low latitudes. In general it was found that the variation of dust in the Martian atmosphere affected the optimal choice for solar power collection mechanisms. Sun tracking systems worked best under clearer conditions and basic horizontal collectors performed best under cloud/hazy conditions.

Dynamics of isolated quantum systems: many-body localization and thermalization

NASA Astrophysics Data System (ADS)

Torres-Herrera, E. Jonathan; Tavora, Marco; Santos, Lea F.

2016-05-01

We show that the transition to a many-body localized phase and the onset of thermalization can be inferred from the analysis of the dynamics of isolated quantum systems taken out of equilibrium abruptly. The systems considered are described by one-dimensional spin-1/2 models with static random magnetic fields and by power-law band random matrices. We find that the short-time decay of the survival probability of the initial state is faster than exponential for sufficiently strong perturbations. This initial evolution does not depend on whether the system is integrable or chaotic, disordered or clean. At long-times, the dynamics necessarily slows down and shows a power-law behavior. The value of the power-law exponent indicates whether the system will reach thermal equilibrium or not. We present how the properties of the spectrum, structure of the initial state, and number of particles that interact simultaneously affect the value of the power-law exponent. We also compare the results for the survival probability with those for few-body observables. EJTH aknowledges financial support from PRODEP-SEP and VIEP-BUAP, Mexico.

A Titan Explorer Mission Utilizing Solar Electric Propulsion and Chemical Propulsion Systems

NASA Technical Reports Server (NTRS)

Cupples, Michael; Coverstone, Vicki

2003-01-01

Mission and Systems analyses were performed for a Titan Explorer Mission scenario utilizing medium class launch vehicles, solar electric propulsion system (SEPS) for primary interplanetary propulsion, and chemical propulsion for capture at Titan. An examination of a range of system factors was performed to determine their affect on the payload delivery capability to Titan. The effect of varying the launch vehicle, solar array power, associated number of SEPS thrusters, chemical propellant combinations, tank liner thickness, and tank composite overwrap stress factor was investigated. This paper provides a parametric survey of the aforementioned set of system factors, delineating their affect on Titan payload delivery, as well as discussing aspects of planetary capture methodology.

Energy Center Structure Optimization by using Smart Technologies in Process Control System

NASA Astrophysics Data System (ADS)

Shilkina, Svetlana V.

2018-03-01

The article deals with practical application of fuzzy logic methods in process control systems. A control object - agroindustrial greenhouse complex, which includes its own energy center - is considered. The paper analyzes object power supply options taking into account connection to external power grids and/or installation of own power generating equipment with various layouts. The main problem of a greenhouse facility basic process is extremely uneven power consumption, which forces to purchase redundant generating equipment idling most of the time, which quite negatively affects project profitability. Energy center structure optimization is largely based on solving the object process control system construction issue. To cut investor’s costs it was proposed to optimize power consumption by building an energy-saving production control system based on a fuzzy logic controller. The developed algorithm of automated process control system functioning ensured more even electric and thermal energy consumption, allowed to propose construction of the object energy center with a smaller number of units due to their more even utilization. As a result, it is shown how practical use of microclimate parameters fuzzy control system during object functioning leads to optimization of agroindustrial complex energy facility structure, which contributes to a significant reduction in object construction and operation costs.

Wood River recovery project -- speed and cooperation

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

Franczak, D.F.; Santschi, M.F.; Sander, S.

1998-12-31

A unit trip is a situation avoided by power generators because it affects their bottom line. The ability to recover from the trip quickly, and restore MW generation is the desired goal. However, what do you do if you lose your unit to a disastrous fire? How do you recover from this situation? This will be the subject of this paper describing such an event which affected the Illinois Power Company`s (IPC) operation. IPC`s Wood River Power Station suffered a disastrous fire which knocked out the Station`s only two operable units--4 and 5. The fire was the result of amore » coal mill explosion and damaged beyond repair, the units control systems and operating capabilities. A total of 488 MW in generating capacity was lost at a time when the IPC system required all available generation now, and in the foreseeable future. This paper will describe the event, the immediate mobilization efforts, and the challenges of recovering both units in the most expedient time frame possible. The keys to the success of the recovery project will be described in detail.« less

Utilization of hydrolysate from lignocellulosic biomass pretreatment to generate electricity by enzymatic fuel cell system.

PubMed

Kim, Sung Bong; Kim, Dong Sup; Yang, Ji Hyun; Lee, Junyoung; Kim, Seung Wook

2016-04-01

The waste hydrolysate after dilute acid pretreatment (DAP) of lignocellulosic biomass was utilized to generate electricity using an enzymatic fuel cell (EFC) system. During DAP, the components of biomass containing hemicellulose and other compounds are hydrolyzed, and glucose is solubilized into the dilute acid solution, called as the hydrolysate liquid. Glucose oxidase (GOD) and laccase (Lac) were assembled on the electrode of the anode and cathode, respectively. Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were measured, and the maximum power density was found to be 1.254×10(3) μW/cm(2). The results indicate that the hydrolysate from DAP is a reliable electrolyte containing the fuel of EFC. Moreover, the impurities in the hydrolysate such as phenols and furans slightly affected the charge transfer on the surface of the electrode, but did not affect the power generation of the EFC system in principal. Copyright © 2016 Elsevier Inc. All rights reserved.

Experimental Investigation of a Direct-drive Hall Thruster and Solar Array System at Power Levels up to 10 kW

NASA Technical Reports Server (NTRS)

Snyder, John S.; Brophy, John R.; Hofer, Richard R.; Goebel, Dan M.; Katz, Ira

2012-01-01

As NASA considers future exploration missions, high-power solar-electric propulsion (SEP) plays a prominent role in achieving many mission goals. Studies of high-power SEP systems (i.e. tens to hundreds of kilowatts) suggest that significant mass savings may be realized by implementing a direct-drive power system, so NASA recently established the National Direct-Drive Testbed to examine technical issues identified by previous investigations. The testbed includes a 12-kW solar array and power control station designed to power single and multiple Hall thrusters over a wide range of voltages and currents. In this paper, single Hall thruster operation directly from solar array output at discharge voltages of 200 to 450 V and discharge powers of 1 to 10 kW is reported. Hall thruster control and operation is shown to be simple and no different than for operation on conventional power supplies. Thruster and power system electrical oscillations were investigated over a large range of operating conditions and with different filter capacitances. Thruster oscillations were the same as for conventional power supplies, did not adversely affect solar array operation, and were independent of filter capacitance from 8 to 80 ?F. Solar array current and voltage oscillations were very small compared to their mean values and showed a modest dependence on capacitor size. No instabilities or anomalous behavior were observed in the thruster or power system at any operating condition investigated, including near and at the array peak power point. Thruster startup using the anode propellant flow as the power 'switch' was shown to be simple and reliable with system transients mitigated by the proper selection of filter capacitance size. Shutdown via cutoff of propellant flow was also demonstrated. A simple electrical circuit model was developed and is shown to have good agreement with the experimental data.

Assessment and mitigation of power quality problems for PUSPATI TRIGA Reactor (RTP)

NASA Astrophysics Data System (ADS)

Zakaria, Mohd Fazli; Ramachandaramurthy, Vigna K.

2017-01-01

An electrical power systems are exposed to different types of power quality disturbances. Investigation and monitoring of power quality are necessary to maintain accurate operation of sensitive equipment especially for nuclear installations. This paper will discuss the power quality problems observed at the electrical sources of PUSPATI TRIGA Reactor (RTP). Assessment of power quality requires the identification of any anomalous behavior on a power system, which adversely affects the normal operation of electrical or electronic equipment. A power quality assessment involves gathering data resources; analyzing the data (with reference to power quality standards) then, if problems exist, recommendation of mitigation techniques must be considered. Field power quality data is collected by power quality recorder and analyzed with reference to power quality standards. Normally the electrical power is supplied to the RTP via two sources in order to keep a good reliability where each of them is designed to carry the full load. The assessment of power quality during reactor operation was performed for both electrical sources. There were several disturbances such as voltage harmonics and flicker that exceeded the thresholds. To reduce these disturbances, mitigation techniques have been proposed, such as to install passive harmonic filters to reduce harmonic distortion, dynamic voltage restorer (DVR) to reduce voltage disturbances and isolate all sensitive and critical loads.

Social challenges when implementing information systems in everyday work in a nursing context.

PubMed

Nilsson, Lina; Eriksén, Sara; Borg, Christel

2014-09-01

Implementation of information systems in healthcare has become a lengthy process where healthcare staff (eg, nurses) are expected to put information into systems without getting the overall picture of the potential usefulness for their own work. The aim of this study was to explore social challenges when implementing information systems in everyday work in a nursing context. Moreover, this study aimed at putting perceived social challenges in a theoretical framework to address them more constructively when implementing information systems in healthcare. Influenced by institutional ethnography, the findings are based on interviews, observations, and written reflections. Power (changing the existing hierarchy, alienation), professional identity (calling on hold, expert becomes novice, changed routines), and encounter (ignorant introductions, preconceived notions) were categories (subcategories) presented in the findings. Social Cognitive Theory, Diffusion of Innovations, organizational culture, and dramaturgical analysis are proposed to set up a theoretical framework. If social challenges are not considered and addressed in the implementation process, it will be affected by nurses' solidarity to existing power structures and their own professional identity. Thus, implementation of information systems affects more aspects in the organization than might have been intended. These aspects need to be taken in to account in the implementation process.

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

NASA Astrophysics Data System (ADS)

Moyer, Rachael M.

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

Partial Discharge Monitoring in Power Transformers Using Low-Cost Piezoelectric Sensors

PubMed Central

Castro, Bruno; Clerice, Guilherme; Ramos, Caio; Andreoli, André; Baptista, Fabricio; Campos, Fernando; Ulson, José

2016-01-01

Power transformers are crucial in an electric power system. Failures in transformers can affect the quality and cause interruptions in the power supply. Partial discharges are a phenomenon that can cause failures in the transformers if not properly monitored. Typically, the monitoring requires high-cost corrective maintenance or even interruptions of the power system. Therefore, the development of online non-invasive monitoring systems to detect partial discharges in power transformers has great relevance since it can reduce significant maintenance costs. Although commercial acoustic emission sensors have been used to monitor partial discharges in power transformers, they still represent a significant cost. In order to overcome this drawback, this paper presents a study of the feasibility of low-cost piezoelectric sensors to identify partial discharges in mineral insulating oil of power transformers. The analysis of the feasibility of the proposed low-cost sensor is performed by its comparison with a commercial acoustic emission sensor commonly used to detect partial discharges. The comparison between the responses in the time and frequency domain of both sensors was carried out and the experimental results indicate that the proposed piezoelectric sensors have great potential in the detection of acoustic waves generated by partial discharges in insulation oil, contributing for the popularization of this noninvasive technique. PMID:27517931

Partial Discharge Monitoring in Power Transformers Using Low-Cost Piezoelectric Sensors.

PubMed

Castro, Bruno; Clerice, Guilherme; Ramos, Caio; Andreoli, André; Baptista, Fabricio; Campos, Fernando; Ulson, José

2016-08-10

Power transformers are crucial in an electric power system. Failures in transformers can affect the quality and cause interruptions in the power supply. Partial discharges are a phenomenon that can cause failures in the transformers if not properly monitored. Typically, the monitoring requires high-cost corrective maintenance or even interruptions of the power system. Therefore, the development of online non-invasive monitoring systems to detect partial discharges in power transformers has great relevance since it can reduce significant maintenance costs. Although commercial acoustic emission sensors have been used to monitor partial discharges in power transformers, they still represent a significant cost. In order to overcome this drawback, this paper presents a study of the feasibility of low-cost piezoelectric sensors to identify partial discharges in mineral insulating oil of power transformers. The analysis of the feasibility of the proposed low-cost sensor is performed by its comparison with a commercial acoustic emission sensor commonly used to detect partial discharges. The comparison between the responses in the time and frequency domain of both sensors was carried out and the experimental results indicate that the proposed piezoelectric sensors have great potential in the detection of acoustic waves generated by partial discharges in insulation oil, contributing for the popularization of this noninvasive technique.

Metrication: A Guide for Consumers.

ERIC Educational Resources Information Center

Consumer and Corporate Affairs Dept., Ottawa (Ontario).

The widespread use of the metric system by most of the major industrial powers of the world has prompted the Canadian government to investigate and consider use of the system. This booklet was developed to aid the consuming public in Canada in gaining some knowledge of metrication and how its application would affect their present economy.…

Impact of CALS on Electronic Publishing Systems and Users.

ERIC Educational Resources Information Center

Beazley, William G.

1990-01-01

The U.S. Department of Defense has begun using its buying power to enforce standards on the vendors and contractors of automatic data processing hardware and software. An example of this, the Computer-Aided Acquisition and Logistic Support (CALS) program, is described, and how it will affect electronic publishing systems is discussed. (five…

Modeling, control, and simulation of grid connected intelligent hybrid battery/photovoltaic system using new hybrid fuzzy-neural method.

PubMed

Rezvani, Alireza; Khalili, Abbas; Mazareie, Alireza; Gandomkar, Majid

2016-07-01

Nowadays, photovoltaic (PV) generation is growing increasingly fast as a renewable energy source. Nevertheless, the drawback of the PV system is its dependence on weather conditions. Therefore, battery energy storage (BES) can be considered to assist for a stable and reliable output from PV generation system for loads and improve the dynamic performance of the whole generation system in grid connected mode. In this paper, a novel topology of intelligent hybrid generation systems with PV and BES in a DC-coupled structure is presented. Each photovoltaic cell has a specific point named maximum power point on its operational curve (i.e. current-voltage or power-voltage curve) in which it can generate maximum power. Irradiance and temperature changes affect these operational curves. Therefore, the nonlinear characteristic of maximum power point to environment has caused to development of different maximum power point tracking techniques. In order to capture the maximum power point (MPP), a hybrid fuzzy-neural maximum power point tracking (MPPT) method is applied in the PV system. Obtained results represent the effectiveness and superiority of the proposed method, and the average tracking efficiency of the hybrid fuzzy-neural is incremented by approximately two percentage points in comparison to the conventional methods. It has the advantages of robustness, fast response and good performance. A detailed mathematical model and a control approach of a three-phase grid-connected intelligent hybrid system have been proposed using Matlab/Simulink. Copyright © 2016 ISA. Published by Elsevier Ltd. All rights reserved.

Effective Control of Bioelectricity Generation from a Microbial Fuel Cell by Logical Combinations of pH and Temperature

PubMed Central

Tang, Jiahuan; Liu, Ting; Yuan, Yong

2014-01-01

In this study, a microbial fuel cell (MFC) with switchable power release is designed, which can be logically controlled by combinations of the most physiologically important parameters such as “temperature” and “pH.” Changes in voltage output in response to temperature and pH changes were significant in which voltage output decreased sharply when temperature was lowered from 30°C to 10°C or pH was decreased from 7.0 to 5.0. The switchability of the MFC comes from the microbial anode whose activity is affected by the combined medium temperature and pH. Changes in temperature and pH cause reversible activation-inactivation of the bioanode, thus affecting the activity of the entire MFC. With temperature and pH as input signals, an AND logic operation is constructed for the MFC whose power density is controlled. The developed system has the potential to meet the requirement of power supplies producing electrical power on-demand for self-powered biosensors or biomedical devices. PMID:24741343

North Europe power transmission system vulnerability during extreme space weather

NASA Astrophysics Data System (ADS)

Piccinelli, Roberta; Krausmann, Elisabeth

2018-01-01

Space weather driven by solar activity can induce geomagnetic disturbances at the Earth's surface that can affect power transmission systems. Variations in the geomagnetic field result in geomagnetically induced currents that can enter the system through its grounding connections, saturate transformers and lead to system instability and possibly collapse. This study analyzes the impact of extreme space weather on the northern part of the European power transmission grid for different transformer designs to understand its vulnerability in case of an extreme event. The behavior of the system was analyzed in its operational mode during a severe geomagnetic storm, and mitigation measures, like line compensation, were also considered. These measures change the topology of the system, thus varying the path of geomagnetically induced currents and inducing a local imbalance in the voltage stability superimposed on the grid operational flow. Our analysis shows that the North European power transmission system is fairly robust against extreme space weather events. When considering transformers more vulnerable to geomagnetic storms, only few episodes of instability were found in correspondence with an existing voltage instability due to the underlying system load. The presence of mitigation measures limited the areas of the network in which bus voltage instabilities arise with respect to the system in which mitigation measures are absent.

Comprehensive evaluation of power grid enterprises' credit rating under the reform of transmission and distribution price

NASA Astrophysics Data System (ADS)

Wang, Yongli; Wang, Gang; Zuo, Yi; Fan, Lisha; Wei, Jiaxiang

2017-03-01

On March 15, 2015, the central office issued the "Opinions on Further Deepening the Reform of Electric Power System" (in the 2015 No. 9). This policy marks the central government officially opened a new round of electricity reform. As a programmatic document under the new situation to comprehensively promote the reform of the power system, No. 9 document will be approved as a separate transmission and distribution of electricity prices, which is the first task of promoting the reform of the power system. Grid tariff reform is not only the transmission and distribution price of a separate approval, more of the grid company input-output relationship and many other aspects of deep-level adjustments. Under the background of the reform of the transmission and distribution price, the main factors affecting the input-output relationship, such as the main business, electricity pricing, and investment approval, financial accounting and so on, have changed significantly. The paper designed the comprehensive evaluation index system of power grid enterprises' credit rating under the reform of transmission and distribution price to reduce the impact of the reform on the company's international rating results and the ability to raise funds.

Energy characterisation of ultrasonic systems for industrial processes.

PubMed

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

2015-03-01

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

Humid free efficient solar panel

NASA Astrophysics Data System (ADS)

Panjwani, Manoj Kumar; Panjwani, Suresh Kumar; Mangi, Fareed Hussain; Khan, Danish; Meicheng, Li

2017-09-01

The paper examines the impact of the humidity on the Solar panels which makes a space for the drastic variation in the power generated and makes the device less efficient. Humidity readily affects the efficiency of the solar cells and creates a minimal layer of water on its surface. It also decreases the efficiency by 10-20% of the total power output produced. Moreover, to handle this issue, all around characterized measures are required to be taken to guarantee the smooth working of the solar panels utilized in humid areas. In connection with this issue, Karachi, the biggest city of Pakistan which is located near the costal line touching Arabian Sea, was taken as a reference city to measure the humidity range. In Karachi, the average humidity lies between 25-70% (as per Pakistan Meteorological Department PMD), that indirectly leads in decreasing power acquired from a Solar Panel and develops various complexities for the solar system. The system on average experiences stability issues, such as those of power fluctuations etc., due to which, the whole solar system installed observes abnormal variations in acquired power. Silica Gel was used as a desiccant material in order to assure dryness over the solar panel. More than four experiments were conducted with the usage of water absorbent to improve the efficiency and to make system more power efficient.

Solar Energy Systems for Lunar Oxygen Generation

NASA Technical Reports Server (NTRS)

Colozza, Anthony J.; Heller, Richard S.; Wong, Wayne A.; Hepp, Aloysius F.

2010-01-01

An evaluation of several solar concentrator-based systems for producing oxygen from lunar regolith was performed. The systems utilize a solar concentrator mirror to provide thermal energy for the oxygen production process. Thermal energy to power a Stirling heat engine and photovoltaics are compared for the production of electricity. The electricity produced is utilized to operate the equipment needed in the oxygen production process. The initial oxygen production method utilized in the analysis is hydrogen reduction of ilmenite. Utilizing this method of oxygen production a baseline system design was produced. This baseline system had an oxygen production rate of 0.6 kg/hr with a concentrator mirror size of 5 m. Variations were performed on the baseline design to show how changes in the system size and process (rate) affected the oxygen production rate. An evaluation of the power requirements for a carbothermal lunar regolith reduction reactor has also been conducted. The reactor had a total power requirement between 8,320 to 9,961 W when producing 1000 kg/year of oxygen. The solar concentrator used to provide the thermal power (over 82 percent of the total energy requirement) would have a diameter of less than 4 m.

Environmental and economic analysis of power generation in a thermophilic biogas plant.

PubMed

Ruiz, D; San Miguel, G; Corona, B; Gaitero, A; Domínguez, A

2018-08-15

This paper investigates the environmental and economic performance of the power production from biogas using Life Cycle Assessment, Life Cycle Costing and Cost Benefit Analysis methodologies. The analysis is based on a commercial thermophilic biogas plant located in Spain where is installed a Combined Heat and Power system that produces electricity that is sold to the grid. Power generation has been assumed as the only function of the biogas system, expanding the system boundaries to include the additional function related to the end-of-life management of the biowastes. Thus environmental burdens from the conventional management of residues were calculated separately and subtracted. The base scenario involves using agri-food waste, sewage sludge and pig/cow manure as substrates. This situation is compared against an alternative scenario where the production of synthetic fertilizer is surrogated by the digestate. The results have shown that the most impacting activities in all impacts categories of power production are primarily attributable to the operation and maintenance of the biogas plant except for water resource depletion and climate change. The avoided emissions associated with the conventional management of pig/cow manure more than offset GHG emissions of the biogas system resulting in a negative impact value of -73.9gCO 2 eq/kWh in the base case scenario. The normalized results show that local impact categories such as primarily human toxicity, fresh water ecotoxicity and particulate matter are the most significantly affected by the biogas system while global impact categories as climate change and ozone depletion are less severely affected. The operation and maintenance phase is also shown to be the largest contributor after the life cycle cost analysis, followed by the construction and dismantling of the biogas plant and the profitability of the project is primarily related to the income obtained from the management of the biowastes used as substrates. Copyright © 2018 Elsevier B.V. All rights reserved.

Numerical Simulations of SCR DeNOx System for a 660MW coal-fired power station

NASA Astrophysics Data System (ADS)

Yongqiang, Deng; Zhongming, Mei; Yijun, Mao; Nianping, Liu; Guoming, Yin

2018-06-01

Aimed at the selective catalytic reduction (SCR) DeNOx system of a 660 MW coal-fired power station, which is limited by low denitrification efficiency, large ammonia consumption and over-high ammonia escape rate, numerical simulations were conducted by employing STAR-CCM+ (CFD tool). The simulations results revealed the problems existed in the SCR DeNOx system. Aimed at limitations of the target SCR DeNOx system, factors affecting the denitrification performance of SCR, including the structural parameters and ammonia injected by the ammonia nozzles, were optimized. Under the optimized operational conditions, the denitrification efficiency of the SCR system was enhanced, while the ammonia escape rate was reduced below 3ppm. This study serves as references for optimization and modification of SCR systems.

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.

Space Weather, Geomagnetic Disturbances and Impact on the High-Voltage Transmission Systems

NASA Technical Reports Server (NTRS)

Pullkkinen, A.

2011-01-01

Geomagnetically induced currents (GIC) affecting the performance of high-voltage power transmission systems are one of the most significant hazards space weather poses on the operability of critical US infrastructure. The severity of the threat was emphasized, for example, in two recent reports: the National Research Council (NRC) report "Severe Space Weather Events--Understanding Societal and Economic Impacts: A Workshop Report" and the North American Electric Reliability Corporation (NERC) report "HighImpact, Low-Frequency Event Risk to the North American Bulk Power System." The NRC and NERC reports demonstrated the important national security dimension of space weather and GIC and called for comprehensive actions to forecast and mitigate the hazard. In this paper we will give a brief overview of space weather storms and accompanying geomagnetic storm events that lead to GIC. We will also review the fundamental principles of how GIC can impact the power transmission systems. Space weather has been a subject of great scientific advances that have changed the wonder of the past to a quantitative field of physics with true predictive power of today. NASA's Solar Shield system aimed at forecasting of GIC in the North American high-voltage power transmission system can be considered as one of the ultimate fruits of those advances. We will review the fundamental principles of the Solar Shield system and provide our view of the way forward in the science of GIC.

Design considerations for space radiators based on the liquid sheet (LSR) concept

NASA Technical Reports Server (NTRS)

Juhasz, Albert J.; Chubb, Donald L.

1991-01-01

Concept development work on space heat rejection subsystems tailored to the requirements of various space power conversion systems is proceeding over a broad front of technologies at NASA LeRC. Included are orbital and planetary surface based radiator concepts utilizing pumped loops, a variety of heat pipe radiator concepts, and the innovative liquid sheet radiator (LSR). The basic feasibility of the LSR concept was investigated in prior work which generated preliminary information indicating the suitability of the LSR concept for space power systems requiring cycle reject heat to be radiated to the space sink at low-to-mid temperatures (300 to 400 K), with silicon oils used for the radiator working fluid. This study is directed at performing a comparative examination of LSR characteristics as they affect the basic design of low earth orbit solar dynamic power conversion systems. The power systems considered were based on the closed Brayton (CBC) and the Free Piston Stirling (FPS) cycles, each with a power output of 2 kWe and using previously tested silicone oil (Dow-Corning Me2) as the radiator working fluid. Conclusions indicate that, due to its ability for direct cold end cooling, an LSR based heat rejection subsystem is far more compatible with a Stirling space power system than with a CBC, which requires LSR coupling by means of an intermediate gas/liquid heat exchanger and adjustment of cycle operating conditions.

Gain and power optimization of the wireless optical system with multilevel modulation.

PubMed

Liu, Xian

2008-06-01

When used in an outdoor environment to expedite networking access, the performance of wireless optical communication systems is affected by transmitter sway. In the design of such systems, much attention has been paid to developing power-efficient schemes. However, the bandwidth efficiency is also an important issue. One of the most natural approaches to promote bandwidth efficiency is to use multilevel modulation. This leads to multilevel pulse amplitude modulation in the context of intensity modulation and direct detection. We develop a model based on the four-level pulse amplitude modulation. We show that the model can be formulated as an optimization problem in terms of the transmitter power, bit error probability, transmitter gain, and receiver gain. The technical challenges raised by modeling and solving the problem include the analytical and numerical treatments for the improper integrals of the Gaussian functions coupled with the erfc function. The results demonstrate that, at the optimal points, the power penalty paid to the doubled bandwidth efficiency is around 3 dB.

Economic analysis of biomass power generation schemes under renewable energy initiative with Renewable Portfolio Standards (RPS) in Korea.

PubMed

Moon, Ji-Hong; Lee, Jeung-Woo; Lee, Uen-Do

2011-10-01

An economic analysis of biomass power generation was conducted. Two key technologies--direct combustion with a steam turbine and gasification with a syngas engine--were mainly examined. In view of the present domestic biomass infrastructure of Korea, a small and distributed power generation system ranging from 0.5 to 5 MW(e) was considered. It was found that gasification with a syngas engine becomes more economically feasible as the plant size decreases. Changes in the economic feasibilities with and without RPS or heat sales were also investigated. A sensitivity analysis of each system was conducted for representative parameters. Regarding the cost of electricity generation, electrical efficiency and fuel cost significantly affect both direct combustion and gasification systems. Regarding the internal rate of return (IRR), the heat sales price becomes important for obtaining a higher IRR, followed by power generation capacity and electrical efficiency. Copyright © 2011 Elsevier Ltd. All rights reserved.

Effects of plasma spray parameters on two layer thermal barrier

NASA Technical Reports Server (NTRS)

Stecura, S.

1981-01-01

The power level and the type of arc gas used during plasma spraying of a two layer thermal barrier system (TBS) were found to affect the life of the system. Life at 1095 C in a cyclic furnace test was improved by about 140 percent by increasing the power during plasma spray applications of the bond and thermal barrier coatings. This improvement is due to increases in the densities of the bond and thermal barrier coatings by 3 and 5 percent, respectively. These increases in densities are equivalent to about 45 and 30 percent reduction in mean porosities, respectively. The addition of hydrogen to the argon arc gas had the same effect as the reduction in power level and caused a reduction in TBS life.

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

Gevorgian, Vahan; Zhang, Yingchen

The electrical frequency of an interconnected power system must be maintained close its nominal level at all times. Excessive under- and overfrequency excursions can lead to load shedding, instability, machine damage, and even blackouts. There is a rising concern in the electric power industry in recent years about the declining amount of inertia and primary frequency response (PFR) in many interconnections. This decline may continue due to increasing penetrations of inverter-coupled generation and the planned retirements of conventional thermal plants. Inverter-coupled variable wind generation is capable of contributing to PFR and inertia with a response that is different from thatmore » of conventional generation. It is not yet entirely understood how such a response will affect the system at different wind power penetration levels. The modeling work presented in this paper evaluates the impact of wind generation's provision of these active power control strategies on a large, synchronous interconnection. All simulations were conducted on the U.S. Western Interconnection with different levels of instantaneous wind power penetrations (up to 80%). The ability of wind power plants to provide PFR - and a combination of synthetic inertial response and PFR - significantly improved the frequency response performance of the system.« less

Designing Effective Persuasive Systems Utilizing the Power of Entanglement: Communication Channel, Strategy and Affect

NASA Astrophysics Data System (ADS)

Li, Haiqing; Chatterjee, Samir

With rapid advances in information and communication technology, computer-mediated communication (CMC) technologies are utilizing multiple IT platforms such as email, websites, cell-phones/PDAs, social networking sites, and gaming environments. However, no studies have compared the effectiveness of a persuasive system using such alternative channels and various persuasive techniques. Moreover, how affective computing impacts the effectiveness of persuasive systems is not clear. This study proposes (1) persuasive technology channels in combination with persuasive strategies will have different persuasive effectiveness; (2) Adding positive emotion to a message that leads to a better overall user experience could increase persuasive effectiveness. The affective computing or emotion information was added to the experiment using emoticons. The initial results of a pilot study show that computer-mediated communication channels along with various persuasive strategies can affect the persuasive effectiveness to varying degrees. These results also shows that adding a positive emoticon to a message leads to a better user experience which increases the overall persuasive effectiveness of a system.

Human Mars Transportation Applications Using Solar Electric Propulsion

NASA Technical Reports Server (NTRS)

Donahue, Benjamin B.; Martin, Jim; Potter, Seth; Henley, Mark; Carrington, Connie (Technical Monitor)

2000-01-01

Advanced solar electric power systems and electric propulsion technology constitute viable elements for conducting human Mars transfer missions that are roughly comparable in performance to similar missions utilizing alternative high thrust systems, with the one exception being their inability to achieve short Earth-Mars trip times. A modest solar electric propulsion human Mars scenario is presented that features the use of conjunction class trajectories in concert with pre-emplacement of surface assets that can be used in a series of visits to Mars. Major elements of the Mars solar electric transfer vehicle can be direct derivatives of present state-of-the-art Solar array and electric thruster systems. During the study, several elements affecting system performance were evaluated, including varying Earth orbit altitude for departure, recapturing the transfer stage at Earth for reuse, varying power system mass-to-power ratio, and assessing solar array degradation on performance induced by Van Allen belt passage. Comparisons are made to chemical propulsion and nuclear thermal propulsion Mars vehicles carrying similar payloads.

Effect of makeup water properties on the condenser fouling in power planr cooling system

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

Safari, I.; Walker, M.; Abbasian, J.

2011-01-01

The thermoelectric power industry in the U.S. uses a large amount of fresh water. As available freshwater for use in thermoelectric power production becomes increasingly limited, use of nontraditional water sources is of growing interest. Utilization of nontraditional water, in cooling systems increases the potential for mineral precipitation on heat exchanger surfaces. In that regard, predicting the accelerated rate of scaling and fouling in condenser is crucial to evaluate the condenser performance. To achieve this goal, water chemistry should be incorporated in cooling system modeling and simulation. This paper addresses the effects of various makeup water properties on the coolingmore » system, namely pH and aqueous speciation, both of which are important factors affecting the fouling rate in the main condenser. Detailed modeling of the volatile species desorption (i.e. CO{sub 2} and NH{sub 3}), the formation of scale in the recirculating system, and the relationship between water quality and the corresponding fouling rates is presented.« less

Power ramp rate capabilities of a 5 kW proton exchange membrane fuel cell system with discrete ejector control

NASA Astrophysics Data System (ADS)

Nikiforow, K.; Pennanen, J.; Ihonen, J.; Uski, S.; Koski, P.

2018-03-01

The power ramp rate capabilities of a 5 kW proton exchange membrane fuel cell (PEMFC) system are studied theoretically and experimentally for grid support service applications. The fuel supply is implemented with a fixed-geometry ejector and a discrete control solution without any anode-side pressure fluctuation suppression methods. We show that the stack power can be ramped up from 2.0 kW to 4.0 kW with adequate fuel supply and low anode pressure fluctuations within only 0.1 s. The air supply is implemented with a centrifugal blower. Air supply ramp rates are studied with a power increase executed within 1 and 0.2 s after the request, the time dictated by grid support service requirements in Finland and the UK. We show that a power ramp-up from 2.0 kW to 3.7 kW is achieved within 1 s with an initial air stoichiometry of 2.5 and within 0.2 s with an initial air stoichiometry of 7.0. We also show that the timing of the power ramp-up affects the achieved ancillary power capacity. This work demonstrates that hydrogen fueled and ejector-based PEMFC systems can provide a significant amount of power in less than 1 s and provide valuable ancillary power capacity for grid support services.

Smith machine counterbalance system affects measures of maximal bench press throw performance.

PubMed

Vingren, Jakob L; Buddhadev, Harsh H; Hill, David W

2011-07-01

Equipment with counterbalance weight systems is commonly used for the assessment of performance in explosive resistance exercise movements, but it is not known if such systems affect performance measures. The purpose of this study was to determine the effect of using a counterbalance weight system on measures of smith machine bench press throw performance. Ten men and 14 women (mean ± SD: age, 25 ± 4 years; height, 173 ± 10 cm; weight, 77.7 ± 18.3 kg) completed maximal smith machine bench press throws under 4 different conditions (2 × 2; counterbalance × load): with or without a counterbalance weight system and using 'light' or 'moderate' net barbell loads. Performance variables (peak force, peak velocity, and peak power) were measured using a linear accelerometer attached to the barbell. The counterbalance weight system resulted in significant (p < 0.001) reductions in measures of peak force (mean difference ± standard error: light: -112 ± 20 N; moderate: -140 ± 23 N), peak velocity (light: -0.49 ± 0.10 m·s; moderate: -0.33 ± 0.07 m·s), and peak power (light: -220 ± 43 W; moderate: -143 ± 28 W) compared with no counterbalance system for both load conditions. Load condition did not affect absolute or percentage reductions from the counterbalance weight system for any variable. In conclusion, the use of a counterbalance weight system reduces accelerometer-based performance measures for the bench press throw exercise at light and moderate loads. This reduction in measures is likely because of an increase in the external resistance during the movement, which results in a discrepancy between the manually input and the actual value for external load. A counterbalance weight system should not be used when measuring performance in explosive resistance exercises with an accelerometer.

Optimizing Power Density and Efficiency of a Double-Halbach Array Permanent-Magnet Ironless Axial-Flux Motor

NASA Technical Reports Server (NTRS)

Duffy, Kirsten P.

2016-01-01

NASA Glenn Research Center is investigating hybrid electric and turboelectric propulsion concepts for future aircraft to reduce fuel burn, emissions, and noise. Systems studies show that the weight and efficiency of the electric system components need to be improved for this concept to be feasible. This effort aims to identify design parameters that affect power density and efficiency for a double-Halbach array permanent-magnet ironless axial flux motor configuration. These parameters include both geometrical and higher-order parameters, including pole count, rotor speed, current density, and geometries of the magnets, windings, and air gap.

Performance and Operational Characteristics for a Dual Brayton Space Power System With Common Gas Inventory

NASA Technical Reports Server (NTRS)

Johnson, Paul K.; Mason, Lee S.

2006-01-01

This paper provides an analytical evaluation on the operation and performance of a dual Brayton common gas system. The NASA Glenn Research Center in-house computer program Closed Cycle System Simulation (CCSS) was used to construct a model of two identical 50 kWe-class recuperated closed-Brayton-cycle (CBC) power conversion units that share a common gas inventory and single heat source. As operating conditions for each CBC change, the total gas inventory is redistributed between the two units and overall system performance is affected. Several steady-state off-design operating points were analyzed by varying turbine inlet temperature and turbo-alternator shaft rotational speed to investigate the interaction of the two units.

Radioisotope Stirling Engine Powered Airship for Atmospheric and Surface Exploration of Titan

NASA Technical Reports Server (NTRS)

Colozza, Anthony J.; Cataldo, Robert L.

2014-01-01

The feasibility of an advanced Stirling radioisotope generator (ASRG) powered airship for the near surface exploration of Titan was evaluated. The analysis did not consider the complete mission only the operation of the airship within the atmosphere of Titan. The baseline airship utilized two ASRG systems with a total of four general-purpose heat source (GPHS) blocks. Hydrogen gas was used to provide lift. The ASRG systems, airship electronics and controls and the science payload were contained in a payload enclosure. This enclosure was separated into two sections, one for the ASRG systems and the other for the electronics and payload. Each section operated at atmospheric pressure but at different temperatures. The propulsion system consisted of an electric motor driving a propeller. An analysis was set up to size the airship that could operate near the surface of Titan based on the available power from the ASRGs. The atmospheric conditions on Titan were modeled and used in the analysis. The analysis was an iterative process between sizing the airship to carry a specified payload and the power required to operate the electronics, payload and cooling system as well as provide power to the propulsion system to overcome the drag on the airship. A baseline configuration was determined that could meet the power requirements and operate near the Titan surface. From this baseline design additional trades were made to see how other factors affected the design such as the flight altitude and payload mass and volume.

Research and application of thermal power unit’s load dynamic adjustment based on extraction steam

NASA Astrophysics Data System (ADS)

Li, Jun; Li, Huicong; Li, Weiwei

2018-02-01

The rapid development of heat and power generation in large power plant has caused tremendous constraints on the load adjustment of power grids and power plants. By introducing the thermodynamic system of thermal power unit, the relationship between thermal power extraction steam and unit’s load has analyzed and calculated. The practical application results show that power capability of the unit affected by extraction and it is not conducive to adjust the grid frequency. By monitoring the load adjustment capacity of thermal power units, especially the combined heat and power generating units, the upper and lower limits of the unit load can be dynamically adjusted by the operator on the grid side. The grid regulation and control departments can effectively control the load adjustable intervals of the operating units and provide reliable for the cooperative action of the power grid and power plants, to ensure the safety and stability of the power grid.

Laser-fluorescence measurement of marine algae

NASA Technical Reports Server (NTRS)

Browell, E. V.

1980-01-01

Progress in remote sensing of algae by laser-induced fluorescence is subject of comprehensive report. Existing single-wavelength and four-wavelength systems are reviewed, and new expression for power received by airborne sensor is derived. Result differs by as much as factor of 10 from those previously reported. Detailed error analysis evluates factors affecting accuracy of laser-fluorosensor systems.

Climate and Water Vulnerability of the US Electricity Grid Under High Penetrations of Renewable Energy

NASA Astrophysics Data System (ADS)

Macknick, J.; Miara, A.; O'Connell, M.; Vorosmarty, C. J.; Newmark, R. L.

2017-12-01

The US power sector is highly dependent upon water resources for reliable operations, primarily for thermoelectric cooling and hydropower technologies. Changes in the availability and temperature of water resources can limit electricity generation and cause outages at power plants, which substantially affect grid-level operational decisions. While the effects of water variability and climate changes on individual power plants are well documented, prior studies have not identified the significance of these impacts at the regional systems-level at which the grid operates, including whether there are risks for large-scale blackouts, brownouts, or increases in production costs. Adequately assessing electric grid system-level impacts requires detailed power sector modeling tools that can incorporate electric transmission infrastructure, capacity reserves, and other grid characteristics. Here, we present for the first time, a study of how climate and water variability affect operations of the power sector, considering different electricity sector configurations (low vs. high renewable) and environmental regulations. We use a case study of the US Eastern Interconnection, building off the Eastern Renewable Generation Integration Study (ERGIS) that explored operational challenges of high penetrations of renewable energy on the grid. We evaluate climate-water constraints on individual power plants, using the Thermoelectric Power and Thermal Pollution (TP2M) model coupled with the PLEXOS electricity production cost model, in the context of broader electricity grid operations. Using a five minute time step for future years, we analyze scenarios of 10% to 30% renewable energy penetration along with considerations of river temperature regulations to compare the cost, performance, and reliability tradeoffs of water-dependent thermoelectric generation and variable renewable energy technologies under climate stresses. This work provides novel insights into the resilience and reliability of different configurations of the US electric grid subject to changing climate conditions.

Post impact behavior of mobile reactor core containment systems

NASA Technical Reports Server (NTRS)

Puthoff, R. L.; Parker, W. G.; Vanbibber, L. E.

1972-01-01

The reactor core containment vessel temperatures after impact, and the design variables that affect the post impact survival of the system are analyzed. The heat transfer analysis includes conduction, radiation, and convection in addition to the core material heats of fusion and vaporization under partially burial conditions. Also, included is the fact that fission products vaporize and transport radially outward and condense outward and condense on cooler surfaces, resulting in a moving heat source. A computer program entitled Executive Subroutines for Afterheat Temperature Analysis (ESATA) was written to consider this complex heat transfer analysis. Seven cases were calculated of a reactor power system capable of delivering up to 300 MW of thermal power to a nuclear airplane.

Cornered: an approach to school bullying and cyberbullying, and forensic implications.

PubMed

Bostic, Jeff Q; Brunt, Colby C

2011-07-01

Bullying is an abuse of power and control that can cause significant harm to individuals. School systems have the difficult task of trying to police this behavior to maintain a safe learning environment for their students. Although there may be an identified bully, the ramifications of the behavior affect the system as a whole. Bullies, targeted victims, and bystanders play an integral role in ameliorating this problem. A change of culture within the school system is often the best, yet often the most difficult, intervention. In addition, cyberbullying has become a powerful avenue for bullying, resulting in significant morbidity within schools. Copyright © 2011 Elsevier Inc. All rights reserved.

Brain-derived neurotrophic factor (BDNF) serum basal levels is not affected by power training in mobility-limited older adults - A randomized controlled trial.

PubMed

Hvid, L G; Nielsen, M K F; Simonsen, C; Andersen, M; Caserotti, P

2017-07-01

Brain-derived neurotrophic factor (BDNF) is a potential important factor involved in neuroplasticity, and may be a mediator for eliciting adaptations in neuromuscular function and physical function in older individuals following physical training. As power training taxes the neural system to a very high extent, it may be particularly effective in terms of eliciting increases in systemic BDNF levels. We examined the effects of 12weeks of power training on mature BDNF (mBDNF) and total BDNF (tBDNF) in mobility-limited older adults from the Healthy Ageing Network of Competence (HANC) study. We included 47 older men and women: n=22 in the training group (TG: progressive high intensity power training, 2 sessions per week; age 82.7±5.4years, 55% women) and n=25 in the control group (CG: no interventions; age 82.2±4.5years, 76% women). Following overnight fasting, basal serum levels of mBDNF and tBDNF were assessed (human ELISA kits) at baseline and post-intervention. At baseline, mBDNF and tBDNF levels were comparable in the two groups, TG and CG. Post-intervention, no significant within-group or between-group changes were observed in mBDNF or tBDNF. Moreover, when divided into responder tertiles based upon changes in mBDNF and tBDNF (i.e. decliners, maintainers, improvers), respectively, comparable findings were observed for TG and CG. Altogether, basal systemic levels of serum mBDNF and tBDNF are not affected in mobility-limited older adults following 12-weeks of power training, and do not appear to be a major mechanistic factor mediating neuroplasticity in mobility-limited older adults. Copyright © 2017 Elsevier Inc. All rights reserved.

Mitigation of Power Quality Problems in Grid-Interactive Distributed Generation System

NASA Astrophysics Data System (ADS)

Bhende, C. N.; Kalam, A.; Malla, S. G.

2016-04-01

Having an inter-tie between low/medium voltage grid and distributed generation (DG), both exposes to power quality (PQ) problems created by each other. This paper addresses various PQ problems arise due to integration of DG with grid. The major PQ problems are due to unbalanced and non-linear load connected at DG, unbalanced voltage variations on transmission line and unbalanced grid voltages which severely affect the performance of the system. To mitigate the above mentioned PQ problems, a novel integrated control of distribution static shunt compensator (DSTATCOM) is presented in this paper. DSTATCOM control helps in reducing the unbalance factor of PCC voltage. It also eliminates harmonics from line currents and makes them balanced. Moreover, DSTATCOM supplies the reactive power required by the load locally and hence, grid need not to supply the reactive power. To show the efficacy of the proposed controller, several operating conditions are considered and verified through simulation using MATLAB/SIMULINK.

Intelligent automotive battery systems

NASA Astrophysics Data System (ADS)

Witehira, P.

A single power-supply battery is incompatible with modern vehicles. A one-cmbination 12 cell/12 V battery, developed by Power Beat International Limited (PBIL), is described. The battery is designed to be a 'drop in' replacement for existing batteries. The cell structures, however, are designed according to load function, i.e., high-current shallow-discharge cycles and low-current deep-discharge cycles. The preferred energy discharge management logic and integration into the power distribution network of the vehicle to provide safe user-friendly usage is described. The system is designed to operate transparent to the vehicle user. The integrity of the volatile high-current cells is maintained by temperature-sensitive voltage control and discharge management. The deep-cycle cells can be fully utilized without affecting startability under extreme conditions. Electric energy management synchronization with engine starting will provide at least 6% overall reduction in hydrocarbon emissions using an intelligent on-board power-supply technology developed by PBIL.

On Market-Based Coordination of Thermostatically Controlled Loads With User Preference

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

Li, Sen; Zhang, Wei; Lian, Jianming

2014-12-15

This paper presents a market-based control framework to coordinate a group of autonomous Thermostatically Controlled Loads (TCL) to achieve the system-level objectives with pricing incentives. The problem is formulated as maximizing the social welfare subject to feeder power constraint. It allows the coordinator to affect the aggregated power of a group of dynamical systems, and creates an interactive market where the users and the coordinator cooperatively determine the optimal energy allocation and energy price. The optimal pricing strategy is derived, which maximizes social welfare while respecting the feeder power constraint. The bidding strategy is also designed to compute the optimalmore » price in real time (e.g., every 5 minutes) based on local device information. The coordination framework is validated with realistic simulations in GridLab-D. Extensive simulation results demonstrate that the proposed approach effectively maximizes the social welfare and decreases power congestion at key times.« less

Impact of lightning strikes on hospital functions.

PubMed

Mortelmans, Luc J M; Van Springel, Gert L J; Van Boxstael, Sam; Herrijgers, Jan; Hoflacks, Stefaan

2009-01-01

Two regional hospitals were struck by lightning during a one-month period. The first hospital, which had 236 beds, suffered a direct strike to the building. This resulted in a direct spread of the power peak and temporary failure of the standard power supply. The principle problems, after restoring standard power supply, were with the fire alarm system and peripheral network connections in the digital radiology systems. No direct impact on the hardware could be found. Restarting the servers resolved all problems. The second hospital, which had 436 beds, had a lightning strike on the premises and mainly experienced problems due to induction. All affected installations had a cable connection from outside in one way or another. The power supplies never were endangered. The main problem was the failure of different communication systems (telephone, radio, intercom, fire alarm system). Also, the electronic entrance control went out. During the days after the lightening strike, multiple software problems became apparent, as well as failures of the network connections controlling the technical support systems. There are very few ways to prepare for induction problems. The use of fiber-optic networks can limit damage. To the knowledge of the authors, these are the first cases of lightning striking hospitals in medical literature.

Joint terminals and relay optimization for two-way power line information exchange systems with QoS constraints

NASA Astrophysics Data System (ADS)

Wu, Xiaolin; Rong, Yue

2015-12-01

The quality-of-service (QoS) criteria (measured in terms of the minimum capacity requirement in this paper) are very important to practical indoor power line communication (PLC) applications as they greatly affect the user experience. With a two-way multicarrier relay configuration, in this paper we investigate the joint terminals and relay power optimization for the indoor broadband PLC environment, where the relay node works in the amplify-and-forward (AF) mode. As the QoS-constrained power allocation problem is highly non-convex, the globally optimal solution is computationally intractable to obtain. To overcome this challenge, we propose an alternating optimization (AO) method to decompose this problem into three convex/quasi-convex sub-problems. Simulation results demonstrate the fast convergence of the proposed algorithm under practical PLC channel conditions. Compared with the conventional bidirectional direct transmission (BDT) system, the relay-assisted two-way information exchange (R2WX) scheme can meet the same QoS requirement with less total power consumption.

The power-consumption-controlled extruder: a tool for pellet production.

PubMed

Kleinebudde, P; Sølvberg, A J; Lindner, H

1994-07-01

Based on the assumption that there is a link between power consumption of an extruder and pellet properties, a control circuit for power consumption was developed. Powder and granulation liquid are fed separately into a twin-screw extruder. The power consumption is controlled by varying the pump rate at a given powder-feed rate; consequently each level of power consumption results in a specific water content of the extrudate for a particular formulation. The shape of pellets depends almost entirely on the level of power consumption irrespective of formulation. The size of dry pellets is additionally affected by a shrinking factor which depends on the water content. The power-consumption-controlled extruder is an appropriate tool for the production of pellets. The system is able to adapt the water content for a formulation automatically.

In-depth analysis and discussions of water absorption-typed high power laser calorimeter

NASA Astrophysics Data System (ADS)

Wei, Ji Feng

2017-02-01

In high-power and high-energy laser measurement, the absorber materials can be easily destroyed under long-term direct laser irradiation. In order to improve the calorimeter's measuring capacity, a measuring system directly using water flow as the absorber medium was built. The system's basic principles and the designing parameters of major parts were elaborated. The system's measuring capacity, the laser working modes, and the effects of major parameters were analyzed deeply. Moreover, the factors that may affect the accuracy of measurement were analyzed and discussed. The specific control measures and methods were elaborated. The self-calibration and normal calibration experiments show that this calorimeter has very high accuracy. In electrical calibration, the average correction coefficient is only 1.015, with standard deviation of only 0.5%. In calibration experiments, the standard deviation relative to a middle-power standard calorimeter is only 1.9%.

The effects of control field detuning on the modulation instability in a three-level quantum well system

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

Borgohain, Nitu, E-mail: nituborgohain.ism@gmail.com; Konar, S.

The paper presents a theoretical study of the modulation instability of a continuous or quasi-continuous optical probe in a three level quantum well system under electromagnetically induced transparency. The modulation instability is affected by the control field detuning, as well as even-order dispersion and by the strength of Kerr (third-order) and quintic (fifth-order) nonlinearities. The fourth-order dispersion reduces the bandwidth over which modulation instability occurs, whereas the quintic nonlinearity saturates the growth of the modulation instability. Detuning the control field from resonance can significantly reduce the growth of the modulation instability at both low and high power levels. At lowmore » powers, the system becomes stable against modulation instability for small detuning of the control field and at high powers modulation instability disappears for larger detuning.« less

Power plant fault detection using artificial neural network

NASA Astrophysics Data System (ADS)

Thanakodi, Suresh; Nazar, Nazatul Shiema Moh; Joini, Nur Fazriana; Hidzir, Hidzrin Dayana Mohd; Awira, Mohammad Zulfikar Khairul

2018-02-01

The fault that commonly occurs in power plants is due to various factors that affect the system outage. There are many types of faults in power plants such as single line to ground fault, double line to ground fault, and line to line fault. The primary aim of this paper is to diagnose the fault in 14 buses power plants by using an Artificial Neural Network (ANN). The Multilayered Perceptron Network (MLP) that detection trained utilized the offline training methods such as Gradient Descent Backpropagation (GDBP), Levenberg-Marquardt (LM), and Bayesian Regularization (BR). The best method is used to build the Graphical User Interface (GUI). The modelling of 14 buses power plant, network training, and GUI used the MATLAB software.

Feasibility Study of a Nuclear-Stirling Plant for the Jupiter Icy Moons Orbiter

NASA Technical Reports Server (NTRS)

Schmitz, Paul C.; Schreiber, Jeffrey G.; Penswick, L. Barry

2005-01-01

NASA is undertaking the design of a new spacecraft to explore the planet Jupiter and its three moons Calisto, Ganymede and Europa. This proposed mission, known as Jupiter Icy Moons Orbiter (JIMO) would use a nuclear reactor and an associated electrical generation system (Reactor Power Plant-RPP) to provide power to the spacecraft. The JIMO spacecraft is envisioned to use this power for science and communications as well as Electric Propulsion (EP). Among other potential power-generating concepts, previous studies have considered Thermoelectric and Brayton Power conversion systems, coupled to a liquid metal reactor for the JIMO mission. This paper will explore trades in system mass and radiator area for a nuclear reactor power conversion system, however this study will focus on Stirling power conversion. The Stirling convertor modeled in this study is based upon the Component Test Power Convertor design that was designed and operated successfully under the Civil Space Technology Initiative for use with the SP-100 nuclear reactor i the 1980's and early 1990's. The study design is such that two of the four convertors would operate at any time to generate the 100 kWe while the others are held in reserve. For this study the Stirling convertors hot-side temperature is 1050 K, would operate at a temperature ratio of 2.4 for a minimum mass system and would have a system efficiency of 29%. The Stirling convertor would generate high voltage (400 volt), 100 Hz single phase AC that is supplied to the Power Management and Distribution system. The waste hear is removed from the Stirling convertors by a flowing liquid sodium-potassium eutectic and then rejected by a shared radiator. The radiator consists of two coplanar wings, which would be deployed after the reactor is in space. System trades were performed to vary cycle state point temperatures and convertor design as well as power output. Other redundancy combinations were considered to understand the affects of convertor size and number of spares to the system mass.

A Wireless Implantable Switched-Capacitor Based Optogenetic Stimulating System

PubMed Central

Lee, Hyung-Min; Kwon, Ki-Yong; Li, Wen

2015-01-01

This paper presents a power-efficient implantable optogenetic interface using a wireless switched-capacitor based stimulating (SCS) system. The SCS efficiently charges storage capacitors directly from an inductive link and periodically discharges them into an array of micro-LEDs, providing high instantaneous power without affecting wireless link and system supply voltage. A custom-designed computer interface in LabVIEW environment wirelessly controls stimulation parameters through the inductive link, and an optrode array enables simultaneous neural recording along with optical stimulation. The 4-channel SCS system prototype has been implemented in a 0.35-μm CMOS process and combined with the optrode array. In vivo experiments involving light-induced local field potentials verified the efficacy of the SCS system. An implantable version of the SCS system with flexible hermetic sealing is under development for chronic experiments. PMID:25570099

Power affects performance when the pressure is on: evidence for low-power threat and high-power lift.

PubMed

Kang, Sonia K; Galinsky, Adam D; Kray, Laura J; Shirako, Aiwa

2015-05-01

The current research examines how power affects performance in pressure-filled contexts. We present low-power-threat and high-power-lift effects, whereby performance in high-stakes situations suffers or is enhanced depending on one's power; that is, the power inherent to a situational role can produce effects similar to stereotype threat and lift. Three negotiations experiments demonstrate that role-based power affects outcomes but only when the negotiation is diagnostic of ability and, therefore, pressure-filled. We link these outcomes conceptually to threat and lift effects by showing that (a) role power affects performance more strongly when the negotiation is diagnostic of ability and (b) underperformance disappears when the low-power negotiator has an opportunity to self-affirm. These results suggest that stereotype threat and lift effects may represent a more general phenomenon: When the stakes are raised high, relative power can act as either a toxic brew (stereotype/low-power threat) or a beneficial elixir (stereotype/high-power lift) for performance. © 2015 by the Society for Personality and Social Psychology, Inc.

Hybrid emergency radiation detection: a wireless sensor network application for consequence management of a radiological release

NASA Astrophysics Data System (ADS)

Kyker, Ronald D.; Berry, Nina; Stark, Doug; Nachtigal, Noel; Kershaw, Chris

2004-08-01

The Hybrid Emergency Radiation Detection (HERD) system is a rapidly deployable ad-hoc wireless sensor network for monitoring the radiation hazard associated with a radiation release. The system is designed for low power, small size, low cost, and rapid deployment in order to provide early notification and minimize exposure. The many design tradeoffs, decisions, and challenges in the implementation of this wireless sensor network design will be presented and compared to the commercial systems available. Our research in a scaleable modular architectural highlights the need and implementation of a system level approach that provides flexibility and adaptability for a variety of applications. This approach seeks to minimize power, provide mission specific specialization, and provide the capability to upgrade the system with the most recent technology advancements by encapsulation and modularity. The implementation of a low power, widely available Real Time Operating System (RTOS) for multitasking with an improvement in code maintenance, portability, and reuse will be presented. Finally future design enhancements technology trends affecting wireless sensor networks will be presented.

Portable concealed weapon detection using millimeter-wave FMCW radar imaging

NASA Astrophysics Data System (ADS)

Johnson, Michael A.; Chang, Yu-Wen

2001-02-01

Unobtrusive detection of concealed weapons on persons or in abandoned bags would provide law enforcement a powerful tool to focus resources and increase traffic throughput in high- risk situations. We have developed a fast image scanning 94 GHz radar system that is suitable for portable operation and remote viewing of radar data. This system includes a novel fast image-scanning antenna that allows for the acquisition of medium resolution 3D millimeter wave images of stationary targets with frame times on order of one second. The 3D radar data allows for potential isolation of concealed weapons from body and environmental clutter such as nearby furniture or other people. The radar is an active system so image quality is not affected indoors, emitted power is however very low so there are no health concerns for operator or targets. The low power operation is still sufficient to penetrate heavy clothing or material. Small system size allows for easy transport and rapid deployment of the system as well as an easy migration path to future hand held systems.

High-efficiency photovoltaic technology including thermoelectric generation

NASA Astrophysics Data System (ADS)

Fisac, Miguel; Villasevil, Francesc X.; López, Antonio M.

2014-04-01

Nowadays, photovoltaic solar energy is a clean and reliable source for producing electric power. Most photovoltaic systems have been designed and built up for use in applications with low power requirements. The efficiency of solar cells is quite low, obtaining best results in monocrystalline silicon structures, with an efficiency of about 18%. When temperature rises, photovoltaic cell efficiency decreases, given that the short-circuit current is slightly increased, and the open-circuit voltage, fill factor and power output are reduced. To ensure that this does not affect performance, this paper describes how to interconnect photovoltaic and thermoelectric technology into a single structure. The temperature gradient in the solar panel is used to supply thermoelectric cells, which generate electricity, achieving a positive contribution to the total balance of the complete system.

Cost related sensitivity analysis for optimal operation of a grid-parallel PEM fuel cell power plant

NASA Astrophysics Data System (ADS)

El-Sharkh, M. Y.; Tanrioven, M.; Rahman, A.; Alam, M. S.

Fuel cell power plants (FCPP) as a combined source of heat, power and hydrogen (CHP&H) can be considered as a potential option to supply both thermal and electrical loads. Hydrogen produced from the FCPP can be stored for future use of the FCPP or can be sold for profit. In such a system, tariff rates for purchasing or selling electricity, the fuel cost for the FCPP/thermal load, and hydrogen selling price are the main factors that affect the operational strategy. This paper presents a hybrid evolutionary programming and Hill-Climbing based approach to evaluate the impact of change of the above mentioned cost parameters on the optimal operational strategy of the FCPP. The optimal operational strategy of the FCPP for different tariffs is achieved through the estimation of the following: hourly generated power, the amount of thermal power recovered, power trade with the local grid, and the quantity of hydrogen that can be produced. Results show the importance of optimizing system cost parameters in order to minimize overall operating cost.

Research on prediction of agricultural machinery total power based on grey model optimized by genetic algorithm

NASA Astrophysics Data System (ADS)

Xie, Yan; Li, Mu; Zhou, Jin; Zheng, Chang-zheng

2009-07-01

Agricultural machinery total power is an important index to reflex and evaluate the level of agricultural mechanization. It is the power source of agricultural production, and is the main factors to enhance the comprehensive agricultural production capacity expand production scale and increase the income of the farmers. Its demand is affected by natural, economic, technological and social and other "grey" factors. Therefore, grey system theory can be used to analyze the development of agricultural machinery total power. A method based on genetic algorithm optimizing grey modeling process is introduced in this paper. This method makes full use of the advantages of the grey prediction model and characteristics of genetic algorithm to find global optimization. So the prediction model is more accurate. According to data from a province, the GM (1, 1) model for predicting agricultural machinery total power was given based on the grey system theories and genetic algorithm. The result indicates that the model can be used as agricultural machinery total power an effective tool for prediction.

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

Jacques V Hugo

This book chapter describes the considerations for the selection of advanced human–system interfaces (HSIs) for the new generation of nuclear power plants. The chapter discusses the technologies that will be needed to support highly automated nuclear power plants, while minimising demands for numbers of operational staff, reducing human error and improving plant efficiency and safety. Special attention is paid to the selection and deployment of advanced technologies in nuclear power plants (NPPs). The chapter closes with an examination of how technologies are likely to develop over the next 10–15 years and how this will affect design choices for the nuclearmore » industry.« less

Impact of sleep loss before learning on cortical dynamics during memory retrieval.

PubMed

Alberca-Reina, E; Cantero, J L; Atienza, M

2015-12-01

Evidence shows that sleep loss before learning decreases activation of the hippocampus during encoding and promotes forgetting. But it remains to be determined which neural systems are functionally affected during memory retrieval after one night of recovery sleep. To investigate this issue, we evaluated memory for pairs of famous people's faces with the same or different profession (i.e., semantically congruent or incongruent faces) after one night of undisturbed sleep in subjects who either underwent 4hours of acute sleep restriction (ASR, N=20) or who slept 8hours the pre-training night (controls, N=20). EEG recordings were collected during the recognition memory task in both groups, and the cortical sources generating this activity localized by applying a spatial beamforming filter in the frequency domain. Even though sleep restriction did not affect accuracy of memory performance, controls showed a much larger decrease of alpha power relative to a baseline period when compared to sleep-deprived subjects. These group differences affected a widespread frontotemporoparietal network involved in retrieval of episodic/semantic memories. Regression analyses further revealed that associative memory in the ASR group was negatively correlated with alpha power in the occipital regions, whereas the benefit of congruency in the same group was positively correlated with delta power in the left lateral prefrontal cortex. Retrieval-related decreases of alpha power have been associated with the reactivation of material-specific memory representations, whereas increases of delta power have been related to inhibition of interferences that may affect the performance of the task. We can therefore draw the conclusion that a few hours of sleep loss in the pre-training night, though insufficient to change the memory performance, is sufficient to alter the processes involved in retrieving and manipulating episodic and semantic information. Copyright © 2015 Elsevier Inc. All rights reserved.

Design of stationary PEFC system configurations to meet heat and power demands

NASA Astrophysics Data System (ADS)

Wallmark, Cecilia; Alvfors, Per

This paper presents heat and power efficiencies of a modeled PEFC system and the methods used to create the system configuration. The paper also includes an example of a simulated fuel cell system supplying a building in Sweden with heat and power. The main method used to create an applicable fuel cell system configuration is pinch technology. This technology is used to evaluate and design a heat exchanger network for a PEFC system working under stationary conditions, in order to find a solution with high heat utilization. The heat exchanger network in the system connecting the reformer, the burner, gas cleaning, hot-water storage and the PEFC stack will affect the heat transferred to the hot-water storage and thereby the heating of the building. The fuel, natural gas, is reformed to a hydrogen-rich gas within a slightly pressurized system. The fuel processor investigated is steam reforming, followed by high- and low-temperature shift reactors and preferential oxidation. The system is connected to the electrical grid for backup and peak demands and to a hot-water storage to meet the varying heat demand for the building. The procedure for designing the fuel cell system installation as co-generation system is described, and the system is simulated for a specific building in Sweden during 1 year. The results show that the fuel cell system in combination with a burner and hot-water storage could supply the building with the required heat without exceeding any of the given limitations. The designed co-generation system will provide the building with most of its power requirements and would further generate income by sale of electricity to the power grid.

Decomposing climate-induced temperature and water effects on the expansion and operation of the US electricity system

NASA Astrophysics Data System (ADS)

Sun, Y.; Eurek, K.; Macknick, J.; Steinberg, D. C.; Averyt, K.; Badger, A.; Livneh, B.

2017-12-01

Climate change has the potential to affect the supply and demands of the U.S. power sector. Rising air temperatures can affect the seasonal and total demand for electricity, alter the thermal efficiency of power plants, and lower the maximum capacity of electric transmission lines. Changes in hydrology can affect seasonal and total availability of water used for power plant operations. Prior studies have examined some climate impacts on the electricity sector, but there has been no systematic study quantifying and comparing the importance of these climate-induced effects in isolation and in combination. Here, we perform a systematic assessment using the Regional Energy Deployment System (ReEDS) electricity sector model in combination with downscaled climate results from four models in the CMIP5 archive that provide contrasting temperature and precipitation trends for key regions in the U.S. The ReEDS model captures dynamic climate and hydrological resource data .when choosing the cost optimal mix of generation resources necessary to balance supply and demand for electricity. We examine how different climate-induced changes in air temperature and water availability, considered in isolation and in combination, may affect energy and economic outcomes at a regional and national level from the present through 2050. Results indicate that temperature-induced impacts on electricity consumption show consistent trends nationwide across all climate scenarios. Hydrological impacts and variability differ by model and tend to have a minor effect on national electricity trends, but can be important determinants regionally. Taken together, this suggests that isolated climate change impacts on the electricity system depend on the geographic scale of interest - the effect of rising temperatures on demand, which is qualitatively robust to the choice of climate model, largely determines impacts on generation, capacity and cost at the national level, whereas other impact pathways may dominate at regional level.

Establishing a Cloud Computing Success Model for Hospitals in Taiwan.

PubMed

Lian, Jiunn-Woei

2017-01-01

The purpose of this study is to understand the critical quality-related factors that affect cloud computing success of hospitals in Taiwan. In this study, private cloud computing is the major research target. The chief information officers participated in a questionnaire survey. The results indicate that the integration of trust into the information systems success model will have acceptable explanatory power to understand cloud computing success in the hospital. Moreover, information quality and system quality directly affect cloud computing satisfaction, whereas service quality indirectly affects the satisfaction through trust. In other words, trust serves as the mediator between service quality and satisfaction. This cloud computing success model will help hospitals evaluate or achieve success after adopting private cloud computing health care services.

Establishing a Cloud Computing Success Model for Hospitals in Taiwan

PubMed Central

Lian, Jiunn-Woei

2017-01-01

The purpose of this study is to understand the critical quality-related factors that affect cloud computing success of hospitals in Taiwan. In this study, private cloud computing is the major research target. The chief information officers participated in a questionnaire survey. The results indicate that the integration of trust into the information systems success model will have acceptable explanatory power to understand cloud computing success in the hospital. Moreover, information quality and system quality directly affect cloud computing satisfaction, whereas service quality indirectly affects the satisfaction through trust. In other words, trust serves as the mediator between service quality and satisfaction. This cloud computing success model will help hospitals evaluate or achieve success after adopting private cloud computing health care services. PMID:28112020

Methods and apparatus for cooling electronics

DOEpatents

Hall, Shawn Anthony; Kopcsay, Gerard Vincent

2014-12-02

Methods and apparatus are provided for choosing an energy-efficient coolant temperature for electronics by considering the temperature dependence of the electronics' power dissipation. This dependence is explicitly considered in selecting the coolant temperature T.sub.0 that is sent to the equipment. To minimize power consumption P.sub.Total for the entire system, where P.sub.Total=P.sub.0+P.sub.Cool is the sum of the electronic equipment's power consumption P.sub.0 plus the cooling equipment's power consumption P.sub.Cool, P.sub.Total is obtained experimentally, by measuring P.sub.0 and P.sub.Cool, as a function of three parameters: coolant temperature T.sub.0; weather-related temperature T.sub.3 that affects the performance of free-cooling equipment; and computational state C of the electronic equipment, which affects the temperature dependence of its power consumption. This experiment provides, for each possible combination of T.sub.3 and C, the value T.sub.0* of T.sub.0 that minimizes P.sub.Total. During operation, for any combination of T.sub.3 and C that occurs, the corresponding optimal coolant temperature T.sub.0* is selected, and the cooling equipment is commanded to produce it.

Water use at pulverized coal power plants with postcombustion carbon capture and storage.

PubMed

Zhai, Haibo; Rubin, Edward S; Versteeg, Peter L

2011-03-15

Coal-fired power plants account for nearly 50% of U.S. electricity supply and about a third of U.S. emissions of CO(2), the major greenhouse gas (GHG) associated with global climate change. Thermal power plants also account for 39% of all freshwater withdrawals in the U.S. To reduce GHG emissions from coal-fired plants, postcombustion carbon capture and storage (CCS) systems are receiving considerable attention. Current commercial amine-based capture systems require water for cooling and other operations that add to power plant water requirements. This paper characterizes and quantifies water use at coal-burning power plants with and without CCS and investigates key parameters that influence water consumption. Analytical models are presented to quantify water use for major unit operations. Case study results show that, for power plants with conventional wet cooling towers, approximately 80% of total plant water withdrawals and 86% of plant water consumption is for cooling. The addition of an amine-based CCS system would approximately double the consumptive water use of the plant. Replacing wet towers with air-cooled condensers for dry cooling would reduce plant water use by about 80% (without CCS) to about 40% (with CCS). However, the cooling system capital cost would approximately triple, although costs are highly dependent on site-specific characteristics. The potential for water use reductions with CCS is explored via sensitivity analyses of plant efficiency and other key design parameters that affect water resource management for the electric power industry.

Development of on-line laser power monitoring system

NASA Astrophysics Data System (ADS)

Ding, Chien-Fang; Lee, Meng-Shiou; Li, Kuan-Ming

2016-03-01

Since the laser was invented, laser has been applied in many fields such as material processing, communication, measurement, biomedical engineering, defense industries and etc. Laser power is an important parameter in laser material processing, i.e. laser cutting, and laser drilling. However, the laser power is easily affected by the environment temperature, we tend to monitor the laser power status, ensuring there is an effective material processing. Besides, the response time of current laser power meters is too long, they cannot measure laser power accurately in a short time. To be more precisely, we can know the status of laser power and help us to achieve an effective material processing at the same time. To monitor the laser power, this study utilize a CMOS (Complementary metal-oxide-semiconductor) camera to develop an on-line laser power monitoring system. The CMOS camera captures images of incident laser beam after it is split and attenuated by beam splitter and neutral density filter. By comparing the average brightness of the beam spots and measurement results from laser power meter, laser power can be estimated. Under continuous measuring mode, the average measuring error is about 3%, and the response time is at least 3.6 second shorter than thermopile power meters; under trigger measuring mode which enables the CMOS camera to synchronize with intermittent laser output, the average measuring error is less than 3%, and the shortest response time is 20 millisecond.

Dynamic Simulation over Long Time Periods with 100% Solar Generation.

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

Concepcion, Ricky James; Elliott, Ryan Thomas

2015-12-01

This project aimed to identify the path forward for dynamic simulation tools to accommodate these needs by characterizing the properties of power systems (with high PV penetration), analyzing how these properties affect dynamic simulation software, and offering solutions for potential problems.

Space Weather Effects on Current and Future Electric Power Systems

NASA Astrophysics Data System (ADS)

Munoz, D.; Dutta, O.; Tandoi, C.; Brandauer, W.; Mohamed, A.; Damas, M. C.

2016-12-01

This work addresses the effects of Geomagnetic Disturbances (GMDs) on the present bulk power system as well as the future smart grid, and discusses the mitigation of these geomagnetic impacts, so as to reduce the vulnerabilities of the electric power network to large space weather events. Solar storm characterized by electromagnetic radiation generates geo-electric fields that result in the flow of Geomagnetically Induced Currents (GICs) through the transmission lines, followed by transformers and the ground. As the ground conductivity and the power network topology significantly vary with the region, it becomes imperative to estimate of the magnitude of GICs for different places. In this paper, the magnitude of GIC has been calculated for New York State (NYS) with the help of extensive modelling of the whole NYS electricity transmission network using real data. Although GIC affects only high voltage levels, e.g. above 300 kV, the presence of coastline in NYS makes the low voltage transmission lines also susceptible to GIC. Besides this, the encroachment of technologies pertaining to smart grid implementation, such as Phasor Measurement Units (PMUs), Microgrids, Flexible AC Transmission System (FACTS), and Information and Communication Technology (ICT) have been analyzed for GMD impacts. Inaccurate PMU results due to scintillation of GPS signals that are affected by electromagnetic interference of solar storm, presence of renewable energy resources in coastal areas that are more vulnerable to GMD, the ability of FACTS devices to either block or pave new path for GICs and so on, shed some light on impacts of GMD on smart grid technologies.

Pulsed and CW adjustable 1942 nm single-mode all-fiber Tm-doped fiber laser system for surgical laser soft tissue ablation applications.

PubMed

Huang, Yize; Jivraj, Jamil; Zhou, Jiaqi; Ramjist, Joel; Wong, Ronnie; Gu, Xijia; Yang, Victor X D

2016-07-25

A surgical laser soft tissue ablation system based on an adjustable 1942 nm single-mode all-fiber Tm-doped fiber laser operating in pulsed or CW mode with nitrogen assistance is demonstrated. Ex vivo ablation on soft tissue targets such as muscle (chicken breast) and spinal cord (porcine) with intact dura are performed at different ablation conditions to examine the relationship between the system parameters and ablation outcomes. The maximum laser average power is 14.4 W, and its maximum peak power is 133.1 W with 21.3 μJ pulse energy. The maximum CW power density is 2.33 × 10⁶ W/cm² and the maximum pulsed peak power density is 2.16 × 10⁷ W/cm². The system parameters examined include the average laser power in CW or pulsed operation mode, gain-switching frequency, total ablation exposure time, and the input gas flow rate. The ablation effects were measured by microscopy and optical coherence tomography (OCT) to evaluate the ablation depth, superficial heat-affected zone diameter (HAZD) and charring diameter (CD). Our results conclude that the system parameters can be tailored to meet different clinical requirements such as ablation for soft tissue cutting or thermal coagulation for future applications of hemostasis.

Improving Operational System Performance of Internet of Things (IoT) in Indonesia Telecomunication Company

NASA Astrophysics Data System (ADS)

Dachyar, M.; Risky, S. A.

2014-06-01

Telecommunications company have to improve their business performance despite of the increase customers every year. In Indonesia, the telecommunication company have provided best services, improving operational systems by designing a framework for operational systems of the Internet of Things (IoT) other name of Machine to Machine (M2M). This study was conducted with expert opinion which further processed by the Analytic Hierarchy Process (AHP) to obtain important factor for organizations operational systems, and the Interpretive Structural Modeling (ISM) to determine factors of organization which found drives the biggest power. This study resulted, the greatest weight of SLA & KPI handling problems. The M2M current dashboard and current M2M connectivity have power to affect other factors and has important function for M2M operations roomates system which can be effectively carried out.

A complete electrical shock hazard classification system and its application

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

Gordon, Lloyd; Cartelli, Laura; Graham, Nicole

Current electrical safety standards evolved to address the hazards of 60-Hz power that are faced primarily by electricians, linemen, and others performing facility and utility work. As a result, this leaves a substantial gap in the management of electrical hazards in Research and Development (R&D) and specialized high voltage and high power equipment. We find substantial use of direct current (dc) electrical energy, and the use of capacitors, inductors, batteries, and radiofrequency (RF) power. The electrical hazards of these forms of electricity and their systems are different than for 50/60 Hz power. This paper proposes a method of classifying allmore » of the electrical shock hazards found in all types of R&D and utilization equipment. Examples of the variation of these hazards from NFPA 70E include (a) high voltage can be harmless, if the available current is sufficiently low, (b) low voltage can be harmful if the available current/power is high, (c) high voltage capacitor hazards are unique and include severe reflex action, affects on the heart, and tissue damage, and (d) arc flash hazard analysis for dc and capacitor systems are not provided in existing standards. This work has led to a comprehensive electrical hazard classification system that is based on various research conducted over the past 100 years, on analysis of such systems in R&D, and on decades of experience. Lastly, the new comprehensive electrical shock hazard classification system uses a combination of voltage, shock current available, fault current available, power, energy, and waveform to classify all forms of electrical hazards.« less

A complete electrical shock hazard classification system and its application

DOE PAGES

Gordon, Lloyd; Cartelli, Laura; Graham, Nicole

2018-02-08

Current electrical safety standards evolved to address the hazards of 60-Hz power that are faced primarily by electricians, linemen, and others performing facility and utility work. As a result, this leaves a substantial gap in the management of electrical hazards in Research and Development (R&D) and specialized high voltage and high power equipment. We find substantial use of direct current (dc) electrical energy, and the use of capacitors, inductors, batteries, and radiofrequency (RF) power. The electrical hazards of these forms of electricity and their systems are different than for 50/60 Hz power. This paper proposes a method of classifying allmore » of the electrical shock hazards found in all types of R&D and utilization equipment. Examples of the variation of these hazards from NFPA 70E include (a) high voltage can be harmless, if the available current is sufficiently low, (b) low voltage can be harmful if the available current/power is high, (c) high voltage capacitor hazards are unique and include severe reflex action, affects on the heart, and tissue damage, and (d) arc flash hazard analysis for dc and capacitor systems are not provided in existing standards. This work has led to a comprehensive electrical hazard classification system that is based on various research conducted over the past 100 years, on analysis of such systems in R&D, and on decades of experience. Lastly, the new comprehensive electrical shock hazard classification system uses a combination of voltage, shock current available, fault current available, power, energy, and waveform to classify all forms of electrical hazards.« less

Sandwich Core Heat-Pipe Radiator for Power and Propulsion Systems

NASA Technical Reports Server (NTRS)

Gibson, Marc; Sanzi, James; Locci, Ivan

2013-01-01

Next-generation heat-pipe radiator technologies are being developed at the NASA Glenn Research Center to provide advancements in heat-rejection systems for space power and propulsion systems. All spacecraft power and propulsion systems require their waste heat to be rejected to space in order to function at their desired design conditions. The thermal efficiency of these heat-rejection systems, balanced with structural requirements, directly affect the total mass of the system. Terrestrially, this technology could be used for thermal control of structural systems. One potential use is radiant heating systems for residential and commercial applications. The thin cross section and efficient heat transportability could easily be applied to flooring and wall structures that could evenly heat large surface areas. Using this heat-pipe technology, the evaporator of the radiators could be heated using any household heat source (electric, gas, etc.), which would vaporize the internal working fluid and carry the heat to the condenser sections (walls and/or floors). The temperature could be easily controlled, providing a comfortable and affordable living environment. Investigating the appropriate materials and working fluids is needed to determine this application's potential success and usage.

Ion accelerator systems for high power 30 cm thruster operation

NASA Technical Reports Server (NTRS)

Aston, G.

1982-01-01

Two and three-grid accelerator systems for high power ion thruster operation were investigated. Two-grid translation tests show that over compensation of the 30 cm thruster SHAG grid set spacing the 30 cm thruster radial plasma density variation and by incorporating grid compensation only sufficient to maintain grid hole axial alignment, it is shown that beam current gains as large as 50% can be realized. Three-grid translation tests performed with a simulated 30 cm thruster discharge chamber show that substantial beamlet steering can be reliably affected by decelerator grid translation only, at net-to-total voltage ratios as low as 0.05.

Using a coupled inductor controlled by fuzzy logic to improve the efficiency of a Buck converter in a PV system

NASA Astrophysics Data System (ADS)

Abouchabana, Nabil; Haddadi, Mourad; Rabhi, Abdelhamid; El Hajjaji, Ahmed

2017-11-01

Photovoltaic generators (PVG) produce a variable power according to the solar radiation (G) and temperature (T). This variation affects the sizing of the components of DC / DC converters, powered by such PVG, and make it difficult. The effects may differ from one component to another. The main and critical one is presented by the inductor, the element that stores the energy during sampled periods. We propose in this work an auto-adaptation of these inductor values to maintain optimal performance of the power yield of these converters. Our idea is to replace the inductor by a coupled inductor where this adjustment is made by the addition of an adjustable electric field in the magnetic core. Low current intensities come from the PVG supply the second inductor of the coupled inductor through a circuit controlled by a fuzzy controller (FC). The whole system is modeled and simulated under MATLAB/SIMULINK for the control part of the system and under PSPICE for the power part of the system. The obtained results show good performances of the proposed converter over the standard one.

The harmonic impact of electric vehicle battery charging

NASA Astrophysics Data System (ADS)

Staats, Preston Trent

The potential widespread introduction of the electric vehicle (EV) presents both opportunities and challenges to the power systems engineers who will be required to supply power to EV batteries. One of the challenges associated with EV battery charging comes from the potentially high harmonic currents associated with the conversion of ac power system voltages to dc EV battery voltages. Harmonic currents lead to increased losses in distribution circuits and reduced life expectancy of such power distribution components as capacitors and transformers. Harmonic current injections also cause harmonic voltages on power distribution networks. These distorted voltages can affect power system loads and specific standards exist regulating acceptable voltage distortion. This dissertation develops and presents the theory required to evaluate the electric vehicle battery charger as a harmonic distorting load and its possible harmonic impact on various aspects of power distribution systems. The work begins by developing a method for evaluating the net harmonic current injection of a large collection of EV battery chargers which accounts for variation in the start-time and initial battery state-of-charge between individual chargers. Next, this method is analyzed to evaluate the effect of input parameter variation on the net harmonic currents predicted by the model. We then turn to an evaluation of the impact of EV charger harmonic currents on power distribution systems, first evaluating the impact of these currents on a substation transformer and then on power distribution system harmonic voltages. The method presented accounts for the uncertainty in EV harmonic current injections by modeling the start-time and initial battery state-of-charge (SOC) of an individual EV battery charger as random variables. Thus, the net harmonic current, and distribution system harmonic voltages are formulated in a stochastic framework. Results indicate that considering variation in start-time and SOC leads to reduced estimates of harmonic current injection when compared to more traditional methods that do not account for variation. Evaluation of power distribution system harmonic voltages suggests that for any power distribution network there is a definite threshold penetration of EVs, below which the total harmonic distortion of voltage exceeds 5% at an insignificant number of buses. Thus, most existing distribution systems will probably be able to accommodate the early introduction of EV battery charging without widespread harmonic voltage problems.

A control strategy for PV stand-alone applications

NASA Astrophysics Data System (ADS)

Slouma, S.; Baccar, H.

2015-04-01

This paper proposes a stand-alone photovoltaic (PV) system study in domestic applications. Because of the decrease in power of photovoltaic module as a consequence of changes in solar radiation and temperature which affect the photovoltaic module performance, the design and control of DC-DC buck converter was proposed for providing power to the load from a photovoltaic source.In fact, the control of this converter is carried out with integrated MPPT (Maximum Power Point Tracking) algorithm which ensures a maximum energy generated by the PV arrays. Moreover, the output stage is composed by a battery energy storage system, dc-ac inverter, LCL filter which enables higher efficiency, low distortion ac waveforms and low leakage currents. The control strategy adopted is cascade control composed by two regulation loops.Simulations performed with PSIM software were able to validate the control system.The realization and testing of the photovoltaic system were achieved in the Photovoltaic laboratory of the Centre for Research and Energy Technologies at the Technopark Borj Cedria. Experimental results verify the effeciency of the proposed system.

Operating experience with the southwire 30-meter high-temperature superconducting power cable

NASA Astrophysics Data System (ADS)

Stovall, J. P.; Lue, J. W.; Demko, J. A.; Fisher, P. W.; Gouge, M. J.; Hawsey, R. A.; Armstrong, J. W.; Hughey, R. L.; Lindsay, D. T.; Roden, M. L.; Sinha, U. K.; Tolbert, J. C.

2002-05-01

Southwire Company is operating a high-temperature superconducting (HTS) cable system at its corporate headquarters. The 30-m long, 3-phase cable system is powering three Southwire manufacturing plants and is rated at 12.4-kV, 1250-A, 60-Hz. Cooling is provided by a pressurized liquid nitrogen system operating at 70-80 K. The cables were energized on January 5, 2000 for on-line testing and operation and in April 2000 were placed into extended service. As of June 1, 2001, the HTS cables have provided 100% of the customer load for 8000 hours. The cryogenic system has been in continuous operation since November 1999. The HTS cable system has not been the cause of any power outages to the average 20 MW industrial load served by the cable. The cable has been exposed to short-circuit currents caused by load-side faults without damage. Based upon field measurements described herein, the cable critical current-a key performance parameter-remains the same and has not been affected by the hours of real-world operation, further proving the viability of this promising technology.

Children Using "Facebook": Teachers' Discursive Constructions of Childhood

ERIC Educational Resources Information Center

Chang-Kredl, Sandra; Kozak, Stephanie

2018-01-01

Conceptualizations of childhood are powerful determinants of adults' interactions with children, and technology and social networking systems are affecting the nature of teachers' knowledge of childhood. We analyzed questionnaire responses from 57 elementary-level teachers from Quebec regarding children's use of "Facebook". Through…

Geo-referenced digital data acquisition and processing system using LiDAR technology : executive summary report.

DOT National Transportation Integrated Search

2006-02-01

Problem: State-of-the-art airborne mapping is in major : transition, which affects both the data acquisition and : data processing technologies. The IT age has brought : powerful sensors and revolutionary new techniques to : acquire spatial data in l...

Development of a differentially balanced magnetic bearing and control system for use with a flywheel energy storage system

NASA Technical Reports Server (NTRS)

Higgins, Mark A.; Plant, David P.; Ries, Douglas M.; Kirk, James A.; Anand, Davinder K.

1992-01-01

The purpose of a magnetically suspended flywheel energy storage system for electric utility load leveling is to provide a means to store energy during times when energy is inexpensive to produce and then return it to the customer during times of peak power demand when generated energy is most expensive. The design of a 20 kWh flywheel energy storage system for electric utility load leveling applications involves the successful integration of a number of advanced technologies so as to minimize the size and cost of the system without affecting its efficiency and reliability. The flywheel energy storage system uses a carbon epoxy flywheel, two specially designed low loss magnetic bearings, a high efficiency motor generator, and a 60 cycle AC power converter all integrated through a microprocessor controller. The basic design is discussed of each of the components that is used in the energy storage design.

Ofeq-2 orbit, attitude, and flight evaluation

NASA Astrophysics Data System (ADS)

Grumer, Michael; Komem, Joseph; Kronenfeld, Joseph; Kubitski, Ophir; Lorber, Vitaly; Shyldkrot, Haim

1992-02-01

The most significant events and phenomena that occurred during the Ofeq-2 flight are evaluated in this work. Particular attention is paid to the physical and technological factors which affected its orbital lifetime. Comparison of Ofeq-2 telemetry results with prelaunch estimations and with Ofeq-1 flight data are presented. The satellite's orbit and mission characteristics are defined and the principal systems of Ofeq-2 are described. Topics addressed include the interaction between the spinner's attitude with respect to the sun and consequent electric power generation. The coning angle development history, the role of the solar data evaluation, and the factors influencing drag are also analyzed. All of these affected the Ofeq-2 power outage-recovery event. The orbit determination and the coning angle evolution estimation methods are discussed in some detail. A brief report on radiation effects on computer RAM (random access memory) is also given. An integrative systems engineering approach summary of the telemetry data reconstruction and analysis concludes the paper.

The influence of SRT on phosphorus removal and sludge characteristics in the HA-A/A-MCO sludge reduction process

NASA Astrophysics Data System (ADS)

Zuo, N.; Ji, F. Y.

2013-02-01

By researching the influence of sludge age (SRT) on phosphorous removal and sludge characteristics in the HA-A/A-MCO (hydrolysis-acidification-anaerobic/anoxic-multistep continuous oxic tank) process, which has the effect of simultaneous phosphorous and nitrogen removal and sludge reduction, it is found that extended SRT is helpful for improving the ability of anaerobic phosphorous release and chemical recovery of phosphate, but the hosphorous removal efficiency is not affected. Extended SRT causes the system to have even more active sludge; it can also lead to the system having a powerful ability of biochemical reaction by using superiority of concentration. Meanwhile, extended SRT can still reduce sludge yield. Extended SRT cannot make soluble metabolic product (SMP) accumulate in the reactor, so that the pollutant removal power is reduced; it also cannot affect the activity of the sludge. However, extended SRT is able to make the coagulation of the sludge hard, and cause the sludge volume index value increase, but cannot cause sludge bulking.

Theoretical explanation of the polarization-converting system achieved by beam shaping and combination technique and its performance under high power conditions

NASA Astrophysics Data System (ADS)

Wang, Peng; Li, Xiao; Shang, YaPing; Xu, XiaoJun

2015-10-01

The fiber laser has very obvious advantages and broad applications in remote welding, 3D cutting and national defense compared with the traditional solid laser. But influenced by heat effect of gain medium, nonlinear effect, stress birefringence effect and other negative factors, it's very difficult to get high power linearly polarized laser just using a single laser. For these limitations a polarization-converting system is designed using beam shaping and combination technique which is able to transform naturally polarized laser to linearly polarized laser at real time to resolve difficulties of generating high-power linearly polarized laser from fiber lasers in this paper. The principle of the Gaussian beam changing into the hollow beam passing through two axicons and the combination of the Gaussian beam and the hollow beam is discussed. In the experimental verification the energy conversion efficiency reached 93.1% with a remarkable enhancement of the extinction ratio from 3% to 98% benefited from the high conversion efficiency of axicons and the system worked fine under high power conditions. The system also kept excellent far field divergence. The experiment phenomenon also agreed with the simulation quite well. The experiment proves that this polarization-converting system will not affect laser structure which controls easily and needs no feedback and controlling system with stable and reliable properties at the same time. It can absolutely be applied to the polarization-conversion of high power laser.

Effects of nuclear electromagnetic pulse (EMP) on synchronous stability of the electric power system

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

Manweiler, R.W.

1975-11-01

The effects of a nuclear electromagnetic pulse (EMP) on the synchronous stability of the electric power transmission and distribution systems are evaluated. The various modes of coupling of EMP to the power system are briefly discussed, with particular emphasis on those perturbations affecting the synchronous stability of the transmission system. A brief review of the fundamental concepts of the stability problem is given, with a discussion of the general characteristics of transient analysis. A model is developed to represent single sets as well as repetitive sets of multiple faults on the distribution systems, as might be produced by EMP. Themore » results of many numerical stability calculations are presented to illustrate the transmission system's response from different types of perturbations. The important parameters of both multiple and repetitive faults are studied, including the dependence of the response on the size of the perturbed area, the fault density, and the effective impedance between the fault location and the transmission system. Both major load reduction and the effect of the opening of tie lines at the time of perturbation are also studied. We conclude that there is a high probability that EMP can induce perturbations on the distribution networks causing a large portion of the transmission network in the perturbed area to lose synchronism. The result would be an immediate and massive power failure. (auth)« less

Occurrence and countermeasures of urban power grid accident

NASA Astrophysics Data System (ADS)

Wei, Wang; Tao, Zhang

2018-03-01

With the advance of technology, the development of network communication and the extensive use of power grids, people can get to know power grid accidents around the world through the network timely. Power grid accidents occur frequently. Large-scale power system blackout and casualty accidents caused by electric shock are also fairly commonplace. All of those accidents have seriously endangered the property and personal safety of the country and people, and the development of society and economy is severely affected by power grid accidents. Through the researches on several typical cases of power grid accidents at home and abroad in recent years and taking these accident cases as the research object, this paper will analyze the three major factors that cause power grid accidents at present. At the same time, combining with various factors and impacts caused by power grid accidents, the paper will put forward corresponding solutions and suggestions to prevent the occurrence of the accident and lower the impact of the accident.

SCADA-based Operator Support System for Power Plant Equipment Fault Forecasting

NASA Astrophysics Data System (ADS)

Mayadevi, N.; Ushakumari, S. S.; Vinodchandra, S. S.

2014-12-01

Power plant equipment must be monitored closely to prevent failures from disrupting plant availability. Online monitoring technology integrated with hybrid forecasting techniques can be used to prevent plant equipment faults. A self learning rule-based expert system is proposed in this paper for fault forecasting in power plants controlled by supervisory control and data acquisition (SCADA) system. Self-learning utilizes associative data mining algorithms on the SCADA history database to form new rules that can dynamically update the knowledge base of the rule-based expert system. In this study, a number of popular associative learning algorithms are considered for rule formation. Data mining results show that the Tertius algorithm is best suited for developing a learning engine for power plants. For real-time monitoring of the plant condition, graphical models are constructed by K-means clustering. To build a time-series forecasting model, a multi layer preceptron (MLP) is used. Once created, the models are updated in the model library to provide an adaptive environment for the proposed system. Graphical user interface (GUI) illustrates the variation of all sensor values affecting a particular alarm/fault, as well as the step-by-step procedure for avoiding critical situations and consequent plant shutdown. The forecasting performance is evaluated by computing the mean absolute error and root mean square error of the predictions.

Coordinated Scheduling for Interdependent Electric Power and Natural Gas Infrastructures

DOE PAGES

Zlotnik, Anatoly; Roald, Line; Backhaus, Scott; ...

2016-03-24

The extensive installation of gas-fired power plants in many parts of the world has led electric systems to depend heavily on reliable gas supplies. The use of gas-fired generators for peak load and reserve provision causes high intraday variability in withdrawals from high-pressure gas transmission systems. Such variability can lead to gas price fluctuations and supply disruptions that affect electric generator dispatch, electricity prices, and threaten the security of power systems and gas pipelines. These infrastructures function on vastly different spatio-temporal scales, which prevents current practices for separate operations and market clearing from being coordinated. Here in this article, wemore » apply new techniques for control of dynamic gas flows on pipeline networks to examine day-ahead scheduling of electric generator dispatch and gas compressor operation for different levels of integration, spanning from separate forecasting, and simulation to combined optimal control. We formulate multiple coordination scenarios and develop tractable physically accurate computational implementations. These scenarios are compared using an integrated model of test networks for power and gas systems with 24 nodes and 24 pipes, respectively, which are coupled through gas-fired generators. The analysis quantifies the economic efficiency and security benefits of gas-electric coordination and dynamic gas system operation.« less

Dynamics of defects in Ce³⁺ doped silica affecting its performance as protective filter in ultraviolet high-power lasers.

PubMed

Demos, Stavros G; Ehrmann, Paul R; Qiu, S Roger; Schaffers, Kathleen I; Suratwala, Tayyab I

2014-11-17

We investigate defects forming in Ce³⁺-doped fused silica samples following exposure to nanosecond ultraviolet laser pulses and their relaxation as a function of time and exposure to low intensity light at different wavelengths. A subset of these defects are responsible for inducing absorption in the visible and near infrared spectral range, which is of critical importance for the use of this material as ultraviolet light absorbing filter in high power laser systems. The dependence of the induced absorption as a function of laser fluence and methods to most efficiently mitigate this effect are presented. Experiments simulating the operation of the material as a UV protection filter for high power laser systems were performed in order to determine limitations and practical operational conditions.

Deconstructing the power resistance relationship for squats: A joint-level analysis.

PubMed

Farris, D J; Lichtwark, G A; Brown, N A T; Cresswell, A G

2016-07-01

Generating high leg power outputs is important for executing rapid movements. Squats are commonly used to increase leg strength and power. Therefore, it is useful to understand factors affecting power output in squatting. We aimed to deconstruct the mechanisms behind why power is maximized at certain resistances in squatting. Ten male rowers (age = 20 ± 2.2 years; height = 1.82 ± 0.03 m; mass = 86 ± 11 kg) performed maximal power squats with resistances ranging from body weight to 80% of their one repetition maximum (1RM). Three-dimensional kinematics was combined with ground reaction force (GRF) data in an inverse dynamics analysis to calculate leg joint moments and powers. System center of mass (COM) velocity and power were computed from GRF data. COM power was maximized across a range of resistances from 40% to 60% 1RM. This range was identified because a trade-off in hip and knee joint powers existed across this range, with maximal knee joint power occurring at 40% 1RM and maximal hip joint power at 60% 1RM. A non-linear system force-velocity relationship was observed that dictated large reductions in COM power below 20% 1RM and above 60% 1RM. These reductions were due to constraints on the control of the movement. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

End-Use Load and Conservation Assessment Program : Co-Instrumentation Test of Two Microcomputer-Based Energy Monitoring Systems.

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

Fishbaugher, M. J.

1985-05-01

The decreasing cost of microcomputers along with improvements in power metering circuitry have changed the way in which electrical energy use is monitored. Although utilities still rely on kilowatt-hour (kWh) meters for billing purposes, a microcomputer-based monitoring system is used when greater temporal and end-use resolution is desired. Because these types of monitoring systems will be used increasingly in large-scale conservation and end-use studies, it is important that their performance be analyzed to determine their accuracy. A co-instrumentation test was devised in which two such microcomputer-based monitoring systems made simultaneous measurements of electrical end-uses in two commercial buildings. The analysismore » of the co-instrumentation data aids in the evaluation of microcomputer-based monitoring systems used for end-use measurements. Separate and independent data loggers were used to measure the same loads simultaneously. In addition to these two systems, a utility billing meter measured the total energy use in each building during the co-instrumentation test. The utility's meters provided a relatively accurate standard by which the performance of both loggers could be judged. The comparison between the SCL and PNL microcomputer-based loggers has shown that power measurement techniques directly affect system performance. The co-instrumentation test has shown that there are certain standards that a monitoring system must meet if it is to perform well. First, it is essential to calibrate a microcomputer-based logger against a known standard load before the system is installed. Second, a microcomputer-based system must have some way of accounting for power factors. Recent advances in power metering circuitry have made it relatively easy to apply these power factors automatically in real time.« less

Power-grade butanol recovery and utilization

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

Noon, R.

1982-02-12

As an alternative to the traditional recovery systems, it was proposed in a previous publication that the n-butanol/acetone/ethanol fermentation products could be recovered as a power grade fuel blend and used directly as a fuel. This would affect a savings in process energy requirements because each chemical component would not have to be processed individually to technical grade purity. Further, some residual water could be tolerated in the fuel blend. To develop such a power grade fuel recovery scheme beyond the conceptual stage, the Energy Research and Resource Division of the Kansas Energy Office undertook a two-fold program to demonstratemore » and test a power grade butanol/acetone/ethanol fuel recovery system, and further to demonstrate the feasibility of using the fuel blend in a standard type engine. A development program was initiated to accomplish the following objectives: design and test an operational power grade butanol recovery plant that would operate at one liter per hour output; and test and assess the performance of power grade butanol in a spark ignition automotive engine. This project has demonstrated that recovery of a power grade butanol fuel blend is simple and can be accomplished at a considered energy advantage over ethanol. It was further demonstrated that such a power grade blend works well in a typical spark ignition engine.« less

Characterization of rainbow trout (Oncorhynchus mykiss) spleen transcriptome and identification of immune-related genes

USDA-ARS?s Scientific Manuscript database

Resistance against specific diseases is affecting profitability in fish production systems including rainbow trout. Limited information is known about functions and mechanisms of the immune gene pathways in teleosts. Immunogenomics are powerful tools to determine immune-related genes/gene pathways a...

Changing Roles in Indian Country

ERIC Educational Resources Information Center

Pember, Mary Annette

2008-01-01

American Indian women are not strangers to leadership and power. In traditional tribal culture, women often hold positions of authority, participating in decisions affecting their families and communities. They are responsible for preserving values and culture as well as caring for their families. Many tribes use a matrilineal system in…

49 CFR 234.249 - Ground tests.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 4 2014-10-01 2014-10-01 false Ground tests. 234.249 Section 234.249... EMERGENCY NOTIFICATION SYSTEMS Maintenance, Inspection, and Testing Inspections and Tests § 234.249 Ground tests. A test for grounds on each energy bus furnishing power to circuits that affect the safety of...

Michael Resch | NREL

Science.gov Websites

producing ammonia. The outcome of this project will be to make ammonia synthesis more sustainable and ) without affecting the ammonia production rate. Such an ammonia synthesis is ideally suitable for small-scale ammonia synthesis system using water and air, powered by wind energy. Instead of developing

Modeling, analysis and control of fuel cell hybrid power systems

NASA Astrophysics Data System (ADS)

Suh, Kyung Won

Transient performance is a key characteristic of fuel cells, that is sometimes more critical than efficiency, due to the importance of accepting unpredictable electric loads. To fulfill the transient requirement in vehicle propulsion and portable fuel cell applications, a fuel cell stack is typically coupled with a battery through a DC/DC converter to form a hybrid power system. Although many power management strategies already exist, they all rely on low level controllers that realize the power split. In this dissertation we design controllers that realize various power split strategies by directly manipulating physical actuators (low level commands). We maintain the causality of the electric dynamics (voltage and current) and investigate how the electric architecture affects the hybridization level and the power management. We first establish the performance limitations associated with a stand-alone and power-autonomous fuel cell system that is not supplemented by an additional energy storage and powers all its auxiliary components by itself. Specifically, we examine the transient performance in fuel cell power delivery as it is limited by the air supplied by a compressor driven by the fuel cell itself. The performance limitations arise from the intrinsic coupling in the fluid and electrical domain between the compressor and the fuel cell stack. Feedforward and feedback control strategies are used to demonstrate these limitations analytically and with simulations. Experimental tests on a small commercial fuel cell auxiliary power unit (APU) confirm the dynamics and the identified limitations. The dynamics associated with the integration of a fuel cell system and a DC/DC converter is then investigated. Decentralized and fully centralized (using linear quadratic techniques) controllers are designed to regulate the power system voltage and to prevent fuel cell oxygen starvation. Regulating these two performance variables is a difficult task and requires a compromise due to the conflicting objectives. The compromise can be mitigated by augmenting the fuel cell power system with an energy buffer such as a battery. We consider two different and popular ways of connecting the battery and the fuel cell to the load and we refer to them as electric architectures. Various controller gains are used to span the fuel cell operation from load-following to load-leveling, and hence, to determine adequate fuel cell-battery sizing (hybridization level) and the associated trends in the system efficiency.

An oscillating wave energy converter with nonlinear snap-through Power-Take-Off systems in regular waves

NASA Astrophysics Data System (ADS)

Zhang, Xian-tao; Yang, Jian-min; Xiao, Long-fei

2016-07-01

Floating oscillating bodies constitute a large class of wave energy converters, especially for offshore deployment. Usually the Power-Take-Off (PTO) system is a directly linear electric generator or a hydraulic motor that drives an electric generator. The PTO system is simplified as a linear spring and a linear damper. However the conversion is less powerful with wave periods off resonance. Thus, a nonlinear snap-through mechanism with two symmetrically oblique springs and a linear damper is applied in the PTO system. The nonlinear snap-through mechanism is characteristics of negative stiffness and double-well potential. An important nonlinear parameter γ is defined as the ratio of half of the horizontal distance between the two springs to the original length of both springs. Time domain method is applied to the dynamics of wave energy converter in regular waves. And the state space model is used to replace the convolution terms in the time domain equation. The results show that the energy harvested by the nonlinear PTO system is larger than that by linear system for low frequency input. While the power captured by nonlinear converters is slightly smaller than that by linear converters for high frequency input. The wave amplitude, damping coefficient of PTO systems and the nonlinear parameter γ affect power capture performance of nonlinear converters. The oscillation of nonlinear wave energy converters may be local or periodically inter well for certain values of the incident wave frequency and the nonlinear parameter γ, which is different from linear converters characteristics of sinusoidal response in regular waves.

Applications of wind generation for power system frequency control, inter-area oscillations damping and parameter identification

NASA Astrophysics Data System (ADS)

Wilches-Bernal, Felipe

Power systems around the world are experiencing a continued increase in wind generation as part of their energy mix. Because of its power electronics interface, wind energy conversion systems interact differently with the grid than conventional generation. These facts are changing the traditional dynamics that regulate power system behavior and call for a re-examination of traditional problems encountered in power systems like frequency response, inter-area oscillations and parameter identification. To address this need, realistic models for wind generation are necessary. The dissertation implements such models in a MATLAB-based flexible environment suited for power system research. The dissertation continues with an analysis of the frequency response of a test power system dependent mainly on a mode referred to as the frequency regulation mode. Using this test system it is shown that its frequency regulation capability is reduced with wind penetration levels of 25% and above. A controller for wind generation to restore the frequency response of the system is then presented. The proposed controller requires the WTG to operate in a deloaded mode, a condition that is obtained through pitching the wind turbine blades. Time simulations at wind penetration levels of 25% and 50% are performed to demonstrate the effectiveness of the proposed controller. Next, the dissertation evaluates how the inter-area oscillation of a two-machine power system is affected by wind integration. The assessment is performed based on the positioning of the WTG, the level of wind penetration, and the loading condition of the system. It is determined that integrating wind reduces the damping of the inter-area mode of the system when performed in an area that imports power. For this worst-case scenario, the dissertation proposes two controllers for wind generation to improve the damping of the inter-area mode. The first controller uses frequency as feedback signal for the active power control of the WTG while the second controller manipulates the reactive power control of the WTG using the current magnitude as the feedback signal. Finally, the dissertation proposes a parameter identification method for identifying and verifying the reactive power control parameters of WTGs. Using voltage and current measurements of a wind unit as an input, the proposed method estimates an optimal set of parameters such that the output current of a standalone WTG model better approximates the measured signal. Because WTG are nonlinear systems, the identification method is solved by a Gauss-Newton iteration used to calculate the solution of a nonlinear least-squares problem. The effectiveness of the proposed method is illustrated using a set of simulated data and actual PMU recordings.

The Study on the Communication Network of Wide Area Measurement System in Electricity Grid

NASA Astrophysics Data System (ADS)

Xiaorong, Cheng; Ying, Wang; Yangdan, Ni

Wide area measurement system(WAMS) is a fundamental part of security defense in Smart Grid, and the communication system of WAMS is an important part of Electric power communication network. For a large regional network is concerned, the real-time data which is transferred in the communication network of WAMS will affect the safe operation of the power grid directly. Therefore, WAMS raised higher requirements for real-time, reliability and security to its communication network. In this paper, the architecture of WASM communication network was studied according to the seven layers model of the open systems interconnection(OSI), and the network architecture was researched from all levels. We explored the media of WAMS communication network, the network communication protocol and network technology. Finally, the delay of the network were analyzed.

A Review on VSC-HVDC Reliability Modeling and Evaluation Techniques

NASA Astrophysics Data System (ADS)

Shen, L.; Tang, Q.; Li, T.; Wang, Y.; Song, F.

2017-05-01

With the fast development of power electronics, voltage-source converter (VSC) HVDC technology presents cost-effective ways for bulk power transmission. An increasing number of VSC-HVDC projects has been installed worldwide. Their reliability affects the profitability of the system and therefore has a major impact on the potential investors. In this paper, an overview of the recent advances in the area of reliability evaluation for VSC-HVDC systems is provided. Taken into account the latest multi-level converter topology, the VSC-HVDC system is categorized into several sub-systems and the reliability data for the key components is discussed based on sources with academic and industrial backgrounds. The development of reliability evaluation methodologies is reviewed and the issues surrounding the different computation approaches are briefly analysed. A general VSC-HVDC reliability evaluation procedure is illustrated in this paper.

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.

Design of the optical system for FSO access

NASA Astrophysics Data System (ADS)

Xu, Xiaojing; Yuan, Xiuhua; Huang, Dexiu

2002-08-01

Free space optics (FSO) is attractive for the 'last mile' communication in recent years for many combining advantages of fiber communication and other wireless technologies. FSO can provide high data rate with low power consumption, high immunity to interference, convenient deployment and flexibility. Optical system is an important section in the FSO transceiver terminal. In this paper the design of optical system based on a single Galileo telescope for both transmit and receive is proposed, and a polarization beam splitter is adopted to apart the receiving light from transmitting light. The configuration can avoid interference from the retroreflecting light of the ocular effectively. Some factors that affect the performance of the optical system are analyzed, such as the geometrical spreading loss and the loss increment according to pointing error and telescope maladjustment. Power budget shows that the system can satisfy the need of access for 1km in the light fog, and 2km in the thin fog.

Optimization analysis of thermal management system for electric vehicle battery pack

NASA Astrophysics Data System (ADS)

Gong, Huiqi; Zheng, Minxin; Jin, Peng; Feng, Dong

2018-04-01

Electric vehicle battery pack can increase the temperature to affect the power battery system cycle life, charge-ability, power, energy, security and reliability. The Computational Fluid Dynamics simulation and experiment of the charging and discharging process of the battery pack were carried out for the thermal management system of the battery pack under the continuous charging of the battery. The simulation result and the experimental data were used to verify the rationality of the Computational Fluid Dynamics calculation model. In view of the large temperature difference of the battery module in high temperature environment, three optimization methods of the existing thermal management system of the battery pack were put forward: adjusting the installation position of the fan, optimizing the arrangement of the battery pack and reducing the fan opening temperature threshold. The feasibility of the optimization method is proved by simulation and experiment of the thermal management system of the optimized battery pack.

Modelling voltage sag mitigation using dynamic voltage restorer and analyzing power quality issue

NASA Astrophysics Data System (ADS)

Ismail, Nor Laili; Hidzir, Hizrin Dayana Mohd; Thanakodi, Suresh; Nazar, Nazatul Shiema Moh; Ibrahim, Pungut; Ali, Che Ku Muhammad Sabri Che Ku

2018-02-01

Power quality problem which are arise due to a fault or a pulsed load can have caused an interruption of critical load. The modern power systems are becoming more sensitive to the quality of the power supplied by the utility company. Voltage sags and swells, flicker, interruptions, harmonic distortion and other distortion to the sinusoidal waveform are the examples of the power quality problems. The most affected due to these problems is industrial customers who use a lot of sensitive equipment. There has suffered a huge loss to these problems. Resulting of broken or damage equipment if voltage sag exceeds the sensitive threshold of the equipment. Thus, device such as Static Synchronous Compensator (STATCOM) and Dynamic Voltage Restorer (DVR) has been created to solve this problem among users. DVR is a custom power device that most effective and efficient. This paper intended to report the DVR operations during voltage sag compensation.

A study on improvement of discharge characteristic by using a transformer in a capacitively coupled plasma

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

Kim, Young-Cheol; Kim, Hyun-Jun; Lee, Hyo-Chang

In a plasma discharge system, the power loss at powered line, matching network, and other transmission line can affect the discharge characteristics such as the power transfer efficiency, voltage and current at powered electrode, and plasma density. In this paper, we propose a method to reduce power loss by using a step down transformer mounted between the matching network and the powered electrode in a capacitively coupled argon plasma. This step down transformer decreases the power loss by reducing the current flowing through the matching network and transmission line. As a result, the power transfer efficiency was increased about 5%–10%more » by using a step down transformer. However, the plasma density was dramatically increased compared to no transformer. This can be understood by the increase in ohmic heating and the decrease in dc-self bias. By simply mounting a transformer, improvement of discharge efficiency can be achieved in capacitively coupled plasmas.« less

Heat Transfer Study for HTS Power Transfer Cables

NASA Technical Reports Server (NTRS)

Augustynowicz, S.; Fesmire, J.

2002-01-01

Thermal losses are a key factor in the successful application of high temperature superconducting (HTS) power cables. Existing concepts and prototypes rely on the use of multilayer insulation (MLI) systems that are subject to large variations in actual performance. The small space available for the thermal insulation materials makes the application even more difficult because of bending considerations, mechanical loading, and the arrangement between the inner and outer piping. Each of these mechanical variables affects the heat leak rate. These factors of bending and spacing are examined in this study. Furthermore, a maintenance-free insulation system (high vacuum level for 20 years or longer) is a practical requirement. A thermal insulation system simulating a section of a flexible FITS power cable was constructed for test and evaluation on a research cryostat. This paper gives experimental data for the comparison of ideal MLI, MLI on rigid piping, and MLI between flexible piping. A section of insulated flexible piping was tested under cryogenic vacuum conditions including simulated bending and spacers.

Feasibility Study of a Nuclear-Stirling Power Plant for the Jupiter Icy Moons Orbiter

NASA Astrophysics Data System (ADS)

Schmitz, Paul C.; Schreiber, Jeffrey G.; Penswick, L. Barry

2005-02-01

NASA is undertaking the design of a new spacecraft to explore the planet Jupiter and its three moons Calisto, Ganymede and Europa. This proposed mission, known as Jupiter Icy Moons Orbiter (JIMO) would use a nuclear reactor and an associated electrical generation system (Reactor Power Plant - RPP) to provide power to the spacecraft. The JIMO spacecraft is envisioned to use this power for science and communications as well as Electric Propulsion (EP). Among other potential power-generating concepts, previous studies have considered Thermoelectric and Brayton power conversion systems, coupled to a liquid metal reactor for the JIMO mission. This paper will explore trades in system mass and radiator area for a nuclear reactor power conversion system, however this study will focus on Stirling power conversion. Stirling convertors have a long heritage operating in both power generation and the cooler industry, and are currently in use in a wide variety of applications. The Stirling convertor modeled in this study is based upon the Component Test Power Convertor design that was designed and operated successfully under the Civil Space Technology Initiative for use with the SP-100 nuclear reactor in the 1980's and early 1990's. The baseline RPP considered in this study consists of four dual-opposed Stirling convertors connected to the reactor by a liquid lithium loop. The study design is such that two of the four convertors would operate at any time to generate the 100 kWe while the others are held in reserve. For this study the Stirling convertors hot-side temperature is 1050 K, would operate at a temperature ratio of 2.4 for a minimum mass system and would have a system efficiency of 29%. The Stirling convertor would generate high voltage (400 volt), 100 Hz single phase AC that is supplied to the Power Management and Distribution system. The waste heat is removed from the Stirling convertors by a flowing liquid sodium-potassium eutectic and then rejected by a shared radiator. The radiator consists of two coplanar wings, which would be deployed after the reactor is in space. For this study design, the radiators would be located behind the conical radiation shield of the reactor and fan out as the radiator's distance from the reactor increases. System trades were performed to vary cycle state point temperatures and convertor design as well as power output. Other redundancy combinations were considered to understand the affects of convertor size and number of spares to the system mass.

Feasibility Study of a Nuclear-Stirling Power Plant for the Jupiter Icy Moons Orbiter

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

Schmitz, Paul C.; Schreiber, Jeffrey G.; Penswick, L. Barry

2005-02-06

NASA is undertaking the design of a new spacecraft to explore the planet Jupiter and its three moons Calisto, Ganymede and Europa. This proposed mission, known as Jupiter Icy Moons Orbiter (JIMO) would use a nuclear reactor and an associated electrical generation system (Reactor Power Plant - RPP) to provide power to the spacecraft. The JIMO spacecraft is envisioned to use this power for science and communications as well as Electric Propulsion (EP). Among other potential power-generating concepts, previous studies have considered Thermoelectric and Brayton power conversion systems, coupled to a liquid metal reactor for the JIMO mission. This papermore » will explore trades in system mass and radiator area for a nuclear reactor power conversion system, however this study will focus on Stirling power conversion. Stirling convertors have a long heritage operating in both power generation and the cooler industry, and are currently in use in a wide variety of applications. The Stirling convertor modeled in this study is based upon the Component Test Power Convertor design that was designed and operated successfully under the Civil Space Technology Initiative for use with the SP-100 nuclear reactor in the 1980's and early 1990's. The baseline RPP considered in this study consists of four dual-opposed Stirling convertors connected to the reactor by a liquid lithium loop. The study design is such that two of the four convertors would operate at any time to generate the 100 kWe while the others are held in reserve. For this study the Stirling convertors hot-side temperature is 1050 K, would operate at a temperature ratio of 2.4 for a minimum mass system and would have a system efficiency of 29%. The Stirling convertor would generate high voltage (400 volt), 100 Hz single phase AC that is supplied to the Power Management and Distribution system. The waste heat is removed from the Stirling convertors by a flowing liquid sodium-potassium eutectic and then rejected by a shared radiator. The radiator consists of two coplanar wings, which would be deployed after the reactor is in space. For this study design, the radiators would be located behind the conical radiation shield of the reactor and fan out as the radiator's distance from the reactor increases. System trades were performed to vary cycle state point temperatures and convertor design as well as power output. Other redundancy combinations were considered to understand the affects of convertor size and number of spares to the system mass.« less

The observation of manual grasp actions affects the control of speech: a combined behavioral and Transcranial Magnetic Stimulation study.

PubMed

Gentilucci, Maurizio; Campione, Giovanna Cristina; Dalla Volta, Riccardo; Bernardis, Paolo

2009-12-01

Does the mirror system affect the control of speech? This issue was addressed in behavioral and Transcranial Magnetic Stimulation (TMS) experiments. In behavioral experiment 1, participants pronounced the syllable /da/ while observing (1) a hand grasping large and small objects with power and precision grasps, respectively, (2) a foot interacting with large and small objects and (3) differently sized objects presented alone. Voice formant 1 was higher when observing power as compared to precision grasp, whereas it remained unaffected by observation of the different types of foot interaction and objects alone. In TMS experiment 2, we stimulated hand motor cortex, while participants observed the two types of grasp. Motor Evoked Potentials (MEPs) of hand muscles active during the two types of grasp were greater when observing power than precision grasp. In experiments 3-5, TMS was applied to tongue motor cortex of participants silently pronouncing the syllable /da/ and simultaneously observing power and precision grasps, pantomimes of the two types of grasps, and differently sized objects presented alone. Tongue MEPs were greater when observing power than precision grasp either executed or pantomimed. Finally, in TMS experiment 6, the observation of foot interaction with large and small objects did not modulate tongue MEPs. We hypothesized that grasp observation activated motor commands to the mouth as well as to the hand that were congruent with the hand kinematics implemented in the observed type of grasp. The commands to the mouth selectively affected postures of phonation organs and consequently basic features of phonological units.

Emotion Recognition from Single-Trial EEG Based on Kernel Fisher's Emotion Pattern and Imbalanced Quasiconformal Kernel Support Vector Machine

PubMed Central

Liu, Yi-Hung; Wu, Chien-Te; Cheng, Wei-Teng; Hsiao, Yu-Tsung; Chen, Po-Ming; Teng, Jyh-Tong

2014-01-01

Electroencephalogram-based emotion recognition (EEG-ER) has received increasing attention in the fields of health care, affective computing, and brain-computer interface (BCI). However, satisfactory ER performance within a bi-dimensional and non-discrete emotional space using single-trial EEG data remains a challenging task. To address this issue, we propose a three-layer scheme for single-trial EEG-ER. In the first layer, a set of spectral powers of different EEG frequency bands are extracted from multi-channel single-trial EEG signals. In the second layer, the kernel Fisher's discriminant analysis method is applied to further extract features with better discrimination ability from the EEG spectral powers. The feature vector produced by layer 2 is called a kernel Fisher's emotion pattern (KFEP), and is sent into layer 3 for further classification where the proposed imbalanced quasiconformal kernel support vector machine (IQK-SVM) serves as the emotion classifier. The outputs of the three layer EEG-ER system include labels of emotional valence and arousal. Furthermore, to collect effective training and testing datasets for the current EEG-ER system, we also use an emotion-induction paradigm in which a set of pictures selected from the International Affective Picture System (IAPS) are employed as emotion induction stimuli. The performance of the proposed three-layer solution is compared with that of other EEG spectral power-based features and emotion classifiers. Results on 10 healthy participants indicate that the proposed KFEP feature performs better than other spectral power features, and IQK-SVM outperforms traditional SVM in terms of the EEG-ER accuracy. Our findings also show that the proposed EEG-ER scheme achieves the highest classification accuracies of valence (82.68%) and arousal (84.79%) among all testing methods. PMID:25061837

Emotion recognition from single-trial EEG based on kernel Fisher's emotion pattern and imbalanced quasiconformal kernel support vector machine.

PubMed

Liu, Yi-Hung; Wu, Chien-Te; Cheng, Wei-Teng; Hsiao, Yu-Tsung; Chen, Po-Ming; Teng, Jyh-Tong

2014-07-24

Electroencephalogram-based emotion recognition (EEG-ER) has received increasing attention in the fields of health care, affective computing, and brain-computer interface (BCI). However, satisfactory ER performance within a bi-dimensional and non-discrete emotional space using single-trial EEG data remains a challenging task. To address this issue, we propose a three-layer scheme for single-trial EEG-ER. In the first layer, a set of spectral powers of different EEG frequency bands are extracted from multi-channel single-trial EEG signals. In the second layer, the kernel Fisher's discriminant analysis method is applied to further extract features with better discrimination ability from the EEG spectral powers. The feature vector produced by layer 2 is called a kernel Fisher's emotion pattern (KFEP), and is sent into layer 3 for further classification where the proposed imbalanced quasiconformal kernel support vector machine (IQK-SVM) serves as the emotion classifier. The outputs of the three layer EEG-ER system include labels of emotional valence and arousal. Furthermore, to collect effective training and testing datasets for the current EEG-ER system, we also use an emotion-induction paradigm in which a set of pictures selected from the International Affective Picture System (IAPS) are employed as emotion induction stimuli. The performance of the proposed three-layer solution is compared with that of other EEG spectral power-based features and emotion classifiers. Results on 10 healthy participants indicate that the proposed KFEP feature performs better than other spectral power features, and IQK-SVM outperforms traditional SVM in terms of the EEG-ER accuracy. Our findings also show that the proposed EEG-ER scheme achieves the highest classification accuracies of valence (82.68%) and arousal (84.79%) among all testing methods.

Link Investigation of IEEE 802.15.4 Wireless Sensor Networks in Forests

PubMed Central

Ding, Xingjian; Sun, Guodong; Yang, Gaoxiang; Shang, Xinna

2016-01-01

Wireless sensor networks are expected to automatically monitor the ecological evolution and wildlife habits in forests. Low-power links (transceivers) are often adopted in wireless sensor network applications, in order to save the precious sensor energy and then achieve long-term, unattended monitoring. Recent research has presented some performance characteristics of such low-power wireless links under laboratory or outdoor scenarios with less obstacles, and they have found that low-power wireless links are unreliable and prone to be affected by the target environment. However, there is still less understanding about how well the low-power wireless link performs in real-world forests and to what extent the complex in-forest surrounding environments affect the link performances. In this paper, we empirically evaluate the low-power links of wireless sensors in three typical different forest environments. Our experiment investigates the performance of the link layer compatible with the IEEE 802.15.4 standard and analyzes the variation patterns of the packet reception ratio (PRR), the received signal strength indicator (RSSI) and the link quality indicator (LQI) under diverse experimental settings. Some observations of this study are inconsistent with or even contradict prior results that are achieved in open fields or relatively clean environments and thus, provide new insights both into effectively evaluating the low-power wireless links and into efficiently deploying wireless sensor network systems in forest environments. PMID:27355957

Link Investigation of IEEE 802.15.4 Wireless Sensor Networks in Forests.

PubMed

Ding, Xingjian; Sun, Guodong; Yang, Gaoxiang; Shang, Xinna

2016-06-27

Wireless sensor networks are expected to automatically monitor the ecological evolution and wildlife habits in forests. Low-power links (transceivers) are often adopted in wireless sensor network applications, in order to save the precious sensor energy and then achieve long-term, unattended monitoring. Recent research has presented some performance characteristics of such low-power wireless links under laboratory or outdoor scenarios with less obstacles, and they have found that low-power wireless links are unreliable and prone to be affected by the target environment. However, there is still less understanding about how well the low-power wireless link performs in real-world forests and to what extent the complex in-forest surrounding environments affect the link performances. In this paper, we empirically evaluate the low-power links of wireless sensors in three typical different forest environments. Our experiment investigates the performance of the link layer compatible with the IEEE 802.15.4 standard and analyzes the variation patterns of the packet reception ratio (PRR), the received signal strength indicator (RSSI) and the link quality indicator (LQI) under diverse experimental settings. Some observations of this study are inconsistent with or even contradict prior results that are achieved in open fields or relatively clean environments and thus, provide new insights both into effectively evaluating the low-power wireless links and into efficiently deploying wireless sensor network systems in forest environments.

Effects of dust accumulation and module cleaning on performance ratio of solar rooftop system and solar power plants

NASA Astrophysics Data System (ADS)

Sakarapunthip, Nattakarn; Chenvidhya, Dhirayut; Chuangchote, Surawut; Kirtikara, Krissanapong; Chenvidhya, Tanokkorn; Onreabroy, Wandee

2017-08-01

Thailand is an agricultural country, with rice, sugar, and cassava as the major export products. Production of rice, sugar cane, and cassava entails agricultural activities that give rise to significant airborne dusts. In this work, five photovoltaic (PV) units (one solar rooftop and four power plants) are selected for the study. From the study of dust accumulation on glass surface located near rice farms, it was found that opaque areas due to the deposition of dust are 11-14% after 1-2-week exposure. As a consequence, PV system performance is affected. Performance ratio was calculated to determine these effects. Overall results reveal that during the dry and hot seasons, dust deposition significantly affects the performance ratio. The performance ratio reduces by 1.6-3% for 1-month dust accumulation and reduces by 6-8% for 2-month dust accumulation. After cleaning the dust accumulated, the performance ratio greatly increases, resulting in the increase in the energy output by 10%. This increase provides economic and cost benefits of PV cleaning. The performance ratio is not significantly changed during the rainy season, which PV modules are relatively clean as the dust is washed away by rain. It was also found that most of the solar power plants in Thailand still rely on manual cleaning of PV modules with washing water followed by wiping. However, only one power plant, employs a machine for cleaning, resulting in lower cleaning costs.

Effect of working power and pressure on plasma properties during the deposition of TiN films in reactive magnetron sputtering plasma measured using Langmuir probe measurement

NASA Astrophysics Data System (ADS)

How, Soo Ren; Nayan, Nafarizal; Khairul Ahmad, Mohd; Fhong Soon, Chin; Zainizan Sahdan, Mohd; Lias, Jais; Shuhaimi Abu Bakar, Ahmad; Arshad, Mohd Khairuddin Md; Hashim, Uda; Yazid Ahmad, Mohd

2018-04-01

The ion, electron density and electron temperature during formation of TiN films in reactive magnetron sputtering system have been investigated for various settings of radio frequency (RF) power and working pressure by using Langmuir probe measurements. The RF power and working pressure able to affect the densities and plasma properties during the deposition process. In this work, a working pressure (100 and 20 mTorr) and RF power (100, 150 and 200 W) have been used for data acquisition of probe measurement. Fundamental of studied on sputter deposition is very important for improvement of film quality and deposition rate. Higher working pressure and RF power able to produce a higher ion density and reduction of electron temperature.

The Impact of CO2 Emission Contraints on U.S. Electric Sector Water Use

EPA Science Inventory

The U.S. electric power sector’s reliance on water makes it vulnerable to increased water temperature and drought resulting from climate change. Here we analyze how constraints on U.S. energy system carbon dioxide (CO2) emissions could affect water withdrawal and consumpti...

Designing Effective Persuasive Systems Utilizing the Power of Entanglement: Communication Channel, Strategy & Affect

ERIC Educational Resources Information Center

Li, Haiqing

2010-01-01

With rapid advancements in information and communication technologies, computer-mediated communication channels such as email, web, mobile smart-phones with SMS, social networking websites (Facebook), multimedia websites, and OEM devices provide users with multiple technology choices to seek information. However, no study has compared the…

Electric turbocompound control system

DOEpatents

Algrain, Marcelo C [Dunlap, IL

2007-02-13

Turbocompound systems can be used to affect engine operation using the energy in exhaust gas that is driving the available turbocharger. A first electrical device acts as a generator in response to turbocharger rotation. A second electrical device acts as a motor to put mechanical power into the engine, typically at the crankshaft. Apparatus, systems, steps, and methods are described to control the generator and motor operations to control the amount of power being recovered. This can control engine operation closer to desirable parameters for given engine-related operating conditions compared to actual. The electrical devices can also operate in "reverse," going between motor and generator functions. This permits the electrical device associated with the crankshaft to drive the electrical device associated with the turbocharger as a motor, overcoming deficient engine operating conditions such as associated with turbocharger lag.

Electro-optical equivalent calibration technology for high-energy laser energy meters

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

Wei, Ji Feng, E-mail: wjfcom2000@163.com; Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang 621900; Graduate School of China Academy of Engineering Physics, Beijing 100088

Electro-optical equivalent calibration with high calibration power and high equivalence is particularly well-suited to the calibration of high-energy laser energy meters. A large amount of energy is reserved during this process, however, which continues to radiate after power-off. This study measured the radiation efficiency of a halogen tungsten lamp during power-on and after power-off in order to calculate the total energy irradiated by a lamp until the high-energy laser energy meter reaches thermal equilibrium. A calibration system was designed based on the measurement results, and the calibration equivalence of the system was analyzed in detail. Results show that measurement precisionmore » is significantly affected by the absorption factor of the absorption chamber and by heat loss in the energy meter. Calibration precision is successfully improved by enhancing the equivalent power and reducing power-on time. The electro-optical equivalent calibration system, measurement uncertainty of which was evaluated as 2.4% (k = 2), was used to calibrate a graphite-cone-absorption-cavity absolute energy meter, yielding a calibration coefficient of 1.009 and measurement uncertainty of 3.5% (k = 2). A water-absorption-type high-energy laser energy meter with measurement uncertainty of 4.8% (k = 2) was considered the reference standard, and compared to the energy meter calibrated in this study, yielded a correction factor of 0.995 (standard deviation of 1.4%).« less

Radioisotope Stirling Engine Powered Airship for Low Altitude Operation on Venus

NASA Technical Reports Server (NTRS)

Colozza, Anthony J.

2012-01-01

The feasibility of a Stirling engine powered airship for the near surface exploration of Venus was evaluated. The heat source for the Stirling engine was limited to 10 general purpose heat source (GPHS) blocks. The baseline airship utilized hydrogen as the lifting gas and the electronics and payload were enclosed in a cooled insulated pressure vessel to maintain the internal temperature at 320 K and 1 Bar pressure. The propulsion system consisted of an electric motor driving a propeller. An analysis was set up to size the airship that could operate near the Venus surface based on the available thermal power. The atmospheric conditions on Venus were modeled and used in the analysis. The analysis was an iterative process between sizing the airship to carry a specified payload and the power required to operate the electronics, payload and cooling system as well as provide power to the propulsion system to overcome the drag on the airship. A baseline configuration was determined that could meet the power requirements and operate near the Venus surface. From this baseline design additional trades were made to see how other factors affected the design such as the internal temperature of the payload chamber and the flight altitude. In addition other lifting methods were evaluated such as an evacuated chamber, heated atmospheric gas and augmented heated lifting gas. However none of these methods proved viable.

NSTAR Ion Thruster and Breadboard Power Processor Functional Integration Test Results

NASA Technical Reports Server (NTRS)

Hamley, John A.; Pinero, Luis R.; Rawlin, Vincent K.; Miller, John R.; Myers, Roger M.; Bowers, Glen E.

1996-01-01

A 2.3 kW Breadboard Power Processing Unit (BBPPU) was developed as part of the NASA Solar Electric Propulsion Technology Application Readiness (NSTAR) Program. The NSTAR program will deliver an electric propulsion system based on a 30 cm xenon ion thruster to the New Millennium (NM) program for use as the primary propulsion system for the initial NM flight. The final development test for the BBPPU, the Functional Integration Test, was carried out to demonstrate all aspects of BBPPU operation with an Engineering Model Thruster. Test objectives included: (1) demonstration and validation of automated thruster start procedures, (2) demonstration of stable closed loop control of the thruster beam current, (3) successful response and recovery to thruster faults, and (4) successful safing of the system during simulated spacecraft faults. These objectives were met over the specified 80-120 VDC input voltage range and 0.5-2.3 output power capability of the BBPPU. Two minor anomalies were noted in discharge and neutralizer keeper current. These anomalies did not affect the stability of the system and were successfully corrected.

Overview of Non-nuclear Testing of the Safe, Affordable 30-kW Fission Engine, Including End-to-End Demonstrator Testing

NASA Technical Reports Server (NTRS)

VanDyke, M. K.; Martin, J. J.; Houts, M. G.

2003-01-01

Successful development of space fission systems will require an extensive program of affordable and realistic testing. In addition to tests related to design/development of the fission system, realistic testing of the actual flight unit must also be performed. At the power levels under consideration (3-300 kW electric power), almost all technical issues are thermal or stress related and will not be strongly affected by the radiation environment. These issues can be resolved more thoroughly, less expensively, and in a more timely fashing with nonnuclear testing, provided it is prototypic of the system in question. This approach was used for the safe, affordable fission engine test article development program and accomplished viz cooperative efforts with Department of Energy labs, industry, universiites, and other NASA centers. This Technical Memorandum covers the analysis, testing, and data reduction of a 30-kW simulated reactor as well as an end-to-end demonstrator, including a power conversion system and an electric propulsion engine, the first of its kind in the United States.

Optimization of a RF-generated CF4/O2 gas plasma sterilization process.

PubMed

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

2003-05-15

A sterilization process with the use of RF-generated (13.56 MHz) CF(4)/O(2) gas plasma was optimized in regards to power, flow rate, exposure time, and RF-system type. The dependency of the sporicidal effect on the spore inoculum positioning in the chamber of the RF systems was also investigated. Dried Bacillus stearothermophilus ATCC 7953 endospores were used as test organisms. The treatments were evaluated on the basis of survival curves and corresponding D values. The only parameter found to affect the sterilization process was the power of the RF system. Higher power resulted in higher kill. Finally, when the samples were placed more than 3-8 cm away from a centrally placed electrode in System 2, the sporicidal effect was reduced. The results are discussed and compared to results from the present literature. The RF excitation source is evaluated to be more appropriate for sterilization processes than the MW source. Copyright 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 65B: 239-244, 2003

Mind the First Step: The Intrapersonal Effects of Affect on the Decision to Initiate Negotiations under Bargaining Power Asymmetry

PubMed Central

Kapoutsis, Ilias; Volkema, Roger; Lampaki, Antonia

2017-01-01

We undertook two vignette studies to examine the role of affect (trait and state) and bargaining power on initiating negotiations, an often overlooked stage of the negotiation process. Using a job negotiation opportunity, we examine three distinct phases of the initiation process—engaging a counterpart, making a request, and optimizing a request. Study 1 examines the effects of two affect dispositions (happiness and sadness), under power asymmetry (low vs. high bargaining power), on the three initiation behaviors. We found that power is pivotal to the decision to engage, request, and optimize. Also, sadness reduces the likelihood of initiation when power is high but is immaterial when power is low. In contrast, individuals who tend to be happy can reverse the adverse effect of powerlessness on requesting, but not on engaging and optimizing. However, happiness does not carry over a positive effect on negotiation initiation, over and above that of power. Study 2 investigated the role of trait affect when individuals are in power asymmetry and when they are induced with sadness or happiness. We found that those with a happy disposition initiate more (engage, request, and optimize) when power is high and experience incidental sadness. Overall, these findings qualify previous research on negotiation initiation and highlight the importance of trait affect and its interaction with state affect as additional driving forces and of power as a boundary condition. “for the error occurs at the beginning, and the beginning as the proverb says is half of the whole, so that even a small mistake at the beginning stands in the same ratio to mistakes at the other stages.” (trans. Aristotle, 1944, 1303b) PMID:28824496

Mind the First Step: The Intrapersonal Effects of Affect on the Decision to Initiate Negotiations under Bargaining Power Asymmetry.

PubMed

Kapoutsis, Ilias; Volkema, Roger; Lampaki, Antonia

2017-01-01

We undertook two vignette studies to examine the role of affect (trait and state) and bargaining power on initiating negotiations, an often overlooked stage of the negotiation process. Using a job negotiation opportunity, we examine three distinct phases of the initiation process-engaging a counterpart, making a request, and optimizing a request. Study 1 examines the effects of two affect dispositions (happiness and sadness), under power asymmetry (low vs. high bargaining power), on the three initiation behaviors. We found that power is pivotal to the decision to engage, request, and optimize. Also, sadness reduces the likelihood of initiation when power is high but is immaterial when power is low. In contrast, individuals who tend to be happy can reverse the adverse effect of powerlessness on requesting, but not on engaging and optimizing. However, happiness does not carry over a positive effect on negotiation initiation, over and above that of power. Study 2 investigated the role of trait affect when individuals are in power asymmetry and when they are induced with sadness or happiness. We found that those with a happy disposition initiate more (engage, request, and optimize) when power is high and experience incidental sadness. Overall, these findings qualify previous research on negotiation initiation and highlight the importance of trait affect and its interaction with state affect as additional driving forces and of power as a boundary condition. " for the error occurs at the beginning, and the beginning as the proverb says is half of the whole, so that even a small mistake at the beginning stands in the same ratio to mistakes at the other stages. " (trans. Aristotle, 1944 , 1303b) .

Loudness of steady sounds - A new theory

NASA Technical Reports Server (NTRS)

Howes, W. L.

1979-01-01

A new mathematical theory for calculating the loudness of steady sounds from power summation and frequency interaction, based on psychoacoustic and physiological information, assuems that loudness is a subjective measure of the electrical energy transmitted along the auditory nerve to the central nervous system. The auditory system consists of the mechanical part modeled by a bandpass filter with a transfer function dependent on the sound pressure, and the electrical part where the signal is transformed into a half-wave reproduction represented by the electrical power in impulsive discharges transmitted along neurons comprising the auditory nerve. In the electrical part the neurons are distributed among artificial parallel channels with frequency bandwidths equal to 'critical bandwidths for loudness', within which loudness is constant for constant sound pressure. The total energy transmitted to the central nervous system is the sum of the energy transmitted in all channels, and the loudness is proportional to the square root of the total filtered sound energy distributed over all channels. The theory explains many psychoacoustic phenomena such as audible beats resulting from closely spaced tones, interaction of sound stimuli which affect the same neurons affecting loudness, and of individually subliminal sounds becoming audible if they lie within the same critical band.

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.

Assessment of the trade-offs and synergies between low-carbon power sector transition and land and water resources of the United Kingdom using the "ForeseerTM" approach

NASA Astrophysics Data System (ADS)

Konadu, D. D.; Sobral Mourao, Z.

2016-12-01

Transitioning to a low-carbon power system has been identified as one of the main strategies for achieving GHG emissions reduction targets stipulated in the UK Climate Change Act (2008). However, projected mix of technologies aimed at achieving the targeted level of decarbonisation have implications for sustainable level natural resource exploitation at different spatial and temporal scales. Critical among these are the impact on land use (food production) and water resources, which are usually not adequately analysed and accounted for in developing these long-term energy system transition strategies and scenarios. Given the importance of the UK power sector to meeting economy-wide emissions targets, the overall environmental consequence of the prescribed scenarios could significantly affect meeting long-term legislated GHG emission reduction targets. It is therefore imperative that synergies and trade-offs between the power systems and these resources are comprehensively analysed. The current study employs an integrated energy and resource use accounting methodology, called ForeseerTM, to assess the land and water requirement for the deployment of the power sector technologies of the UK Committee on Climate Change (CCC) Carbon Budget scenarios. This is analysed under different scenarios of energy crop yield and electricity infrastructure location. The outputs are then compared with sustainable limits of resource exploitation to establish the environmental tractability of the scenarios. The results show that even if stringent environmental and land use restrictions are applied, all the projected bioenergy and ground-mounted solar PV can be deployed within the UK with no significant impacts on land use and food production. However, inland water resources would be significantly affected if high Carbon Capture and Storage deployment, and without new nuclear capacity. Overall, the output highlights that contrary to the notion of the inevitability of CCS deployment in delivering emissions reduction targets, a future without CCS poses the least overall environmental impacts.

Controlling the Laser Guide Star power density distribution at Sodium layer by combining Pre-correction and Beam-shaping

NASA Astrophysics Data System (ADS)

Huang, Jian; Wei, Kai; Jin, Kai; Li, Min; Zhang, YuDong

2018-06-01

The Sodium laser guide star (LGS) plays a key role in modern astronomical Adaptive Optics Systems (AOSs). The spot size and photon return of the Sodium LGS depend strongly on the laser power density distribution at the Sodium layer and thus affect the performance of the AOS. The power density distribution is degraded by turbulence in the uplink path, launch system aberrations, the beam quality of the laser, and so forth. Even without any aberrations, the TE00 Gaussian type is still not the optimal power density distribution to obtain the best balance between the measurement error and temporal error. To optimize and control the LGS power density distribution at the Sodium layer to an expected distribution type, a method that combines pre-correction and beam-shaping is proposed. A typical result shows that under strong turbulence (Fried parameter (r0) of 5 cm) and for a quasi-continuous wave Sodium laser (power (P) of 15 W), in the best case, our method can effectively optimize the distribution from the Gaussian type to the "top-hat" type and enhance the photon return flux of the Sodium LGS; at the same time, the total error of the AOS is decreased by 36% with our technique for a high power laser and poor seeing.

Space-based solar power conversion and delivery systems study. Volume 3: Economic analysis of space-based solar power systems

NASA Technical Reports Server (NTRS)

Hazelrigg, G. A., Jr.

1976-01-01

A variety of economic and programmatic issues are discussed concerning the development and deployment of a fleet of space-based solar power satellites (SSPS). The costs, uncertainties and risks associated with the current photovoltaic SSPS configuration, and with issues affecting the development of an economically viable SSPS development program are analyzed. The desirability of a low earth orbit (LEO) demonstration satellite and a geosynchronous (GEO) pilot satellite is examined and critical technology areas are identified. In addition, a preliminary examination of utility interface issues is reported. The main focus of the effort reported is the development of SSPS unit production, and operation and maintenance cost models suitable for incorporation into a risk assessment (Monte Carlo) model (RAM). It is shown that the key technology area deals with the productivity of man in space, not, as might be expected, with some hardware component technology.

Medical management of the consequences of the Fukushima nuclear power plant incident.

PubMed

Hachiya, Misao; Tominaga, Takako; Tatsuzaki, Hideo; Akashi, Makoto

2014-02-01

A huge earthquake struck the northeast coast of the main island of Japan on March 11, 2011, triggering a tsunami with 14-15 meter-high waves hitting the area. The earthquake was followed by numerous sustained aftershocks. The earthquake affected the nuclear power plant (NPP) in Fukushima prefecture, resulting in large amounts of radioactive materials being released into the environment. The major nuclides released on land were ¹³¹I, ¹³⁴Cs, and ¹³⁷Cs. Therefore, almost 170,000 people had to be evacuated or stay indoors. Besides the NPP and the telecommunications system, the earthquake also affected infrastructures such as the supplies of water and electricity as well as the radiation monitoring system. The local hospital system was dysfunctional; hospitals designated as radiation-emergency facilities were not able to function because of damage from the earthquake and tsunami, and some of them were located within a 20 km radius of the NPP, the designated evacuation zone. Local fire department personnel were also asked to evacuate. Furthermore, the affected hospitals had not established their evacuation plans at that time. We have learned from this "combined disaster" that the potential for damage to lifelines as well as the monitoring systems for radiation in case of an earthquake requires our intense focus and vigilance, and that hospitals need comprehensive plans for evacuation, including patients requiring life support equipment during and after a nuclear disaster. There is an urgent need for a "combined disaster" strategy, and this should be emphasized in current disaster planning and response. © 2013 Wiley Periodicals, Inc.

Light Water Reactor Sustainability Program Advanced Instrumentation, Information, and Control Systems Technologies Technical Program Plan for FY 2016

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

Hallbert, Bruce Perry; Thomas, Kenneth David

2015-10-01

Reliable instrumentation, information, and control (II&C) systems technologies are essential to ensuring safe and efficient operation of the U.S. light water reactor (LWR) fleet. These technologies affect every aspect of nuclear power plant (NPP) and balance-of-plant operations. In 1997, the National Research Council conducted a study concerning the challenges involved in modernization of digital instrumentation and control systems in NPPs. Their findings identified the need for new II&C technology integration.

Accuracy analysis of pointing control system of solar power station

NASA Technical Reports Server (NTRS)

Hung, J. C.; Peebles, P. Z., Jr.

1978-01-01

The first-phase effort concentrated on defining the minimum basic functions that the retrodirective array must perform, identifying circuits that are capable of satisfying the basic functions, and looking at some of the error sources in the system and how they affect accuracy. The initial effort also examined three methods for generating torques for mechanical antenna control, performed a rough analysis of the flexible body characteristics of the solar collector, and defined a control system configuration for mechanical pointing control of the array.

Design of control system based on SCM music fountain

NASA Astrophysics Data System (ADS)

Li, Biqing; Li, Zhao; Jiang, Suping

2018-06-01

The design of the design of a microprocessor controlled by simple circuit, introduced this design applied to the components, and draw the main flow chart presentation. System is the use of an external music source, the intensity of the input audio signal lights will affect the light off, the fountain spray of water level will be based on changes in the lantern light off. This design uses a single-chip system is simple, powerful, good reliability and low cost.

Improving turbine performance by cooling inlet air using a waste heat powered ejector refrigerator

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

Kowalski, G.J.

1996-12-31

Stationary turbines are used to produce electricity in many areas of the world. Their performance is adversely affected by high ambient temperatures. Several means of reducing the turbine inlet temperature (offpeak water chiller and ice storage and absorption refrigeration systems) are being proposed as a means of increasing turbine output. In the present investigation the feasibility of increasing turbine output power by using its exhaust gases to power an ejector refrigeration system is demonstrated. The advantages of the ejector refrigeration are: it operates on a non-CFC fluid, its small number of moving parts and its small size. The analysis focusesmore » on United Technologies FT4 turbine with a base load output of 21.6 MW. It is demonstrated that the proposed system can decrease the turbine inlet temperature from 296.2 K to 277.6 K which increases the turbine output by 12.8% during periods of high ambient temperature and improves yearly averaged power output by 5.5% in a temperature climate. It is shown that the energy in the turbine exhaust has the potential of producing additional cooling beyond that required to reduce the inlet temperature.« less

Turkish nurses' assessments of their power and the factors that affect it.

PubMed

Basaran, Seher; Duygulu, Sergul

2015-11-01

To explore nurses' self-assessments of power and their opinions regarding factors affecting power in Turkey using a cross-sectional, descriptive study. In order to safely and cost-effectively care for patients, nurses must perceive themselves as powerful and have the use and control of power resources. The study sample consisted of 297 nurses in six hospitals: two government hospitals, two university hospitals and two private hospitals. Data were collected using the Demographic Data Form and Power Question Form. Nurses regarded themselves as 'quite powerful' regarding persuasion (53.2%) and referent power (43.4%). Many nurses also regarded themselves as having positional power and 'quite powerful' regarding, reward (44.1%) and legitimate power (34.7%). Nurses saw themselves as least powerful in resource power (48.1%). Individual, educational and organisational factors were the main factors affecting personal and positional power sources. Turkish nurses regarded themselves as above average on being powerful in both the personal and positional power base but not in resource power. We recommend that nurses, educators and managers develop strategies to support nurses' power as a way to enhance the patient care outcomes. © 2014 John Wiley & Sons Ltd.

Coal-fuelled systems for peaking power with 100% CO2 capture through integration of solid oxide fuel cells with compressed air energy storage

NASA Astrophysics Data System (ADS)

Nease, Jake; Adams, Thomas A.

2014-04-01

In this study, a coal-fuelled integrated solid oxide fuel cell (SOFC) and compressed air energy storage (CAES) system in a load-following power production scenario is discussed. Sixteen SOFC-based plants with optional carbon capture and sequestration (CCS) and syngas shifting steps are simulated and compared to a state-of-the-art supercritical pulverised coal (SCPC) plant. Simulations are performed using a combination of MATLAB and Aspen Plus v7.3. It was found that adding CAES to a SOFC-based plant can provide load-following capabilities with relatively small effects on efficiencies (1-2% HHV depending on the system configuration) and levelized costs of electricity (∼0.35 ¢ kW-1 h-1). The load-following capabilities, as measured by least-squares metrics, show that this system may utilize coal and achieve excellent load-tracking that is not adversely affected by the inclusion of CCS. Adding CCS to the SOFC/CAES system reduces measurable direct CO2 emission to zero. A seasonal partial plant shutdown schedule is found to reduce fuel consumption by 9.5% while allowing for cleaning and maintenance windows for the SOFC stacks without significantly affecting the performance of the system (∼1% HHV reduction in efficiency). The SOFC-based systems with CCS are found to become economically attractive relative to SCPC above carbon taxes of 22 ton-1.

Power and trust in organizational relations: an empirical study in Turkish public hospitals.

PubMed

Bozaykut, Tuba; Gurbuz, F Gulruh

2015-01-01

Given the salience of the interplay between trust and power relations in organizational settings, this paper examines the perceptions of social power and its effects on trust in supervisors within the context of public hospitals. Following the theoretical background from which the study model is developed, the recent situation of hospitals within Turkish healthcare system is discussed to further elucidate the working conditions of physicians. Sample data were collected employing a structured questionnaire that was distributed to physicians working at seven different public hospitals. The statistical analyses indicate that perceptions of supervisors' social power affect subordinates' trust in supervisors. Although coercive power is found to have the greatest impact on trust in supervisors, the influence of the power base is weak. In addition, the results show that perceptions of social power differ between genders. However, the results do not support any of the hypotheses regarding the relations between trust in supervisors and the examined demographic variables. Copyright © 2014 John Wiley & Sons, Ltd.

Architecture, Voltage, and Components for a Turboelectric Distributed Propulsion Electric Grid

NASA Technical Reports Server (NTRS)

Armstrong, Michael J.; Blackwelder, Mark; Bollman, Andrew; Ross, Christine; Campbell, Angela; Jones, Catherine; Norman, Patrick

2015-01-01

The development of a wholly superconducting turboelectric distributed propulsion system presents unique opportunities for the aerospace industry. However, this transition from normally conducting systems to superconducting systems significantly increases the equipment complexity necessary to manage the electrical power systems. Due to the low technology readiness level (TRL) nature of all components and systems, current Turboelectric Distributed Propulsion (TeDP) technology developments are driven by an ambiguous set of system-level electrical integration standards for an airborne microgrid system (Figure 1). While multiple decades' worth of advancements are still required for concept realization, current system-level studies are necessary to focus the technology development, target specific technological shortcomings, and enable accurate prediction of concept feasibility and viability. An understanding of the performance sensitivity to operating voltages and an early definition of advantageous voltage regulation standards for unconventional airborne microgrids will allow for more accurate targeting of technology development. Propulsive power-rated microgrid systems necessitate the introduction of new aircraft distribution system voltage standards. All protection, distribution, control, power conversion, generation, and cryocooling equipment are affected by voltage regulation standards. Information on the desired operating voltage and voltage regulation is required to determine nominal and maximum currents for sizing distribution and fault isolation equipment, developing machine topologies and machine controls, and the physical attributes of all component shielding and insulation. Voltage impacts many components and system performance.

Study of the rheological properties of a fermentation broth of the fungus Beauveria bassiana in a bioreactor under different hydrodynamic conditions.

PubMed

Núñez-Ramírez, Diola Marina; Medina-Torres, Luis; Valencia-López, José Javier; Calderas, Fausto; López Miranda, Javier; Medrano-Roldán, Hiram; Solís-Soto, Aquiles

2012-11-01

Fermentation with filamentous fungi in a bioreactor is a complex dynamic process that is affected by flow conditions and the evolution of the rheological properties of the medium. These properties are mainly affected by the biomass concentration and the morphology of the fungus. In this work, the rheological properties of a fermentation with the fungus Beauveria bassiana under different hydrodynamic conditions were studied and the rheological behavior of this broth was simulated through a mixture of carboxymethyl cellulose sodium and cellulose fibers (CMCNa-SF). The bioreactor was a 10 L CSTR tank operated at different stir velocities. Rheological results were similar at 100 and 300 rpm for both systems. However, there was a significant increase in the viscosity accompanied by a change in the consistence index, calculated according to the power law model, for both systems at 800 rpm. The systems exhibited shear-thinning behavior at all stir velocities, which was determined with the power law model. The mixing time was observed to increase as the cellulose content in the system increased and, consequently, the efficiency of mixing diminished. These results are thought to be due to the rheological and morphological similarities of the two fungal systems. These results will help in the optimization of scale-up production of these fungi.

A new visualization approach for identifying mutations that affect differentiation and organization of the Drosophila ommatidia.

PubMed

Pichaud, F; Desplan, C

2001-03-01

The Drosophila eye is widely used as a model system to study neuronal differentiation, survival and axon projection. Photoreceptor differentiation starts with the specification of a founder cell R8, which sequentially recruits other photoreceptor neurons to the ommatidium. The eight photoreceptors that compose each ommatidium exist in two chiral forms organized along two axes of symmetry and this pattern represents a paradigm to study tissue polarity. We have developed a method of fluoroscopy to visualize the different types of photoreceptors and the organization of the ommatidia in living animals. This allowed us to perform an F(1) genetic screen to isolate mutants affecting photoreceptor differentiation, survival or planar polarity. We illustrate the power of this detection system using known genetic backgrounds and new mutations that affect ommatidial differentiation, morphology or chirality.

Nonlinear predictive control for durability enhancement and efficiency improvement in a fuel cell power system

NASA Astrophysics Data System (ADS)

Luna, Julio; Jemei, Samir; Yousfi-Steiner, Nadia; Husar, Attila; Serra, Maria; Hissel, Daniel

2016-10-01

In this work, a nonlinear model predictive control (NMPC) strategy is proposed to improve the efficiency and enhance the durability of a proton exchange membrane fuel cell (PEMFC) power system. The PEMFC controller is based on a distributed parameters model that describes the nonlinear dynamics of the system, considering spatial variations along the gas channels. Parasitic power from different system auxiliaries is considered, including the main parasitic losses which are those of the compressor. A nonlinear observer is implemented, based on the discretised model of the PEMFC, to estimate the internal states. This information is included in the cost function of the controller to enhance the durability of the system by means of avoiding local starvation and inappropriate water vapour concentrations. Simulation results are presented to show the performance of the proposed controller over a given case study in an automotive application (New European Driving Cycle). With the aim of representing the most relevant phenomena that affects the PEMFC voltage, the simulation model includes a two-phase water model and the effects of liquid water on the catalyst active area. The control model is a simplified version that does not consider two-phase water dynamics.

Design and optimization of geothermal power generation, heating, and cooling

NASA Astrophysics Data System (ADS)

Kanoglu, Mehmet

Most of the world's geothermal power plants have been built in 1970s and 1980s following 1973 oil crisis. Urgency to generate electricity from alternative energy sources and the fact that geothermal energy was essentially free adversely affected careful designs of plants which would maximize their performance for a given geothermal resource. There are, however, tremendous potentials to improve performance of many existing geothermal power plants by retrofitting, optimizing the operating conditions, re-selecting the most appropriate binary fluid in binary plants, and considering cogeneration such as a district heating and/or cooling system or a system to preheat water entering boilers in industrial facilities. In this dissertation, some representative geothermal resources and existing geothermal power plants in Nevada are investigated to show these potentials. Economic analysis of a typical geothermal resource shows that geothermal heating and cooling may generate up to 3 times as much revenue as power generation alone. A district heating/cooling system is designed for its incorporation into an existing 27 MW air-cooled binary geothermal power plant. The system as designed has the capability to meet the entire heating needs of an industrial park as well as 40% of its cooling needs, generating potential revenues of $14,040,000 per year. A study of the power plant shows that evaporative cooling can increase the power output by up to 29% in summer by decreasing the condenser temperature. The power output of the plant can be increased by 2.8 percent by optimizing the maximum pressure in the cycle. Also, replacing the existing working fluid isobutane by butane, R-114, isopentane, and pentane can increase the power output by up to 2.5 percent. Investigation of some well-known geothermal power generation technologies as alternatives to an existing 12.8 MW single-flash geothermal power plant shows that double-flash, binary, and combined flash/binary designs can increase the net power output by up to 31 percent, 35 percent, and 54 percent, respectively, at optimum operating conditions. An economic comparison of these designs appears to favor the combined flash/binary design, followed by the double-flash design.

High-Resolution Uitra Low Power, Intergrated Aftershock and Microzonation System

NASA Astrophysics Data System (ADS)

Passmore, P.; Zimakov, L. G.

2012-12-01

Rapid Aftershock Mobilization plays an essential role in the understanding of both focal mechanism and rupture propagation caused by strong earthquakes. A quick assessment of the data provides a unique opportunity to study the dynamics of the entire earthquake process in-situ. Aftershock study also provides practical information for local authorities regarding the post earthquake activity, which is very important in order to conduct the necessary actions for public safety in the area affected by the strong earthquake. Refraction Technology, Inc. has developed a self-contained, fully integrated Aftershock System, model 160-03, providing the customer simple and quick deployment during aftershock emergency mobilization and microzonation studies. The 160-03 has no external cables or peripheral equipment for command/control and operation in the field. The 160-03 contains three major components integrated in one case: a) 24-bit resolution state-of-the art low power ADC with CPU and Lid interconnect boards; b) power source; and c) three component 2 Hz sensors (two horizontals and one vertical), and built-in ±4g accelerometer. Optionally, the 1 Hz sensors can be built-in the 160-03 system at the customer's request. The self-contained rechargeable battery pack provides power autonomy up to 7 days during data acquisition at 200 sps on continuous three weak motion and triggered three strong motion recording channels. For longer power autonomy, the 160-03 Aftershock System battery pack can be charged from an external source (solar power system). The data in the field is recorded to a built-in swappable USB flash drive. The 160-03 configuration is fixed based on a configuration file stored on the system, so no external command/control interface is required for parameter setup in the field. For visual control of the system performance in the field, the 160-03 has a built-in LED display which indicates the systems recording status as well as a hot swappable USB drive and battery status. The detailed specifications and performance are presented and discussed.;

Embedded electronics for a 64-channel wireless brain implant

NASA Astrophysics Data System (ADS)

Burgert, Johann D.; Malasek, Jan; Martel, Sylvain M.; Wiseman, Colette; Fofonoff, Timothy; Dyer, Robert; Hunter, Ian W.; Hatsopoulos, Nicholas; Donoghue, John

2001-10-01

The Telemetric Electrode Array System (TEAS) is a surgically implantable device for the study of neural activity in the brain. An 8x8 array of electrodes collects intra-cortical neural signals and connects them to an analog front end. The front end amplifies and digitizes these microvolt-level signals with 12 bits of resolution and at 31KHz per channel. Peak detection is used to extract the information carrying features of these signals, which are transmitted over a Bluetooth-based radio link at 725 Kbit/sec. The electrode array is made up of 1mm tall, 60-micron square electrodes spaced 500 microns tip-to-tip. A flex circuit connector provides mechanical isolation between the brain and the electronics, which are mounted to the cranium. Power consumption and management is a critical aspect of the design. The entire system must operate off a surgically implantable battery. With this power source, the system must provide the functionality of a wireless, 64-channel oscilloscope for several hours. The system also provides a low-power sleep mode during which the battery can be inductively charged. Power dissipation and biocompatibility issues also affect the design of the electronics for the probe. The electronics system must fit between the skull and the skin of the test subject. Thus, circuit miniaturization and microassembly techniques are essential to construct the probe's electronics.

Flight, orientation, and homing abilities of honeybees following exposure to 2.45-GHz CW microwaves.

PubMed

Gary, N E; Westerdahl, B B

1981-01-01

Foraging-experienced honeybees retained normal flight, orientation, and memory functions after 30 minutes' exposure to 2.45-GHz CW microwaves at power densities from 3 to 50 mW/cm2. These experiments were conducted at power densities approximating and exceeding those that would be present above receiving antennas of the proposed solar power satellite (SPS) energy transmission system and for a duration exceeding that which honeybees living outside a rectenna might be expected to spend within the rectenna on individual foraging trips. There was no evidence that airborne invertebrates would be significantly affected during transient passage through microwaves associated with SPS ground-based microwave receiving stations.

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

Okumura, Teppei; Seljak, Uroš; Desjacques, Vincent, E-mail: teppei@ewha.ac.kr, E-mail: useljak@berkeley.edu, E-mail: dvince@physik.uzh.ch

It was recently shown that the power spectrum in redshift space can be written as a sum of cross-power spectra between number weighted velocity moments, of which the lowest are density and momentum density. We investigate numerically the properties of these power spectra for simulated galaxies and dark matter halos and compare them to the dark matter power spectra, generalizing the concept of the bias in density-density power spectra. Because all of the quantities are number weighted this approach is well defined even for sparse systems such as massive halos. This contrasts to the previous approaches to RSD where velocitymore » correlations have been explored, but velocity field is a poorly defined concept for sparse systems. We find that the number density weighting leads to a strong scale dependence of the bias terms for momentum density auto-correlation and cross-correlation with density. This trend becomes more significant for the more biased halos and leads to an enhancement of RSD power relative to the linear theory. Fingers-of-god effects, which in this formalism come from the correlations of the higher order moments beyond the momentum density, lead to smoothing of the power spectrum and can reduce this enhancement of power from the scale dependent bias, but are relatively small for halos with no small scale velocity dispersion. In comparison, for a more realistic galaxy sample with satellites the small scale velocity dispersion generated by satellite motions inside the halos leads to a larger power suppression on small scales, but this depends on the satellite fraction and on the details of how the satellites are distributed inside the halo. We investigate several statistics such as the two-dimensional power spectrum P(k,μ), where μ is the angle between the Fourier mode and line of sight, its multipole moments, its powers of μ{sup 2}, and configuration space statistics. Overall we find that the nonlinear effects in realistic galaxy samples such as luminous red galaxies affect the redshift space clustering on very large scales: for example, the quadrupole moment is affected by 10% for k < 0.1hMpc{sup −1}, which means that these effects need to be understood if we want to extract cosmological information from the redshift space distortions.« less

Evaluating the Impacts of Climate Change on the Operations and Future Development of the U.S. Electricity System

NASA Astrophysics Data System (ADS)

Newmark, R. L.; Cohen, S. M.; Averyt, K.; Macknick, J.; Meldrum, J.; Sullivan, P.

2014-12-01

Climate change has the potential to exacerbate reliability concerns for the power sector through changes in water availability and air temperatures. The power sector is responsible for 41% of U.S. freshwater withdrawals, primarily for power plant cooling needs, and any changes in the water available for the power sector, given increasing competition among water users, could affect decisions about new power plant builds and reliable operations for existing generators. Similarly, increases in air temperatures can reduce power plant efficiencies, which in turn increases fuel consumption as well as water withdrawal and consumption rates. This analysis describes an initial link between climate, water, and electricity systems using the National Renewable Energy Laboratory's (NREL) Regional Energy Deployment System (ReEDS) electricity system capacity expansion model. Average surface water runoff projections from Coupled Model Intercomparison Project 5 (CMIP5) data are applied to surface water available to generating capacity in ReEDS, and electric sector growth is compared with and without climate-influenced water availability for the 134 electricity balancing regions in the ReEDS model. In addition, air temperature changes are considered for their impacts on electricity load, transmission capacity, and power plant efficiencies and water use rates. Mean climate projections have only a small impact on national or regional capacity growth and water use because most regions have sufficient unappropriated or previously retired water access to offset climate impacts. Climate impacts are notable in southwestern states, which experience reduced water access purchases and a greater share of water acquired from wastewater and other higher-cost water resources. The electric sector climate impacts demonstrated herein establish a methodology to be later exercised with more extreme climate scenarios and a more rigorous representation of legal and physical water availability.

Automated assessment of joint synovitis activity from medical ultrasound and power doppler examinations using image processing and machine learning methods.

PubMed

Cupek, Rafal; Ziębiński, Adam

2016-01-01

Rheumatoid arthritis is the most common rheumatic disease with arthritis, and causes substantial functional disability in approximately 50% patients after 10 years. Accurate measurement of the disease activity is crucial to provide an adequate treatment and care to the patients. The aim of this study is focused on a computer aided diagnostic system that supports an assessment of synovitis severity. This paper focus on a computer aided diagnostic system that was developed within joint Polish-Norwegian research project related to the automated assessment of the severity of synovitis. Semiquantitative ultrasound with power Doppler is a reliable and widely used method of assessing synovitis. Synovitis is estimated by ultrasound examiner using the scoring system graded from 0 to 3. Activity score is estimated on the basis of the examiner's experience or standardized ultrasound atlases. The method needs trained medical personnel and the result can be affected by a human error. The porotype of a computer-aided diagnostic system and algorithms essential for an analysis of ultrasonic images of finger joints are main scientific output of the MEDUSA project. Medusa Evaluation System prototype uses bone, skin, joint and synovitis area detectors for mutual structural model based evaluation of synovitis. Finally, several algorithms that support the semi-automatic or automatic detection of the bone region were prepared as well as a system that uses the statistical data processing approach in order to automatically localize the regions of interest. Semiquantitative ultrasound with power Doppler is a reliable and widely used method of assessing synovitis. Activity score is estimated on the basis of the examiner's experience and the result can be affected by a human error. In this paper we presented the MEDUSA project which is focused on a computer aided diagnostic system that supports an assessment of synovitis severity.

CompatPM: enabling energy efficient multimedia workloads for distributed mobile platforms

NASA Astrophysics Data System (ADS)

Nathuji, Ripal; O'Hara, Keith J.; Schwan, Karsten; Balch, Tucker

2007-01-01

The computation and communication abilities of modern platforms are enabling increasingly capable cooperative distributed mobile systems. An example is distributed multimedia processing of sensor data in robots deployed for search and rescue, where a system manager can exploit the application's cooperative nature to optimize the distribution of roles and tasks in order to successfully accomplish the mission. Because of limited battery capacities, a critical task a manager must perform is online energy management. While support for power management has become common for the components that populate mobile platforms, what is lacking is integration and explicit coordination across the different management actions performed in a variety of system layers. This papers develops an integration approach for distributed multimedia applications, where a global manager specifies both a power operating point and a workload for a node to execute. Surprisingly, when jointly considering power and QoS, experimental evaluations show that using a simple deadline-driven approach to assigning frequencies can be non-optimal. These trends are further affected by certain characteristics of underlying power management mechanisms, which in our research, are identified as groupings that classify component power management as "compatible" (VFC) or "incompatible" (VFI) with voltage and frequency scaling. We build on these findings to develop CompatPM, a vertically integrated control strategy for power management in distributed mobile systems. Experimental evaluations of CompatPM indicate average energy improvements of 8% when platform resources are managed jointly rather than independently, demonstrating that previous attempts to maximize battery life by simply minimizing frequency are inappropriate from a platform-level perspective.

Fuel Cell Power Plant Initiative. Volume 1; Solid Oxide Fuel Cell/Logistics Fuel Processor 27 kWe Power System Demonstration for ARPA

NASA Technical Reports Server (NTRS)

Veyo, S.E.

1997-01-01

This report describes the successful testing of a 27 kWe Solid Oxide Fuel Cell (SOFC) generator fueled by natural gas and/or a fuel gas produced by a brassboard logistics fuel preprocessor (LFP). The test period began on May 24, 1995 and ended on February 26, 1996 with the successful completion of all program requirements and objectives. During this time period, this power system produced 118.2 MWh of electric power. No degradation of the generator's performance was measured after 5582 accumulated hours of operation on these fuels: local natural gas - 3261 hours, jet fuel reformate gas - 766 hours, and diesel fuel reformate gas - 1555 hours. This SOFC generator was thermally cycled from full operating temperature to room temperature and back to operating temperature six times, because of failures of support system components and the occasional loss of test site power, without measurable cell degradation. Numerous outages of the LFP did not interrupt the generator's operation because the fuel control system quickly switched to local natural gas when an alarm indicated that the LFP reformate fuel supply had been interrupted. The report presents the measured electrical performance of the generator on all three fuel types and notes the small differences due to fuel type. Operational difficulties due to component failures are well documented even though they did not affect the overall excellent performance of this SOFC power generator. The final two appendices describe in detail the LFP design and the operating history of the tested brassboard LFP.

Stick-slip friction and ageing in Velcro®

NASA Astrophysics Data System (ADS)

Mariani, Lisa; Angiolillo, Paul

2014-03-01

The mesoscopic hook and loop system of Velcro® provides a model of stick-slip friction that exhibits behavior reminiscent of results seen in nanoscale model systems. The friction is linearly dependent on contact area and independent of driving velocity. Morever, there is a power law dependence of the friction on loading, with exponent between 1/4 and 1/3. Furthermore, the evolution of stick-slip to more smooth sliding, as controlled by contact area, is also noted. These transition predictions follow power law profiles, as well, with respect to increasing contact area. Thus, the hook-and-loop system shows to be a good mesoscale model system of stick-slip friction and provides a link between nanoscale and macroscale friction. Through an investigation into the ageing of the hooks in the system, the data suggests that the hooks age during the shearing regime and take a characteristic time to return to initial attachment strength. Additionally, there does not appear to be a significant affect of ageing on the kinetic friction experienced by the system.

Finite-size scaling of eigenstate thermalization

NASA Astrophysics Data System (ADS)

Beugeling, W.; Moessner, R.; Haque, Masudul

2014-04-01

According to the eigenstate thermalization hypothesis (ETH), even isolated quantum systems can thermalize because the eigenstate-to-eigenstate fluctuations of typical observables vanish in the limit of large systems. Of course, isolated systems are by nature finite and the main way of computing such quantities is through numerical evaluation for finite-size systems. Therefore, the finite-size scaling of the fluctuations of eigenstate expectation values is a central aspect of the ETH. In this work, we present numerical evidence that for generic nonintegrable systems these fluctuations scale with a universal power law D-1/2 with the dimension D of the Hilbert space. We provide heuristic arguments, in the same spirit as the ETH, to explain this universal result. Our results are based on the analysis of three families of models and several observables for each model. Each family includes integrable members and we show how the system size where the universal power law becomes visible is affected by the proximity to integrability.

Modeling, Analysis, and Impedance Design of Battery Energy Stored Single-Phase Quasi-Z Source Photovoltaic Inverter System

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

Xue, Yaosuo

The battery energy stored quasi-Z-source (BES-qZS) based photovoltaic (PV) power generation system combines advantages of the qZS inverter and the battery energy storage system. However, the second harmonic (2 ) power ripple will degrade the system's performance and affect the system's design. An accurate model to analyze the 2 ripple is very important. The existing models did not consider the battery, and with the assumption L1=L2 and C1=C2, which causes the non-optimized design for the impedance parameters of qZS network. This paper proposes a comprehensive model for single-phase BES-qZS-PV inverter system, where the battery is considered and without any restrictionmore » of L1, L2, C1, and C2. A BES-qZS impedance design method based on the built model is proposed to mitigate the 2 ripple. Simulation and experimental results verify the proposed 2 ripple model and design method.« less

Perceived Uncertainty Sources in Wind Power Plant Design

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

Damiani, Rick R

This presentation for the Fourth Wind Energy Systems Engineering Workshop covers some of the uncertainties that still impact turbulent wind operation and how these affect design and structural reliability; identifies key sources and prioritization for R and D; and summarizes an analysis of current procedures, industry best practice, standards, and expert opinions.

Academic Language, Power and the Impact of Western Knowledge Production on Indigenous Student Learning

ERIC Educational Resources Information Center

O'Brien, Karen

2008-01-01

This paper explores the prescriptive, distancing and separating qualities that exist in Western systems of knowledge production. It examines scientific language and how discrimination takes place in the university setting and explores the ways in which academic knowledge production affects the learning experiences, participation and completion…

10 CFR Appendix B to Part 50 - Quality Assurance Criteria for Nuclear Power Plants and Fuel Reprocessing Plants

Code of Federal Regulations, 2014 CFR

2014-01-01

... related to the design, fabrication, construction, and testing of the structures, systems, and components... components. The pertinent requirements of this appendix apply to all activities affecting the safety-related..., which comprises those quality assurance actions related to the physical characteristics of a material...

The Transforming Power of Narrative in Teacher Education

ERIC Educational Resources Information Center

Chan, Esther Yim-mei

2012-01-01

The focus of this study is to examine pre-service teachers' experiences of learning through narrative inquiry that gives insight into how teachers' development and knowledge construction can be improved. The article begins by inquiring into the learning culture in the Hong Kong context and explaining how the examination system affects knowledge…

40 CFR 60.102a - Emissions limitations.

Code of Federal Regulations, 2012 CFR

2012-07-01

... precipitator: (i) The 3-hour rolling average total power and secondary current to the entire system must not... provided in paragraph (f)(3), each owner or operator of an affected sulfur recovery plant shall comply with... plant with a capacity greater than 20 long tons per day (LTD): (i) For a sulfur recovery plant with an...

40 CFR 60.102a - Emissions limitations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... precipitator: (i) The 3-hour rolling average total power and secondary current to the entire system must not... provided in paragraph (f)(3), each owner or operator of an affected sulfur recovery plant shall comply with... plant with a capacity greater than 20 long tons per day (LTD): (i) For a sulfur recovery plant with an...

40 CFR 60.102a - Emissions limitations.

Code of Federal Regulations, 2010 CFR

2010-07-01

... precipitator: (i) The 3-hour rolling average total power and secondary current to the entire system must not... provided in paragraph (f)(3), each owner or operator of an affected sulfur recovery plant shall comply with... plant with a capacity greater than 20 long tons per day (LTD): (i) For a sulfur recovery plant with an...

78 FR 50405 - Amended Application for Presidential Permit; Northern Pass Transmission LLC

Federal Register 2010, 2011, 2012, 2013, 2014

2013-08-19

... project would adversely affect the operation of the U.S. electric power supply system under normal and... proposed project. Northern Pass is wholly owned by NU Transmission Ventures, Inc., a wholly-owned..., that would meet the needs of the Project.'' On July 1, 2013, Northern Pass submitted an amended...

Understanding the Impacts of Quality Assessment: An Exploratory Use of Cultural Theory

ERIC Educational Resources Information Center

Veiga, Amelia; Rosa, Maria Joao; Amaral, Alberto

2011-01-01

Cultural theory is tentatively used to understand how far quality assessment affects institutions by influencing the group and grid dimensions. This paper argues that the self-assessment phase of the Portuguese system, in use until recently, promoted the egalitarian (logic of mistrusting power and expertise) and the individualist (logic of freedom…

78 FR 23308 - Petitions for Modification of Application of Existing Mandatory Safety Standards

Federal Register 2010, 2011, 2012, 2013, 2014

2013-04-18

... electrical condition of the slope conveyor system. (c) Immediate reporting of any hazards or mechanical... Affected: 30 CFR 75.1710-1(a)(4) (Canopies or cabs; self-propelled diesel-powered and electric face... existing standard to permit the use of shuttle cars without canopies in heights less than forty eight...

Female Participation in the Occupation System: A Comparative Development

ERIC Educational Resources Information Center

Weiss, Jane E.; And Others

1976-01-01

Uses cross national data to examine how economic, political and educational structures affect both the participation of women in the labor force and their employment in more powerful and well rewarded positions, and assesses the relevance of comparative studies of women as a status group to national public policy considerations. (Author/JM)

78 FR 45918 - Application for Presidential Permit; Soule River Hydroelectric Project

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-30

... Hydro. Soule Hydro proposes to construct and operate a high-voltage alternating current (HVAC... 8-mile long, 138 kilovolt (kV) HVAC 3-phase submarine cable that would be laid on the floor of... whether the proposed project would adversely affect the operation of the U.S. electric power supply system...

The Play of Risk, Affect, and the Enterprising Self in a Fourth-Grade Classroom

ERIC Educational Resources Information Center

Bialostok, Steven; Kamberelis, George

2012-01-01

As a predominant discourse of the early twenty-first century, the new capitalism (and its companion cultural system, neoliberalism) privilege flexibility, risk, emotional intelligence, and the enterprising self. New capitalist discourses exert powerful and pervasive effects across all dimensions of human experience and activity from personal…

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.

General formula for the incidence factor of a solar heliostat receiver system.

PubMed

Wei, L Y

1980-09-15

A general formula is derived for the effective incidence factor of an array of heliostat mirrors for solar power collection. The formula can be greatly simplified for arrays of high symmetry and offers quick computation of the performance of the array. It shows clearly how the mirror distribution and locations affect the overall performance and thus provide a useful guidance for the design of a solar heliostat receiver system.

Electrical safety during transplantation.

PubMed

Amicucci, G L; Di Lollo, L; Fiamingo, F; Mazzocchi, V; Platania, G; Ranieri, D; Razzano, R; Camin, G; Sebastiani, G; Gentile, P

2010-01-01

Technologic innovations enable management of medical equipment and power supply systems, with improvements that can affect the technical aspects, economics, and quality of medical service. Herein are outlined some technical guidelines, proposed by Istituto Superiore per la Prevenzione e la Sicurezza del Lavoro, for increasing the effectiveness of the power supply system and the safety of patients and surgeons in the operating room, with particular focus on transplantation. The dependence of diagnoses and therapies on operation of the electrical equipment can potentially cause great risk to patients. Moreover, it is possible that faulty electrical equipment could produce current that may flow through the patient. Because patients are particularly vulnerable when their natural protection is considerably decreased, as during transplantation or other surgery, power supply systems must operate with a high degree of reliability and quality to prevent risk, and must be designed to reduce hazards from direct and indirect contact. Reliability of the power supply system is closely related to the quality of the project, choice of materials, and management of the system (eg, quality and frequency of servicing). Among the proposed guidelines, other than normal referencing, are (1) adoption of a monitoring system to improve the quality of the electrical parameters in the operating room, (2) institution of emergency procedures for management of electrical faults, (3) a procedure for management of fires in the operating room, (4) and maintenance interventions and inspections of medical devices to maintain minimal requirements of safety and performance. Copyright 2010 Elsevier Inc. All rights reserved.

The role of the relatives in opt-in systems of postmortal organ procurement.

PubMed

den Hartogh, Govert

2012-05-01

In almost all opt-in systems of postmortal organ procurement, if the deceased has not made a decision about donation, his relatives will be asked to make it. Can this decision power be justified? I consider three possible justifications. (1) We could presume the deceased to have delegated this power to his relatives. (2) It could be argued that, if the deceased has not made a decision, a proxy decision has to be made in his best interests. (3) The relatives could have a standing of their own because they are singled out from the parties whose interests are being affected by the decision by the special relation they had to the deceased. None of these arguments turns out to be convincing.

Evaluation of the communication quality of free-space laser communication based on the power-in-the-bucket method.

PubMed

Yin, Xianghui; Wang, Rui; Wang, Shaoxin; Wang, Yukun; Jin, Chengbin; Cao, Zhaoliang; Xuan, Li

2018-02-01

Atmospheric turbulence seriously affects the quality of free-space laser communication. The Strehl ratio (SR) is used to evaluate the effect of atmospheric turbulence on the receiving energy of free-space laser communication systems. However, the SR method does not consider the area of the laser-receiving end face. In this study, the power-in-the-bucket (PIB) method is demonstrated to accurately evaluate the effect of turbulence on the receiving energy. A theoretical equation is first obtained to calculate PIB. Simulated and experimental validations are then performed to verify the effectiveness of the theoretical equation. This work may provide effective guidance for the design and evaluation of free-space laser communication systems.

Implications of using thermocouple thermometry in 27 MHz capacitively coupled interstitial hyperthermia.

PubMed

Crezee, J; van der Koijk, J F; Kaatee, R S; Lagendijk, J J

1997-04-01

The 27 MHz Multi Electrode Current Source (MECS) interstitial hyperthermia system uses segmented electrodes, 10-20 mm long, to steer the 3D power deposition. This power control at a scale of 1-2 cm requires detailed and accurate temperature feedback data. To this end seven-point thermocouples are integrated into the probes. The aim of this work was to evaluate the feasibility and reliability of integrated thermometry in the 27 MHz MECS system, with special attention to the interference between electrode and thermometry and its effect on system performance. We investigated the impact of a seven-sensor thermocouple probe (outer diameter 150 microns) on the apparent impedance and power output of a 20 mm dual electrode (O.D. 1.5 mm) in a polyethylene catheter in a muscle equivalent medium (sigma 1 = 0.6 S m-1). The cross coupling between electrode and thermocouple was found to be small (1-2 pF) and to cause no problems in the dual-electrode mode, and only minimal problems in the single-electrode mode. Power loss into the thermometry system can be prevented using simple filters. The temperature readings are reliable and representative of the actual tissue temperature around the electrode. Self-heating effects, occurring in some catheter materials, are eliminated by sampling the temperature after a short power-off interval. We conclude that integrated thermocouple thermometry is compatible with 27 MHz capacitively coupled interstitial hyperthermia. The performance of the system is not affected and the temperatures measured are a reliable indication of the maximum tissue temperatures.

Marketing implications of the shift in power of the hospital.

PubMed

Rayburn, J M; Rayburn, L G

1995-01-01

With the introduction of the Prospective Payment System, hospital accountants' role changed from reimbursement maximizers to an important role in decision making. Faced with increased competition, hospitals are installing financial controls. Hospital marketers are also engaging in external promotional and health awareness campaigns and expanding their services to stabilize income and reduce the effects of a changing environment. Thus, hospitals operate in a more competitive environment with increasing uncertainty. When faced with uncertainty, organizations often believe that they must convince society that their existence is legitimate. Increasing specialization and organizational complexity in health care professions have made the expert important. Experts, such as the role assumed by hospital accountants and physicians, maintain power because the organization depends on them for their special skills and information. Marketing should also develop an internal marketing program to reach these power influencers. Scarce resource coupled with uncertainty move hospital accountants as experts into the power equation in the changing control of the U.S. healthcare system. Previously, the physician was the major source of hospital power. Since accountants often serve as monitors of scarce resources, information about the resource allocation directly affects the distribution of power. Marketers should acknowledge that this places hospital accountants in a critical role of assisting their institutions in adapting to a new environment.

Implications of Climate Change on the Heat Budget of Lentic Systems Used for Power Station Cooling: Case Study Clinton Lake, Illinois.

PubMed

Quijano, Juan C; Jackson, P Ryan; Santacruz, Santiago; Morales, Viviana M; García, Marcelo H

2016-01-05

We use a numerical model to analyze the impact of climate change-in particular higher air temperatures-on a nuclear power station that recirculates the water from a reservoir for cooling. The model solves the hydrodynamics, the transfer of heat in the reservoir, and the energy balance at the surface. We use the numerical model to (i) quantify the heat budget in the reservoir and determine how this budget is affected by the combined effect of the power station and climate change and (ii) quantify the impact of climate change on both the downstream thermal pollution and the power station capacity. We consider four different scenarios of climate change. Results of simulations show that climate change will reduce the ability to dissipate heat to the atmosphere and therefore the cooling capacity of the reservoir. We observed an increase of 25% in the thermal load downstream of the reservoir, and a reduction in the capacity of the power station of 18% during the summer months for the worst-case climate change scenario tested. These results suggest that climate change is an important threat for both the downstream thermal pollution and the generation of electricity by power stations that use lentic systems for cooling.

Implications of climate change on the heat budget of lentic systems used for power station cooling: Case study Clinton Lake, Illinois

USGS Publications Warehouse

Quijano, Juan C; Jackson, P. Ryan; Santacruz, Santiago; Morales, Viviana M; Garcia, Marcelo H.

2016-01-01

We use a numerical model to analyze the impact of climate change--in particular higher air temperatures--on a nuclear power station that recirculates the water from a reservoir for cooling. The model solves the hydrodynamics, the transfer of heat in the reservoir, and the energy balance at the surface. We use the numerical model to (i) quantify the heat budget in the reservoir and determine how this budget is affected by the combined effect of the power station and climate change and (ii) quantify the impact of climate change on both the downstream thermal pollution and the power station capacity. We consider four different scenarios of climate change. Results of simulations show that climate change will reduce the ability to dissipate heat to the atmosphere and therefore the cooling capacity of the reservoir. We observed an increase of 25% in the thermal load downstream of the reservoir, and a reduction in the capacity of the power station of 18% during the summer months for the worst-case climate change scenario tested. These results suggest that climate change is an important threat for both the downstream thermal pollution and the generation of electricity by power stations that use lentic systems for cooling.

Phase-stable, multi-µJ femtosecond pulses from a repetition-rate tunable Ti:Sa-oscillator-seeded Yb-fiber amplifier

NASA Astrophysics Data System (ADS)

Saule, T.; Holzberger, S.; De Vries, O.; Plötner, M.; Limpert, J.; Tünnermann, A.; Pupeza, I.

2017-01-01

We present a high-power, MHz-repetition-rate, phase-stable femtosecond laser system based on a phase-stabilized Ti:Sa oscillator and a multi-stage Yb-fiber chirped-pulse power amplifier. A 10-nm band around 1030 nm is split from the 7-fs oscillator output and serves as the seed for subsequent amplification by 54 dB to 80 W of average power. The µJ-level output is spectrally broadened in a solid-core fiber and compressed to 30 fs with chirped mirrors. A pulse picker prior to power amplification allows for decreasing the repetition rate from 74 MHz by a factor of up to 4 without affecting the pulse parameters. To compensate for phase jitter added by the amplifier to the feed-forward phase-stabilized seeding pulses, a self-referencing feed-back loop is implemented at the system output. An integrated out-of-loop phase noise of less than 100 mrad was measured in the band from 0.4 Hz to 400 kHz, which to the best of our knowledge corresponds to the highest phase stability ever demonstrated for high-power, multi-MHz-repetition-rate ultrafast lasers. This system will enable experiments in attosecond physics at unprecedented repetition rates, it offers ideal prerequisites for the generation and field-resolved electro-optical sampling of high-power, broadband infrared pulses, and it is suitable for phase-stable white light generation.

Effect of workload setting on propulsion technique in handrim wheelchair propulsion.

PubMed

van Drongelen, Stefan; Arnet, Ursina; Veeger, Dirkjan H E J; van der Woude, Lucas H V

2013-03-01

To investigate the influence of workload setting (speed at constant power, method to impose power) on the propulsion technique (i.e. force and timing characteristics) in handrim wheelchair propulsion. Twelve able-bodied men participated in this study. External forces were measured during handrim wheelchair propulsion on a motor driven treadmill at different velocities and constant power output (to test the forced effect of speed) and at power outputs imposed by incline vs. pulley system (to test the effect of method to impose power). Outcome measures were the force and timing variables of the propulsion technique. FEF and timing variables showed significant differences between the speed conditions when propelling at the same power output (p < 0.01). Push time was reduced while push angle increased. The method to impose power only showed slight differences in the timing variables, however not in the force variables. Researchers and clinicians must be aware of testing and evaluation conditions that may differently affect propulsion technique parameters despite an overall constant power output. Copyright © 2012 IPEM. Published by Elsevier Ltd. All rights reserved.

Variability of individual genetic load: consequences for the detection of inbreeding depression.

PubMed

Restoux, Gwendal; Huot de Longchamp, Priscille; Fady, Bruno; Klein, Etienne K

2012-03-01

Inbreeding depression is a key factor affecting the persistence of natural populations, particularly when they are fragmented. In species with mixed mating systems, inbreeding depression can be estimated at the population level by regressing the average progeny fitness by the selfing rate of their mothers. We applied this method using simulated populations to investigate how population genetic parameters can affect the detection power of inbreeding depression. We simulated individual selfing rates and genetic loads from which we computed fitness values. The regression method yielded high statistical power, inbreeding depression being detected as significant (5 % level) in 92 % of the simulations. High individual variation in selfing rate and high mean genetic load led to better detection of inbreeding depression while high among-individual variation in genetic load made it more difficult to detect inbreeding depression. For a constant sampling effort, increasing the number of progenies while decreasing the number of individuals per progeny enhanced the detection power of inbreeding depression. We discuss the implication of among-mother variability of genetic load and selfing rate on inbreeding depression studies.

Effects of signal artefacts on electroencephalography spectral power during sleep: quantifying the effectiveness of automated artefact-rejection algorithms.

PubMed

Liu, Jianbo; Ramakrishnan, Sridhar; Laxminarayan, Srinivas; Neal, Maxwell; Cashmere, David J; Germain, Anne; Reifman, Jaques

2018-02-01

Electroencephalography (EEG) recordings during sleep are often contaminated by muscle and ocular artefacts, which can affect the results of spectral power analyses significantly. However, the extent to which these artefacts affect EEG spectral power across different sleep states has not been quantified explicitly. Consequently, the effectiveness of automated artefact-rejection algorithms in minimizing these effects has not been characterized fully. To address these issues, we analysed standard 10-channel EEG recordings from 20 subjects during one night of sleep. We compared their spectral power when the recordings were contaminated by artefacts and after we removed them by visual inspection or by using automated artefact-rejection algorithms. During both rapid eye movement (REM) and non-REM (NREM) sleep, muscle artefacts contaminated no more than 5% of the EEG data across all channels. However, they corrupted delta, beta and gamma power levels substantially by up to 126, 171 and 938%, respectively, relative to the power level computed from artefact-free data. Although ocular artefacts were infrequent during NREM sleep, they affected up to 16% of the frontal and temporal EEG channels during REM sleep, primarily corrupting delta power by up to 33%. For both REM and NREM sleep, the automated artefact-rejection algorithms matched power levels to within ~10% of the artefact-free power level for each EEG channel and frequency band. In summary, although muscle and ocular artefacts affect only a small fraction of EEG data, they affect EEG spectral power significantly. This suggests the importance of using artefact-rejection algorithms before analysing EEG data. © 2017 European Sleep Research Society.

Origin and Consequences of the Relationship between Protein Mean and Variance

PubMed Central

Vallania, Francesco Luigi Massimo; Sherman, Marc; Goodwin, Zane; Mogno, Ilaria; Cohen, Barak Alon; Mitra, Robi David

2014-01-01

Cell-to-cell variance in protein levels (noise) is a ubiquitous phenomenon that can increase fitness by generating phenotypic differences within clonal populations of cells. An important challenge is to identify the specific molecular events that control noise. This task is complicated by the strong dependence of a protein's cell-to-cell variance on its mean expression level through a power-law like relationship (σ2∝μ1.69). Here, we dissect the nature of this relationship using a stochastic model parameterized with experimentally measured values. This framework naturally recapitulates the power-law like relationship (σ2∝μ1.6) and accurately predicts protein variance across the yeast proteome (r2 = 0.935). Using this model we identified two distinct mechanisms by which protein variance can be increased. Variables that affect promoter activation, such as nucleosome positioning, increase protein variance by changing the exponent of the power-law relationship. In contrast, variables that affect processes downstream of promoter activation, such as mRNA and protein synthesis, increase protein variance in a mean-dependent manner following the power-law. We verified our findings experimentally using an inducible gene expression system in yeast. We conclude that the power-law-like relationship between noise and protein mean is due to the kinetics of promoter activation. Our results provide a framework for understanding how molecular processes shape stochastic variation across the genome. PMID:25062021

A Significant Role for Renewables in a Low-Carbon Energy Economy?

NASA Astrophysics Data System (ADS)

Newmark, R. L.

2015-12-01

Renewables currently make up a small (but growing) fraction of total U.S. electricity generation. In some regions, renewable growth has resulted in instantaneous penetration levels of wind and solar in excess of 60% of demand. With decreasing costs, abundant resource potential and low carbon emissions and water requirements, wind and solar are increasingly becoming attractive new generation options. However, factors such as resource variability and geographic distribution of prime resources raise questions regarding the extent to which our power system can rely on variable generation resources. Here, we describe scenario analyses designed to tackle engineering and economic challenges associated with variable generation, along with insights derived from research results. These analyses demonstrate the operability of high renewable systems and quantify some of the engineering challenges (and solutions) associated with maintaining reliability. Key questions addressed include the operational and economic impacts of increasing levels of variable generation on the U.S. power system. Since reliability and economic efficiency are measured across a variety of time frames, and with a variety of metrics, a suite of tools addressing different system impacts are used to understand how new resources affect incumbent resources and operational practices. We summarize a range of modeled scenarios, focusing on ones with 80% RE in the United States and >30% variable wind and solar in the East and the West. We also summarize the environmental impacts and benefits estimated for these and similar scenarios. Results provide key insights to inform the technical, operational and regulatory evolution of the U.S. power system. This work is extended internationally through the 21st Century Power Partnership's collaborations on power system transformation, with active collaboration in Canada, Mexico, India, China and South Africa, among others.

The role of perceived impact on relationship quality in pharmacists' willingness to influence indication-based off-label prescribing decisions.

PubMed

Basak, Ramsankar; Bentley, John P; McCaffrey, David J; Bouldin, Alicia S; Banahan, Benjamin F

2015-05-01

Little is known about factors that affect pharmacists' roles in off-label prescribing. This study examined the effect of perceived impact on relationship quality (IRQ) on hospital pharmacists' willingness to influence a physician's decision regarding an indication-based off-label medication order (WTIP) (i.e., beyond FDA-approved indications) and the moderating roles of the appropriateness of the medication order and the relative expert power of the pharmacist. Pharmacists practicing in U.S. hospitals, recruited from membership rolls of state affiliates of the American Society of Health-System Pharmacists, were sent an electronic link to a questionnaire via their respective affiliates. A cross-sectional, randomized, 2 × 2 experimental design was used; participants were assigned to one of the indication-based off-label medication order scenarios. Relative expert power (i.e., power differential between the pharmacist and the physician) and appropriateness of the prescription were manipulated. Perceived IRQ was measured with multiple items. Pharmacists' WTIP in the scenario was the outcome variable. A total of 243 responses were included in multiple linear regression analyses. After controlling for dependence power, information power, communication effectiveness, perceived responsibility, and attitude, pharmacists' WTIP was negatively affected by perceived IRQ (estimate = -0.309, P < 0.05). This effect was more pronounced in groups exposed to the scenario where the pharmacist had lower relative expert power (estimate = -0.438, P < 0.05) and where the medication was less appropriate (estimate = -0.503, P < 0.05). Although willing to ensure rationality of off-label prescribing, pharmacists' WTIP was affected by a complex array of factors - the perceived impact of influence attempts on relationship quality between the pharmacist and the prescriber, the pharmacist's relative expert power, and the appropriateness of the off-label prescription. Increasing pharmacists' expert power and collaboration with physicians and promoting pharmacists' multifaceted contribution, collaborative or independent, to patient care may facilitate pharmacist services in off-label pharmaceutical care. Published by Elsevier Ltd.

Performance of unified power quality conditioner (UPQC) based on fuzzy controller for attenuating of voltage and current harmonics

NASA Astrophysics Data System (ADS)

Milood Almelian, Mohamad; Mohd, Izzeldin I.; Asghaiyer Omran, Mohamed; Ullah Sheikh, Usman

2018-04-01

Power quality-related issues such as current and voltage distortions can adversely affect home and industrial appliances. Although several conventional techniques such as the use of passive and active filters have been developed to increase power quality standards, these methods have challenges and are inadequate due to the increasing number of applications. The Unified Power Quality Conditioner (UPQC) is a modern strategy towards correcting the imperfections of voltage and load current supply. A UPQC is a combination of both series and shunt active power filters in a back-to-back manner with a common DC link capacitor. The control of the voltage of the DC link capacitor is important in achieving a desired UPQC performance. In this paper, the UPQC with a Fuzzy logic controller (FLC) was used to precisely eliminate the imperfections of voltage and current harmonics. The results of the simulation studies using MATLAB/Simulink and Simpower system programming for R-L load associated through an uncontrolled bridge rectifier was used to assess the execution process. The UPQC with FLC was simulated for a system with distorted load current and a system with distorted source voltage and load current. The outcome of the comparison of %THD in the load current and source voltage before and after using UPQC for the two cases was presented.

Wireless miniature implantable devices and ASICs for monitoring, treatment, and study of glaucoma and cardiac disease

NASA Astrophysics Data System (ADS)

Chow, Eric Y.

Glaucoma affects about 65 million people and is the second leading cause of blindness in the world. Although the condition is irreversible and incurable, early detection is vital to slowing and even stopping the progression of the disease. Our work focuses on the design, fabrication, and assembly of a continuous active glaucoma intraocular pressure (IOP) monitor that provides clinicians with the necessary data to more accurately diagnose and treat patients. Major benefits of an active monitoring device include the potential to develop a closed-loop treatment system and to operate independently for extended periods of time. The fully wireless operation uses gigahertzfrequency electromagnetic wave propagation, which allows for an orientation independent transfer of power and data over reasonable distances. Our system is comprised of a MEMS capacitive sensor, capacitive power storage array, ASIC, and monopole antenna assembled into a biocompatible liquid crystal polymer (LCP) package. We have performed in vivo trials on rabbits, both chronic and acute, to validate system functionality, fully wireless feasibility, and biocompatibility. Heart failure (HF) affects approximately 2% of the adult population in developed countries and 6-10% of people over the age of 65. Continuous monitoring of blood pressure, flow, and chemistry from a minimally invasive device can serve as a diagnostic and early-warning system for cardiac health. We developed a miniaturized system attached to the outer surface of an FDA approved stent, used as both the antenna for wireless telemetry/powering and structural support. The system comprises of a MEMS pressure sensor, ASIC for the sensor interface and wireless capabilities, LCP substrate, and FDA approved stent. In vivo studies on pigs validated functionality and fully wireless operation and demonstrate the feasibility of a stent-based wireless implant for continuous monitoring of blood pressure as well as other parameters including oxygen, flow and turbulence, chemistry, and glucose.

How coupling affects closely packed rectenna arrays used for wireless power transmission

NASA Astrophysics Data System (ADS)

Walls, Deidra; Choi, Sang H.; Yoon, Hargsoon; Geddis, Demetris; Song, Kyo D.

2017-04-01

The development of power transmission by microwave beam power harvesting attracts manufactures for use of wireless power transmission. Optimizing maximum conversion efficiency is affected by many design parameters, and has been mainly focused previously. Combining several rectennas in one array potentially aides in the amount of microwave energy that can be harvested for energy conversion. Closely packed rectenna arrays is the result of the demand to minimize size and weight for flexibility. This paper specifically focuses on the coupling effects on power; mutual coupling, comparing sparameters and gain total while varying effective parameters. This paper investigates how coupling between each dipole positively and negatively affects the microwave energy, harvesting, and the design limitations.

Wide field-of-view bifocal eyeglasses

NASA Astrophysics Data System (ADS)

Barbero, Sergio; Rubinstein, Jacob

2015-09-01

When vision is affected simultaneously by presbyopia and myopia or hyperopia, a solution based on eyeglasses implies a surface with either segmented focal regions (e.g. bifocal lenses) or a progressive addition profile (PALs). However, both options have the drawback of reducing the field-of-view for each power position, which restricts the natural eye-head movements of the wearer. To avoid this serious limitation we propose a new solution which is essentially a bifocal power-adjustable optical design ensuring a wide field-of-view for every viewing distance. The optical system is based on the Alvarez principle. Spherical refraction correction is considered for different eccentric gaze directions covering a field-of-view range up to 45degrees. Eye movements during convergence for near objects are included. We designed three bifocal systems. The first one provides 3 D for far vision (myopic eye) and -1 D for near vision (+2 D Addition). The second one provides a +3 D addition with 3 D for far vision. Finally the last system is an example of reading glasses with +1 D power Addition.

A portable magneto-optical trap with prospects for atom interferometry in civil engineering

NASA Astrophysics Data System (ADS)

Hinton, A.; Perea-Ortiz, M.; Winch, J.; Briggs, J.; Freer, S.; Moustoukas, D.; Powell-Gill, S.; Squire, C.; Lamb, A.; Rammeloo, C.; Stray, B.; Voulazeris, G.; Zhu, L.; Kaushik, A.; Lien, Y.-H.; Niggebaum, A.; Rodgers, A.; Stabrawa, A.; Boddice, D.; Plant, S. R.; Tuckwell, G. W.; Bongs, K.; Metje, N.; Holynski, M.

2017-06-01

The high precision and scalable technology offered by atom interferometry has the opportunity to profoundly affect gravity surveys, enabling the detection of features of either smaller size or greater depth. While such systems are already starting to enter into the commercial market, significant reductions are required in order to reach the size, weight and power of conventional devices. In this article, the potential for atom interferometry based gravimetry is assessed, suggesting that the key opportunity resides within the development of gravity gradiometry sensors to enable drastic improvements in measurement time. To push forward in realizing more compact systems, techniques have been pursued to realize a highly portable magneto-optical trap system, which represents the core package of an atom interferometry system. This can create clouds of 107 atoms within a system package of 20 l and 10 kg, consuming 80 W of power. This article is part of the themed issue 'Quantum technology for the 21st century'.

Designation of a polarization-converting system and its enhancement of double-frequency efficiency

NASA Astrophysics Data System (ADS)

Wang, Peng; Li, Xiao; Shang, YaPing; Xu, XiaoJun

2015-08-01

A polarization-converting system is designed by using axicons and wave plate transforming naturally polarized laser to linearly polarized laser at real time to resolve difficulties of generating high-power linearly polarized laser. The energy conversion efficiency reaches 96.9% with an enhancement of extinction ratio from 29.7% to 98%. The system also keeps excellent far field divergence. In the one-way SHG experiment the double frequency efficiency reached 4.32% using the generated linearly polarized laser, much higher than that of the naturally polarized laser but lower than that of the linearly polarized laser from PBS. And the phenomenon of the SHG experiment satisfies the principle of phase matching. The experiment proves that this polarization-converting system will not affect laser structure which controls easily and needs no feedback and controlling system with stable and reliable properties at the same time. It can absolutely be applied to the polarization-conversion of high power laser and enhance the SHG efficiency and the energy efficiency.

A portable magneto-optical trap with prospects for atom interferometry in civil engineering

PubMed Central

Perea-Ortiz, M.; Winch, J.; Briggs, J.; Freer, S.; Moustoukas, D.; Powell-Gill, S.; Squire, C.; Lamb, A.; Rammeloo, C.; Stray, B.; Voulazeris, G.; Zhu, L.; Kaushik, A.; Lien, Y.-H.; Niggebaum, A.; Rodgers, A.; Stabrawa, A.; Boddice, D.; Plant, S. R.; Tuckwell, G. W.; Bongs, K.; Metje, N.; Holynski, M.

2017-01-01

The high precision and scalable technology offered by atom interferometry has the opportunity to profoundly affect gravity surveys, enabling the detection of features of either smaller size or greater depth. While such systems are already starting to enter into the commercial market, significant reductions are required in order to reach the size, weight and power of conventional devices. In this article, the potential for atom interferometry based gravimetry is assessed, suggesting that the key opportunity resides within the development of gravity gradiometry sensors to enable drastic improvements in measurement time. To push forward in realizing more compact systems, techniques have been pursued to realize a highly portable magneto-optical trap system, which represents the core package of an atom interferometry system. This can create clouds of 107 atoms within a system package of 20 l and 10 kg, consuming 80 W of power. This article is part of the themed issue ‘Quantum technology for the 21st century’. PMID:28652493

A portable magneto-optical trap with prospects for atom interferometry in civil engineering.

PubMed

Hinton, A; Perea-Ortiz, M; Winch, J; Briggs, J; Freer, S; Moustoukas, D; Powell-Gill, S; Squire, C; Lamb, A; Rammeloo, C; Stray, B; Voulazeris, G; Zhu, L; Kaushik, A; Lien, Y-H; Niggebaum, A; Rodgers, A; Stabrawa, A; Boddice, D; Plant, S R; Tuckwell, G W; Bongs, K; Metje, N; Holynski, M

2017-08-06

The high precision and scalable technology offered by atom interferometry has the opportunity to profoundly affect gravity surveys, enabling the detection of features of either smaller size or greater depth. While such systems are already starting to enter into the commercial market, significant reductions are required in order to reach the size, weight and power of conventional devices. In this article, the potential for atom interferometry based gravimetry is assessed, suggesting that the key opportunity resides within the development of gravity gradiometry sensors to enable drastic improvements in measurement time. To push forward in realizing more compact systems, techniques have been pursued to realize a highly portable magneto-optical trap system, which represents the core package of an atom interferometry system. This can create clouds of 10 7 atoms within a system package of 20 l and 10 kg, consuming 80 W of power.This article is part of the themed issue 'Quantum technology for the 21st century'. © 2017 The Author(s).

A distributed big data storage and data mining framework for solar-generated electricity quantity forecasting

NASA Astrophysics Data System (ADS)

Wang, Jianzong; Chen, Yanjun; Hua, Rui; Wang, Peng; Fu, Jia

2012-02-01

Photovoltaic is a method of generating electrical power by converting solar radiation into direct current electricity using semiconductors that exhibit the photovoltaic effect. Photovoltaic power generation employs solar panels composed of a number of solar cells containing a photovoltaic material. Due to the growing demand for renewable energy sources, the manufacturing of solar cells and photovoltaic arrays has advanced considerably in recent years. Solar photovoltaics are growing rapidly, albeit from a small base, to a total global capacity of 40,000 MW at the end of 2010. More than 100 countries use solar photovoltaics. Driven by advances in technology and increases in manufacturing scale and sophistication, the cost of photovoltaic has declined steadily since the first solar cells were manufactured. Net metering and financial incentives, such as preferential feed-in tariffs for solar-generated electricity; have supported solar photovoltaics installations in many countries. However, the power that generated by solar photovoltaics is affected by the weather and other natural factors dramatically. To predict the photovoltaic energy accurately is of importance for the entire power intelligent dispatch in order to reduce the energy dissipation and maintain the security of power grid. In this paper, we have proposed a big data system--the Solar Photovoltaic Power Forecasting System, called SPPFS to calculate and predict the power according the real-time conditions. In this system, we utilized the distributed mixed database to speed up the rate of collecting, storing and analysis the meteorological data. In order to improve the accuracy of power prediction, the given neural network algorithm has been imported into SPPFS.By adopting abundant experiments, we shows that the framework can provide higher forecast accuracy-error rate less than 15% and obtain low latency of computing by deploying the mixed distributed database architecture for solar-generated electricity.

Preliminary power train design for a state-of-the-art electric vehicle

NASA Technical Reports Server (NTRS)

Mighdoll, P.; Hahn, W. F.

1978-01-01

Power train designs which can be implemented within the current state-of-the-art were identified by means of a review of existing electric vehicles and suitable off-the-shelf components. The affect of various motor/transmission combinations on vehicle range over the SAE J227a schedule D cycle was evaluated. The selected, state-of-the-art power train employs a dc series wound motor, SCR controller, variable speed transmission, regenerative braking, drum brakes and radial ply tires. Vehicle range over the SAE cycle can be extended by approximately 20% by the further development of separately excited, shunt wound DC motors and electrical controllers. Approaches which could improve overall power train efficiency, such as AC motor systems, are identified. However, future emphasis should remain on batteries, tires and lightweight structures if substantial range improvements are to be achieved.

Task six report: Spacecraft communication terminal evaluation. [analysis of space communication at six different wavelengths in radio and optical frequency regions

NASA Technical Reports Server (NTRS)

1973-01-01

An analytical comparison is made of space communication accomplished at six different wavelengths. In the radio band, 2.25, 7.5, and 14.5 GHz systems are analyzed, while at optical wavelengths, 0.53, 1.06 and 10.6 micron systems are examined. The purpose of the comparison is to determine which of these systems will require the least hardware weight to perform a given communication task. The problem is solved by requiring each communication system to meet a given performance while selecting combinations of transmitted power and antenna diameter to obtain the least overall system weight. This performance is provided while maintaining practical values for parameters other than antenna diameter and power, which also affect system performance. The results of the analysis indicate that for future data links over ranges of 42,000 to 84,000 km and with data bandwidths of 100 to 1000 MHz, the CO2 laser system will provide the required performance with the least total system weight impact on a spacecraft.

Comparative Study Between Wind and Photovoltaic (PV) Systems

NASA Astrophysics Data System (ADS)

Taha, Wesam

This paper reviews two renewable energy systems; wind and photovoltaic (PV) systems. The common debate between the two of them is to conclude which one is better, in terms of cost and efficiency. Therefore, comparative study, in terms of cost and efficiency, is attempted. Regarding total cost of both, wind and PV systems, many parameters must be taken into consideration such as availability of energy (either wind or solar), operation and maintenance, availability of costumers, political influence, and the components used in building the system. The main components and parameters that play major role in determining the overall efficiency of wind systems are the wind turbine generator (WTG), gearbox and control technologies such as power, and speed control. On the other hand, in grid-connected PV systems (GCPVS), converter architecture along with maximum power point tracking (MPPT) algorithm and inverter topologies are the issues that affects the efficiency significantly. Cost and efficiency analyses of both systems have been carried out based on the statistics available till today and would be useful in the progress of renewable energy penetration throughout the world.

Using kinematic reduction for studying grasping postures. An application to power and precision grasp of cylinders.

PubMed

Jarque-Bou, N; Gracia-Ibáñez, V; Sancho-Bru, J L; Vergara, M; Pérez-González, A; Andrés, F J

2016-09-01

The kinematic analysis of human grasping is challenging because of the high number of degrees of freedom involved. The use of principal component and factorial analyses is proposed in the present study to reduce the hand kinematics dimensionality in the analysis of posture for ergonomic purposes, allowing for a comprehensive study without losing accuracy while also enabling velocity and acceleration analyses to be performed. A laboratory study was designed to analyse the effect of weight and diameter in the grasping posture for cylinders. This study measured the hand posture from six subjects when transporting cylinders of different weights and diameters with precision and power grasps. The hand posture was measured using a Vicon(®) motion-tracking system, and the principal component analysis was applied to reduce the kinematics dimensionality. Different ANOVAs were performed on the reduced kinematic variables to check the effect of weight and diameter of the cylinders, as well as that of the subject. The results show that the original twenty-three degrees of freedom of the hand were reduced to five, which were identified as digit arching, closeness, palmar arching, finger adduction and thumb opposition. Both cylinder diameter and weight significantly affected the precision grasping posture: diameter affects closeness, palmar arching and opposition, while weight affects digit arching, palmar arching and closeness. The power-grasping posture was mainly affected by the cylinder diameter, through digit arching, closeness and opposition. The grasping posture was largely affected by the subject factor and this effect couldn't be attributed only to hand size. In conclusion, this kinematic reduction allowed identifying the effect of the diameter and weight of the cylinders in a comprehensive way, being diameter more important than weight. Copyright © 2016 Elsevier Ltd. All rights reserved.

EEG-based Affect and Workload Recognition in a Virtual Driving Environment for ASD Intervention

PubMed Central

Wade, Joshua W.; Key, Alexandra P.; Warren, Zachary E.; Sarkar, Nilanjan

2017-01-01

objective To build group-level classification models capable of recognizing affective states and mental workload of individuals with autism spectrum disorder (ASD) during driving skill training. Methods Twenty adolescents with ASD participated in a six-session virtual reality driving simulator based experiment, during which their electroencephalogram (EEG) data were recorded alongside driving events and a therapist’s rating of their affective states and mental workload. Five feature generation approaches including statistical features, fractal dimension features, higher order crossings (HOC)-based features, power features from frequency bands, and power features from bins (Δf = 2 Hz) were applied to extract relevant features. Individual differences were removed with a two-step feature calibration method. Finally, binary classification results based on the k-nearest neighbors algorithm and univariate feature selection method were evaluated by leave-one-subject-out nested cross-validation to compare feature types and identify discriminative features. Results The best classification results were achieved using power features from bins for engagement (0.95) and boredom (0.78), and HOC-based features for enjoyment (0.90), frustration (0.88), and workload (0.86). Conclusion Offline EEG-based group-level classification models are feasible for recognizing binary low and high intensity of affect and workload of individuals with ASD in the context of driving. However, while promising the applicability of the models in an online adaptive driving task requires further development. Significance The developed models provide a basis for an EEG-based passive brain computer interface system that has the potential to benefit individuals with ASD with an affect- and workload-based individualized driving skill training intervention. PMID:28422647

Challenge Students to Design an Energy-Efficient Home

ERIC Educational Resources Information Center

Griffith, Jack

2008-01-01

This article presents an activity that gives students a practical understanding of how much energy the average home consumes and wastes, and shows how the construction technologies used in home design affect overall energy usage. In this activity, students will outline the cost of a home's electrical system, give a breakdown of how much power the…

Opinion, Dialogue, Review: Childhood Is Killing "Our" Children: Some Thoughts on the Columbine High School Shootings and the Agentive Child.

ERIC Educational Resources Information Center

Cook, Daniel Thomas

2000-01-01

Analyzes the cause of the massacre at Colorado's Columbine high school by other students. Considers the incident systemic of opposing tendencies, values, and motives surrounding childhood and the weakening of the power to affect one's surroundings due to the dominance of commercial culture. (JPB)

Pulmonary-impedance power spectral analysis: A facile means of detecting radiation-induced gastrointestinal distress and performance decrement in man

NASA Technical Reports Server (NTRS)

Rick, R. C.; Lushbaugh, C. C.; Mcdow, E.; Frome, E.

1972-01-01

Changes in respiratory variance revealed by power spectral analysis of the pulmonary impedance pneumogram can be used to detect and measure stresses directly or indirectly affecting human respiratory function. When gastrointestinal distress occurred during a series of 5 total-body exposures of 30 R at a rate of 1.5 R/min, it was accompanied by typical shifts in pulmonary impedance power spectra. These changes did not occur after protracted exposure of 250 R (30 R daily) at 1.5 R/hr that failed to cause radiation sickness. This system for quantitating respiratory effort can also be used to detect alterations in one's ability to perform under controlled exercise conditions.

Government as Institutional Entrepreneur: Extending Working Life in the UK and Japan.

PubMed

Flynn, Matthew; Schröder, Heike; Higo, Masa; Yamada, Atsuhiro

2014-07-01

Through the lens of Institutional Entrepreneurship, this paper discusses how governments use the levers of power afforded through business and welfare systems to affect change in the organisational management of older workers. It does so using national stakeholder interviews in two contrasting economies: the United Kingdom and Japan. Both governments have taken a 'light-touch' approach to work and retirement. However, the highly institutionalised Japanese system affords the government greater leverage than that of the liberal UK system in changing employer practices at the workplace level.

Spiral spectrum of Airy beams propagation through moderate-to-strong turbulence of maritime atmosphere.

PubMed

Zhu, Yun; Zhang, Yixin; Hu, Zhengda

2016-05-16

The spatial coherence radius in moderate-to-strong maritime turbulence is derived on the basis of the modified Rytov approximation. Models are developed to simulate the spiral spectrum of Airy beams propagating through moderate-to-strong maritime turbulence. In the moderate-to-strong irradiance fluctuation region, we analyze the effects of maritime turbulence on the spread of the spiral spectrum of Airy beams in a horizontal propagation path. Results indicate that the increment in the inner-scale significantly increases the received power. By contrast, the outer-scale elicits a negligible effect on the received power if the ratio of the inner-scale to the outer-scale is less than 0.01. The outer-scale affects the received power only if the ratio is greater than 0.01. The performance of a light source is essential for the received power of Airy beams carrying orbital angular momentum (OAM) through moderate-to-strong maritime turbulence. Airy beams with longer wavelengths, smaller OAM numbers, larger radii of the main ring, and smaller diameters of the circular aperture are less affected by maritime turbulence. Autofocusing of Airy beams is beneficial for the propagation of the spiral spectrum in a certain propagation distance. These results contribute to the design of optical communication systems with OAM encoding for moderate-to-strong maritime turbulence.

Factors that influence the radiofrequency power output of GSM mobile phones.

PubMed

Erdreich, Linda S; Van Kerkhove, Maria D; Scrafford, Carolyn G; Barraj, Leila; McNeely, Mark; Shum, Mona; Sheppard, Asher R; Kelsh, Michael

2007-08-01

Epidemiological studies of mobile phone use and risk of brain cancer have relied on self-reported use, years as a subscriber, and billing records as exposure surrogates without addressing the level of radiofrequency (RF) power output. The objective of this study was to measure environmental, behavioral and engineering factors affecting the RF power output of GSM mobile phones during operation. We estimated the RF-field exposure of volunteer subjects who made mobile phone calls using software-modified phones (SMPs) that recorded output power settings. Subjects recruited from three geographic areas in the U.S. were instructed to log information (place, time, etc.) for each call made and received during a 5-day period. The largest factor affecting energy output was study area, followed by user movement and location (inside or outside), use of a hands-free device, and urbanicity, although the two latter factors accounted for trivial parts of overall variance. Although some highly statistically significant differences were identified, the effects on average energy output rate were usually less than 50% and were generally comparable to the standard deviation. These results provide information applicable to improving the precision of exposure metrics for epidemiological studies of GSM mobile phones and may have broader application for other mobile phone systems and geographic locations.

Assessment of destabilizing factor for automatic control systems in propulsion systems of mechatronic and maritime transport objects

NASA Astrophysics Data System (ADS)

Zhilenkov, A. A.; Kapitonov, A. A.

2017-10-01

It is known that many of today’s ships and vessels have a shaft generator as a part of their power plants. Modern automatic control systems used in the world’s fleet do not enable their shaft generators to operate in parallel with the main diesel generators for long-term sustenance of the total load of the ship network. On the other hand, according to our calculations and experiments, a shaft generator operated in parallel with the main power plant helps save at least 10% of fuel while making the power system of the ship more efficient, reliable, and eco-friendly. The fouling and corrosion of the propeller as well as the weather conditions of navigation affect its modulus of resistance. It changes the free component of the transient process of shaft generator stress frequency changes in transient processes. While the shaft generator and the diesel generator of the ship power plant are paralleled, there emerges an angle between their EMF. This results in equalizing currents generated between them. The altering torque in the drive-shaft line—propeller system causes torsional fluctuations of the ship shaft line. To compensate for the effect of destabilizing factors and torsional fluctuations of the shaft line on the dynamic characteristics of the transient process that alters the RPM of the main engine, sliding mode controls can be used. To synthesize such a control, one has to evaluate the effect of destabilizing factors.

Numerical investigation of the electric field distribution and the power deposition in the resonant cavity of a microwave electrothermal thruster

NASA Astrophysics Data System (ADS)

Yildiz, Mehmet Serhan; Celik, Murat

2017-04-01

Microwave electrothermal thruster (MET), an in-space propulsion concept, uses an electromagnetic resonant cavity as a heating chamber. In a MET system, electromagnetic energy is converted to thermal energy via a free floating plasma inside a resonant cavity. To optimize the power deposition inside the cavity, the factors that affect the electric field distribution and the resonance conditions must be accounted for. For MET thrusters, the length of the cavity, the dielectric plate that separates the plasma zone from the antenna, the antenna length and the formation of a free floating plasma have direct effects on the electromagnetic wave transmission and thus the power deposition. MET systems can be tuned by adjusting the lengths of the cavity or the antenna. This study presents the results of a 2-D axis symmetric model for the investigation of the effects of cavity length, antenna length, separation plate thickness, as well as the presence of free floating plasma on the power absorption. Specifically, electric field distribution inside the resonant cavity is calculated for a prototype MET system developed at the Bogazici University Space Technologies Laboratory. Simulations are conducted for a cavity fed with a constant power input of 1 kW at 2.45 GHz using COMSOL Multiphysics commercial software. Calculations are performed for maximum plasma electron densities ranging from 1019 to 1021 #/m3. It is determined that the optimum antenna length changes with changing plasma density. The calculations show that over 95% of the delivered power can be deposited to the plasma when the system is tuned by adjusting the cavity length.

[The consolidation of private health plans in Brazil: challenges for the regulator].

PubMed

Ocké-Reis, Carlos Octávio

2007-01-01

The effects of the financial consolidation of Brazil's private health plan market warrants investigation, as this trend could enhance the power of large plans and affect the financing of the National Health System. From the standpoint of the political economics of this sector, while reflecting on the features of this consolidation, this paper discusses whether this more powerful market clout might require the State to adopt a more active stance, especially if it wishes to enforce the normative principles of the National Supplementary Health Regulator in order to protect consumers, ensure regulated competition and defend the public interest.

The mechanism of the effect of a plasma layer with negative permittivity on the antenna radiation field

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

Wang, Chunsheng, E-mail: wangcs@hit.edu.cn; Liu, Hui; Jiang, Binhao

A model of a plasma–antenna system is developed to study the mechanism of the effect of the plasma layer on antenna radiation. Results show a plasma layer with negative permittivity is inductive, and thus affects the phase difference between electric and magnetic fields. In the near field of antenna radiation, a plasma layer with proper parameters can compensate the capacitivity of the vacuum and enhance the radiation power. In the far field of antenna radiation, the plasma layer with negative permittivity increases the inductivity of the vacuum and reduces the radiation power.

Guidelines for Electromagnetic Interference Testing of Power Plant Equipment: Revision 3 to TR-102323

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

J. Cunningham and J. Shank

2004-11-01

To continue meeting safety and reliability requirements while controlling costs, operators of nuclear power plants must be able to replace and upgrade equipment in a cost-effective manner. One issue that has been problematic for new plant equipment and especially for digital instrumentation and control (I&C) systems in recent years is electromagnetic compatibility (EMC). The EMC issue usually involves testing to show that critical equipment will not be adversely affected by electromagnetic interference (EMI) in the plant environment. This guide will help nuclear plant engineers address EMC issues and qualification testing in a consistent, comprehensive manner.

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

NASA Astrophysics Data System (ADS)

Cox, Brian; Treyer, Karin

2015-02-01

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

Flow Batteries for Microfluidic Networks – Configuring An Electroosmotic Pump for Non-Terminal Positions

PubMed Central

He, Chiyang; Lu, Joann J.; Jia, Zhijian; Wang, Wei; Wang, Xiayan; Dasgupta, Purnendu K.; Liu, Shaorong

2011-01-01

A micropump provides flow and pressure for a lab-on-chip device, just as a battery supplies current and voltage for an electronic system. Numerous micropumps have been developed, but none is as versatile as a battery. One cannot easily insert a micropump into a nonterminal position of a fluidic line without affecting the rest of the fluidic system, one cannot simply connect several micropumps in series to enhance the pressure output, etc. In this work we develop a flow battery (or pressure power supply) to address this issue. A flow battery consists of a +EOP (in which the liquid flows in the same direction as the field gradient) and a −EOP (in which the liquid flows opposite to the electric field gradient), and the outlet of the +EOP is directly connected to the inlet of the −EOP. An external high voltage is applied to this outlet-inlet joint via a short gel-filled capillary that allows ions but not bulk liquid flow, while the +EOP’s inlet and the −EOP’s outlet (the flow battery’s inlet and outlet) are grounded. This flow battery can be deployed anywhere in a fluidic network without electrically affecting the rest of the system. Several flow batteries can be connected in series to enhance the pressure output to drive HPLC separations. In a fluidic system powered by flow batteries, a hydraulic Ohm’s law can be applied to analyze system pressures and flow rates. PMID:21375230

The Case for Distributed Engine Control in Turbo-Shaft Engine Systems

NASA Technical Reports Server (NTRS)

Culley, Dennis E.; Paluszewski, Paul J.; Storey, William; Smith, Bert J.

2009-01-01

The turbo-shaft engine is an important propulsion system used to power vehicles on land, sea, and in the air. As the power plant for many high performance helicopters, the characteristics of the engine and control are critical to proper vehicle operation as well as being the main determinant to overall vehicle performance. When applied to vertical flight, important distinctions exist in the turbo-shaft engine control system due to the high degree of dynamic coupling between the engine and airframe and the affect on vehicle handling characteristics. In this study, the impact of engine control system architecture is explored relative to engine performance, weight, reliability, safety, and overall cost. Comparison of the impact of architecture on these metrics is investigated as the control system is modified from a legacy centralized structure to a more distributed configuration. A composite strawman system which is typical of turbo-shaft engines in the 1000 to 2000 hp class is described and used for comparison. The overall benefits of these changes to control system architecture are assessed. The availability of supporting technologies to achieve this evolution is also discussed.

Modulation of α power and functional connectivity during facial affect recognition.

PubMed

Popov, Tzvetan; Miller, Gregory A; Rockstroh, Brigitte; Weisz, Nathan

2013-04-03

Research has linked oscillatory activity in the α frequency range, particularly in sensorimotor cortex, to processing of social actions. Results further suggest involvement of sensorimotor α in the processing of facial expressions, including affect. The sensorimotor face area may be critical for perception of emotional face expression, but the role it plays is unclear. The present study sought to clarify how oscillatory brain activity contributes to or reflects processing of facial affect during changes in facial expression. Neuromagnetic oscillatory brain activity was monitored while 30 volunteers viewed videos of human faces that changed their expression from neutral to fearful, neutral, or happy expressions. Induced changes in α power during the different morphs, source analysis, and graph-theoretic metrics served to identify the role of α power modulation and cross-regional coupling by means of phase synchrony during facial affect recognition. Changes from neutral to emotional faces were associated with a 10-15 Hz power increase localized in bilateral sensorimotor areas, together with occipital power decrease, preceding reported emotional expression recognition. Graph-theoretic analysis revealed that, in the course of a trial, the balance between sensorimotor power increase and decrease was associated with decreased and increased transregional connectedness as measured by node degree. Results suggest that modulations in α power facilitate early registration, with sensorimotor cortex including the sensorimotor face area largely functionally decoupled and thereby protected from additional, disruptive input and that subsequent α power decrease together with increased connectedness of sensorimotor areas facilitates successful facial affect recognition.

Executive summary. [application of laser oriented and radio frequency techniques for space communication

NASA Technical Reports Server (NTRS)

1973-01-01

The scope of Technology Forecasting for Space Communications is very wide, covering virtually every technology that can directly or indirectly affect space communications. The assigned effort, however, was directed toward a series of studies which individually examined important aspects of space communications and which collectively was interrelated. The contributions of the individual tasks and their interrelationship are indicated. The total effort of the tasks was fairly evenly divided between laser oriented and radio frequency tasks. The investigations show that laser communications have a current state of the art which would allow operational systems to be implemented in the 1975 to 1980 time frame. Further, these systems, when operated over ranges in the order of synchronous ranges (42,000 km)and transmitting data rates of 10 to the 8th power 10 to the 9th power bits per second will have a smaller total weight impact on a spacecraft than do radio systems.

Stochastic Analysis of the Efficiency of a Wireless Power Transfer System Subject to Antenna Variability and Position Uncertainties

PubMed Central

Rossi, Marco; Stockman, Gert-Jan; Rogier, Hendrik; Vande Ginste, Dries

2016-01-01

The efficiency of a wireless power transfer (WPT) system in the radiative near-field is inevitably affected by the variability in the design parameters of the deployed antennas and by uncertainties in their mutual position. Therefore, we propose a stochastic analysis that combines the generalized polynomial chaos (gPC) theory with an efficient model for the interaction between devices in the radiative near-field. This framework enables us to investigate the impact of random effects on the power transfer efficiency (PTE) of a WPT system. More specifically, the WPT system under study consists of a transmitting horn antenna and a receiving textile antenna operating in the Industrial, Scientific and Medical (ISM) band at 2.45 GHz. First, we model the impact of the textile antenna’s variability on the WPT system. Next, we include the position uncertainties of the antennas in the analysis in order to quantify the overall variations in the PTE. The analysis is carried out by means of polynomial-chaos-based macromodels, whereas a Monte Carlo simulation validates the complete technique. It is shown that the proposed approach is very accurate, more flexible and more efficient than a straightforward Monte Carlo analysis, with demonstrated speedup factors up to 2500. PMID:27447632

On enhancing energy harvesting performance of the photovoltaic modules using an automatic cooling system and assessing its economic benefits of mitigating greenhouse effects on the environment

NASA Astrophysics Data System (ADS)

Wang, Jen-Cheng; Liao, Min-Sheng; Lee, Yeun-Chung; Liu, Cheng-Yue; Kuo, Kun-Chang; Chou, Cheng-Ying; Huang, Chen-Kang; Jiang, Joe-Air

2018-02-01

The performance of photovoltaic (PV) modules under outdoor operation is greatly affected by their location and environmental conditions. The temperature of a PV module gradually increases as it is exposed to solar irradiation, resulting in degradation of its electrical characteristics and power generation efficiency. This study adopts wireless sensor network (WSN) technology to develop an automatic water-cooling system for PV modules in order to improve their PV power generation efficiency. A temperature estimation method is developed to quickly and accurately estimate the PV module temperatures based on weather data provided from the WSN monitoring system. Further, an estimation method is also proposed for evaluation of the electrical characteristics and output power of the PV modules, which is performed remotely via a control platform. The automatic WSN-based water-cooling mechanism is designed to avoid the PV module temperature from reaching saturation. Equipping each PV module with the WSN-based cooling system, the ambient conditions are monitored automatically so that the temperature of the PV module is controlled by sprinkling water on the panel surface. The field-test experiment results show an increase in the energy harvested by the PV modules of approximately 17.75% when using the proposed WSN-based cooling system.

Engine-integrated solid oxide fuel cells for efficient electrical power generation on aircraft

NASA Astrophysics Data System (ADS)

Waters, Daniel F.; Cadou, Christopher P.

2015-06-01

This work investigates the use of engine-integrated catalytic partial oxidation (CPOx) reactors and solid oxide fuel cells (SOFCs) to reduce fuel burn in vehicles with large electrical loads like sensor-laden unmanned air vehicles. Thermodynamic models of SOFCs, CPOx reactors, and three gas turbine (GT) engine types (turbojet, combined exhaust turbofan, separate exhaust turbofan) are developed and checked against relevant data and source material. Fuel efficiency is increased by 4% and 8% in the 50 kW and 90 kW separate exhaust turbofan systems respectively at only modest cost in specific power (8% and 13% reductions respectively). Similar results are achieved in other engine types. An additional benefit of hybridization is the ability to provide more electric power (factors of 3 or more in some cases) than generator-based systems before encountering turbine inlet temperature limits. A sensitivity analysis shows that the most important parameters affecting the system's performance are operating voltage, percent fuel oxidation, and SOFC assembly air flows. Taken together, this study shows that it is possible to create a GT-SOFC hybrid where the GT mitigates balance of plant losses and the SOFC raises overall system efficiency. The result is a synergistic system with better overall performance than stand-alone components.

Stochastic Analysis of the Efficiency of a Wireless Power Transfer System Subject to Antenna Variability and Position Uncertainties.

PubMed

Rossi, Marco; Stockman, Gert-Jan; Rogier, Hendrik; Vande Ginste, Dries

2016-07-19

The efficiency of a wireless power transfer (WPT) system in the radiative near-field is inevitably affected by the variability in the design parameters of the deployed antennas and by uncertainties in their mutual position. Therefore, we propose a stochastic analysis that combines the generalized polynomial chaos (gPC) theory with an efficient model for the interaction between devices in the radiative near-field. This framework enables us to investigate the impact of random effects on the power transfer efficiency (PTE) of a WPT system. More specifically, the WPT system under study consists of a transmitting horn antenna and a receiving textile antenna operating in the Industrial, Scientific and Medical (ISM) band at 2.45 GHz. First, we model the impact of the textile antenna's variability on the WPT system. Next, we include the position uncertainties of the antennas in the analysis in order to quantify the overall variations in the PTE. The analysis is carried out by means of polynomial-chaos-based macromodels, whereas a Monte Carlo simulation validates the complete technique. It is shown that the proposed approach is very accurate, more flexible and more efficient than a straightforward Monte Carlo analysis, with demonstrated speedup factors up to 2500.

Effective of diode laser on teeth enamel in the teeth whitening treatment

NASA Astrophysics Data System (ADS)

Klunboot, U.; Arayathanitkul, K.; Chitaree, R.; Emarat, N.

2011-12-01

This research purpose is to investigate the changing of teeth color and to study the surface of teeth after treatment by laser diode at different power densities for tooth whitening treatment. In the experiment, human-extracted teeth samples were divided into 7 groups of 6 teeth each. After that laser diode was irradiated to teeth, which were coated by 38% concentration of hydrogen peroxide, during for 20, 30 and 60 seconds at power densities of 10.9 and 52.1 W/cm2. The results of teeth color change were described by the CIEL*a*b* systems and the damage of teeth surface were investigated by scanning electron microscopy (SEM). The results showed that the power density of the laser diode could affect the whiteness of teeth. The high power density caused more luminous teeth than the low power density did, but on the other hand the high power density also caused damage to the teeth surface. Therefore, the laser diode at the low power densities has high efficiency for tooth whitening treatment and it has a potential for other clinical applications.

Coupled dynamic systems and Le Chatelier's principle in noise control

NASA Astrophysics Data System (ADS)

Maidanik, G.; Becker, K. J.

2004-05-01

Investigation of coupling an externally driven dynamic system-a master dynamic system-to a passive one-an adjunct dynamic system-reveals that the response of the adjunct dynamic system affects the precoupled response of the master dynamic system. The responses, in the two dynamic systems when coupled, are estimated by the stored energies (Es) and (E0), respectively. Since the adjunct dynamic system, prior to coupling, was with zero (0) stored energy, E0s=0, the precoupled stored energy (E00) in the master dynamic system is expected to be reduced to (E0) when coupling is instituted; i.e., one expects E0

The impact of the Morgantown power plant on the Potomac estuary: an interpretive summary of the 1972-1973 investigations. Final interpretive report

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

Bongers, L.H.; Polgar, T.T.; Lippson, A.J.

1975-12-01

This report summarizes and interprets the findings of aquatic field studies conducted at PEPCO's Morgantown generating station. The purpose of this investigation was to determine if power plant operations would adversely affect the aquatic ecosystem of the Potomac River. The field studies, conducted in 1972 and 1973, include investigations of physical effects and of biological responses to heat, chlorination, and passage through the plants cooling system. Key cooling system operation characteristics were systematically varied while measurements were conducted. On the basis of these entrainment and site investigations, it was possible to arrive at value judgments on the significance of observedmore » plant effects. Both impingement and entrainment effects were considered in these studies.« less

iCalm: wearable sensor and network architecture for wirelessly communicating and logging autonomic activity.

PubMed

Fletcher, Richard Ribon; Dobson, Kelly; Goodwin, Matthew S; Eydgahi, Hoda; Wilder-Smith, Oliver; Fernholz, David; Kuboyama, Yuta; Hedman, Elliott Bruce; Poh, Ming-Zher; Picard, Rosalind W

2010-03-01

Widespread use of affective sensing in healthcare applications has been limited due to several practical factors, such as lack of comfortable wearable sensors, lack of wireless standards, and lack of low-power affordable hardware. In this paper, we present a new low-cost, low-power wireless sensor platform implemented using the IEEE 802.15.4 wireless standard, and describe the design of compact wearable sensors for long-term measurement of electrodermal activity, temperature, motor activity, and photoplethysmography. We also illustrate the use of this new technology for continuous long-term monitoring of autonomic nervous system and motion data from active infants, children, and adults. We describe several new applications enabled by this system, discuss two specific wearable designs for the wrist and foot, and present sample data.

Developmental validation of the PowerPlex(®) 21 System.

PubMed

Ensenberger, Martin G; Hill, Carolyn R; McLaren, Robert S; Sprecher, Cynthia J; Storts, Douglas R

2014-03-01

The PowerPlex(®) 21 System is a STR multiplex that has been optimized for casework samples while still being capable of database workflows including direct amplification. The loci included in the multiplex offer increasing overlap with core loci used in different countries and regions throughout the world. The PowerPlex(®) 21 System contains D1S1656, D2S1338, D3S1358, D5S818, D6S1043, D7S820, D8S1179, D12S391, D13S317, D16S539, D18S51, D19S433, D21S11, Amelogenin, CSF1PO, FGA, Penta D, Penta E, TH01, TPOX, and vWA. These loci represent all 13 core CODIS loci in addition to loci commonly used in Asia and Europe. A developmental validation study was completed to document performance capabilities and limitations of the PowerPlex(®) 21 System. Data from this validation work served as the basis for the following conclusions: genotyping of single-source samples was reliable across a range of template DNA concentrations with >95% alleles called at 50 pg. Direct amplification of samples from FTA(®) storage cards was successfully performed using the reagents provided with the system and modified cycling protocols provided in the technical manual. Mixture analysis showed that over 95% of minor alleles were detected at 1:9 ratios. Reaction conditions including volume and annealing temperature as well as the concentrations of primers, DNA polymerase, magnesium, and Master Mix were shown to be optimal and able to withstand moderate variations without affecting system performance. Reproducible results were generated by different users at different sites. Finally, concordance studies showed consistent results when comparing the PowerPlex(®) 21 System with other commercially available STR-genotyping systems. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Power in everyday life.

PubMed

Smith, Pamela K; Hofmann, Wilhelm

2016-09-06

How does power manifest itself in everyday life? Using experience-sampling methodology, we investigated the prevalence, sources, and correlates of power in people's natural environments. Participants experienced power-relevant situations regularly, though not frequently. High power was not restricted to a limited few: almost half of the sample reported experiencing high-power positions. Positional power and subjective feelings of power were strongly related but had unique relations with several individual difference measures and independent effects on participants' affect, cognition, and interpersonal relations. Subjective feelings of power resulted more from within-participant situational fluctuation, such as the social roles participants held at different times, than from stable differences between people. Our data supported some theoretical predictions about power's effects on affect, cognition, and interpersonal relations, but qualified others, particularly highlighting the role of responsibility in power's effects. Although the power literature has focused on high power, we found stronger effects of low power than high power.

Optimal design of a vibration-based energy harvester using magnetostrictive material (MsM)

NASA Astrophysics Data System (ADS)

Hu, J.; Xu, F.; Huang, A. Q.; Yuan, F. G.

2011-01-01

In this study, an optimal vibration-based energy harvesting system using magnetostrictive material (MsM) was designed and tested to enable the powering of a wireless sensor. In particular, the conversion efficiency, converting from magnetic to electric energy, is approximately modeled from the magnetic field induced by the beam vibration. A number of factors that affect the output power such as the number of MsM layers, coil design and load matching are analyzed and explored in the design optimization. From the measurements, the open-circuit voltage can reach 1.5 V when the MsM cantilever beam operates at the second natural frequency 324 Hz. The AC output power is 970 µW, giving a power density of 279 µW cm - 3. The attempt to use electrical reactive components (either inductors or capacitors) to resonate the system at any frequency has also been analyzed and tested experimentally. The results showed that this approach is not feasible to optimize the power. Since the MsM device has low output voltage characteristics, a full-wave quadrupler has been designed to boost the rectified output voltage. To deliver the maximum output power to the load, a complex conjugate impedance matching between the load and the MsM device is implemented using a discontinuous conduction mode (DCM) buck-boost converter. The DC output power after the voltage quadrupler reaches 705 µW and the corresponding power density is 202 µW cm - 3. The output power delivered to a lithium rechargeable battery is around 630 µW, independent of the load resistance.

Environmental Assessment for Proposed Royal Saudi Air Force F-15SA Beddown at Mountain Home Air Force Base

DTIC Science & Technology

2012-08-16

designed for sophisticated air-to- ground attack capabilities and air-to-air superiority missions, using two crewmembers, a pilot and a weapon systems ...was added to the area of potential ground disturbance. This area comprises a total of 14.08 acres for all projects. As yet undefined infrastructure...upgrades, such as connecting new facilities to water and power systems would also add to the affected areas/ potential area of ground disturbance on

Planning, budgeting, and controlling--one look at the future: case-mix cost accounting.

PubMed Central

Thompson, J D; Averill, R F; Fetter, R B

1979-01-01

This paper outlines the system for cost accounting and managerial control which is an extension of the usually accepted departmental costing systems and takes as its units the 383 Diagnosis Related Groups (DRGs) considered to be the hospital's products. It is held that such an approach offers hospital managers a more powerful, analytic, budgeting, and cost-finding tool and offers the opportunity to involve the medical staff in the issues of how their practice patterns are affecting hospital costs. PMID:511578

Planning, budgeting, and controlling--one look at the future: case-mix cost accounting.

PubMed

Thompson, J D; Averill, R F; Fetter, R B

1979-01-01

This paper outlines the system for cost accounting and managerial control which is an extension of the usually accepted departmental costing systems and takes as its units the 383 Diagnosis Related Groups (DRGs) considered to be the hospital's products. It is held that such an approach offers hospital managers a more powerful, analytic, budgeting, and cost-finding tool and offers the opportunity to involve the medical staff in the issues of how their practice patterns are affecting hospital costs.

Power MOSFET-diode-based limiter for high-frequency ultrasound systems.

PubMed

Choi, Hojong; Kim, Min Gon; Cummins, Thomas M; Hwang, Jae Youn; Shung, K Kirk

2014-10-01

The purpose of the limiter circuits used in the ultrasound imaging systems is to pass low-voltage echo signals generated by ultrasonic transducers while preventing high-voltage short pulses transmitted by pulsers from damaging front-end circuits. Resistor-diode-based limiters (a 50 Ω resistor with a single cross-coupled diode pair) have been widely used in pulse-echo measurement and imaging system applications due to their low cost and simple architecture. However, resistor-diode-based limiters may not be suited for high-frequency ultrasound transducer applications since they produce large signal conduction losses at higher frequencies. Therefore, we propose a new limiter architecture utilizing power MOSFETs, which we call a power MOSFET-diode-based limiter. The performance of a power MOSFET-diode-based limiter was evaluated with respect to insertion loss (IL), total harmonic distortion (THD), and response time (RT). We compared these results with those of three other conventional limiter designs and showed that the power MOSFET-diode-based limiter offers the lowest IL (-1.33 dB) and fastest RT (0.10 µs) with the lowest suppressed output voltage (3.47 Vp-p) among all the limiters at 70 MHz. A pulse-echo test was performed to determine how the new limiter affected the sensitivity and bandwidth of the transducer. We found that the sensitivity and bandwidth of the transducer were 130% and 129% greater, respectively, when combined with the new power MOSFET-diode-based limiter versus the resistor-diode-based limiter. Therefore, these results demonstrate that the power MOSFET-diode-based limiter is capable of producing lower signal attenuation than the three conventional limiter designs at higher frequency operation. © The Author(s) 2014.

(Un)Disciplined futures: Women of color feminism as a disruptive to white affect studies.

PubMed

Garcia-Rojas, Claudia

2017-07-03

The aim of this article is to demonstrate how women of color feminism predates and disrupts dominant dialogues in the field of White affect studies. I introduce the concept of White affect studies as an arena of inquiry that draws from Western-European theories and literatures and architects a sociopolitical structure of affect that positions White affects as universal. Scholars contributing to the field of White affect studies posit theories of affect, embodiment, subjectivity, phenomenology, violence, war, and more, while disregarding the theoretical contributions made by women of color feminism in thinking through these notions and social issues. This is done by engaging in a citational practice that results in an epistemic erasure of women of color feminist thought. The voices of women of color feminists are thus disqualified, and their theoretical contributions are not acknowledged as significant or relevant in conceptualizing affect, affective economies, and the social. By turning to the writings of women of color feminists, I demonstrate how their theories on embodiment, subjectivity, and social structures predate the institutionalization of White affect studies. Feminists of color from the past and present have and continue to theorize through a language of self their experiences as subjects embedded within matrices of violence, power, and pleasure. Lorde, Martinez, and Chinchilla write about the ways in which lesbian and queer women of color institute different affects that counter dominant structures of emotion, systems of power, and heterosexual modes of being. In developing conceptual methodologies, Lorde, Martinez, and Chinchilla are able to weave into the dominant discursive logic a language of self that both introduces new queer subjectivities, while reinterpreting existing forms of thought, thereby contesting mainstream economies of White affects and White affect studies. It is through a language of self that Lorde, Martinez, and Chinchilla develop an ethic of survival that countermobilizes against White hegemonic apparatuses.

Effects of Pedal Speed and Crank Length on Pedaling Mechanics during Submaximal Cycling.

PubMed

Barratt, Paul Richard; Martin, James C; Elmer, Steve J; Korff, Thomas

2016-04-01

During submaximal cycling, the neuromuscular system has the freedom to select different intermuscular coordination strategies. From both a basic science and an applied perspective, it is important to understand how the central nervous system adjusts pedaling mechanics in response to changes in pedaling conditions. To determine the effect of changes in pedal speed (a marker of muscle shortening velocity) and crank length (a marker of muscle length) on pedaling mechanics during submaximal cycling. Fifteen trained cyclists performed submaximal isokinetic cycling trials (90 rpm, 240 W) using pedal speeds of 1.41 to 1.61 m·s(-1) and crank lengths of 150 to 190 mm. Joint powers were calculated using inverse dynamics. Increases in pedal speed and crank length caused large increases knee and hip angular excursions and velocities (P < 0.05), whereas ankle angular kinematics stayed relatively constant (P > 0.05). Joint moments and joint powers were less affected by changes in the independent variables, but some interesting effects and trends were observed. Most noteworthy, knee extension moments and powers tended to decrease, whereas hip extension power tended to increase with an increase in crank length. The distribution of joint moments and powers is largely maintained across a range of pedaling conditions. The crank length induced differences in knee extension moments, and powers may represent a trade-off between the central nervous system's attempts to simultaneously minimize muscle metabolic and mechanical stresses. These results increase our understanding of the neural and mechanical mechanisms underlying multi-joint task performance, and they have practical relevance to coaches, athletes, and clinicians.

Integration of Thermal Energy Harvesting in Semi-Active Piezoelectric Shunt-Damping Systems

NASA Astrophysics Data System (ADS)

Lubieniecki, Michał; Uhl, Tadeusz

2015-01-01

The opportunities to energize a broad range of devices by use of energy available almost anywhere and in many forms are almost unlimited. A major advantage of energy harvesting is the manufacture of small autonomous electronic devices with no need for power supply and maintenance. Shunt damping circuits, although unfavorably affected by the size and mass of bulky coil inductors, started to base on synthetic inductors losing their passivity. In this paper we report a study of the feasibility of powering shunt damping circuits by use of thermal energy otherwise irrevocably lost from a bearing. The heat generated in the bearing is converted thermoelectrically into electric energy which is then used to power synthetic inductance circuitry. We show that the power demand of such circuit can be satisfied by use of a thermoelectric generator paired with a moderately loaded bearing.

Organic content influences sediment microbial fuel cell performance and community structure.

PubMed

Zhao, Qing; Li, Ruying; Ji, Min; Ren, Zhiyong Jason

2016-11-01

This study constructed sediment microbial fuel cells (SMFCs) with different organic loadings without the amendment of external substrates, and it investigated how such variation affects electricity generation and microbial community structure. Results found sediment characteristics significantly influenced SMFC performance and appropriate organic content is important to maintain stable power outputs. SMFCs with loss of ignition (LOI) of 5% showed the most reliable performance in this study, while high organic content (LOI 10-16%) led to higher but very unstable voltage output because of biogas accumulation and worm activities. SMFCs with low organic content (1-3%) showed low power output. Different bacterial communities were found in SMFCs shown various power generation performance even those with similar organic contents. Thermodesulfovibrionaceae was found closely related to the system startup and Desulfobulbaceae showed great abundance in SMFCs with high power production. Copyright © 2016 Elsevier Ltd. All rights reserved.

Geothermal Water Use: Life Cycle Water Consumption, Water Resource Assessment, and Water Policy Framework

DOE Data Explorer

Schroeder, Jenna N.

2014-06-10

This report examines life cycle water consumption for various geothermal technologies to better understand factors that affect water consumption across the life cycle (e.g., power plant cooling, belowground fluid losses) and to assess the potential water challenges that future geothermal power generation projects may face. Previous reports in this series quantified the life cycle freshwater requirements of geothermal power-generating systems, explored operational and environmental concerns related to the geochemical composition of geothermal fluids, and assessed future water demand by geothermal power plants according to growth projections for the industry. This report seeks to extend those analyses by including EGS flash, both as part of the life cycle analysis and water resource assessment. A regional water resource assessment based upon the life cycle results is also presented. Finally, the legal framework of water with respect to geothermal resources in the states with active geothermal development is also analyzed.

Decoupled Modulation Control

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

Wang, Shaobu; Huang, Renke; Huang, Zhenyu

The objective of this research work is to develop decoupled modulation control methods for damping inter-area oscillations with low frequencies, so the damping control can be more effective and easier to design with less interference among different oscillation modes in the power system. A signal-decoupling algorithm was developed that can enable separation of multiple oscillation frequency contents and extraction of a “pure” oscillation frequency mode that are fed into Power System Stabilizers (PSSs) as the modulation input signals. As a result, instead of introducing interferences between different oscillation modes from the traditional approaches, the output of the new PSS modulationmore » control signal mainly affects only one oscillation mode of interest. The new decoupled modulation damping control algorithm has been successfully developed and tested on the standard IEEE 4-machine 2-area test system and a minniWECC system. The results are compared against traditional modulation controls, which demonstrates the validity and effectiveness of the newly-developed decoupled modulation damping control algorithm.« less

Military markets for solar thermal electric power systems

NASA Technical Reports Server (NTRS)

Hauger, J. S.

1980-01-01

The Department of Defense maintains an inventory of over 1,800 MW of engine-generators 15 KW and larger, with an estimated procurement rate of over 140 MW/year. Nearly the entire requirement could be met by advanced heat engines of the types being developed as point-focussing, distributed receiver power plants. A conceptual system consisting of a heat engine which efficiently burns liquid fossil or synthetic fuels, with a 'solarization kit' for conversion to hybrid solar operation could meet existing DOD requirements for new systems which are quieter, lighter, and multi-fueled. An estimated 24 percent (33 MW/year) or more could operationally benefit from the solar option. Baseline cost projections indicate levelized energy cost goals of 210 to 120 mills/KWh (15 to 1000 KW systems). Fuel cost escalation is the major factor affecting the value of the solar option. A baseline calculation for fuel at $0.59/gal in spring, 1979, escalating at 8 percent above general inflation indicates a value of $2700/KWe for a solarization kit.

Feasible Electricity Infrastructure Pathways in the Context of Climate-Water Change Constraints

NASA Astrophysics Data System (ADS)

Miara, A.; Vorosmarty, C. J.; Macknick, J.; Cohen, S. M.; Tidwell, V. C.; Newmark, R. L.; Fekete, B. M.; Corsi, F.; Sun, Y.; Proussevitch, A. A.; Glidden, S.

2017-12-01

The carbon and water intensity of US electricity generation has recently decreased due to the natural gas revolution and deployment of renewable technologies. Yet, power plants that require water for cooling still provide 80% of electricity generation and projected climate-water conditions may limit their power output and affect reliability. Understanding the connections and tradeoffs across water, electricity and climate systems is timely, as the nation tries to mitigate and adapt to a changing climate. Electricity expansion models are used to provide insight on power sector pathways given certain policy goals and economic conditions, but do not typically account for productivity limitations due to physical climate-water constraints. Here, we account for such constraints by coupling an electricity expansion model (Regional Energy Deployment System - ReEDS) with the combined Water Balance and Thermoelectric Power and Thermal Pollution Models (WBM-TP2M), which calculate the available capacity at power plants as a function of hydrologic flows, climate conditions, power plant technology and environmental regulations. To fully capture and incorporate climate-water impacts into ReEDS, a specific rule-set was designed for the temporal and spatial downscaling and up-scaling of ReEDS results into WBM-TP2M inputs and visa versa - required to achieve a modeling `loop' that will enable convergence on a feasible solution in the context of economic and geophysical constraints and opportunities. This novel modeling approach is the next phase of research for understanding electricity system vulnerabilities and adaptation measures using energy-water-climate modeling, which to-date has been limited by a focus on individual generators without analyzing power generation as a collective regional system. This study considers four energy policy/economic pathways under future climate-water resource conditions, designed under the National Energy Water System assessment framework. Results highlight the importance of linking Earth-system and economic modeling tools and provide insight on potential electricity infrastructure pathways that are sustainable, in terms lowering both water use and carbon emissions, and reliable in the face of future climate-water resource constraints.

Assessment of economic factors affecting the satellite power system. Volume 1: System cost factors

NASA Technical Reports Server (NTRS)

Hazelrigg, G. A., Jr.

1978-01-01

The factors relevant to SPS costing and selection of preferred SPS satellite configurations were studied. The issues discussed are: (1) consideration of economic factors in the SPS system that relate to selection of SPS satellite configuration; (2) analysis of the proper rate of interest for use in SPS system definition studies; and (3) the impacts of differential inflation on SPS system definition costing procedures. A cost-risk comparison of the SPS satellite configurations showed a significant difference in the levelized cost of power from them. It is concluded, that this difference is the result more of differences in the procedures for assessing costs rather than in the satellite technologies required or of any advantages of one satellite configuration over the other. Analysis of the proper rate of interest for use in SPS system is 4 percent. The major item of differential inflation to be expected over this period of time is the real cost of labor. This cost is likely to double between today and the period of SPS construction.

Assessment of the Use of Nanofluids in Spacecraft Active Thermal Control Systems

NASA Technical Reports Server (NTRS)

Ungar, Eugene K.; Erickson, Lisa R.

2011-01-01

The addition of metallic nanoparticles to a base heat transfer fluid can dramatically increase its thermal conductivity. These nanofluids have been shown to have advantages in some heat transport systems. Their enhanced properties can allow lower system volumetric flow rates and can reduce the required pumping power. Nanofluids have been suggested for use as working fluids for spacecraft Active Thermal Control Systems (ATCSs). However, there are no studies showing the end-to-end effect of nanofluids on the design and performance of spacecraft ATCSs. In the present work, a parametric study is performed to assess the use of nanofluids in a spacecraft ATCSs. The design parameters of the current Orion capsule and the tabulated thermophysical properties of nanofluids are used to assess the possible benefits of nanofluids and how their incorporation affects the overall design of a spacecraft ATCS. The study shows that the unique system and component-level design parameters of spacecraft ATCSs render them best suited for pure working fluids. The addition of nanoparticles to typical spacecraft thermal control working fluids actually results in an increase in the system mass and required pumping power.

Influence of transcranial direct current stimulation of the dorsolateral prefrontal cortex on pain related emotions: a study using electroencephalographic power spectrum analysis.

PubMed

Maeoka, Hiroshi; Matsuo, Atsushi; Hiyamizu, Makoto; Morioka, Shu; Ando, Hiroshi

2012-03-14

Pain is a multidimensional experience with sensory-discriminative, cognitive-evaluative and affective-motivational components. Emotional factors such as unpleasantness or anxiety are known to have influence on pain in humans. The aim of this single-blinded, cross over study was to evaluate the effects of transcranial direct current stimulation (tDCS) on emotional aspects of pain in pain alleviation. Fifteen subjects (5 females, 10 males) volunteered to participate in this study. In an oddball paradigm, three categories of 20 pictures (unpleasant, neutral, and pleasant) served as rare target pictures from the International Affective Picture System (IAPS). The power of the delta (1-4 Hz), theta (4-8 Hz), alpha (8-12 Hz), beta (12-25 Hz), and gamma (30-40 Hz) frequency bands in the three categories were measured using electroencephalography during an oddball paradigm at pre- and post-anodal or sham tDCS above the left dorsolateral prefrontal cortex (DLPFC). Results showed that the beta band power was significantly increased, and the alpha band power was significantly decreased during unpleasant pictures after anodal tDCS compared with sham tDCS. Furthermore, regarding unpleasant pictures, subjective reports of Self Assessment Manikin (SAM) for emotional valence after anodal tDCS showed a significant decrease of unpleasantness. Therefore, emotional aspects of pain may be effectively alleviated by tDCS of the left DLPFC as was shown not only by subjective evaluation, but also by objective observation of cerebral neural activity. This processing may be mediated by facilitation of the descending pain inhibitory system through enhancing neural activity of the left DLPFC. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

The Motor and the Brake of the Trailing Leg in Human Walking: Leg Force Control Through Ankle Modulation and Knee Covariance

PubMed Central

Toney, Megan E.; Chang, Young-Hui

2016-01-01

Human walking is a complex task, and we lack a complete understanding of how the neuromuscular system organizes its numerous muscles and joints to achieve consistent and efficient walking mechanics. Focused control of select influential task-level variables may simplify the higher-level control of steady state walking and reduce demand on the neuromuscular system. As trailing leg power generation and force application can affect the mechanical efficiency of step-to-step transitions, we investigated how joint torques are organized to control leg force and leg power during human walking. We tested whether timing of trailing leg force control corresponded with timing of peak leg power generation. We also applied a modified uncontrolled manifold analysis to test whether individual or coordinated joint torque strategies most contributed to leg force control. We found that leg force magnitude was adjusted from step-to-step to maintain consistent leg power generation. Leg force modulation was primarily determined by adjustments in the timing of peak ankle plantar-flexion torque, while knee torque was simultaneously covaried to dampen the effect of ankle torque on leg force. We propose a coordinated joint torque control strategy in which the trailing leg ankle acts as a motor to drive leg power production while trailing leg knee torque acts as a brake to refine leg power production. PMID:27334888

75 FR 33853 - Maine Yankee Atomic Power Company; Independent Spent Fuel Storage Installation; Issuance of...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-15

...) Surveillance Requirement 3.1.6.1 to verify the operability of the concrete cask heat removal system to maintain... Amendment No. 5 for one storage canister at the MY ISFSI. The affected storage canister had a heat load of 9..., and the LCO 3.1.4 time limit for a canister [[Page 33855

Cannabis Essential Oil: A Preliminary Study for the Evaluation of the Brain Effects

PubMed Central

Loiacono, Idalba; Lanzo, Giovanni; Gori, Luigi; Macchi, Claudio; Epifani, Francesco

2018-01-01

We examined the effects of essential oil from legal (THC <0.2% w/v) hemp variety on the nervous system in 5 healthy volunteers. GC/EIMS and GC/FID analysis of the EO showed that the main components were myrcene and β-caryophyllene. The experiment consisted of measuring autonomic nervous system (ANS) parameters; evaluations of the mood state; and electroencephalography (EEG) recording before treatment, during treatment, and after hemp inhalation periods as compared with control conditions. The results revealed decreased diastolic blood pressure, increased heart rate, and significant increased skin temperature. The subjects described themselves as more energetic, relaxed, and calm. The analysis EEG showed a significant increase in the mean frequency of alpha (8–13 Hz) and significant decreased mean frequency and relative power of beta 2 (18,5–30 Hz) waves. Moreover, an increased power, relative power, and amplitude of theta (4–8 Hz) and alpha brain waves activities and an increment in the delta wave (0,5–4 Hz) power and relative power was recorded in the posterior region of the brain. These results suggest that the brain wave activity and ANS are affected by the inhalation of the EO of Cannabis sativa suggesting a neuromodular activity in cases of stress, depression, and anxiety. PMID:29576792

Cannabis Essential Oil: A Preliminary Study for the Evaluation of the Brain Effects.

PubMed

Gulluni, Nadia; Re, Tania; Loiacono, Idalba; Lanzo, Giovanni; Gori, Luigi; Macchi, Claudio; Epifani, Francesco; Bragazzi, Nicola; Firenzuoli, Fabio

2018-01-01

We examined the effects of essential oil from legal (THC <0.2% w/v) hemp variety on the nervous system in 5 healthy volunteers. GC/EIMS and GC/FID analysis of the EO showed that the main components were myrcene and β -caryophyllene. The experiment consisted of measuring autonomic nervous system (ANS) parameters; evaluations of the mood state; and electroencephalography (EEG) recording before treatment, during treatment, and after hemp inhalation periods as compared with control conditions. The results revealed decreased diastolic blood pressure, increased heart rate, and significant increased skin temperature. The subjects described themselves as more energetic, relaxed, and calm. The analysis EEG showed a significant increase in the mean frequency of alpha (8-13 Hz) and significant decreased mean frequency and relative power of beta 2 (18,5-30 Hz) waves. Moreover, an increased power, relative power, and amplitude of theta (4-8 Hz) and alpha brain waves activities and an increment in the delta wave (0,5-4 Hz) power and relative power was recorded in the posterior region of the brain. These results suggest that the brain wave activity and ANS are affected by the inhalation of the EO of Cannabis sativa suggesting a neuromodular activity in cases of stress, depression, and anxiety.

Impact of climate change on future concentrated solar power (CSP) production

NASA Astrophysics Data System (ADS)

Wild, Martin; Folini, Doris; Henschel, Florian

2017-02-01

Traditionally, for the planning and assessment of solar power plants, the amount of solar radiation incident on the Earth's surface is assumed to be invariable over the years. However, with changing climate and air pollution levels, solar resources may no longer be stable over time and undergo substantial decadal changes. Observational records covering several decades indeed confirm long-term changes in this quantity. In a previous study (Wild et al. 2015, Solar Energy)1 we examined how the latest generation of climate models (CMIP5) projects potential changes in surface solar radiation over the coming decades, and how this may affect, in combination with the expected greenhouse warming, future power output from photovoltaic (PV) systems. In the present complementary study, we use the CMIP5 model projections to estimate possible future changes in power output from Concentrated Solar Power (CSP) systems due to changing climate and air pollution levels up to the mid-21th century. The results indicate a potential for future increases in CSP production in many parts of the globe, with few exceptions such as the North of India and the irrelevant polar areas. Compared to the changes in PV production, the estimated future production changes by CSP are larger by a factor of 4.

[Governance in Guatemalan municipal development councils: an analysis of actors and power relationships].

PubMed

Flores, Walter; Gómez-Sánchez, Ismael

2010-01-01

Decentralisation and other public policies have created public spaces for participation in most Latin-American countries where community representatives, together with municipal authorities and other public functionaries, decide on social investment plans, including health services and infrastructure. The municipal development council system constitutes such public space in Guatemala. This study analysed such system's governance in a sample of 6 rural municipalities. A descriptive design was used, applying qualitative and quantitative techniques to study three central categories: the strategic actors, the rules of the game and power asymmetry levels amongst actors. The findings revealed inconsistencies amongst the actors who had to participate according to the legal framework and those actors who actually did so in practice. Divergent interests were also identified for participating which affected the possibility of reaching consensus during decision-making. Analysing the rules of the game led to identifying formal and non-formal mechanisms favouring some actors' ability to influence decisions. Analysing power asymmetry levels led to identifying that community representatives had fewer power resources than institutional representatives (local government and other government organisations). Community representatives also face different barriers blocking their participation and perceive a lesser capacity to influence decision-making. Existing barriers and fewer power resources experienced by community representatives reduce their abilities to influence decision-making in municipal development councils.

Impact of Uncertainty from Load-Based Reserves and Renewables on Dispatch Costs and Emissions

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

Li, Bowen; Maroukis, Spencer D.; Lin, Yashen

2016-11-21

Aggregations of controllable loads are considered to be a fast-responding, cost-efficient, and environmental-friendly candidate for power system ancillary services. Unlike conventional service providers, the potential capacity from the aggregation is highly affected by factors like ambient conditions and load usage patterns. Previous work modeled aggregations of controllable loads (such as air conditioners) as thermal batteries, which are capable of providing reserves but with uncertain capacity. A stochastic optimal power flow problem was formulated to manage this uncertainty, as well as uncertainty in renewable generation. In this paper, we explore how the types and levels of uncertainty, generation reserve costs, andmore » controllable load capacity affect the dispatch solution, operational costs, and CO2 emissions. We also compare the results of two methods for solving the stochastic optimization problem, namely the probabilistically robust method and analytical reformulation assuming Gaussian distributions. Case studies are conducted on a modified IEEE 9-bus system with renewables, controllable loads, and congestion. We find that different types and levels of uncertainty have significant impacts on dispatch and emissions. More controllable loads and less conservative solution methodologies lead to lower costs and emissions.« less

Irradiation planning for automated treatment of psoriasis with a high-power excimer laser

NASA Astrophysics Data System (ADS)

Klämpfl, Florian; Schmidt, Michael; Hagenah, Hinnerk; Görtler, Andreas; Wolfsgruber, Frank; Lampalzer, Ralf; Kaudewitz, Peter

2006-02-01

American and European statistics have shown that 1-2 per cent of the human population is affected by the skin disease psoriasis. Recent research reports promising treatment results when irradiating skin areas affected by psoriasis with high powered excimer lasers with a wavelength of 308 nm. In order to apply the necessary high energy dose without hurting healthy parts of the skin new approaches regarding the system technology must be considered. The aim of the current research project is the development of a sensor-based, automated laser treatment system for psoriasis. In this paper we present the algorithms used to cope with the diffculties of irradiating irregularly shaped areas on curved surfaces with a predefined energy level using a pulsed laser. Patients prefer the treatment to take as little time as possible. This also helps to reduce costs. Thus the distribution of laser pulses on the surface to achieve the given energy level on every point of the surface has to be calculated within a limited time frame. The remainder of the paper will describe in detail an efficient method to plan and optimize the laser pulse distribution. Towards the end, some first results will be presented.

Performance comparison of Islamic and commercial banks in Malaysia

NASA Astrophysics Data System (ADS)

Azizud-din, Azimah; Hussin, Siti Aida Sheikh; Zahid, Zalina

2016-10-01

The steady growth in the size and increase in the number of Islamic banks show that the Islamic banking system is considered as an alternative to the conventional banking system. Due to this, comparisons in term of performance measurements and evaluation of the financial health for both type of banks are essential. The main purpose of this study is to analyse the differences between Islamic and commercial banks performance. Five years secondary data were collected from the annual report for each bank. Return on Asset ratio is chosen as the dependent variable, while capital adequacy, asset quality, management quality, earning, liquidity and sensitivity to market risk (CAMELS) are the independent variables. Descriptive analyses were done to understand the data. The independent t-test and Mann Whitney test show the differences of Islamic and commercial banks based on the financial variables. The stepwise and hierarchical multiple regressions were used to determine the factor that affects profitability performance of banks. Results show that Islamic banks are better in term of profitability performance, earning power performance, liquidity performance and sensitive to market risk. The factors that affect profitability performance are capital adequacy, earning power and liquidity variable.

The impact of climate change on photovoltaic power generation in Europe

PubMed Central

Jerez, Sonia; Tobin, Isabelle; Vautard, Robert; Montávez, Juan Pedro; López-Romero, Jose María; Thais, Françoise; Bartok, Blanka; Christensen, Ole Bøssing; Colette, Augustin; Déqué, Michel; Nikulin, Grigory; Kotlarski, Sven; van Meijgaard, Erik; Teichmann, Claas; Wild, Martin

2015-01-01

Ambitious climate change mitigation plans call for a significant increase in the use of renewables, which could, however, make the supply system more vulnerable to climate variability and changes. Here we evaluate climate change impacts on solar photovoltaic (PV) power in Europe using the recent EURO-CORDEX ensemble of high-resolution climate projections together with a PV power production model and assuming a well-developed European PV power fleet. Results indicate that the alteration of solar PV supply by the end of this century compared with the estimations made under current climate conditions should be in the range (−14%;+2%), with the largest decreases in Northern countries. Temporal stability of power generation does not appear as strongly affected in future climate scenarios either, even showing a slight positive trend in Southern countries. Therefore, despite small decreases in production expected in some parts of Europe, climate change is unlikely to threaten the European PV sector. PMID:26658608

Electricity generation in a membrane-less microbial fuel cell with down-flow feeding onto the cathode.

PubMed

Zhu, Feng; Wang, Wancheng; Zhang, Xiaoyan; Tao, Guanhong

2011-08-01

A novel membrane-less microbial fuel cell (MFC) with down-flow feeding was constructed to generate electricity. Wastewater was fed directly onto the cathode which was horizontally installed in the upper part of the MFC. Oxygen could be utilized readily from the air. The concentration of dissolved oxygen in the influent wastewater had little effect on the power generation. A saturation-type relationship was observed between the initial COD and the power generation. The influent flow rate could affect greatly the power density. Fed by the synthetic glucose wastewater with a COD value of 3500 mg/L at a flow rate of 4.0 mL/min, the developed MFC could produce a maximum power density of 37.4 mW/m(2). Its applicability was further evaluated by the treatment of brewery wastewater. The system could be scaled up readily due to its simple configuration, easy operation and relatively high power density. Copyright © 2011 Elsevier Ltd. All rights reserved.

Reactive power optimization strategy considering analytical impedance ratio

NASA Astrophysics Data System (ADS)

Wu, Zhongchao; Shen, Weibing; Liu, Jinming; Guo, Maoran; Zhang, Shoulin; Xu, Keqiang; Wang, Wanjun; Sui, Jinlong

2017-05-01

In this paper, considering the traditional reactive power optimization cannot realize the continuous voltage adjustment and voltage stability, a dynamic reactive power optimization strategy is proposed in order to achieve both the minimization of network loss and high voltage stability with wind power. Due to the fact that wind power generation is fluctuant and uncertain, electrical equipments such as transformers and shunt capacitors may be operated frequently in order to achieve minimization of network loss, which affect the lives of these devices. In order to solve this problem, this paper introduces the derivation process of analytical impedance ratio based on Thevenin equivalent. Thus, the multiple objective function is proposed to minimize the network loss and analytical impedance ratio. Finally, taking the improved IEEE 33-bus distribution system as example, the result shows that the movement of voltage control equipment has been reduced and network loss increment is controlled at the same time, which proves the applicable value of this strategy.

Does Powerful Language Training Affect Student Participation, Impression Formation, and Gender Communication in Online Discussions?

ERIC Educational Resources Information Center

Thomas, Crystal Ann

2012-01-01

The purpose of this dissertation was to investigate whether powerful language training affected student participation, impression formation, and gender communication style in online discussions. Powerful language was defined as a lack of the use of powerless language. Participants in this study were 507 freshmen taking a first-year college…

Economic Dispatch for Microgrid Containing Electric Vehicles via Probabilistic Modeling: Preprint

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

Yao, Yin; Gao, Wenzhong; Momoh, James

In this paper, an economic dispatch model with probabilistic modeling is developed for a microgrid. The electric power supply in a microgrid consists of conventional power plants and renewable energy power plants, such as wind and solar power plants. Because of the fluctuation in the output of solar and wind power plants, an empirical probabilistic model is developed to predict their hourly output. According to different characteristics of wind and solar power plants, the parameters for probabilistic distribution are further adjusted individually for both. On the other hand, with the growing trend in plug-in electric vehicles (PHEVs), an integrated microgridmore » system must also consider the impact of PHEVs. The charging loads from PHEVs as well as the discharging output via the vehicle-to-grid (V2G) method can greatly affect the economic dispatch for all of the micro energy sources in a microgrid. This paper presents an optimization method for economic dispatch in a microgrid considering conventional power plants, renewable power plants, and PHEVs. The simulation results reveal that PHEVs with V2G capability can be an indispensable supplement in a modern microgrid.« less

Power in everyday life

PubMed Central

Hofmann, Wilhelm

2016-01-01

How does power manifest itself in everyday life? Using experience-sampling methodology, we investigated the prevalence, sources, and correlates of power in people’s natural environments. Participants experienced power-relevant situations regularly, though not frequently. High power was not restricted to a limited few: almost half of the sample reported experiencing high-power positions. Positional power and subjective feelings of power were strongly related but had unique relations with several individual difference measures and independent effects on participants’ affect, cognition, and interpersonal relations. Subjective feelings of power resulted more from within-participant situational fluctuation, such as the social roles participants held at different times, than from stable differences between people. Our data supported some theoretical predictions about power’s effects on affect, cognition, and interpersonal relations, but qualified others, particularly highlighting the role of responsibility in power’s effects. Although the power literature has focused on high power, we found stronger effects of low power than high power. PMID:27551069

Scheduling for energy and reliability management on multiprocessor real-time systems

NASA Astrophysics Data System (ADS)

Qi, Xuan

Scheduling algorithms for multiprocessor real-time systems have been studied for years with many well-recognized algorithms proposed. However, it is still an evolving research area and many problems remain open due to their intrinsic complexities. With the emergence of multicore processors, it is necessary to re-investigate the scheduling problems and design/develop efficient algorithms for better system utilization, low scheduling overhead, high energy efficiency, and better system reliability. Focusing cluster schedulings with optimal global schedulers, we study the utilization bound and scheduling overhead for a class of cluster-optimal schedulers. Then, taking energy/power consumption into consideration, we developed energy-efficient scheduling algorithms for real-time systems, especially for the proliferating embedded systems with limited energy budget. As the commonly deployed energy-saving technique (e.g. dynamic voltage frequency scaling (DVFS)) will significantly affect system reliability, we study schedulers that have intelligent mechanisms to recuperate system reliability to satisfy the quality assurance requirements. Extensive simulation is conducted to evaluate the performance of the proposed algorithms on reduction of scheduling overhead, energy saving, and reliability improvement. The simulation results show that the proposed reliability-aware power management schemes could preserve the system reliability while still achieving substantial energy saving.

A Simulation Environment for the Dynamic Evaluation of Disaster Preparedness Policies and Interventions

PubMed Central

Lewis, Bryan; Swarup, Samarth; Bisset, Keith; Eubank, Stephen; Marathe, Madhav; Barrett, Chris

2013-01-01

Disasters affect a society at many levels. Simulation based studies often evaluate the effectiveness of one or two response policies in isolation and are unable to represent impact of the policies to coevolve with others. Similarly, most in-depth analyses are based on a static assessment of the “aftermath” rather than capturing dynamics. We have developed a data-centric simulation environment for applying a systems approach to a dynamic analysis of complex combinations of disaster responses. We analyze an improvised nuclear detonation in Washington DC with this environment. The simulated blast affects the transportation system, communications infrastructure, electrical power system, behaviors and motivations of population, and health status of survivors. The effectiveness of partially restoring wireless communications capacity is analyzed in concert with a range of other disaster response policies. Despite providing a limited increase in cell phone communication, overall health was improved. PMID:23903394

Modeling the Impacts of Solar Distributed Generation on U.S. Water Resources

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

Amanda, Smith; Omitaomu, Olufemi A; Jaron, Peck

2015-01-01

Distributed electric power generation technologies typically use little or no water per unit of electrical energy produced; in particular, renewable energy sources such as solar PV systems do not require cooling systems and present an opportunity to reduce water usage for power generation. Within the US, the fuel mix used for power generation varies regionally, and certain areas use more water for power generation than others. The need to reduce water usage for power generation is even more urgent in view of climate change uncertainties. In this paper, we present an example case within the state of Tennessee, one ofmore » the top four states in water consumption for power generation and one of the states with little or no potential for developing centralized renewable energy generations. The potential for developing PV generation within Knox County, Tennessee, is studied, along with the potential for reducing water withdrawal and consumption within the Tennessee Valley stream region. Electric power generation plants in the region are quantified for their electricity production and expected water withdrawal and consumption over one year, where electrical generation data is provided over one year and water usage is modeled based on the cooling system(s) in use. Potential solar PV electrical production is modeled based on LiDAR data and weather data for the same year. Our proposed methodology can be summarized as follows: First, the potential solar generation is compared against the local grid demand. Next, electrical generation reductions are specified that would result in a given reduction in water withdrawal and a given reduction in water consumption, and compared with the current water withdrawal and consumption rates for the existing fuel mix. The increase in solar PV development that would produce an equivalent amount of power, is determined. In this way, we consider how targeted local actions may affect the larger stream region through thoughtful energy development. This model can be applied to other regions, other types of distributed generation, and used as a framework for modeling alternative growth scenarios in power production capacity in addition to modeling adjustments to existing capacity.« less

Reactive power management and voltage control in deregulated power markets

NASA Astrophysics Data System (ADS)

Spangler, Robert G.

The research that is the subject of this dissertation is about the management of reactive power and voltage support in the wholesale open access power markets in the United States (US). The purpose of this research is to place decisions about open access market structures, as they relate to reactive power and voltage control, on a logical and consistent economic basis, given the engineering needs of a commercial electric power system. An examination of the electricity markets operating in the US today reveals that current approaches to reactive power management and voltage support are extensions of those based on historical, regulated monopoly electric service. A case for change is built by first looking at the subject of reactive power from an engineering viewpoint and then from an economic perspective. Ultimately, a set of market rules for managing reactive power and voltage support is proposed. The proposal suggests that cost recovery for static and dynamic VARs is appropriately accomplished through the regulated transmission cost of service. Static VAR cost recovery should follow traditional rate recovery methodologies. In the case of dynamic VARs, this work provides a methodology based on the microeconomic theory of the firm for determining such cost. It further suggests that an operational strategy that reduces and limits the use of dynamic VARs, during normal operations, is appropriate. This latter point leads to an increase in the fixed cost of the transmission network but prevents price spikes and short supply situations from affecting, or being affected by, the reactive capability limitations associated with dynamic VARs supplied from synchronous generators. The rules are consistent with a market structure that includes competitive generation and their application will result in the communication of a clear understanding of the responsibilities, related to voltage control, of each type of market entity. In this sense, their application will contribute to the efficient functioning of the wholesale open access markets.

A techno-economic comparison of fuel processors utilizing diesel for solid oxide fuel cell auxiliary power units

NASA Astrophysics Data System (ADS)

Nehter, Pedro; Hansen, John Bøgild; Larsen, Peter Koch

Ultra-low sulphur diesel (ULSD) is the preferred fuel for mobile auxiliary power units (APU). The commercial available technologies in the kW-range are combustion engine based gensets, achieving system efficiencies about 20%. Solid oxide fuel cells (SOFC) promise improvements with respect to efficiency and emission, particularly for the low power range. Fuel processing methods i.e., catalytic partial oxidation, autothermal reforming and steam reforming have been demonstrated to operate on diesel with various sulphur contents. The choice of fuel processing method strongly affects the SOFC's system efficiency and power density. This paper investigates the impact of fuel processing methods on the economical potential in SOFC APUs, taking variable and capital cost into account. Autonomous concepts without any external water supply are compared with anode recycle configurations. The cost of electricity is very sensitive on the choice of the O/C ratio and the temperature conditions of the fuel processor. A sensitivity analysis is applied to identify the most cost effective concept for different economic boundary conditions. The favourite concepts are discussed with respect to technical challenges and requirements operating in the presence of sulphur.

System for detecting and limiting electrical ground faults within electrical devices

DOEpatents

Gaubatz, Donald C.

1990-01-01

An electrical ground fault detection and limitation system for employment with a nuclear reactor utilizing a liquid metal coolant. Elongate electromagnetic pumps submerged within the liquid metal coolant and electrical support equipment experiencing an insulation breakdown occasion the development of electrical ground fault current. Without some form of detection and control, these currents may build to damaging power levels to expose the pump drive components to liquid metal coolant such as sodium with resultant undesirable secondary effects. Such electrical ground fault currents are detected and controlled through the employment of an isolated power input to the pumps and with the use of a ground fault control conductor providing a direct return path from the affected components to the power source. By incorporating a resistance arrangement with the ground fault control conductor, the amount of fault current permitted to flow may be regulated to the extent that the reactor may remain in operation until maintenance may be performed, notwithstanding the existence of the fault. Monitors such as synchronous demodulators may be employed to identify and evaluate fault currents for each phase of a polyphase power, and control input to the submerged pump and associated support equipment.

On phaser-based processing of impulse radio UWB over fiber systems employing SOA

NASA Astrophysics Data System (ADS)

Taki, H.; Azou, S.; Hamie, A.; Al Housseini, A.; Alaeddine, A.; Sharaiha, A.

2017-07-01

In this study, we adopt a phaser-based processing to enhance the performance of impulse radio over fiber system utilizing SOA. The amplifier has been placed at a distance in the optical link, so as to extend the coverage area of proposed transceiver. Operating in the linear or saturation region for SOA, adds ASE noise or strong nonlinearities acting on the propagated pulses, respectively. Both lead to a degradation in the power efficiency and bit error rate performance. By applying up and down analog chirping technique, we have reduced the ASE power and nonlinearity simultaneously. Based on the 5th Gaussian pulse and Abraha's combination of doublets, a significant improvement has been achieved at extremely low and high input powers entering the amplifier (<-15 dBm and 0 dBm), recording a very good bit error rate performance and power efficiency. Better signal quality was observed after photo-detector, due to the fact that waveforms with lower frequency components are less affected by SOA nonlinearity. Our scheme has proved to be effective for 1 Gbps OOK and 0.5 Gbps PPM transmissions, while reaching a distance of 160 km in the optical fiber.

Industrial applications of high-average power high-peak power nanosecond pulse duration Nd:YAG lasers

NASA Astrophysics Data System (ADS)

Harrison, Paul M.; Ellwi, Samir

2009-02-01

Within the vast range of laser materials processing applications, every type of successful commercial laser has been driven by a major industrial process. For high average power, high peak power, nanosecond pulse duration Nd:YAG DPSS lasers, the enabling process is high speed surface engineering. This includes applications such as thin film patterning and selective coating removal in markets such as the flat panel displays (FPD), solar and automotive industries. Applications such as these tend to require working spots that have uniform intensity distribution using specific shapes and dimensions, so a range of innovative beam delivery systems have been developed that convert the gaussian beam shape produced by the laser into a range of rectangular and/or shaped spots, as required by demands of each project. In this paper the authors will discuss the key parameters of this type of laser and examine why they are important for high speed surface engineering projects, and how they affect the underlying laser-material interaction and the removal mechanism. Several case studies will be considered in the FPD and solar markets, exploring the close link between the application, the key laser characteristics and the beam delivery system that link these together.

Decentralized control of units in smart grids for the support of renewable energy supply

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

Sonnenschein, Michael, E-mail: Michael.Sonnenschein@Uni-Oldenburg.DE; Lünsdorf, Ontje, E-mail: Ontje.Luensdorf@OFFIS.DE; Bremer, Jörg, E-mail: Joerg.Bremer@Uni-Oldenburg.DE

Due to the significant environmental impact of power production from fossil fuels and nuclear fission, future energy systems will increasingly rely on distributed and renewable energy sources (RES). The electrical feed-in from photovoltaic (PV) systems and wind energy converters (WEC) varies greatly both over short and long time periods (from minutes to seasons), and (not only) by this effect the supply of electrical power from RES and the demand for electrical power are not per se matching. In addition, with a growing share of generation capacity especially in distribution grids, the top-down paradigm of electricity distribution is gradually replaced bymore » a bottom-up power supply. This altogether leads to new problems regarding the safe and reliable operation of power grids. In order to address these challenges, the notion of Smart Grids has been introduced. The inherent flexibilities, i.e. the set of feasible power schedules, of distributed power units have to be controlled in order to support demand–supply matching as well as stable grid operation. Controllable power units are e.g. combined heat and power plants, power storage systems such as batteries, and flexible power consumers such as heat pumps. By controlling the flexibilities of these units we are particularly able to optimize the local utilization of RES feed-in in a given power grid by integrating both supply and demand management measures with special respect to the electrical infrastructure. In this context, decentralized systems, autonomous agents and the concept of self-organizing systems will become key elements of the ICT based control of power units. In this contribution, we first show how a decentralized load management system for battery charging/discharging of electrical vehicles (EVs) can increase the locally used share of supply from PV systems in a low voltage grid. For a reliable demand side management of large sets of appliances, dynamic clustering of these appliances into uniformly controlled appliance sets is necessary. We introduce a method for self-organized clustering for this purpose and show how control of such clusters can affect load peaks in distribution grids. Subsequently, we give a short overview on how we are going to expand the idea of self-organized clusters of units into creating a virtual control center for dynamic virtual power plants (DVPP) offering products at a power market. For an efficient organization of DVPPs, the flexibilities of units have to be represented in a compact and easy to use manner. We give an introduction how the problem of representing a set of possibly 10{sup 100} feasible schedules can be solved by a machine-learning approach. In summary, this article provides an overall impression how we use agent based control techniques and methods of self-organization to support the further integration of distributed and renewable energy sources into power grids and energy markets. - Highlights: • Distributed load management for electrical vehicles supports local supply from PV. • Appliances can self-organize into so called virtual appliances for load control. • Dynamic VPPs can be controlled by extensively decentralized control centers. • Flexibilities of units can efficiently be represented by support-vector descriptions.« less

A Fundamental Study on Spectrum Center Estimation of Solar Spectral Irradiation by the Statistical Pattern Recognition

NASA Astrophysics Data System (ADS)

Iijima, Aya; Suzuki, Kazumi; Wakao, Shinji; Kawasaki, Norihiro; Usami, Akira

With a background of environmental problems and energy issues, it is expected that PV systems will be introduced rapidly and connected with power grids on a large scale in the future. For this reason, the concern to which PV power generation will affect supply and demand adjustment in electric power in the future arises and the technique of correctly grasping the PV power generation becomes increasingly important. The PV power generation depends on solar irradiance, temperature of a module and solar spectral irradiance. Solar spectral irradiance is distribution of the strength of the light for every wavelength. As the spectrum sensitivity of solar cell depends on kind of solar cell, it becomes important for exact grasp of PV power generation. Especially the preparation of solar spectral irradiance is, however, not easy because the observational instrument of solar spectral irradiance is expensive. With this background, in this paper, we propose a new method based on statistical pattern recognition for estimating the spectrum center which is representative index of solar spectral irradiance. Some numerical examples obtained by the proposed method are also presented.

Effects of massive wind power integration on short-term water resource management in central Chile - a grid-wide study

NASA Astrophysics Data System (ADS)

Haas, J.; Olivares, M. A.; Palma, R.

2013-12-01

In central Chile, water from reservoirs and streams is mainly used for irrigation and power generation. Hydropower reservoirs operation is particularly challenging because: i) decisions at each plant impact the entire power system, and ii) the existence of large storage capacity implies inter-temporal ties. An Independent System Operator (ISO) decides the grid-wide optimal allocation of water for power generation, under irrigation-related constraints. To account for the long-term opportunity cost of water, a future cost function is determined and used in the short term planning. As population growth and green policies demand increasing levels of renewable energy in power systems, deployment of wind farms and solar plants is rising quickly. However, their power output is highly fluctuating on short time scales, affecting the operation of power plants, particularly those fast responding units as hydropower reservoirs. This study addresses these indirect consequences of massive introduction of green energy sources on reservoir operations. Short-term reservoir operation, under different wind penetration scenarios, is simulated using a replica of Chile's ISO's scheduling optimization tools. Furthermore, an ongoing study is exploring the potential to augment the capacity the existing hydro-power plants to better cope with the balancing needs due to a higher wind power share in the system. As reservoir releases determine to a great extent flows at downstream locations, hourly time series of turbined flows for 24-hour periods were computed for selected combinations between new wind farms and increased capacity of existing hydropower plants. These time series are compiled into subdaily hydrologic alteration (SDHA) indexes (Zimmerman et al, 2010). The resulting sample of indexes is then analyzed using duration curves. Results show a clear increase in the SDHA for every reservoir of the system as more fluctuating renewables are integrated into the system. High-fluctuation events become more frequent. While the main load-following reservoirs are very susceptible to even small levels of additional wind power, the remaining withstand greater amounts before producing a significant SDHA. The additional effect of augmented installed capacity of existing hydropower plants on the SDHA is modest. The increase in SDHA calls for alternative operational constraints beyond the current practice based exclusively on minimum instream flows. Previous research by this group has shown the potential of maximum ramping rates constraints to efficiently achieve improvement in the SDHA. This alternative is being studied as part of a project currently in progress. This may contribute to make hydropower projects more socially acceptable and environmentally sound.

Influence of power density on polymerization behavior and bond strengths of dual-cured resin direct core foundation systems.

PubMed

Oto, Tatsuki; Yasuda, Genta; Tsubota, Keishi; Kurokawa, Hiroyasu; Miyazaki, Masashi; Platt, Jeffrey A

2009-01-01

This study examined the influence of power density on dentin bond strength and polymerization behavior of dual-cured direct core foundation resin systems. Two commercially available dual-cured direct core foundation resin systems, Clearfil DC Core Automix with Clearfil DC Bond and UniFil Core with Self-Etching Bond, were studied. Bovine mandibular incisors were mounted in autopolymerizing resin and the facial dentin surfaces were ground wet on 600-grit SiC paper. Dentin surfaces were treated according to manufacturer's recommendations. The resin pastes were condensed into the mold and cured with the power densities of 0 (no irradiation), 100, 200, 400 and 600 mW/cm2. Ten specimens per group were stored in 37 degrees C water for 24 hours, then shear tested at a crosshead speed of 1.0 mm/minute in a universal testing machine. An ultrasonic measurement device was used to measure the ultrasonic velocities through the core foundation resins. The power densities selected were 0 (no irradiation), 200, and 600 mW/cm2, and ultrasonic velocity was calculated. ANOVA and Tukey HSD tests were performed at a level of 0.05. The highest bond strengths were obtained when the resin pastes were cured with the highest power density for both core foundation systems (16.8 +/- 1.9 MPa for Clearfil DC Core Automix, 15.6 +/- 2.9 MPa for UniFil Core). When polymerized with the power densities under 200 mW/cm2, significantly lower bond strengths were observed compared to those obtained with the power density of 600 mW/cm2. As the core foundation resins hardened, the sonic velocities increased and this tendency differed among the power density of the curing unit. When the sonic velocities at three minutes after the start of measurements were compared, there were no significant differences among different irradiation modes for UniFil Core, while a significant decrease in sonic velocity was obtained when the resin paste was chemically polymerized compared with dual-polymerization for Clearfil DC Core Automix. The data suggests that the dentin bond strengths and polymerization behavior of the dual-cured, direct core foundation systems are still affected by the power density of the curing unit. With a careful choice of the core foundation systems and power density of the curing unit, the benefit of using resin composites to endodontically-treated teeth might be acceptable.

Reconceptualizing resistance: sociology and the affective dimension of resistance.

PubMed

Hynes, Maria

2013-12-01

This paper re-examines the sociological study of resistance in light of growing interest in the concept of affect. Recent claims that we are witness to an 'affective turn' and calls for a 'new sociological empiricism' sensitive to affect indicate an emerging paradigm shift in sociology. Yet, mainstream sociological study of resistance tends to have been largely unaffected by this shift. To this end, this paper presents a case for the significance of affect as a lens by which to approach the study of resistance. My claim is not simply that the forms of actions we would normally recognize as resistance have an affective dimension. Rather, it is that the theory of affect broadens 'resistance' beyond the purview of the two dominant modes of analysis in sociology; namely, the study of macropolitical forms, on the one hand, and the micropolitics of everyday resistance on the other. This broadened perspective challenges the persistent assumption that ideological forms of power and resistance are the most pertinent to the contemporary world, suggesting that much power and resistance today is of a more affective nature. In making this argument, it is a Deleuzian reading of affect that is pursued, which opens up to a level of analysis beyond the common understanding of affect as emotion. I argue that an affective approach to resistance would pay attention to those barely perceptible transitions in power and mobilizations of bodily potential that operate below the conscious perceptions and subjective emotions of social actors. These affective transitions constitute a new site at which both power and resistance operate. © London School of Economics and Political Science 2013.

Adequacy assessment of composite generation and transmission systems incorporating wind energy conversion systems

NASA Astrophysics Data System (ADS)

Gao, Yi

The development and utilization of wind energy for satisfying electrical demand has received considerable attention in recent years due to its tremendous environmental, social and economic benefits, together with public support and government incentives. Electric power generation from wind energy behaves quite differently from that of conventional sources. The fundamentally different operating characteristics of wind energy facilities therefore affect power system reliability in a different manner than those of conventional systems. The reliability impact of such a highly variable energy source is an important aspect that must be assessed when the wind power penetration is significant. The focus of the research described in this thesis is on the utilization of state sampling Monte Carlo simulation in wind integrated bulk electric system reliability analysis and the application of these concepts in system planning and decision making. Load forecast uncertainty is an important factor in long range planning and system development. This thesis describes two approximate approaches developed to reduce the number of steps in a load duration curve which includes load forecast uncertainty, and to provide reasonably accurate generating and bulk system reliability index predictions. The developed approaches are illustrated by application to two composite test systems. A method of generating correlated random numbers with uniform distributions and a specified correlation coefficient in the state sampling method is proposed and used to conduct adequacy assessment in generating systems and in bulk electric systems containing correlated wind farms in this thesis. The studies described show that it is possible to use the state sampling Monte Carlo simulation technique to quantitatively assess the reliability implications associated with adding wind power to a composite generation and transmission system including the effects of multiple correlated wind sites. This is an important development as it permits correlated wind farms to be incorporated in large practical system studies without requiring excessive increases in computer solution time. The procedures described in this thesis for creating monthly and seasonal wind farm models should prove useful in situations where time period models are required to incorporate scheduled maintenance of generation and transmission facilities. There is growing interest in combining deterministic considerations with probabilistic assessment in order to evaluate the quantitative system risk and conduct bulk power system planning. A relatively new approach that incorporates deterministic and probabilistic considerations in a single risk assessment framework has been designated as the joint deterministic-probabilistic approach. The research work described in this thesis illustrates that the joint deterministic-probabilistic approach can be effectively used to integrate wind power in bulk electric system planning. The studies described in this thesis show that the application of the joint deterministic-probabilistic method provides more stringent results for a system with wind power than the traditional deterministic N-1 method because the joint deterministic-probabilistic technique is driven by the deterministic N-1 criterion with an added probabilistic perspective which recognizes the power output characteristics of a wind turbine generator.

Design and Analysis Techniques for Concurrent Blackboard Systems. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Mcmanus, John William

1992-01-01

Blackboard systems are a natural progression of knowledge-based systems into a more powerful problem solving technique. They provide a way for several highly specialized knowledge sources to cooperate to solve large, complex problems. Blackboard systems incorporate the concepts developed by rule-based and expert systems programmers and include the ability to add conventionally coded knowledge sources. The small and specialized knowledge sources are easier to develop and test, and can be hosted on hardware specifically suited to the task that they are solving. The Formal Model for Blackboard Systems was developed to provide a consistent method for describing a blackboard system. A set of blackboard system design tools has been developed and validated for implementing systems that are expressed using the Formal Model. The tools are used to test and refine a proposed blackboard system design before the design is implemented. My research has shown that the level of independence and specialization of the knowledge sources directly affects the performance of blackboard systems. Using the design, simulation, and analysis tools, I developed a concurrent object-oriented blackboard system that is faster, more efficient, and more powerful than existing systems. The use of the design and analysis tools provided the highly specialized and independent knowledge sources required for my concurrent blackboard system to achieve its design goals.

Aircraft Detection System Ensures Free-Space Laser Safety

NASA Technical Reports Server (NTRS)

Smithgall, Brian; Wilson, Keith E.

2004-01-01

As scientists continue to explore our solar system, there are increasing demands to return greater volumes of data from smaller deep-space probes. Accordingly, NASA is studying advanced strategies based on free-space laser transmissions, which offer secure, high-bandwidth communications using smaller subsystems of much lower power and mass than existing ones. These approaches, however, can pose a danger to pilots in the beam path because the lasers may illuminate aircraft and blind them. Researchers thus are investigating systems that will monitor the surrounding airspace for aircraft that could be affected. This paper presents current methods for safe free space laser propagation.

Evaluation and Application of Overvoltage into Communication Equipment Due to Potential Rise at Earthing Terminal of Distribution Line Induced by Lightning Surge

NASA Astrophysics Data System (ADS)

Ito, Katsuji; Hirose, Yasuo

Overvoltage induced by surge currents due to thunderstorm lightnings causes harmful breakdown troubles of CATV communication equipment installed in and with power distribution systems. In this paper, the origin and natures of surge currents, their invading route into the system, and the system components such as earth impedances affecting over voltages are studied. Transient analyses are then performed using an equivalent circuit to evaluate over voltages. Application of the obtained results to the field fault data of communication equipment and possible protection method of them are discussed.

Parasitic Effects of Grounding Paths on Common-Mode EMI Filter's Performance in Power Electronics Systems

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

Wang, Shuo; Maillet, Yoann; Wang, Fei

2010-01-01

High-frequency common-mode (CM) electromagnetic-interference (EMI) noise is difficult to suppress in electronics systems. EMI filters are used to suppress CM noise, but their performance is greatly affected by the parasitic effects of the grounding paths. In this paper, the parasitic effects of the grounding paths on an EMI filter's performance are investigated in a motor-drive system. The effects of the mutual inductance between two grounding paths are explored. Guidelines for the grounding of CM EMI filters are derived. Simulations and experiments are finally carried out to verify the theoretical analysis.

Photovoltaics as a terrestrial energy source. Volume 1: An introduction

NASA Technical Reports Server (NTRS)

Smith, J. L.

1980-01-01

Photovoltaic (PV) systems were examined their potential for terrestrial application and future development. Photovoltaic technology, existing and potential photovoltaic applications, and the National Photovoltaics Program are reviewed. The competitive environment for this electrical source, affected by the presence or absence of utility supplied power is evaluated in term of systems prices. The roles of technological breakthroughs, directed research and technology development, learning curves, and commercial demonstrations in the National Program are discussed. The potential for photovoltaics to displace oil consumption is examined, as are the potential benefits of employing PV in either central-station or non-utility owned, small, distributed systems.

Implementation study of wearable sensors for activity recognition systems.

PubMed

Rezaie, Hamed; Ghassemian, Mona

2015-08-01

This Letter investigates and reports on a number of activity recognition methods for a wearable sensor system. The authors apply three methods for data transmission, namely 'stream-based', 'feature-based' and 'threshold-based' scenarios to study the accuracy against energy efficiency of transmission and processing power that affects the mote's battery lifetime. They also report on the impact of variation of sampling frequency and data transmission rate on energy consumption of motes for each method. This study leads us to propose a cross-layer optimisation of an activity recognition system for provisioning acceptable levels of accuracy and energy efficiency.

Effects of space weather on high-latitude ground systems

NASA Astrophysics Data System (ADS)

Pirjola, Risto

Geomagnetically induced currents (GIC) in technological systems, such as power grids, pipelines, cables and railways, are a ground manifestation of space weather. The first GIC observations were already made in early telegraph equipment more than 150 years ago. In power networks, GIC may saturate transformers with possible harmful consequences extending even to a collapse of the whole system or to permanent damage of transformers. In pipelines, GIC and the associated pipe-to-soil voltages may enhance corrosion or disturb surveys associated with corrosion control. GIC are driven by the geoelectric field induced by a geomagnetic variation at the Earth’s surface. The electric and magnetic fields are primarily produced by ionospheric currents and secondarily affected by the ground conductivity. Of great importance is the auroral electrojet with other rapidly varying currents indicating that GIC are a particular high-latitude problem. In this paper, we summarize the GIC research done in Finland during about 25 years, and discuss the calculation of GIC in a given network. Special attention is paid to modelling a power system. It is shown that, when considering GIC at a site, it is usually sufficient to take account for a smaller grid in the vicinity of the particular site. Modelling GIC also provides a basis for developing forecasting and warning methods of GIC.

Effects of Rifaximin on Central Responses to Social Stress-a Pilot Experiment.

PubMed

Wang, Huiying; Braun, Christoph; Enck, Paul

2018-04-30

Probiotics that promote the gut microbiota have been reported to reduce stress responses, and improve memory and mood. Whether and how antibiotics that eliminate or inhibit pathogenic and commensal gut bacteria also affect central nervous system functions in humans is so far unknown. In a double-blinded randomized study, 16 healthy volunteers (27.00 ± 1.60 years; 9 males) received either rifaximin (600 mg/day) (a poorly absorbable antibiotic) or placebo for 7 days. Before and after the drug intervention, brain activities during rest and during a social stressor inducing feelings of exclusion (Cyberball game) were measured using magnetoencephalography. Social exclusion significantly affected (p < 0.001) mood and increased exclusion perception. Magnetoencephalography showed brain regions with higher activations during exclusion as compared to inclusion, in different frequency bands. Seven days of rifaximin increased prefrontal and right cingulate alpha power during resting state. Low beta power showed an interaction of intervention (rifaximin, placebo) × condition (inclusion, exclusion) during the Cyberball game in the bilateral prefrontal and left anterior cingulate cortex. Only in the rifaximin group, a decrease (p = 0.004) in power was seen comparing exclusion to inclusion; the reduced beta-1 power was negatively correlated with a change in the subjective exclusion perception score. Social stress affecting brain functioning in a specific manner is modulated by rifaximin. Contrary to our hypothesis that antibiotics have advert effects on mood, the antibiotic exhibited stress-reducing effects similar to reported effects of probiotics (supported by NeuroGUT, a EU 7th Framework Programme ITN no. 607652; ClinicalTrials.gov identifier number NCT02793193).

Understanding Local Policy Elites' Perceptions on the Benefits and Risks Associated with High-Voltage Power Line Installations in the State of Arkansas.

PubMed

Moyer, Rachael M; Song, Geoboo

2016-10-01

Recently, a controversial policy debate has arisen concerning the installation of high-voltage power lines in northwest Arkansas. While proponents argue that such an installation is inevitable to efficiently and reliably support the identified electric load in the region, opponents claim that the lines will degrade the natural environment and hamper the tourism-based local economy in affected regions, notably in Ozark Mountain areas. Of particular interest is to understand how local policy elites perceive the benefits and risks associated with such divisive proposals, which is critical for comprehending the formation and changes of related government policies. Based upon the dual process theory of judgment, this study systematically investigates the triadic relationships between (a) more profound personal value predispositions, (b) affects and feelings, and (c) perceived benefits and risks related to the proposed installation of high-voltage power lines among local policy elites in the state of Arkansas. In doing so, we analyze original data collected from a statewide Internet survey of 420 local leaders and key policymakers about their opinions on the related issues, while considering other factors claimed by previous literature to influence risk perceptions, including trust, knowledge level, and demographic characteristics. Analytical results suggest that grid-group cultural predispositions, as deeply held core values within local policy elites' individual belief systems, both directly and indirectly-through affective feelings-shape perceived utility associated with the installation of high-voltage power lines. We conclude this article by suggesting some practical considerations for better designing policy addressing controversial issues of this nature. © 2016 Society for Risk Analysis.

Design and Operation of an Electrochemical Methanol Concentration Sensor for Direct Methanol Fuel Cell Systems

NASA Technical Reports Server (NTRS)

Narayanan, S. R.; Valdez, T. I.; Chun, W.

2000-01-01

The development of a 150-Watt packaged power source based on liquid feed direct methanol fuel cells is being pursued currently at the Jet propulsion Laboratory for defense applications. In our studies we find that the concentration of methanol in the fuel circulation loop affects the electrical performance and efficiency the direct methanol fuel cell systems significantly. The practical operation of direct methanol fuel cell systems, therefore, requires accurate monitoring and control of methanol concentration. The present paper reports on the principle and demonstration of an in-house developed electrochemical sensor suitable for direct methanol fuel cell systems.

Space-based solar power conversion and delivery systems study. Volume 5: Economic analysis

NASA Technical Reports Server (NTRS)

1977-01-01

Space-based solar power conversion and delivery systems are studied along with a variety of economic and programmatic issues relevant to their development and deployment. The costs, uncertainties and risks associated with the current photovoltaic Satellite Solar Power System (SSPS) configuration, and issues affecting the development of an economically viable SSPS development program are addressed. In particular, the desirability of low earth orbit (LEO) and geosynchronous (GEO) test satellites is examined and critical technology areas are identified. The development of SSPS unit production (nth item), and operation and maintenance cost models suitable for incorporation into a risk assessment (Monte Carlo) model (RAM) are reported. The RAM was then used to evaluate the current SSPS configuration expected costs and cost-risk associated with this configuration. By examining differential costs and cost-risk as a function of postulated technology developments, the critical technologies, that is, those which drive costs and/or cost-risk, are identified. It is shown that the key technology area deals with productivity in space, that is, the ability to fabricate and assemble large structures in space, not, as might be expected, with some hardware component technology.

Comparison Between Oil-mist and Oil-jet Lubrication of High-speed, Small-bore, Angular-contact Ball Bearings

NASA Technical Reports Server (NTRS)

Pinel, Stanley I.; Signer, Hans R.; Zaretsky, Erwin V.

2001-01-01

Parametric tests were conducted with an optimized 35-mm-bore-angular-contact ball bearing on a high-speed, high-temperature bearing tester. Results from both air-oil mist lubrication and oil-jet lubrication systems used to lubricate the bearing were compared to speeds of 2.5 x 10(exp 6) DN. The maximum obtainable speed with air-oil mist lubrication is 2.5 x 10(exp 6) DN. Lower bearing temperatures and higher power losses are obtained with oil-jet lubrication than with air-oil mist lubrication. Bearing power loss is a direct function of oil flow to the bearing and independent of oil delivery system. For a given oil-flow rate, bearing temperature and power loss increase with increases in speed. Bearing life is an inverse function of temperature, the difference in temperature between the individual bearing ring components, and the resultant elastohydrodynamic (EHD) film thicknesses. Bearing life is independent of the oil delivery system except as it affects temperature. Cage slip increased with increases in speed. Cage slip as high as 7 percent was measured and was generally higher with air-oil mist lubrication than with oil-jet lubrication.

Power Plant Bromide Discharges and Downstream Drinking Water Systems in Pennsylvania.

PubMed

Good, Kelly D; VanBriesen, Jeanne M

2017-10-17

Coal-fired power plants equipped with wet flue gas desulfurization (FGD) systems have been implicated in increasing bromide levels and subsequent increases in disinfection byproducts at downstream drinking water plants. Bromide was not included as a regulated constituent in the recent steam electric effluent limitations guidelines and standards (ELGs) since the U.S. EPA analysis suggested few drinking water facilities would be affected by bromide discharges from power plants. The present analysis uses a watershed approach to identify Pennsylvania drinking water intakes downstream of wet FGD discharges and to assess the potential for bromide discharge effects. Twenty-two (22) public drinking water systems serving 2.5 million people were identified as being downstream of at least one wet FGD discharge. During mean August conditions (generally low-flow, minimal dilution) in receiving rivers, the median predicted bromide concentrations contributed by wet FGD at Pennsylvania intake locations ranged from 5.2 to 62 μg/L for the Base scenario (including only natural bromide in coal) and from 16 to 190 μg/L for the Bromide Addition scenario (natural plus added bromide for mercury control); ranges depend on bromide loads and receiving stream dilution capacity.

An integrated neuro-robotic interface for stroke rehabilitation using the NASA X1 powered lower limb exoskeleton.

PubMed

He, Yongtian; Nathan, Kevin; Venkatakrishnan, Anusha; Rovekamp, Roger; Beck, Christopher; Ozdemir, Recep; Francisco, Gerard E; Contreras-Vidal, Jose L

2014-01-01

Stroke remains a leading cause of disability, limiting independent ambulation in survivors, and consequently affecting quality of life (QOL). Recent technological advances in neural interfacing with robotic rehabilitation devices are promising in the context of gait rehabilitation. Here, the X1, NASA's powered robotic lower limb exoskeleton, is introduced as a potential diagnostic, assistive, and therapeutic tool for stroke rehabilitation. Additionally, the feasibility of decoding lower limb joint kinematics and kinetics during walking with the X1 from scalp electroencephalographic (EEG) signals--the first step towards the development of a brain-machine interface (BMI) system to the X1 exoskeleton--is demonstrated.

Three-dimensional propagation and absorption of high frequency Gaussian beams in magnetoactive plasmas

NASA Astrophysics Data System (ADS)

Nowak, S.; Orefice, A.

1994-05-01

In today's high frequency systems employed for plasma diagnostics, power heating, and current drive the behavior of the wave beams is appreciably affected by the self-diffraction phenomena due to their narrow collimation. In the present article the three-dimensional propagation of Gaussian beams in inhomogeneous and anisotropic media is analyzed, starting from a properly formulated dispersion relation. Particular attention is paid, in the case of electromagnetic electron cyclotron (EC) waves, to the toroidal geometry characterizing tokamak plasmas, to the power density evolution on the advancing wave fronts, and to the absorption features occurring when a beam crosses an EC resonant layer.

Effect of heater geometry and cavity volume on the sensitivity of a thermal convection-based tilt sensor

NASA Astrophysics Data System (ADS)

Han, Maeum; Keon Kim, Jae; Kong, Seong Ho; Kang, Shin-Won; Jung, Daewoong

2018-06-01

This paper reports a micro-electro-mechanical-system (MEMS)-based tilt sensor using air medium. Since the working mechanism of the sensor is the thermal convection in a sealed chamber, structural parameters that can affect thermal convection must be considered to optimize the performance of the sensor. This paper presents the experimental results that were conducted by optimizing several parameters such as the heater geometry, input power and cavity volume. We observed that an increase in the heating power and cavity volume can improve the sensitivity, and heater geometry plays important role in performance of the sensor.

Active implantable medical device EMI assessment for wireless power transfer operating in LF and HF bands.

PubMed

Hikage, Takashi; Nojima, Toshio; Fujimoto, Hiroshi

2016-06-21

The electromagnetic interference (EMI) imposed on active implantable medical devices by wireless power transfer systems (WPTSs) is discussed based upon results of in vitro experiments. The purpose of this study is to present comprehensive EMI test results gathered from implantable-cardiac pacemakers and implantable cardioverter defibrillators exposed to the electromagnetic field generated by several WPTSs operating in low-frequency (70 kHz-460 kHz) and high-frequency (6.78 MHz) bands. The constructed in vitro experimental test system based upon an Irnich's flat torso phantom was applied. EMI test experiments are conducted on 14 types of WPTSs including Qi-compliant system and EV-charging WPT system mounted on current production EVs. In addition, a numerical simulation model for active implantable medical device (AIMD) EMI estimation based on the experimental test system is newly proposed. The experimental results demonstrate the risk of WPTSs emitting intermittent signal to affect the correct behavior of AIMDs when operating at very short distances. The proposed numerical simulation model is applicable to obtain basically the EMI characteristics of various types of WPTSs.

Active implantable medical device EMI assessment for wireless power transfer operating in LF and HF bands

NASA Astrophysics Data System (ADS)

Hikage, Takashi; Nojima, Toshio; Fujimoto, Hiroshi

2016-06-01

The electromagnetic interference (EMI) imposed on active implantable medical devices by wireless power transfer systems (WPTSs) is discussed based upon results of in vitro experiments. The purpose of this study is to present comprehensive EMI test results gathered from implantable-cardiac pacemakers and implantable cardioverter defibrillators exposed to the electromagnetic field generated by several WPTSs operating in low-frequency (70 kHz-460 kHz) and high-frequency (6.78 MHz) bands. The constructed in vitro experimental test system based upon an Irnich’s flat torso phantom was applied. EMI test experiments are conducted on 14 types of WPTSs including Qi-compliant system and EV-charging WPT system mounted on current production EVs. In addition, a numerical simulation model for active implantable medical device (AIMD) EMI estimation based on the experimental test system is newly proposed. The experimental results demonstrate the risk of WPTSs emitting intermittent signal to affect the correct behavior of AIMDs when operating at very short distances. The proposed numerical simulation model is applicable to obtain basically the EMI characteristics of various types of WPTSs.

Comprehensive evaluation of impacts of distributed generation integration in distribution network

NASA Astrophysics Data System (ADS)

Peng, Sujiang; Zhou, Erbiao; Ji, Fengkun; Cao, Xinhui; Liu, Lingshuang; Liu, Zifa; Wang, Xuyang; Cai, Xiaoyu

2018-04-01

All Distributed generation (DG) as the supplement to renewable energy centralized utilization, is becoming the focus of development direction of renewable energy utilization. With the increasing proportion of DG in distribution network, the network power structure, power flow distribution, operation plans and protection are affected to some extent. According to the main impacts of DG, a comprehensive evaluation model of distributed network with DG is proposed in this paper. A comprehensive evaluation index system including 7 aspects, along with their corresponding index calculation method is established for quantitative analysis. The indices under different access capacity of DG in distribution network are calculated based on the IEEE RBTS-Bus 6 system and the evaluation result is calculated by analytic hierarchy process (AHP). The proposed model and method are verified effective and validity through case study.

Effects of motor congruence on visual working memory.

PubMed

Quak, Michel; Pecher, Diane; Zeelenberg, Rene

2014-10-01

Grounded-cognition theories suggest that memory shares processing resources with perception and action. The motor system could be used to help memorize visual objects. In two experiments, we tested the hypothesis that people use motor affordances to maintain object representations in working memory. Participants performed a working memory task on photographs of manipulable and nonmanipulable objects. The manipulable objects were objects that required either a precision grip (i.e., small items) or a power grip (i.e., large items) to use. A concurrent motor task that could be congruent or incongruent with the manipulable objects caused no difference in working memory performance relative to nonmanipulable objects. Moreover, the precision- or power-grip motor task did not affect memory performance on small and large items differently. These findings suggest that the motor system plays no part in visual working memory.

Engineering and socioeconomic impacts of earthquakes: An analysis of electricity lifeline disruptions in the New Madrid area

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

Shinozuka, M.; Rose, A.; Eguchi, R.T.

1998-12-31

This monograph examines the potential effects of a repeat of the New Madrid earthquake to the metropolitan Memphis area. The authors developed a case study of the impact of such an event to the electric power system, and analyzed how this disruption would affect society. In nine chapters and 189 pages, the book traces the impacts of catastrophic earthquakes through a curtailment of utility lifeline services to its host regional economy and beyond. the monographs` chapters include: Modeling the Memphis economy; seismic performance of electric power systems; spatial analysis techniques for linking physical damage to economic functions; earthquake vulnerability andmore » emergency preparedness among businesses; direct economic impacts; regional economic impacts; socioeconomic and interregional impacts; lifeline risk reduction; and public policy formulation and implementation.« less

Research on optimization of combustion efficiency of thermal power unit based on genetic algorithm

NASA Astrophysics Data System (ADS)

Zhou, Qiongyang

2018-04-01

In order to improve the economic performance and reduce pollutant emissions of thermal power units, the characteristics of neural network in establishing boiler combustion model are analyzed based on the analysis of the main factors affecting boiler efficiency by using orthogonal method. In addition, on the basis of this model, the genetic algorithm is used to find the best control amount of the furnace combustion in a certain working condition. Through the genetic algorithm based on real number encoding and roulette selection is concluded: the best control quantity at a condition of furnace combustion can be combined with the boiler combustion system model for neural network training. The precision of the neural network model is further improved, and the basic work is laid for the research of the whole boiler combustion optimization system.

Validation of spatially resolved all sky imager derived DNI nowcasts

NASA Astrophysics Data System (ADS)

Kuhn, Pascal; Wilbert, Stefan; Schüler, David; Prahl, Christoph; Haase, Thomas; Ramirez, Lourdes; Zarzalejo, Luis; Meyer, Angela; Vuilleumier, Laurent; Blanc, Philippe; Dubrana, Jean; Kazantzidis, Andreas; Schroedter-Homscheidt, Marion; Hirsch, Tobias; Pitz-Paal, Robert

2017-06-01

Mainly due to clouds, Direct Normal Irradiance (DNI) displays short-term local variabilities affecting the efficiency of concentrating solar power (CSP) plants. To enable efficient plant operation, DNI nowcasts in high spatial and temporal resolutions for 15 to 30 minutes ahead are required. Ground-based All Sky Imagers (ASI) can be used to detect, track and predict 3D positions of clouds possibly shading the plant. The accuracy and reliability of these ASI-derived DNI nowcasts must be known to allow its application in solar power plants. Within the framework of the European project DNICast, an ASI-based nowcasting system was developed and implemented at the Plataforma Solar de Almería (PSA). Its validation methodology and validation results are presented in this work. The nowcasting system outperforms persistence forecasts for volatile irradiance situations.

Influence of El Niño Southern Oscillation on global hydropower production

NASA Astrophysics Data System (ADS)

Ng, Jia Yi; Turner, Sean W. D.; Galelli, Stefano

2017-03-01

El Niño Southern Oscillation (ENSO) strongly influences the global climate system, affecting hydrology in many of the world’s river basins. This raises the prospect of ENSO-driven variability in global and regional hydroelectric power generation. Here we study these effects by generating time series of power production for 1593 hydropower dams, which collectively represent more than half of the world’s existing installed hydropower capacity. The time series are generated by forcing a detailed dam model with monthly-resolution, 20th century inflows—the model includes plant specifications, storage dynamics and realistic operating schemes, and runs irrespectively of the dam construction year. More than one third of simulated dams exhibit statistically significant annual energy production anomalies in at least one of the two ENSO phases of El Niño and La Niña. For most dams, the variability of relative anomalies in power production tends to be less than that of the forcing inflows—a consequence of dam design specifications, namely maximum turbine release rate and reservoir storage, which allows inflows to accumulate for power generation in subsequent dry years. Production is affected most prominently in Northwest United States, South America, Central America, the Iberian Peninsula, Southeast Asia and Southeast Australia. When aggregated globally, positive and negative energy production anomalies effectively cancel each other out, resulting in a weak and statistically insignificant net global anomaly for both ENSO phases.

Study of Parameters Affecting the Level of Ultrasound Exposure with In Vitro Set-Ups

NASA Astrophysics Data System (ADS)

Leskinen, Jarkko J.; Hynynen, Kullervo

2010-03-01

Ultrasound (US) exposures are widely used with in vitro cell systems e.g. in stem cell and tissue engineering research. However, without the knowledge of factors affecting the level of US exposure, the outcome of the biological result may vary from test to test or even be misinterpreted. Thereby, some of the factors affecting in vitro US exposures were studied. The level of US exposure was characterized in standard commercial cell culturing plates. The temperature distributions were measured inside the wells using infrared camera and fine wire thermocouples, and pressure and intensity distributions using a laser vibrometer and a schlieren system. The measurements were made at operating frequency of around 1 MHz with varying temporal parameters and powers (up to 2 W of acoustic power). Heat accumulation between the wells varied up to 40-50% depending on the location of the well on the plate. This well-to-well variation was be linked to the activity of reporter plasmid on osteoblastic cells. Similar temperature variations within the wells were also measured. Small sub-wavelength change in the exposure distance or, respectively, liquid volume inside the well was found to alter the acoustic field in both magnitude and shape due the standing waves. The gathered data reveals the complexity of the acoustic field in a typical in vitro set-up and gives new information about the environment of the in vitro cells during US exposures. This data may be especially useful when US set-ups are designed or characterized.

GIS based evaluation of crop suitability for agricultural sustainability around Kolaghat thermal power plant, India.

PubMed

Adak, Subhas; Adhikari, Kalyan; Brahmachari, Koushik

2016-09-01

Fly ash exhaust from Kolaghat thermal power plant, West Bengal, India,?? affects the areas within the radius of 3 - 4 km. Land information system indicated that surface texture within 4 km was silty loam and clay content increased with increase of distance. Soil pH was alkaline (7.58-8.01) in affected circles, whereas soil was acidic (5.95-6.41) in rest of block. Organic carbon (OC) is roving from 0.36 to 0.64% in the nearer circles which is lesser from others. The present Crop suitability analysis revealed that 96.98 % area was suitable (S1) for maize, sesame, jute, whereas these were cultivated in less than 1% of land. Flowers are the best suitable (S1) in 88.9 % but it was grown in 6.02 % area.? The present rice area within 4 km of KTPP is showing moderately suitable (S2) and S1 for the rest. Wheat is moderately suitable (S2) in the almost all the circles.? Cultivation of vegetable crops is limited in the affected circles while the highly suitable (S1) comprises 67.49 % for the remaining areas though it covered only 6.01 % of the block.? This evaluation precisely improves more than 300% from the earlier cropping intensity of 177.95 %. Suitability based land use allocation serves as stepping stone to promote agricultural sustainability. Geographic information system (GIS) model has been developed to assess site specific crop suitability for sustainable agricultural planning.

No Time for Dead Time: Use the Fourier Amplitude Differences to Normalize Dead-time-affected Periodograms

NASA Astrophysics Data System (ADS)

Bachetti, Matteo; Huppenkothen, Daniela

2018-02-01

Dead time affects many of the instruments used in X-ray astronomy, by producing a strong distortion in power density spectra. This can make it difficult to model the aperiodic variability of the source or look for quasi-periodic oscillations. Whereas in some instruments a simple a priori correction for dead-time-affected power spectra is possible, this is not the case for others such as NuSTAR, where the dead time is non-constant and long (∼2.5 ms). Bachetti et al. (2015) suggested the cospectrum obtained from light curves of independent detectors within the same instrument as a possible way out, but this solution has always only been a partial one: the measured rms was still affected by dead time because the width of the power distribution of the cospectrum was modulated by dead time in a frequency-dependent way. In this Letter, we suggest a new, powerful method to normalize dead-time-affected cospectra and power density spectra. Our approach uses the difference of the Fourier amplitudes from two independent detectors to characterize and filter out the effect of dead time. This method is crucially important for the accurate modeling of periodograms derived from instruments affected by dead time on board current missions like NuSTAR and Astrosat, but also future missions such as IXPE.

GNOCIS an update of the generic NO{sub x} control intelligent system

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

Holmes, R.; Mayes, I.; Irons, R.

1996-01-01

GNOCIS is an on-line enhancement to existing power plant Digital Control Systems (DCS) designed to reduce NO{sub x} emissions while meeting other operational constraints, such as heat rate and CO emissions. It can also be used to minimize unburned carbon while meeting a specified NO{sub x} limit, or any combination of emissions/performance variables that can be quantified by a common metric and are affected by DCS - adjustable parameters. The core of the system is an adaptive neural network model of the NO{sub x} generation characteristics of the boiler. The software applies an optimizing procedure to identify the best setpointsmore » for the plant. The recommended setpoints can be either conveyed to the operator via the DCS in an advisory mode, or implemented automatically in a closed-loop mode. GNOCIS is designed to run on a stand-alone workstation connected to the DCS via the data highway. Sensor validation techniques have been incorporated. The goal for GNOSIS is to deliver 10-35% reductions in NO{sub x} from baseline conditions while maintaining or improving other operational constraints. Preliminary results are presented for demonstrations at two power plants: (1) 500-MW T-fired boiler at PowerGen`s Kingsnorth Station, (2) 250-MW Opposed-fired boiler at Alabama Power Company`s Gaston Station.« less

The Disposition of Concern: An Exploration into the Affects of the Power-Knowledge Dynamics Uncovered during Research into Pupils' Perceptions of Terrorism

ERIC Educational Resources Information Center

Quartermaine, Angela

2017-01-01

In recent years, counter-terrorism measures have become incorporated into the UK education system, with the latest 2015 "Counter-Terrorism and Security Act" expanding on previous government policy by making it mandatory for schools to be actively involved with counter-terrorism measures [Clause 21, H.M. Government 2015.…

Energy Storage Opportunities and Capabilities in a Type 3 Wind Turbine Generator: Preprint

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

Muljadi, Eduard; Gevorgian, Vahan; Hoke, Andy

Wind power plants and other renewable power plants with power electronic interfaces are capable of delivering frequency response (both governor and/or inertial response) to the grid by a control action; thus, the reduction of available online inertia as conventional power plants are retired can be compensated by designing renewable power plant controls to include frequency response. The source of energy to be delivered as inertial response is determined by the type of generation and control strategy chosen. The cost of energy storage is expected to drop over time, and global research activities on energy storage are very active, funded bothmore » by the private industry and governments. Different industry sectors (e.g., transportation, energy) are the major drivers of the recent storage research and development. This work investigates the opportunities and capabilities of deploying energy storage in renewable power plants. In particular, we focus on wind power plants with doubly-fed induction generators, or Type 3 wind turbine generator (WTGs). We find that the total output power of a system with Type 3 WTGs with energy storage can deliver a power boost during inertial response that is up to 45% higher than one without energy storage without affecting the torque limit, thus enabling an effective delivery of ancillary services to the grid.« less

Mechanical energy and power flow analysis of wheelchair use with different camber settings.

PubMed

Huang, Yueh-Chu; Guo, Lan-Yuen; Tsai, Chung-Ying; Su, Fong-Chin

2013-04-01

It has been suggested that minimisation of energy cost is one of the primary determinants of wheelchair designs. Wheel camber is one important parameter related to wheelchair design and its angle may affect usability during manual propulsion. However, there is little available literature addressing the effect of wheel camber on the mechanical energy or power flow involved in manual wheelchair propulsion. Twelve normal subjects (mean age, 22.3 years; SD, 1.6 years) participated in this study. A video-tracking system and an instrumented wheel were used to collect 3D kinematic and kinetic data. Wheel camber of 0° and 15° was chosen to examine the difference between mechanical power and power flow of the upper extremity during manual wheelchair propulsion. The work calculated from power flow and the discrepancy between the mechanical work and power flow work of upper extremity had significantly greater values with increased camber. The upper arm had a larger active muscle power compared with that in the forearm and hand segments. While propelling the increased camber, the magnitude of both the proximal and distal joint power and proximal muscle power was increased in all three segments. While the propelling wheel with camber not only needs a greater energy cost but also there is greater energy loss.

Power and resistance within the hospital's hierarchical system: the experiences of chronically ill patients.

PubMed

Griscti, Odette; Aston, Megan; Warner, Grace; Martin-Misener, Ruth; McLeod, Deborah

2017-01-01

To explore experiences of chronically ill patients and registered nurses when they negotiate patient care in hospital settings. Specifically, we explored how social and institutional discourses shape power relations during the negotiation process. The hospital system is embedded in a hierarchical structure where the voice of the healthcare provider as expert is often given more importance than the patient. This system has been criticised as being oppressive to patients who are perceived to be lower in the hierarchy. In this study, we illustrate how the hospital's hierarchical system is not always oppressing but can also create moments of empowerment for patients. A feminist poststructuralist approach informed by the teaching of Foucault was used to explore power relations between nurses and patients when negotiating patient care in hospital settings. Eight individuals who suffered from chronic illness shared their stories about how they negotiated their care with nurses in hospital settings. The interviews were tape-recorded. Discourse analysis was used to analyse the data. Patients recounted various experiences when their voices were not heard because the current hospital system privileged the healthcare provider experts' advice over the patients' voice. The hierarchical structure of hospital supported these dynamics by privileging nurses as gatekeepers of service, by excluding the patients' input in the nursing notes and through a process of self-regulation. However, patients in this study were not passive recipients of care and used their agency creatively to resist these discourses. Nurses need to be mindful of how the hospital's hierarchical system tends to place nurses in a position of power, and how their authoritative position may positively or adversely affect the negotiation of patient care. © 2016 John Wiley & Sons Ltd.

Joint Transmit Power Allocation and Splitting for SWIPT Aided OFDM-IDMA in Wireless Sensor Networks

PubMed Central

Li, Shanshan; Zhou, Xiaotian; Wang, Cheng-Xiang; Yuan, Dongfeng; Zhang, Wensheng

2017-01-01

In this paper, we propose to combine Orthogonal Frequency Division Multiplexing-Interleave Division Multiple Access (OFDM-IDMA) with Simultaneous Wireless Information and Power Transfer (SWIPT), resulting in SWIPT aided OFDM-IDMA scheme for power-limited sensor networks. In the proposed system, the Receive Node (RN) applies Power Splitting (PS) to coordinate the Energy Harvesting (EH) and Information Decoding (ID) process, where the harvested energy is utilized to guarantee the iterative Multi-User Detection (MUD) of IDMA to work under sufficient number of iterations. Our objective is to minimize the total transmit power of Source Node (SN), while satisfying the requirements of both minimum harvested energy and Bit Error Rate (BER) performance from individual receive nodes. We formulate such a problem as a joint power allocation and splitting one, where the iteration number of MUD is also taken into consideration as the key parameter to affect both EH and ID constraints. To solve it, a sub-optimal algorithm is proposed to determine the power profile, PS ratio and iteration number of MUD in an iterative manner. Simulation results verify that the proposed algorithm can provide significant performance improvement. PMID:28677636

Joint Transmit Power Allocation and Splitting for SWIPT Aided OFDM-IDMA in Wireless Sensor Networks.

PubMed

Li, Shanshan; Zhou, Xiaotian; Wang, Cheng-Xiang; Yuan, Dongfeng; Zhang, Wensheng

2017-07-04

In this paper, we propose to combine Orthogonal Frequency Division Multiplexing-Interleave Division Multiple Access (OFDM-IDMA) with Simultaneous Wireless Information and Power Transfer (SWIPT), resulting in SWIPT aided OFDM-IDMA scheme for power-limited sensor networks. In the proposed system, the Receive Node (RN) applies Power Splitting (PS) to coordinate the Energy Harvesting (EH) and Information Decoding (ID) process, where the harvested energy is utilized to guarantee the iterative Multi-User Detection (MUD) of IDMA to work under sufficient number of iterations. Our objective is to minimize the total transmit power of Source Node (SN), while satisfying the requirements of both minimum harvested energy and Bit Error Rate (BER) performance from individual receive nodes. We formulate such a problem as a joint power allocation and splitting one, where the iteration number of MUD is also taken into consideration as the key parameter to affect both EH and ID constraints. To solve it, a sub-optimal algorithm is proposed to determine the power profile, PS ratio and iteration number of MUD in an iterative manner. Simulation results verify that the proposed algorithm can provide significant performance improvement.

Design of a Virtual Reality System for Affect Analysis in Facial Expressions (VR-SAAFE); Application to Schizophrenia.

PubMed

Bekele, E; Bian, D; Peterman, J; Park, S; Sarkar, N

2017-06-01

Schizophrenia is a life-long, debilitating psychotic disorder with poor outcome that affects about 1% of the population. Although pharmacotherapy can alleviate some of the acute psychotic symptoms, residual social impairments present a significant barrier that prevents successful rehabilitation. With limited resources and access to social skills training opportunities, innovative technology has emerged as a potentially powerful tool for intervention. In this paper, we present a novel virtual reality (VR)-based system for understanding facial emotion processing impairments that may lead to poor social outcome in schizophrenia. We henceforth call it a VR System for Affect Analysis in Facial Expressions (VR-SAAFE). This system integrates a VR-based task presentation platform that can minutely control facial expressions of an avatar with or without accompanying verbal interaction, with an eye-tracker to quantitatively measure a participants real-time gaze and a set of physiological sensors to infer his/her affective states to allow in-depth understanding of the emotion recognition mechanism of patients with schizophrenia based on quantitative metrics. A usability study with 12 patients with schizophrenia and 12 healthy controls was conducted to examine processing of the emotional faces. Preliminary results indicated that there were significant differences in the way patients with schizophrenia processed and responded towards the emotional faces presented in the VR environment compared with healthy control participants. The preliminary results underscore the utility of such a VR-based system that enables precise and quantitative assessment of social skill deficits in patients with schizophrenia.

Development and evaluation of totally implantable ventricular assist system using a vibrating flow pump and transcutaneous energy transmission system with amorphous fibers.

PubMed

Yambe, T; Hashimoto, H; Kobayashi, S; Sonobe, T; Naganuma, S; Nanka, S S; Matsuki, H; Yoshizawa, M; Tabayashi, K; Takayasu, H; Takeda, H; Nitta, S

1997-01-01

We have developed a vibrating flow pump (VFP) that can generate oscillated blood flow with a relatively high frequency (10-50 Hz) for a totally implantable ventricular assist system (VAS). To evaluate the newly developed VAS, left heart bypasses, using the VFP, were performed in chronic animal experiments. Hemodynamic parameters were recorded in a data recorder in healthy adult goats during an awake condition and analyzed in a personal computer system through an alternating-direct current converter. Basic performance of the total system with a transcutaneous energy transmission system were satisfactory. During left ventricular assistance with the VFP, Mayer wave fluctuations of hemodynamics were decreased in the power spectrum, the fractal dimensions of the hemodynamics were significantly decreased, and peripheral vascular resistance was significantly decreased. These results suggest that cardiovascular regulatory nonlinear dynamics, which mediate the hemodynamics, may be affected by left ventricular bypass with oscillated flow. The decreased power of the Mayer wave in the spectrum caused the limit cycle attractor of the hemodynamics and decreased peripheral resistance. These results suggest that this newly developed VAS is useful for the totally implantable system with unique characteristics that can control hemodynamic properties.

Legionnaires' disease bacteria in power plant cooling systems: Phase 2

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

Tyndall, R.L.; Christensen, S.W.; Solomon, J.A.

1985-04-01

Legionnaires' Disease Bacteria (Legionella) are a normal component of the aquatic community. The study investigated various environmental factors that affect Legionella profiles in power plant cooling waters. The results indicate that each of the four factors investigated (incubation temperature, water quality, the presence and type of associated biota, and the nature of the indigenous Legionella population) is important in determining the Legionella profile of these waters. Simple predictive relationships were not found. At incubation temperatures of 32/sup 0/ and 37/sup 0/C, waters from a power plant where infectious Legionella were not observed stimulated the growth of stock Legionella cultures moremore » than did waters from plants where infectious Legionella were prevalent. This observation is consistent with Phase I results, which showed that densities of Legionella were frequently reduced in closed-cycle cooling systems despite the often higher infectivity of Legionella in closed-cycle waters. In contrast, water from power plants where infectious Legionella were prevalent supported the growth of indigenous Legionella pneumophila at 42/sup 0/C, while water from a power plant where infectious Legionella were absent did not support growth of indigenous Legionella. Some Legionella are able to withstand a water temperature of 85/sup 0/C for several hours, thus proving more tolerant than was previously realized. Finally, the observation that water from two power plants where infectious Legionella were prevalent usually supported the growth of Group A Legionella at 45/sup 0/C indicates the presence, of soluble Legionella growth promoters in these waters. This test system could allow for future identification and control of these growth promoters and, hence, of Legionella. 25 refs., 23 figs., 10 tabs.« less

Synchrophasor Sensing and Processing based Smart Grid Security Assessment for Renewable Energy Integration

NASA Astrophysics Data System (ADS)

Jiang, Huaiguang

With the evolution of energy and power systems, the emerging Smart Grid (SG) is mainly featured by distributed renewable energy generations, demand-response control and huge amount of heterogeneous data sources. Widely distributed synchrophasor sensors, such as phasor measurement units (PMUs) and fault disturbance recorders (FDRs), can record multi-modal signals, for power system situational awareness and renewable energy integration. An effective and economical approach is proposed for wide-area security assessment. This approach is based on wavelet analysis for detecting and locating the short-term and long-term faults in SG, using voltage signals collected by distributed synchrophasor sensors. A data-driven approach for fault detection, identification and location is proposed and studied. This approach is based on matching pursuit decomposition (MPD) using Gaussian atom dictionary, hidden Markov model (HMM) of real-time frequency and voltage variation features, and fault contour maps generated by machine learning algorithms in SG systems. In addition, considering the economic issues, the placement optimization of distributed synchrophasor sensors is studied to reduce the number of the sensors without affecting the accuracy and effectiveness of the proposed approach. Furthermore, because the natural hazards is a critical issue for power system security, this approach is studied under different types of faults caused by natural hazards. A fast steady-state approach is proposed for voltage security of power systems with a wind power plant connected. The impedance matrix can be calculated by the voltage and current information collected by the PMUs. Based on the impedance matrix, locations in SG can be identified, where cause the greatest impact on the voltage at the wind power plants point of interconnection. Furthermore, because this dynamic voltage security assessment method relies on time-domain simulations of faults at different locations, the proposed approach is feasible, convenient and effective. Conventionally, wind energy is highly location-dependent. Many desirable wind resources are located in rural areas without direct access to the transmission grid. By connecting MW-scale wind turbines or wind farms to the distributions system of SG, the cost of building long transmission facilities can be avoid and wind power supplied to consumers can be greatly increased. After the effective wide area monitoring (WAM) approach is built, an event-driven control strategy is proposed for renewable energy integration. This approach is based on support vector machine (SVM) predictor and multiple-input and multiple-output (MIMO) model predictive control (MPC) on linear time-invariant (LTI) and linear time-variant (LTV) systems. The voltage condition of the distribution system is predicted by the SVM classifier using synchrophasor measurement data. The controllers equipped with wind turbine generators are triggered by the prediction results. Both transmission level and distribution level are designed based on this proposed approach. Considering economic issues in the power system, a statistical scheduling approach to economic dispatch and energy reserves is proposed. The proposed approach focuses on minimizing the overall power operating cost with considerations of renewable energy uncertainty and power system security. The hybrid power system scheduling is formulated as a convex programming problem to minimize power operating cost, taking considerations of renewable energy generation, power generation-consumption balance and power system security. A genetic algorithm based approach is used for solving the minimization of the power operating cost. In addition, with technology development, it can be predicted that the renewable energy such as wind turbine generators and PV panels will be pervasively located in distribution systems. The distribution system is an unbalanced system, which contains single-phase, two-phase and three-phase loads, and distribution lines. The complex configuration brings a challenge to power flow calculation. A topology analysis based iterative approach is used to solve this problem. In this approach, a self-adaptive topology recognition method is used to analyze the distribution system, and the backward/forward sweep algorithm is used to generate the power flow results. Finally, for the numerical simulations, the IEEE 14-bus, 30-bus, 39-bus and 118-bus systems are studied for fault detection, identification and location. Both transmission level and distribution level models are employed with the proposed control strategy for voltage stability of renewable energy integration. The simulation results demonstrate the effectiveness of the proposed methods. The IEEE 24-bus reliability test system (IEEE-RTS), which is commonly used for evaluating the price stability and reliability of power system, is used as the test bench for verifying and evaluating system performance of the proposed scheduling approach.

Drug policy and administration affecting quality of life of the poor in Thailand.

PubMed

Prutipinyo, Chardsumon; Sirichotiratana, Nithat

2011-09-01

This study aims to analyze drug policy and administration affecting quality of life of the poor in Thailand. Review of official reports and related documents, for the past 10 years (from 2000-2010). By imposing compulsory licensing, the Thai government maintains negotiating power over the price of pharmaceutical products with the patent holders of the original drugs. This gives an opportunity for relevant government agencies to produce or import patented drugs. At present, there are many problems and obstacles. The findings show that developing countries need to strengthen their negotiating power so that the pharmaceutical manufacturers cannot take advantage through mechanisms provided for such as compulsory licensing and provisions for flexibility in Trade-Related Intellectual Property Rights (TRIPS) agreement. Furthermore, these countries must support and empower the local pharmaceutical manufacturers to produce generic drugs. Developing countries should ensure that their populations have confidence in universal coverage service and medical systems regarding the quality of generic drugs.

Environmental and biomedical applications of natural metal stable isotope variations

USGS Publications Warehouse

Bullen, T.D.; Walczyk, T.

2009-01-01

etal stable isotopes are now being used to trace metal contaminants in the environment and as indicators of human systemic function where metals play a role. Stable isotope abundance variations provide information about metal sources and the processes affecting metals in complex natural systems, complementing information gained from surrogate tracers, such as metal abundance ratios or biochemical markers of metal metabolism. The science is still in its infancy, but the results of initial studies confirm that metal stable isotopes can provide a powerful tool for forensic and biomedical investigations.

Use of the flight simulator in the design of a STOL research aircraft.

NASA Technical Reports Server (NTRS)

Spitzer, R. E.; Rumsey, P. C.; Quigley, H. C.

1972-01-01

Piloted simulator tests on the NASA-Ames Flight Simulator for Advanced Aircraft motion base played a major role in guiding the design of the Modified C-8A 'Buffalo' augmentor wing jet flap STOL research airplane. Design results are presented for the flight control systems, lateral-directional SAS, hydraulic systems, and engine and thrust vector controls. Emphasis is given to lateral control characteristics on STOL landing approach, engine-out control and recovery techniques in the powered-lift regime, and operational flight procedures which affected airplane design.

Depressed mood, positive affect, and heart rate variability in patients with suspected coronary artery disease.

PubMed

Bhattacharyya, Mimi R; Whitehead, Daisy L; Rakhit, Roby; Steptoe, Andrew

2008-11-01

To test associations between heart rate variability (HRV), depressed mood, and positive affect in patients with suspected coronary artery disease (CAD). Depression is associated with impaired HRV post acute cardiac events, but evidence in patients with stable coronary artery disease (CAD) is inconsistent. Seventy-six patients (52 men, 24 women; mean age = 61.1 years) being investigated for suspected CAD on the basis of symptomatology and positive noninvasive tests, completed 24-hour electrocardiograms. The Beck Depression Inventory (BDI) was administered, and positive and depressed affect was measured over the study period with the Day Reconstruction Method (DRM). A total of 46 (60.5%) patients were later found to have definite CAD. HRV was analyzed, using spectral analysis. Typical diurnal profiles of HRV were observed, with greater normalized high frequency (HF) and lower normalized low frequency (LF) power in the night compared with the day. BDI depression scores were not consistently associated with HRV. But positive affect was associated with greater normalized HF power (p = .039) and reduced normalized LF power (p = .007) independently of age, gender, medication with beta blockers, CAD status, body mass index, smoking, and habitual physical activity level. In patients with definite CAD, depressed affect assessed using the DRM was associated with reduced normalized HF power and heightened normalized LF power (p = .007) independently of covariates. Relationships between depression and HRV in patients with CAD may depend on affective experience over the monitoring period. Enhanced parasympathetic cardiac control may be a process through which positive affect protects against cardiovascular disease.

Prediction of energy balance and utilization for solar electric cars

NASA Astrophysics Data System (ADS)

Cheng, K.; Guo, L. M.; Wang, Y. K.; Zafar, M. T.

2017-11-01

Solar irradiation and ambient temperature are characterized by region, season and time-domain, which directly affects the performance of solar energy based car system. In this paper, the model of solar electric cars used was based in Xi’an. Firstly, the meteorological data are modelled to simulate the change of solar irradiation and ambient temperature, and then the temperature change of solar cell is calculated using the thermal equilibrium relation. The above work is based on the driving resistance and solar cell power generation model, which is simulated under the varying radiation conditions in a day. The daily power generation and solar electric car cruise mileage can be predicted by calculating solar cell efficiency and power. The above theoretical approach and research results can be used in the future for solar electric car program design and optimization for the future developments.

Enhancing the calculation accuracy of performance characteristics of power-generating units by correcting general measurands based on matching energy balances

NASA Astrophysics Data System (ADS)

Shchinnikov, P. A.; Safronov, A. V.

2014-12-01

General principles of a procedure for matching energy balances of thermal power plants (TPPs), whose use enhances the accuracy of information-measuring systems (IMSs) during calculations of performance characteristics (PCs), are stated. To do this, there is the possibility for changing values of measured and calculated variables within intervals determined by measurement errors and regulations. An example of matching energy balances of the thermal power plants with a T-180 turbine is made. The proposed procedure allows one to reduce the divergence of balance equations by 3-4 times. It is shown also that the equipment operation mode affects the profit deficiency. Dependences for the divergence of energy balances on the deviation of input parameters and calculated data for the fuel economy before and after matching energy balances are represented.

Anterior Eye Imaging with Optical Coherence Tomography

NASA Astrophysics Data System (ADS)

Huang, David; Li, Yan; Tang, Maolong

The development of corneal and anterior segment optical coherence tomography (OCT) technology has advanced rapidly in recently years. The scan geometry and imaging wavelength are both important choices to make in designing anterior segment OCT systems. Rectangular scan geometry offers the least image distortion and is now used in most anterior OCT systems. The wavelength of OCT light source affects resolution and penetration. An optimal choice of the OCT imaging wavelength (840, 1,050, or 1,310 nm) depends on the application of interest. Newer generation Fourier-domain OCT technology can provide scan speed 100-1000 times faster than the time-domain technology. Various commercial anterior OCT systems are available on the market. A wide spectrum of diagnostic and surgical applications using anterior segment OCT had been investigated, including mapping of corneal and epithelial thicknesses, keratoconus screening, measuring corneal refractive power, corneal surgery planning and evaluation in LASIK, intracorneal ring implantation, assessment of angle closure glaucoma, anterior chamber biometry and intraocular lens implants, intraocular lens power calculation, and eye bank donor cornea screening.

Developing Signal-Pattern-Recognition Programs

NASA Technical Reports Server (NTRS)

Shelton, Robert O.; Hammen, David

2006-01-01

Pattern Interpretation and Recognition Application Toolkit Environment (PIRATE) is a block-oriented software system that aids the development of application programs that analyze signals in real time in order to recognize signal patterns that are indicative of conditions or events of interest. PIRATE was originally intended for use in writing application programs to recognize patterns in space-shuttle telemetry signals received at Johnson Space Center's Mission Control Center: application programs were sought to (1) monitor electric currents on shuttle ac power busses to recognize activations of specific power-consuming devices, (2) monitor various pressures and infer the states of affected systems by applying a Kalman filter to the pressure signals, (3) determine fuel-leak rates from sensor data, (4) detect faults in gyroscopes through analysis of system measurements in the frequency domain, and (5) determine drift rates in inertial measurement units by regressing measurements against time. PIRATE can also be used to develop signal-pattern-recognition software for different purposes -- for example, to monitor and control manufacturing processes.

Soft, thin skin-mounted power management systems and their use in wireless thermography

NASA Astrophysics Data System (ADS)

Lee, Jung Woo; Xu, Renxiao; Lee, Seungmin; Jang, Kyung-In; Yang, Yichen; Banks, Anthony; Yu, Ki Jun; Kim, Jeonghyun; Xu, Sheng; Ma, Siyi; Jang, Sung Woo; Won, Phillip; Li, Yuhang; Kim, Bong Hoon; Choe, Jo Young; Huh, Soojeong; Kwon, Yong Ho; Huang, Yonggang; Paik, Ungyu; Rogers, John A.

2016-05-01

Power supply represents a critical challenge in the development of body-integrated electronic technologies. Although recent research establishes an impressive variety of options in energy storage (batteries and supercapacitors) and generation (triboelectric, piezoelectric, thermoelectric, and photovoltaic devices), the modest electrical performance and/or the absence of soft, biocompatible mechanical properties limit their practical use. The results presented here form the basis of soft, skin-compatible means for efficient photovoltaic generation and high-capacity storage of electrical power using dual-junction, compound semiconductor solar cells and chip-scale, rechargeable lithium-ion batteries, respectively. Miniaturized components, deformable interconnects, optimized array layouts, and dual-composition elastomer substrates, superstrates, and encapsulation layers represent key features. Systematic studies of the materials and mechanics identify optimized designs, including unusual configurations that exploit a folded, multilayer construct to improve the functional density without adversely affecting the soft, stretchable characteristics. System-level examples exploit such technologies in fully wireless sensors for precision skin thermography, with capabilities in continuous data logging and local processing, validated through demonstrations on volunteer subjects in various realistic scenarios.

Soft, thin skin-mounted power management systems and their use in wireless thermography.

PubMed

Lee, Jung Woo; Xu, Renxiao; Lee, Seungmin; Jang, Kyung-In; Yang, Yichen; Banks, Anthony; Yu, Ki Jun; Kim, Jeonghyun; Xu, Sheng; Ma, Siyi; Jang, Sung Woo; Won, Phillip; Li, Yuhang; Kim, Bong Hoon; Choe, Jo Young; Huh, Soojeong; Kwon, Yong Ho; Huang, Yonggang; Paik, Ungyu; Rogers, John A

2016-05-31

Power supply represents a critical challenge in the development of body-integrated electronic technologies. Although recent research establishes an impressive variety of options in energy storage (batteries and supercapacitors) and generation (triboelectric, piezoelectric, thermoelectric, and photovoltaic devices), the modest electrical performance and/or the absence of soft, biocompatible mechanical properties limit their practical use. The results presented here form the basis of soft, skin-compatible means for efficient photovoltaic generation and high-capacity storage of electrical power using dual-junction, compound semiconductor solar cells and chip-scale, rechargeable lithium-ion batteries, respectively. Miniaturized components, deformable interconnects, optimized array layouts, and dual-composition elastomer substrates, superstrates, and encapsulation layers represent key features. Systematic studies of the materials and mechanics identify optimized designs, including unusual configurations that exploit a folded, multilayer construct to improve the functional density without adversely affecting the soft, stretchable characteristics. System-level examples exploit such technologies in fully wireless sensors for precision skin thermography, with capabilities in continuous data logging and local processing, validated through demonstrations on volunteer subjects in various realistic scenarios.

Soft, thin skin-mounted power management systems and their use in wireless thermography

PubMed Central

Lee, Jung Woo; Xu, Renxiao; Lee, Seungmin; Jang, Kyung-In; Yang, Yichen; Banks, Anthony; Yu, Ki Jun; Kim, Jeonghyun; Xu, Sheng; Ma, Siyi; Jang, Sung Woo; Won, Phillip; Li, Yuhang; Kim, Bong Hoon; Choe, Jo Young; Huh, Soojeong; Kwon, Yong Ho; Huang, Yonggang; Paik, Ungyu; Rogers, John A.

2016-01-01

Power supply represents a critical challenge in the development of body-integrated electronic technologies. Although recent research establishes an impressive variety of options in energy storage (batteries and supercapacitors) and generation (triboelectric, piezoelectric, thermoelectric, and photovoltaic devices), the modest electrical performance and/or the absence of soft, biocompatible mechanical properties limit their practical use. The results presented here form the basis of soft, skin-compatible means for efficient photovoltaic generation and high-capacity storage of electrical power using dual-junction, compound semiconductor solar cells and chip-scale, rechargeable lithium-ion batteries, respectively. Miniaturized components, deformable interconnects, optimized array layouts, and dual-composition elastomer substrates, superstrates, and encapsulation layers represent key features. Systematic studies of the materials and mechanics identify optimized designs, including unusual configurations that exploit a folded, multilayer construct to improve the functional density without adversely affecting the soft, stretchable characteristics. System-level examples exploit such technologies in fully wireless sensors for precision skin thermography, with capabilities in continuous data logging and local processing, validated through demonstrations on volunteer subjects in various realistic scenarios. PMID:27185907

Practical Design of an Energy Harvester Considering Wheel Rotation for Powering Intelligent Tire Systems

NASA Astrophysics Data System (ADS)

Zhu, Bing; Han, Jiayi; Zhao, Jian; Deng, Weiwen

2017-04-01

Intelligent tires are essentially a data acquisition system based on a number of complex intelligent sensors inside the tire. Intelligent tires which are capable of boosting the performance of the vehicle have the key problem of energy supply. A practical energy harvester was here designed to support the electric equipment in the intelligent tires and make it feasible for them to work steadily and constantly. This harvester takes the centrifugal force caused by the rotation of the wheel, which could affect the resonance frequency of the piezoelectric cantilever, into account. First, the vibration characteristics of the wheel were analyzed by road test, and the optimal arrangement for vibration energy usage was determined. Then, a piezoelectric vibration energy harvester was designed according to a series of formulas that took the effect of centrifugal force on resonance frequency into account. Finally, a road test was carried out to test the generated energy of the energy harvester excited by the vibration of the wheel. The results showed that the electric power meets the need of general low-power consumption triaxial accelerometers used in intelligent tires.

Satellite power system (SPS) military implications

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

Bain, C.N.

1978-10-01

This study was conducted to examine military implications of the NASA Reference SPS and to identify important military related study tasks that could be completed during fiscal year 1979. Primary areas of investigation were the potential of the SPS as a weapon, for supporting U.S. military preparedness and for affecting international relations. In addition, the SPS's relative vulnerability to overt military action, terrorist attacks, and sabotage was considered. The SPS could act as an electronic warfare weapon and, with modification, as a marginally effective energy-beaming weapon. The system could support military preparedness by providing energy for a strong and stablemore » U.S. economy and by providing a powered platform for military systems, system segments, and operations. The SPS would be vulnerable to military action, terrorism and sabotage unless hardened against these attacks by design, security, and a self-defense system. Tasks identified for completion in fiscal year 1979 include (a) a detailed vulnerability study, (b) evaluation of an SPS self-defense system concept, (c) determination of the effect of SPS flexibility to deliver different sized electrical loads on the ability to gain SPS support from individual nations, and (d) investigation of the effect of SPS deployment schedule on obtaining needed agreements, providing security, and controlling risks of armed conflict. A fifth and long-term task would consist of a worldwide survey identifiying military implications of the SPS that result from the specific requirements of potential SPS power customers.« less

Feasibility of an ultra-low power digital signal processor platform as a basis for a fully implantable brain-computer interface system.

PubMed

Wang, Po T; Gandasetiawan, Keulanna; McCrimmon, Colin M; Karimi-Bidhendi, Alireza; Liu, Charles Y; Heydari, Payam; Nenadic, Zoran; Do, An H

2016-08-01

A fully implantable brain-computer interface (BCI) can be a practical tool to restore independence to those affected by spinal cord injury. We envision that such a BCI system will invasively acquire brain signals (e.g. electrocorticogram) and translate them into control commands for external prostheses. The feasibility of such a system was tested by implementing its benchtop analogue, centered around a commercial, ultra-low power (ULP) digital signal processor (DSP, TMS320C5517, Texas Instruments). A suite of signal processing and BCI algorithms, including (de)multiplexing, Fast Fourier Transform, power spectral density, principal component analysis, linear discriminant analysis, Bayes rule, and finite state machine was implemented and tested in the DSP. The system's signal acquisition fidelity was tested and characterized by acquiring harmonic signals from a function generator. In addition, the BCI decoding performance was tested, first with signals from a function generator, and subsequently using human electroencephalogram (EEG) during eyes opening and closing task. On average, the system spent 322 ms to process and analyze 2 s of data. Crosstalk (<;-65 dB) and harmonic distortion (~1%) were minimal. Timing jitter averaged 49 μs per 1000 ms. The online BCI decoding accuracies were 100% for both function generator and EEG data. These results show that a complex BCI algorithm can be executed on an ULP DSP without compromising performance. This suggests that the proposed hardware platform may be used as a basis for future, fully implantable BCI systems.

Evaluation of Emerging Energy-Efficient Heterogeneous Computing Platforms for Biomolecular and Cellular Simulation Workloads.

PubMed

Stone, John E; Hallock, Michael J; Phillips, James C; Peterson, Joseph R; Luthey-Schulten, Zaida; Schulten, Klaus

2016-05-01

Many of the continuing scientific advances achieved through computational biology are predicated on the availability of ongoing increases in computational power required for detailed simulation and analysis of cellular processes on biologically-relevant timescales. A critical challenge facing the development of future exascale supercomputer systems is the development of new computing hardware and associated scientific applications that dramatically improve upon the energy efficiency of existing solutions, while providing increased simulation, analysis, and visualization performance. Mobile computing platforms have recently become powerful enough to support interactive molecular visualization tasks that were previously only possible on laptops and workstations, creating future opportunities for their convenient use for meetings, remote collaboration, and as head mounted displays for immersive stereoscopic viewing. We describe early experiences adapting several biomolecular simulation and analysis applications for emerging heterogeneous computing platforms that combine power-efficient system-on-chip multi-core CPUs with high-performance massively parallel GPUs. We present low-cost power monitoring instrumentation that provides sufficient temporal resolution to evaluate the power consumption of individual CPU algorithms and GPU kernels. We compare the performance and energy efficiency of scientific applications running on emerging platforms with results obtained on traditional platforms, identify hardware and algorithmic performance bottlenecks that affect the usability of these platforms, and describe avenues for improving both the hardware and applications in pursuit of the needs of molecular modeling tasks on mobile devices and future exascale computers.

Dynamic hydrologic economic modeling of tradeoffs in hydroelectric systems

NASA Astrophysics Data System (ADS)

Kern, Jordan D.

Hydropower producers face a future beset by unprecedented changes in the electric power industry, including the rapid growth of installed wind power capacity and a vastly increased supply of natural gas due to horizontal hydraulic fracturing (or "fracking"). There is also increased concern surrounding the potential for climate change to impact the magnitude and frequency of droughts. These developments may significantly alter the financial landscape for hydropower producers and have important ramifications for the environmental impacts of dams. Incorporating wind energy into electric power systems has the potential to affect price dynamics in electricity markets and, in so doing, alter the short-term financial signals on which dam operators rely to schedule reservoir releases. Chapter 1 of this doctoral dissertation develops an integrated reservoir-power system model for assessing the impact of large scale wind power integration of hydropower resources. Chapter 2 explores how efforts to reduce the carbon footprint of electric power systems by using wind energy to displace fossil fuel-based generation may inadvertently yield further impacts to river ecosystems by disrupting downstream flow patterns. Increased concern about the potential for climate change to alter the frequency and magnitude of droughts has led to growing interest in "index insurance" that compensates hydropower producers when values of an environmental variable (or index), such as reservoir inflows, crosses an agreed upon threshold (e.g., low flow conditions). Chapter 3 demonstrates the need for such index insurance contracts to also account for changes in natural gas prices in order to be cost-effective. Chapter 4 of this dissertation analyzes how recent low natural gas prices (partly attributable to fracking) have reduced the cost of implementing ramp rate restrictions at dams, which help restore sub-daily variability in river flows by limiting the flexibility of dam operators in scheduling reservoir releases concurrent with peak electricity demand.

Preparatory power posing affects nonverbal presence and job interview performance.

PubMed

Cuddy, Amy J C; Wilmuth, Caroline A; Yap, Andy J; Carney, Dana R

2015-07-01

The authors tested whether engaging in expansive (vs. contractive) "power poses" before a stressful job interview--preparatory power posing--would enhance performance during the interview. Participants adopted high-power (i.e., expansive, open) poses or low-power (i.e., contractive, closed) poses, and then prepared and delivered a speech to 2 evaluators as part of a mock job interview. All interview speeches were videotaped and coded for overall performance and hireability and for 2 potential mediators: verbal content (e.g., structure, content) and nonverbal presence (e.g., captivating, enthusiastic). As predicted, those who prepared for the job interview with high- (vs. low-) power poses performed better and were more likely to be chosen for hire; this relation was mediated by nonverbal presence, but not by verbal content. Although previous research has focused on how a nonverbal behavior that is enacted during interactions and observed by perceivers affects how those perceivers evaluate and respond to the actor, this experiment focused on how a nonverbal behavior that is enacted before the interaction and unobserved by perceivers affects the actor's performance, which, in turn, affects how perceivers evaluate and respond to the actor. This experiment reveals a theoretically novel and practically informative result that demonstrates the causal relation between preparatory nonverbal behavior and subsequent performance and outcomes. (c) 2015 APA, all rights reserved).

SER assistant: An expert system for safety evaluation reports

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

DeChaine, M.D.; Levine, S.H.; Feltus, M.A.

1993-01-01

The SER Assistant is an expert system that assists engineers to write safety evaluation reports (SERs). Section 50.59 of the Code of Federal Regulations allows modifications to be made to nuclear power plants without prior US Nuclear Regulatory Commission approval if two conditions are satisfied. First, the change must not affect the technical specifications of the plant. Second, the modification must not affect a part of the plant described in the final safety analysis report, or if it does, it must not create an unreviewed safety question. The purpose of an SER is to ensure that these conditions are satisfiedmore » for the proposed modification. The SER Assistant aids this process by providing relevant, but directed, questions and information as well as giving engineers an organized environment to document their thought processes.« less

Research on high power intra-channel crosstalk attack in optical networks

NASA Astrophysics Data System (ADS)

Ren, Shuai; Zhang, Yinfa; Wang, Jingyu; Zhang, Jumei; Rao, Xuejun; Fang, Yuanyuan

2017-02-01

The mechanism of high power intra-channel crosstalk attack is analyzed theoretically and the conclusion that power of attack signal and crosstalk coefficient of optical switch are the main factors for which high power intra-channel have destructive effect on quality of legitimate signals is drawn. Effects of high power intra-channel crosstalk attack on quality of legitimate signals and its capability of attack propagation are investigated quantitatively by building the simulation system in VPI software. The results show that legitimate signals through the first and the second stage optical switch are affected by attack and legitimate signal through the third stage optical switch is almost unaffected by attack when power of original attack signal (OAS) is above 20dB more than that of legitimate signals and crosstalk coefficient of optical switch is -20dB at optical cross connect 1 (OXC1). High power intra-channel crosstalk attack has a certain capability of attack propagation. Attack capability of OAS can be propagated to OXC3 when power of OAS is 27dB more than that of legitimate signals and crosstalk coefficient of optical switch is -20dB. We also find that the secondary attack signal (SAS) does not have capability of attack propagation.

Bases of social power, leadership styles, and organizational commitment.

PubMed

Pierro, Antonio; Raven, Bertram H; Amato, Clara; Bélanger, Jocelyn J

2013-01-01

Affective organizational commitment reflects the extent to which organizational members are loyal and willing to work toward organizational objectives (Meyer & Allen, 1997). In particular, affective organizational commitment holds very important implications at all organizational levels (e.g., turnover rates, performance, and citizenship behavior). Whereas previous research has evinced the positive influence of transformational and charismatic leadership styles on affective commitment toward the organization (Bass & Avolio, 1994), little is known with regard to the nature of this relationship. In line with the interpersonal power/interaction model, the present investigation aimed to investigate the mechanism at play between transformational leadership style and affective organizational commitment. Specifically, we hypothesized that transformational leadership style would increase affective organizational commitment through its effect on willingness to comply with soft bases of power. In two studies, we subjected the foregoing hypotheses to empirical scrutiny. In Study 1, the proposed mediation model was empirically supported with Italian employees in the public sector. Attesting to the robustness of our findings, Study 2 replicated the findings of Study 1 with Italian employees from the public and private sectors. In addition, Study 2 replicated Study 1 using a different measure of transformational leadership. Both Study 1 and Study 2 provided results consistent with our hypotheses. Specifically, the present paper reports empirical evidence that (1) the more participants report having a transformational leader, the more willing they become to comply with soft (but not harsh) power bases, (2) in turn, greater willingness to comply with soft (but not harsh) power bases increases one's affective organizational commitment. These findings provide additional support for the interpersonal power/interaction model and pave the way for new research directions.

Double Retort System for Materials Compatibility Testing

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

V. Munne; EV Carelli

2006-02-23

With Naval Reactors (NR) approval of the Naval Reactors Prime Contractor Team (NRPCT) recommendation to develop a gas cooled reactor directly coupled to a Brayton power conversion system as the Space Nuclear Power Plant (SNPP) for Project Prometheus (References a and b) there was a need to investigate compatibility between the various materials to be used throughout the SNPP. Of particular interest was the transport of interstitial impurities from the nickel-base superalloys, which were leading candidates for most of the piping and turbine components to the refractory metal alloys planned for use in the reactor core. This kind of contaminationmore » has the potential to affect the lifetime of the core materials. This letter provides technical information regarding the assembly and operation of a double retort materials compatibility testing system and initial experimental results. The use of a double retort system to test materials compatibility through the transfer of impurities from a source to a sink material is described here. The system has independent temperature control for both materials and is far less complex than closed loops. The system is described in detail and the results of three experiments are presented.« less

Coordination and decision making of regulation, operation, and market activities in power systems

NASA Astrophysics Data System (ADS)

Nakashima, Tomoaki

Electric power has been traditionally supplied to customers at regulated rates by vertically integrated utilities (VIUs), which own generation, transmission, and distribution systems. However, the regulatory authorities of VIUs are promoting competition in their businesses to lower the price of electric energy. Consequently, in new deregulated circumstances, many suppliers and marketers compete in the generation market, and conflict of interest may often occur over transmission. Therefore, a neutral entity, called an independent system operator (ISO), which operates the power system independently, has been established to give market participants nondiscriminatory access to transmission sectors with a natural monopoly, and to facilitate competition in generation sectors. Several types of ISOs are established at present, with their respective regions and authorities. The ISO receives many requests from market participants to transfer power, and must evaluate the feasibility of their requests under the system's condition. In the near future, regulatory authorities may impose various objectives on the ISOs. Then, based on the regulators' policies, the ISO must determine the optimal schedules from feasible solutions, or change the market participants' requests. In a newly developed power market, market participants will conduct their transactions in order to maximize their profit. The most crucial information in conducting power transactions is price and demand. A direct transaction between suppliers and consumers may become attractive because of its stability of price, while in a power exchange market, gaming and speculation of participants may push up electricity prices considerably. To assist the consumers in making effective decisions, suitable methods for forecasting volatile market price are necessary. This research has been approached from three viewpoints: Firstly, from the system operator's point of view, desirable system operation and power market structure are explored. Two typical ISO models, centralized and decentralized, have been identified and compared. These ISO models have been simulated to observe the advantages and disadvantages of the different systems. If no powerful players exist, the centralized system would achieve the maximum market efficiency. However, in decentralized systems, freedom of trade protects market participants from strategic bidding caused by powerful players. Reduced market efficiency is the price markets have to pay to prevent strategic bidding. Secondly, from the regulator's point of view, the effects of different policies imposed by regulators on power transactions are examined. The optimal schedule could be affected greatly by the ideal goals and their allowable values. Therefore, when the ISO defines its objectives and their allowable ranges, an agreeable conclusion among market participants is required. Fuzzy multiobjective optimization methods can be suitably applied to the scheduling of the ISO, reflecting its objectives and their allowable ranges properly. Thirdly, from market participants' point of view, models to represent and forecast the price and demand of power are developed. Electricity consumption and price are forecasted based on possibility theory and fuzzy autoregression. The fuzzy model can represent highly volatile demand-price relations as a range, and gives the possibility distribution of prices. Based on the proposed model, a procedure to help consumers decide whether to accept a bilateral transaction contract or market-based purchases of electricity has been developed. The same procedure can also be used by an electricity supplier or broker to determine an offering price.

Modeling water resources as a constraint in electricity capacity expansion models

NASA Astrophysics Data System (ADS)

Newmark, R. L.; Macknick, J.; Cohen, S.; Tidwell, V. C.; Woldeyesus, T.; Martinez, A.

2013-12-01

In the United States, the electric power sector is the largest withdrawer of freshwater in the nation. The primary demand for water from the electricity sector is for thermoelectric power plant cooling. Areas likely to see the largest near-term growth in population and energy usage, the Southwest and the Southeast, are also facing freshwater scarcity and have experienced water-related power reliability issues in the past decade. Lack of water may become a barrier for new conventionally-cooled power plants, and alternative cooling systems will impact technology cost and performance. Although water is integral to electricity generation, it has long been neglected as a constraint in future electricity system projections. Assessing the impact of water resource scarcity on energy infrastructure development is critical, both for conventional and renewable energy technologies. Efficiently utilizing all water types, including wastewater and brackish sources, or utilizing dry-cooling technologies, will be essential for transitioning to a low-carbon electricity system. This work provides the first demonstration of a national electric system capacity expansion model that incorporates water resources as a constraint on the current and future U.S. electricity system. The Regional Electricity Deployment System (ReEDS) model was enhanced to represent multiple cooling technology types and limited water resource availability in its optimization of electricity sector capacity expansion to 2050. The ReEDS model has high geographic and temporal resolution, making it a suitable model for incorporating water resources, which are inherently seasonal and watershed-specific. Cooling system technologies were assigned varying costs (capital, operations and maintenance), and performance parameters, reflecting inherent tradeoffs in water impacts and operating characteristics. Water rights supply curves were developed for each of the power balancing regions in ReEDS. Supply curves include costs and availability of freshwater (surface and groundwater) and alternative water resources (municipal wastewater and brackish groundwater). In each region, a new power plant must secure sufficient water rights for operation before being built. Water rights constraints thus influence the type of power plant, cooling system, or location of new generating capacity. Results indicate that the aggregate national generating capacity by fuel type and associated carbon dioxide emissions change marginally with the inclusion of water rights. Water resource withdrawals and consumption, however, can vary considerably. Regional water resource dynamics indicate substantial differences in the location where power plant-cooling system technology combinations are built. These localized impacts highlight the importance of considering water resources as a constraint in the electricity sector when evaluating costs, transmission infrastructure needs, and externalities. Further scenario evaluations include assessments of how climate change could affect the availability of water resources, and thus the development of the electricity sector.

Assessment of Solid Sorbent Systems for Post-Combustion Carbon Dioxide Capture at Coal-Fired Power Plants

NASA Astrophysics Data System (ADS)

Glier, Justin C.

In an effort to lower future CO2 emissions, a wide range of technologies are being developed to scrub CO2 from the flue gases of fossil fuel-based electric power and industrial plants. This thesis models one of several early-stage post-combustion CO2 capture technologies, solid sorbent-based CO2 capture process, and presents performance and cost estimates of this system on pulverized coal power plants. The spreadsheet-based software package Microsoft Excel was used in conjunction with AspenPlus modelling results and the Integrated Environmental Control Model to develop performance and cost estimates for the solid sorbent-based CO2 capture technology. A reduced order model also was created to facilitate comparisons among multiple design scenarios. Assumptions about plant financing and utilization, as well as uncertainties in heat transfer and material design that affect heat exchanger and reactor design were found to produce a wide range of cost estimates for solid sorbent-based systems. With uncertainties included, costs for a supercritical power plant with solid sorbent-based CO2 capture ranged from 167 to 533 per megawatt hour for a first-of-a-kind installation (with all costs in constant 2011 US dollars) based on a 90% confidence interval. The median cost was 209/MWh. Post-combustion solid sorbent-based CO2 capture technology is then evaluated in terms of the potential cost for a mature system based on historic experience as technologies are improved with sequential iterations of the currently available system. The range costs for a supercritical power plant with solid sorbent-based CO2 capture was found to be 118 to 189 per megawatt hour with a nominal value of 163 per megawatt hour given the expected range of technological improvement in the capital and operating costs and efficiency of the power plant after 100 GW of cumulative worldwide experience. These results suggest that the solid sorbent-based system will not be competitive with currently available liquid amine-systems in the absence of significant new improvements in solid sorbent properties and process system design to reduce the heat exchange surface area in the regenerator and cross-flow heat exchanger. Finally, the importance of these estimates for policy makers is discussed.

Thermal pollution impacts on rivers and power supply in the Mississippi River watershed

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

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

Thermal pollution from power plants degrades riverine ecosystems with ramifications beyond the natural environment as it affects power supply. The transport of thermal effluents along river reaches may lead to plant-to-plant interferences by elevating condenser inlet temperatures at downstream locations, which lower thermal efficiencies and trigger regulatory-forced power curtailments. We evaluate thermal pollution impacts on rivers and power supply across 128 plants with once-through cooling technologies in the Mississippi River watershed. By leveraging river network topologies with higher resolutions (0.05 degrees) than previous studies, we reveal the need to address the issue in a more spatially resolved manner, capable ofmore » uncovering diverse impacts across individual plants, river reaches and sub-basins. Results show that the use of coarse river network resolutions may lead to substantial overestimations in magnitude and length of impaired river reaches. Overall, there is a modest limitation on power production due to thermal pollution, given existing infrastructure, regulatory and climate conditions. However, tradeoffs between thermal pollution and electricity generation show important implications for the role of alternative cooling technologies and environmental regulation under current and future climates. Recirculating cooling technologies may nearly eliminate thermal pollution and improve power system reliability under stressed climate-water conditions. Regulatory limits also reduce thermal pollution, but at the expense of significant reductions in electricity generation capacity. However, results show several instances when power production capacity rises at individual plants when regulatory limits reduce upstream thermal pollution. Furthermore, these dynamics across energy-water systems highlight the need for high-resolution simulations and the value of coherent planning and optimization across infrastructure with mutual dependencies on natural resources to overcome climate-water constraints on productivity and bring to fruition energy and environmental win-win opportunities.« less

Thermal pollution impacts on rivers and power supply in the Mississippi River watershed

DOE PAGES

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

2018-03-08

Thermal pollution from power plants degrades riverine ecosystems with ramifications beyond the natural environment as it affects power supply. The transport of thermal effluents along river reaches may lead to plant-to-plant interferences by elevating condenser inlet temperatures at downstream locations, which lower thermal efficiencies and trigger regulatory-forced power curtailments. We evaluate thermal pollution impacts on rivers and power supply across 128 plants with once-through cooling technologies in the Mississippi River watershed. By leveraging river network topologies with higher resolutions (0.05 degrees) than previous studies, we reveal the need to address the issue in a more spatially resolved manner, capable ofmore » uncovering diverse impacts across individual plants, river reaches and sub-basins. Results show that the use of coarse river network resolutions may lead to substantial overestimations in magnitude and length of impaired river reaches. Overall, there is a modest limitation on power production due to thermal pollution, given existing infrastructure, regulatory and climate conditions. However, tradeoffs between thermal pollution and electricity generation show important implications for the role of alternative cooling technologies and environmental regulation under current and future climates. Recirculating cooling technologies may nearly eliminate thermal pollution and improve power system reliability under stressed climate-water conditions. Regulatory limits also reduce thermal pollution, but at the expense of significant reductions in electricity generation capacity. However, results show several instances when power production capacity rises at individual plants when regulatory limits reduce upstream thermal pollution. Furthermore, these dynamics across energy-water systems highlight the need for high-resolution simulations and the value of coherent planning and optimization across infrastructure with mutual dependencies on natural resources to overcome climate-water constraints on productivity and bring to fruition energy and environmental win-win opportunities.« less

Thermal pollution impacts on rivers and power supply in the Mississippi River watershed

NASA Astrophysics Data System (ADS)

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

2018-03-01

Thermal pollution from power plants degrades riverine ecosystems with ramifications beyond the natural environment as it affects power supply. The transport of thermal effluents along river reaches may lead to plant-to-plant interferences by elevating condenser inlet temperatures at downstream locations, which lower thermal efficiencies and trigger regulatory-forced power curtailments. We evaluate thermal pollution impacts on rivers and power supply across 128 plants with once-through cooling technologies in the Mississippi River watershed. By leveraging river network topologies with higher resolutions (0.05°) than previous studies, we reveal the need to address the issue in a more spatially resolved manner, capable of uncovering diverse impacts across individual plants, river reaches and sub-basins. Results show that the use of coarse river network resolutions may lead to substantial overestimations in magnitude and length of impaired river reaches. Overall, there is a modest limitation on power production due to thermal pollution, given existing infrastructure, regulatory and climate conditions. However, tradeoffs between thermal pollution and electricity generation show important implications for the role of alternative cooling technologies and environmental regulation under current and future climates. Recirculating cooling technologies may nearly eliminate thermal pollution and improve power system reliability under stressed climate-water conditions. Regulatory limits also reduce thermal pollution, but at the expense of significant reductions in electricity generation capacity. However, results show several instances when power production capacity rises at individual plants when regulatory limits reduce upstream thermal pollution. These dynamics across energy-water systems highlight the need for high-resolution simulations and the value of coherent planning and optimization across infrastructure with mutual dependencies on natural resources to overcome climate-water constraints on productivity and bring to fruition energy and environmental win-win opportunities.

CO2 conversion in non-thermal plasma and plasma/g-C3N4 catalyst hybrid processes

NASA Astrophysics Data System (ADS)

Lu, Na; Sun, Danfeng; Zhang, Chuke; Jiang, Nan; Shang, Kefeng; Bao, Xiaoding; Li, Jie; Wu, Yan

2018-03-01

Carbon dioxide conversion at atmosphere pressure and low temperature has been studied in a cylindrical dielectric barrier discharge (DBD) reactor. Pure CO2 feed flows to the discharge zone and typical filamentary discharges were obtained in each half-cycle of the applied voltage. The gas temperature increased with discharge time and discharge power, which was found to affect the CO2 decomposition deeply. As the DBD reactor was cooled to ambient temperature, both the conversion of CO2 and the CO yield were enhanced. Especially the energy efficiencies changed slightly with the increase of discharge power and were much higher in cooling condition comparing to those without cooling. At a discharge power of 40 W, the energy efficiency under cooling condition was approximately six times more than that without cooling. Gas flow rate was observed to affect CO2 conversion and 0.1 L min-1 was obtained as optimum gas flow rate under cooling condition. In addition, the CO2 conversion rate in plasma/g-C3N4 catalyst hybrid system was twice times as that in plasma-alone system. In case of cooling, the existence of g-C3N4 catalyst contributed to a 47% increase of CO2 conversion compared to the sole plasma process. The maximum energy-efficiency with g-C3N4 was 0.26 mmol kJ-1 at 20 W, which increased by 157% compared to that without g-C3N4. The synergistic effect of DBD plasma with g-C3N4 on pure CO2 conversion was verified.

Double-Line-Frequency Ripple Model, Analysis & Impedance Design for Energy Stored Single-Phase Quasi-Z Source Photovoltaic System

DOE PAGES

Liang, Weihua; Liu, Yushan; Ge, Baoming; ...

2017-09-08

The battery energy stored quasi-Z-source (BESqZS) based photovoltaic (PV) power generation system combines advantages of the qZS inverter and the battery energy storage system. But, the second harmonic (2ω) power ripple degrades the system’s performance and affects the system’s design. An accurate model to analyze the 2ω ripple is very important. The existing models did not consider the battery, or assumed a symmetric qZS network with L 1=L 2 and C 1=C 2, which limits the design freedom and causes oversized impedance parameters. Our paper proposes a comprehensive model for the single-phase BES-qZS-PV inverter system, where the battery is consideredmore » and there is no restriction of L 1=L 2 and C 1=C 2. Based on the built model, a BES-qZS impedance design method is proposed to mitigate the 2ω ripple with asymmetric qZS network. Simulation and experimental results verify the proposed 2ω ripple model and impedance design method.« less

Effect of superconducting solenoid model cores on spanwise iron magnet roll control

NASA Technical Reports Server (NTRS)

Britcher, C. P.

1985-01-01

Compared with conventional ferromagnetic fuselage cores, superconducting solenoid cores appear to offer significant reductions in the projected cost of a large wind tunnel magnetic suspension and balance system. The provision of sufficient magnetic roll torque capability has been a long-standing problem with all magnetic suspension and balance systems; and the spanwise iron magnet scheme appears to be the most powerful system available. This scheme utilizes iron cores which are installed in the wings of the model. It was anticipated that the magnetization of these cores, and hence the roll torque generated, would be affected by the powerful external magnetic field of the superconducting solenoid. A preliminary study has been made of the effect of the superconducting solenoid fuselage model core concept on the spanwise iron magnet roll torque generation schemes. Computed data for one representative configuration indicate that reductions in available roll torque occur over a range of applied magnetic field levels. These results indicate that a 30-percent increase in roll electromagnet capacity over that previously determined will be required for a representative 8-foot wind tunnel magnetic suspension and balance system design.

The Immune System and Developmental Programming of Brain and Behavior

PubMed Central

Bilbo, Staci D.; Schwarz, Jaclyn M.

2012-01-01

The brain, endocrine, and immune systems are inextricably linked. Immune molecules have a powerful impact on neuroendocrine function, including hormone-behavior interactions, during health as well as sickness. Similarly, alterations in hormones, such as during stress, can powerfully impact immune function or reactivity. These functional shifts are evolved, adaptive responses that organize changes in behavior and mobilize immune resources, but can also lead to pathology or exacerbate disease if prolonged or exaggerated. The developing brain in particular is exquisitely sensitive to both endogenous and exogenous signals, and increasing evidence suggests the immune system has a critical role in brain development and associated behavioral outcomes for the life of the individual. Indeed, there are associations between many neuropsychiatric disorders and immune dysfunction, with a distinct etiology in neurodevelopment. The goal of this review is to describe the important role of the immune system during brain development, and to discuss some of the many ways in which immune activation during early brain development can affect the later-life outcomes of neural function, immune function, mood and cognition. PMID:22982535

Double-Line-Frequency Ripple Model, Analysis & Impedance Design for Energy Stored Single-Phase Quasi-Z Source Photovoltaic System

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

Liang, Weihua; Liu, Yushan; Ge, Baoming

The battery energy stored quasi-Z-source (BESqZS) based photovoltaic (PV) power generation system combines advantages of the qZS inverter and the battery energy storage system. But, the second harmonic (2ω) power ripple degrades the system’s performance and affects the system’s design. An accurate model to analyze the 2ω ripple is very important. The existing models did not consider the battery, or assumed a symmetric qZS network with L 1=L 2 and C 1=C 2, which limits the design freedom and causes oversized impedance parameters. Our paper proposes a comprehensive model for the single-phase BES-qZS-PV inverter system, where the battery is consideredmore » and there is no restriction of L 1=L 2 and C 1=C 2. Based on the built model, a BES-qZS impedance design method is proposed to mitigate the 2ω ripple with asymmetric qZS network. Simulation and experimental results verify the proposed 2ω ripple model and impedance design method.« less